1.
Habitat
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A habitat is an ecological or environmental area that is inhabited by a particular species of animal, plant, or other type of organism. The term typically refers to the zone in which the organism lives and it is the natural environment in which an organism lives, or the physical environment that surrounds a species population. Every organism has certain habitat needs for the conditions in which it will thrive, habitat types include polar, temperate, subtropical and tropical. The terrestrial vegetation type may be forest, steppe, grassland, the word habitat has been in use since about 1755 and derives from the Latin third-person singular present indicative of habitāre, to inhabit, from habēre, to have or to hold. Habitat can be defined as the environment of an organism. It is similar in meaning to a biotope, an area of environmental conditions associated with a particular community of plants. Generally speaking, animal communities are reliant on specific types of plant communities, some plants and animals are generalists, and their habitat requirements are met in a wide range of locations. The small white butterfly for example is found on all the continents of the world apart from Antarctica and its larvae feed on a wide range of Brassicas and various other plant species, and it thrives in any open location with diverse plant associations. Disturbance is important in the creation of biodiverse habitats, in the absence of disturbance, a climax vegetation cover develops that prevents the establishment of other species. Lightning strikes and toppled trees in tropical forests allow species richness to be maintained as pioneering species move in to fill the gaps created. Similarly coastal habitats can become dominated by kelp until the seabed is disturbed by a storm, another cause of disturbance is when an area may be overwhelmed by an invasive introduced species which is not kept under control by natural enemies in its new habitat. Terrestrial habitat types include forests, grasslands, wetlands and deserts, within these broad biomes are more specific habitats with varying climate types, temperature regimes, soils, altitudes and vegetation types. Many of these habitats grade into each other and each one has its own communities of plants. A habitat may suit a particular species well, but its presence or absence at any particular location depends to some extent on chance, on its dispersal abilities, freshwater habitats include rivers, streams, lakes, ponds, marshes and bogs. Although some organisms are found across most of these habitats, the majority have more specific requirements, similarly, aquatic plants can be floating, semi-submerged, submerged or grow in permanently or temporarily saturated soils besides bodies of water. Marine habitats include brackish water, estuaries, bays, the sea, the intertidal zone. Further variations include rock pools, sand banks, mudflats, brackish lagoons, sandy and pebbly beaches, the benthic zone or seabed provides a home for both static organisms, anchored to the substrate, and for a large range of organisms crawling on or burrowing into the surface. A desert is not the kind of habitat that favours the presence of amphibians, with their requirement for water to keep their skins moist, nevertheless, some frogs live in deserts, creating moist habitats underground and hibernating while conditions are adverse
2.
Biodiversity
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Biodiversity, a contraction of biological diversity, generally refers to the variety and variability of life on Earth. One of the most widely used definitions defines it in terms of the variability within species and it is a measure of the variety of organisms present in different ecosystems. This can refer to genetic variation, ecosystem variation, or species variation within an area, biome, terrestrial biodiversity tends to be greater near the equator, which seems to be the result of the warm climate and high primary productivity. Biodiversity is not distributed evenly on Earth, and is richest in the tropics and these tropical forest ecosystems cover less than 10 per cent of earths surface, and contain about 90 percent of the worlds species. Marine biodiversity tends to be highest along coasts in the Western Pacific, there are latitudinal gradients in species diversity. Biodiversity generally tends to cluster in hotspots, and has been increasing through time, the number and variety of plants, animals and other organisms that exist is known as biodiversity. It is a component of nature and it ensures the survival of human species by providing food, fuel, shelter, medicines. The richness of biodiversity depends on the conditions and area of the region. All species of plants taken together are known as flora and about 300,000 species of plants are known to date, all species of animals taken together are known as fauna which includes birds, mammals, fish, reptiles, insects, crustaceans, molluscs, etc. Rapid environmental changes typically cause mass extinctions, more than 99 percent of all species, amounting to over five billion species, that ever lived on Earth are estimated to be extinct. Estimates on the number of Earths current species range from 10 million to 14 million, of which about 1.2 million have been documented and over 86 percent have not yet been described. More recently, in May 2016, scientists reported that 1 trillion species are estimated to be on Earth currently with only one-thousandth of one percent described, the total amount of related DNA base pairs on Earth is estimated at 5.0 x 1037 and weighs 50 billion tonnes. In comparison, the mass of the biosphere has been estimated to be as much as 4 TtC. In July 2016, scientists reported identifying a set of 355 genes from the Last Universal Common Ancestor of all living on Earth. The age of the Earth is about 4.54 billion years old, there are microbial mat fossils found in 3.48 billion-year-old sandstone discovered in Western Australia. Other early physical evidence of a substance is graphite in 3.7 billion-year-old meta-sedimentary rocks discovered in Western Greenland. More recently, in 2015, remains of life were found in 4.1 billion-year-old rocks in Western Australia. According to one of the researchers, If life arose relatively quickly on Earth, then it could be common in the universe
3.
Natural resources
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Natural resources are resources that exist without actions of humankind. This includes all valued characteristics such as magnetic, gravitational, on earth it includes, sunlight, atmosphere, water, land along with all vegetation and animal life that naturally subsists upon or within the heretofore identified characteristics and substances. Particular areas such as the rainforest in Fatu-Hiva are often characterized by the biodiversity and geodiversity existent in their ecosystems, Natural resources may be further classified in different ways. Natural resources are materials and components that can be found within the environment, every man-made product is composed of natural resources. Some natural resources such as sunlight and air can be found everywhere, however, most resources only occur in small sporadic areas, and are referred to as localised resources. There are very few resources that are considered inexhaustible – these are solar radiation, geothermal energy, the vast majority of resources are theoretically exhaustible, which means they have a finite quantity and can be depleted if managed improperly. There are various methods of categorizing natural resources, these include source of origin, stage of development, fossil fuels such as coal and petroleum are also included in this category because they are formed from decayed organic matter. Abiotic – Abiotic resources are those that come from non-living, non-organic material, examples of abiotic resources include land, fresh water, air and heavy metals including ores such as gold, iron, copper, silver, etc. For example, petroleum occurs with sedimentary rocks in various regions, Actual resources — Actual resources are those that have been surveyed, their quantity and quality determined and are being used in present times. The development of a resource, such as wood processing depends upon the technology available. Reserve resources — The part of a resource which can be developed profitably in the future is called a reserve resource. Stock resources — Stock resources are those that have been surveyed, renewability is a very popular topic and many natural resources can be categorized as either renewable or non-renewable, Renewable resources — Renewable resources can be replenished naturally. Some of these resources, like sunlight, air, wind, water, etc. are continuously available, though many renewable resources do not have such a rapid recovery rate, these resources are susceptible to depletion by over-use. Non-renewable resources – Non-renewable resources either form slowly or do not naturally form in the environment, minerals are the most common resource included in this category. Some resources actually naturally deplete in amount without human interference, the most notable of these being radio-active elements such as uranium, of these, the metallic minerals can be re-used by recycling them, but coal and petroleum cannot be recycled. Once they are used they take millions of years to replenish. Resource extraction involves any activity that withdraws resources from nature and this can range in scale from the traditional use of preindustrial societies, to global industry. Extractive industries are, along with agriculture, the basis of the sector of the economy
4.
Urbanization
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Urbanization refers to the population shift from rural to urban areas, the gradual increase in the proportion of people living in urban areas, and the ways in which each society adapts to the change. It is predominantly the process by which towns and cities are formed, the United Nations projected that half of the worlds population would live in urban areas at the end of 2008. It is predicted that by 2050 about 64% of the developing world and that is equivalent to approximately 3 billion urbanites by 2050, much of which will occur in Africa and Asia. Notably, the United Nations has also projected that nearly all global population growth from 2017 to 2030 will be absorbed by cities. Urbanization is relevant to a range of disciplines, including geography, sociology, economics, urban planning, the phenomenon has been closely linked to modernization, industrialization, and the sociological process of rationalization. Urbanization can be seen as a condition at a set time or as an increase in that condition over time. The first major change in settlement patterns was the accumulation of hunter-gatherers into villages many years ago. This unprecedented movement of people is forecast to continue and intensify during the few decades. Outside Asia, Mexico City, São Paulo, London, New York City, Lagos, in England the proportion of the population living in cities jumped from 17% in 1801 to 72% in 1891. Growing trade around the world also allowed cereals to be imported from North America and refrigerated meat from Australasia, spatially, cities also expanded due to the development of public transport systems, which facilitated commutes of longer distances to the city centre for the working class. Urbanization rapidly spread across the Western world and, since the 1950s, at the turn of the 20th century, just 15% of the world population lived in cities. According to the UN the year 2007 witnessed the turning point when more than 50% of the population were living in cities. Living in a city can provide opportunities of proximity, diversity, as against this, there may be alienation issues, stress, increased cost of living, and negative social aspects that result from mass marginalization. In cities, money, services, wealth and opportunities are centralized, many rural inhabitants come to the city to seek their fortune and alter their social position. Businesses, which provide jobs and exchange capital, are concentrated in urban areas. Whether the source is trade or tourism, it is also through the ports or banking systems, commonly located in cities, many people move into cities for the economic opportunities, but this does not fully explain the very high recent urbanization rates in places like China and India. Rural flight is a factor to urbanization. Farm living has always been susceptible to environmental conditions, and in times of drought, flood or pestilence
5.
Agriculture
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Agriculture is the cultivation and breeding of animals, plants and fungi for food, fiber, biofuel, medicinal plants and other products used to sustain and enhance human life. Agriculture was the key development in the rise of human civilization. The study of agriculture is known as agricultural science, the history of agriculture dates back thousands of years, and its development has been driven and defined by greatly different climates, cultures, and technologies. Industrial agriculture based on large-scale monoculture farming has become the dominant agricultural methodology, genetically modified organisms are an increasing component of agriculture, although they are banned in several countries. Agricultural food production and water management are increasingly becoming global issues that are fostering debate on a number of fronts, the major agricultural products can be broadly grouped into foods, fibers, fuels, and raw materials. Specific foods include cereals, vegetables, fruits, oils, meats, fibers include cotton, wool, hemp, silk and flax. Raw materials include lumber and bamboo, other useful materials are also produced by plants, such as resins, dyes, drugs, perfumes, biofuels and ornamental products such as cut flowers and nursery plants. The word agriculture is a late Middle English adaptation of Latin agricultūra, from ager, field, Agriculture usually refers to human activities, although it is also observed in certain species of ant, termite and ambrosia beetle. To practice agriculture means to use resources to produce commodities which maintain life, including food, fiber, forest products, horticultural crops. This definition includes arable farming or agronomy, and horticulture, all terms for the growing of plants, even then, it is acknowledged that there is a large amount of knowledge transfer and overlap between silviculture and agriculture. In traditional farming, the two are often combined even on small landholdings, leading to the term agroforestry, Agriculture began independently in different parts of the globe, and included a diverse range of taxa. At least 11 separate regions of the Old and New World were involved as independent centers of origin, wild grains were collected and eaten from at least 105,000 years ago. Pigs were domesticated in Mesopotamia around 15,000 years ago, rice was domesticated in China between 13,500 and 8,200 years ago, followed by mung, soy and azuki beans. Sheep were domesticated in Mesopotamia between 13,000 and 11,000 years ago. From around 11,500 years ago, the eight Neolithic founder crops, emmer and einkorn wheat, hulled barley, peas, lentils, bitter vetch, chick peas and flax were cultivated in the Levant. Cattle were domesticated from the aurochs in the areas of modern Turkey. In the Andes of South America, the potato was domesticated between 10,000 and 7,000 years ago, along with beans, coca, llamas, alpacas, sugarcane and some root vegetables were domesticated in New Guinea around 9,000 years ago. Sorghum was domesticated in the Sahel region of Africa by 7,000 years ago, cotton was domesticated in Peru by 5,600 years ago, and was independently domesticated in Eurasia at an unknown time
6.
Mining
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Mining is extraction of valuable minerals or other geological materials from the earth usually from an orebody, lode, vein, seam, reef or placer deposits. These deposits form a mineralized package that is of economic interest to the miner, ores recovered by mining include metals, coal, oil shale, gemstones, limestone, chalk, dimension stone, rock salt, potash, gravel, and clay. Mining is required to obtain any material that cannot be grown through agricultural processes, Mining in a wider sense includes extraction of any non-renewable resource such as petroleum, natural gas, or even water. Mining of stones and metal has been a human activity since pre-historic times, Mining operations usually create a negative environmental impact, both during the mining activity and after the mine has closed. Hence, most of the nations have passed regulations to decrease the impact. Work safety has long been a concern as well, and modern practices have significantly improved safety in mines, levels of metals recycling are generally low. Unless future end-of-life recycling rates are stepped up, some rare metals may become unavailable for use in a variety of consumer products, due to the low recycling rates, some landfills now contain higher concentrations of metal than mines themselves. Since the beginning of civilization, people have used stone, ceramics and, later and these were used to make early tools and weapons, for example, high quality flint found in northern France, southern England and Poland was used to create flint tools. Flint mines have been found in areas where seams of the stone were followed underground by shafts. The mines at Grimes Graves and Krzemionki are especially famous, other hard rocks mined or collected for axes included the greenstone of the Langdale axe industry based in the English Lake District. The oldest-known mine on archaeological record is the Lion Cave in Swaziland, at this site Paleolithic humans mined hematite to make the red pigment ochre. Mines of an age in Hungary are believed to be sites where Neanderthals may have mined flint for weapons. Ancient Egyptians mined malachite at Maadi, at first, Egyptians used the bright green malachite stones for ornamentations and pottery. Later, between 2613 and 2494 BC, large building projects required expeditions abroad to the area of Wadi Maghareh in order to secure minerals and other resources not available in Egypt itself. Quarries for turquoise and copper were found at Wadi Hammamat, Tura, Aswan and various other Nubian sites on the Sinai Peninsula. Mining in Egypt occurred in the earliest dynasties, the gold mines of Nubia were among the largest and most extensive of any in Ancient Egypt. These mines are described by the Greek author Diodorus Siculus, who mentions fire-setting as one used to break down the hard rock holding the gold. One of the complexes is shown in one of the earliest known maps, the miners crushed the ore and ground it to a fine powder before washing the powder for the gold dust
7.
Logging
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Logging is the cutting, skidding, on-site processing, and loading of trees or logs onto trucks or skeleton cars. In forestry, the logging is sometimes used in a narrow sense concerning the logistics of moving wood from the stump to somewhere outside the forest. However, in usage, the term may be used to indicate a range of forestry or silviculture activities. Illegal logging refers to what in forestry might be called timber theft by the timber mafia and it can also refer to the harvesting, transportation, purchase, or sale of timber in violation of laws. Clearcut logging is not necessarily considered a type of logging but a harvesting or silviculture method, in the forest products industry logging companies may be referred to as logging contractors, with the smaller, non-union crews referred to as gyppo loggers. Cutting trees with the highest value and leaving those with lower value and it is sometimes called selective logging, and confused with selection cutting, the practice of managing stands by harvesting a proportion of trees. Logging usually refers to above-ground forestry logging, submerged forests exist on land that has been flooded by damming to create reservoirs. Such trees are logged using underwater logging or by the lowering of the reservoirs in question, ootsa Lake and Williston Lake in British Columbia, Canada are notable examples where timber recovery has been needed to remove inundated forests. Clearcutting, or clearfelling, is a method of harvesting that removes all the standing trees in a selected area. Silviculture objectives for clearcutting, and a focus on forestry distinguish it from deforestation, other methods include shelterwood cutting, group selective, single selective, seed-tree cutting, patch cut, and retention cutting. The above operations can be carried out by different methods, of which the three are considered industrial methods, Trees are felled and then delimbed and topped at the stump. The log is then transported to the landing, where it is bucked and loaded on a truck and this leaves the slash in the cut area, where it must be further treated if wild land fires are of concern. This ability is due to the advancement in the style felling head that can be used, the trees are then delimbed, topped, and bucked at the landing. This method requires that slash be treated at the landing, in areas with access to cogeneration facilities, the slash can be chipped and used for the production of electricity or heat. Full-tree harvesting also refers to utilization of the tree including branches. Cut-to-length logging is the process of felling, delimbing, bucking, harvesters fell the tree, delimb, and buck it, and place the resulting logs in bunks to be brought to the landing by a skidder or forwarder. This method is available for trees up to 900 mm in diameter. Harvesters are employed effectively in level to steep terrain
8.
Trawling
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Trawling is a method of fishing that involves pulling a fishing net through the water behind one or more boats. The net that is used for trawling is called a trawl, the boats that are used for trawling are called trawlers or draggers. Trawlers vary in size from open boats with as little as 30 hp engines to large factory trawlers with over 10,000 hp. Trawling can be carried out by one trawler or by two trawlers fishing cooperatively, Trawling can be contrasted with trolling, where baited fishing lines instead of trawls are drawn through the water. Trolling is used both for recreational and commercial fishing whereas trawling is used mainly for commercial fishing, Trawling is also commonly used as a scientific sampling, or survey, method. Trawling can be divided into bottom trawling and midwater trawling, depending on how high the trawl is in the water column, Bottom trawling is towing the trawl along or close to the sea floor. Midwater trawling is towing the trawl through free water above the bottom of the ocean or benthic zone, midwater trawling is also known as pelagic trawling. The gear itself can vary a great deal, pelagic trawls are typically much larger than bottom trawls, with very large mesh openings in the net, little or no ground gear, and little or no chaffing gear. Additionally, pelagic trawl doors have different shapes than bottom trawl doors, when two boats are used, the horizontal spread of the net is provided by the boats, with one or in the case of pelagic trawling two warps attached to each boat. However, single-boat trawling is more common, here, the horizontal spread of the net is provided by trawl doors. Trawl doors are available in sizes and shapes and may be specialized to keep in contact with the sea bottom or to remain elevated in the water. In all cases, doors essentially act as wings, using a shape to provide horizontal spread. As with all wings, the vessel must go at a certain speed for the doors to remain standing. This speed varies, but is generally in the range of 2. 5–4.0 knots, the vertical opening of a trawl net is created using flotation on the upper edge and weight on the lower edge of the net mouth. The configuration of the footrope varies based on the expected bottom shape, the more uneven the bottom, the more robust the footrope configuration must be to prevent net damage. This is used to catch shrimp, shellfish, cod, scallops, trawls are funnel-shaped nets that have a closed-off tail where the fish are collected and is open on the top end as the mouth. Trawl nets can also be modified, such as changing mesh size, although trawling today is heavily regulated in some nations, it remains the target of many protests by environmentalists. Environmental concerns related to trawling refer to two areas, the lack of selectivity and the damage which the trawl does to the seabed
9.
Urban sprawl
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In addition to describing a particular form of urbanization, the term also relates to the social and environmental consequences associated with this development. In Continental Europe the term peri-urbanisation is often used to denote similar dynamics and phenomena, There is widespread disagreement about what constitutes sprawl and how to quantify it. For example, some commentators measure sprawl only with the number of residential units per acre in a given area. But others associate it with decentralization, discontinuity, segregation of uses, the term urban sprawl is highly politicized, and almost always has negative connotations. It is criticized for causing environmental degradation, and intensifying segregation and undermining the vitality of existing urban areas, due to the pejorative meaning of the term, few openly support urban sprawl as such. The term has become a cry for managing urban growth. Definitions of sprawl vary, researchers in the field acknowledge that the term lacks precision and he argued that a better way to identify sprawl was to use indicators rather than characteristics because this was a more flexible and less arbitrary method. He proposed using accessibility and functional space as indicators. Ewings approach has been criticized for assuming that sprawl is defined by negative characteristics, what constitutes sprawl may be considered a matter of degree and will always be somewhat subjective under many definitions of the term. The following characteristics are associated with sprawl, This refers to a situation where commercial, residential, institutional and industrial areas are separated from one another. Consequently, large tracts of land are devoted to a use and are segregated from one another by open space, infrastructure. The degree to which different land uses are mixed together is used as an indicator of sprawl in studies of the subject. Job sprawl is another land use symptom of urban sprawl and car-dependent communities, spatial mismatch is related to job sprawl and economic environmental justice. Job sprawl has been documented and measured in various ways and it has been shown to be a growing trend in Americas metropolitan areas. The Brookings Institution has published articles on the topic. In 2005, author Michael Stoll defined job sprawl simply as jobs located more than 5-mile radius from the CBD, and measured the concept based on year 2000 U. S. Census data. These two authors used three geographic rings limited to a 35-mile radius around the CBD,3 miles or less,3 to 10 miles and this compares to the year 1998 -23. 3%,34. 2%, and 42. 5% in those respective rings. The study shows CBD employment share shrinking, and job growth focused in the suburban and exurban outer metropolitan rings, Sprawl is often characterized as consisting of low-density development
10.
Extinction
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In biology and ecology, extinction is the end of an organism or of a group of organisms, normally a species. The moment of extinction is considered to be the death of the last individual of the species, although the capacity to breed. Because a species range may be very large, determining this moment is difficult. This difficulty leads to such as Lazarus taxa, where a species presumed extinct abruptly reappears after a period of apparent absence. More than 99 percent of all species, amounting to five billion species. Estimates on the number of Earths current species range from 10 million to 14 million, of which about 1.2 million have been documented and over 86 percent have not yet been described. More recently, in May 2016, scientists reported that 1 trillion species are estimated to be on Earth currently with only one-thousandth of one percent described, the relationship between animals and their ecological niches has been firmly established. Mass extinctions are relatively rare events, however, isolated extinctions are quite common, only recently have extinctions been recorded and scientists have become alarmed at the current high rate of extinctions. Most species that become extinct are never scientifically documented, some scientists estimate that up to half of presently existing plant and animal species may become extinct by 2100. A dagger symbol next to a name is often used to indicate its extinction. A species is extinct when the last existing member dies, Extinction therefore becomes a certainty when there are no surviving individuals that can reproduce and create a new generation. Pinpointing the extinction of a species requires a definition of that species. If it is to be declared extinct, the species in question must be distinguishable from any ancestor or daughter species. Extinction of a plays a key role in the punctuated equilibrium hypothesis of Stephen Jay Gould. In ecology, extinction is often used informally to refer to local extinction, in which a species ceases to exist in the area of study. This phenomenon is known as extirpation. Local extinctions may be followed by a replacement of the species taken from other locations, species which are not extinct are termed extant. Those that are extant but threatened by extinction are referred to as threatened or endangered species, currently an important aspect of extinction is human attempts to preserve critically endangered species
11.
Habitat fragmentation
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Habitat fragmentation describes the emergence of discontinuities in an organisms preferred environment, causing population fragmentation and ecosystem decay. Not only causes loss of the amount of habitat, but by creating small, habitat fragmentation is the landscape level of the phenomenon, and patch level process. Thus meaning, it covers, the areas, edge effects. Evidence of habitat destruction through natural processes such as volcanism, fire, habitats which were once continuous become divided into separate fragments. After intensive clearing, the separate fragments tend to be small islands isolated from each other by cropland, pasture, pavement. The latter is often the result of slash and burn farming in tropical forests, one of the major ways that habitat fragmentation affects biodiversity is by reducing the amount of suitable habitat available for organisms. Habitat fragmentation often involves both habitat destruction and the subdivision of previously continuous habitat, plants and other sessile organisms are disproportionately affected by some types of habitat fragmentation because they cannot respond quickly to the altered spatial configuration of the habitat. As the remaining patches are smaller, they tend to support smaller populations of species. Small populations are at a risk of a variety of genetic consequences that influence their long-term survival. Remnant populations often contain only a subset of the diversity found in the previously continuous habitat. Processes that act upon underlying genetic diversity such as adaptation have a pool of fitness-maintaining alleles to survive in the face of environmental change. Populations can maintain genetic diversity through migration, in continuous habitats, migrants have few barriers to establish themselves in suitable sites. The percentage preservation of habitats is closely related to both genetic and species biodiversity preservation. Generally a 10% remnant contiguous habitat will result in a 50% biodiversity loss, minor fluctuations in climate, resources, or other factors that would be unremarkable and quickly corrected in large populations can be catastrophic in small, isolated populations. Thus fragmentation of habitat is an important cause of species extinction, population dynamics of subdivided populations tend to vary asynchronously. In an unfragmented landscape a declining population can be rescued by immigration from an expanding population. In fragmented landscapes, the distance between fragments may prevent this from happening, additionally, unoccupied fragments of habitat that are separated from a source of immigrants by some barrier are less likely to be repopulated than adjoining fragments. Even small species such as the Columbia spotted frog are reliant on the rescue effect, studies showed 25% of juveniles travel a distance over 200m compared to 4% of adults
12.
Climate change
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Climate change is a change in the statistical distribution of weather patterns when that change lasts for an extended period of time. Climate change may refer to a change in weather conditions. Climate change is caused by such as biotic processes, variations in solar radiation received by Earth, plate tectonics. Certain human activities have also identified as significant causes of recent climate change. Scientists actively work to understand past and future climate by using observations, more recent data are provided by the instrumental record. The most general definition of change is a change in the statistical properties of the climate system when considered over long periods of time. Accordingly, fluctuations over periods shorter than a few decades, such as El Niño, the term climate change is often used to refer specifically to anthropogenic climate change. Anthropogenic climate change is caused by activity, as opposed to changes in climate that may have resulted as part of Earths natural processes. In this sense, especially in the context of environmental policy, within scientific journals, global warming refers to surface temperature increases while climate change includes global warming and everything else that increasing greenhouse gas levels affect. A related term is climatic change, in 1966, the World Meteorological Organization proposed the term climatic change to encompass all forms of climatic variability on time-scales longer than 10 years, regardless of cause. Change was a given and climatic was used as an adjective to describe this kind of change, when it was realized that human activities had a potential to drastically alter the climate, the term climate change replaced climatic change as the dominant term to reflect an anthropogenic cause. Climate change was incorporated in the title of the Intergovernmental Panel on Climate Change, Climate change, used as a noun, became an issue rather than the technical description of changing weather. On the broadest scale, the rate at which energy is received from the Sun and this energy is distributed around the globe by winds, ocean currents, and other mechanisms to affect the climates of different regions. Factors that can shape climate are called climate forcings or forcing mechanisms, there are a variety of climate change feedbacks that can either amplify or diminish the initial forcing. Some parts of the system, such as the oceans and ice caps, respond more slowly in reaction to climate forcings. There are also key factors which when exceeded can produce rapid change. Forcing mechanisms can be internal or external. Internal forcing mechanisms are natural processes within the system itself
13.
Invasive species
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One study pointed out widely divergent perceptions of the criteria for invasive species among researchers and concerns with the subjectivity of the term invasive. Such invasive species may be either plants or animals and may disrupt by dominating a region, wilderness areas, particular habitats and this includes non-native invasive plant species labeled as exotic pest plants and invasive exotics growing in native plant communities. It has been used in this sense by government organizations as well as groups such as the International Union for Conservation of Nature. The European Union defines Invasive Alien Species as those that are, firstly, outside their natural distribution area and it is also used by land managers, botanists, researchers, horticulturalists, conservationists, and the public for noxious weeds. The kudzu vine, Andean Pampas grass, and yellow starthistle are examples, an alternate usage broadens the term to include indigenous or native species along with non-native species, that have colonized natural areas. Deer are an example, considered to be overpopulating their native zones and adjacent suburban gardens, by some in the Northeastern, sometimes the term is used to describe a non-native or introduced species that has become widespread. However, not every introduced species has adverse effects on the environment, a nonadverse example is the common goldfish, which is found throughout the United States, but rarely achieves high densities. Scientists include species and ecosystem factors among the mechanisms that when combined, while all species compete to survive, invasive species appear to have specific traits or specific combinations of traits that allow them to outcompete native species. In some cases, the competition is about rates of growth, in other cases, species interact with each other more directly. Researchers disagree about the usefulness of traits as invasiveness markers, one study found that of a list of invasive and noninvasive species, 86% of the invasive species could be identified from the traits alone. Another study found invasive species tended to have only a subset of the presumed traits. Repeated patterns of movement, such as ships sailing to and from ports or cars driving up. An introduced species might become if it can outcompete native species for resources such as nutrients, light, physical space, water. If these species evolved under great competition or predation, then the new environment may host fewer able competitors, allowing the invader to proliferate quickly. Ecosystems in which are being used to their fullest capacity by native species can be modeled as zero-sum systems in which any gain for the invader is a loss for the native, however, such unilateral competitive superiority is not the rule. For example, barbed goatgrass was introduced to California on serpentine soils, which have low water-retention, low nutrient levels, a high magnesium/calcium ratio, and possible heavy metal toxicity. Plant populations on these soils tend to low density, but goatgrass can form dense stands on these soils. Some species, like Kalanchoe daigremontana, produce allelopathic compounds, that might have an effect on competing species
14.
Water pollution
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Water pollution is the contamination of water bodies. This form of environmental degradation occurs when pollutants are directly or indirectly discharged into water bodies without adequate treatment to remove harmful compounds, Water pollution affects the entire biosphere – plants and organisms living in these bodies of water. In almost all cases the effect is damaging not only to individual species and population, Water pollution is a major global problem which requires ongoing evaluation and revision of water resource policy at all levels. It has been suggested that pollution is the leading worldwide cause of deaths and diseases. An estimated 580 people in India die of water related illness every day. About 90 percent of the water in the cities of China is polluted, as of 2007, half a billion Chinese had no access to safe drinking water. In addition to the problems of water pollution in developing countries. The head of Chinas national development agency said in 2007 that one quarter the length of Chinas seven main rivers were so poisoned the water harmed the skin. Natural phenomena such as volcanoes, algae blooms, storms, and earthquakes also cause changes in water quality. Although interrelated, surface water and groundwater have often studied and managed as separate resources. Surface water seeps through the soil and becomes groundwater, conversely, groundwater can also feed surface water sources. Sources of surface water pollution are generally grouped into two based on their origin. Point source water pollution refers to contaminants that enter a waterway from a single, identifiable source, examples of sources in this category include discharges from a sewage treatment plant, a factory, or a city storm drain. The U. S. Clean Water Act defines point source for regulatory enforcement purposes, the CWA definition of point source was amended in 1987 to include municipal storm sewer systems, as well as industrial storm water, such as from construction sites. Nonpoint source pollution refers to contamination that does not originate from a single discrete source. NPS pollution is often the cumulative effect of small amounts of contaminants gathered from a large area, a common example is the leaching out of nitrogen compounds from fertilized agricultural lands. Nutrient runoff in storm water from sheet flow over a field or a forest are also cited as examples of NPS pollution. Contaminated storm water washed off of parking lots, roads and highways, however, because this runoff is typically channeled into storm drain systems and discharged through pipes to local surface waters, it becomes a point source
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Noise pollution
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Noise pollution or noise disturbance is the disturbing or excessive noise that may harm the activity or balance of human or animal life. The source of most outdoor noise worldwide is caused by machines and transportation systems, motor vehicles, aircraft. Outdoor noise is summarized by the environmental noise. Poor urban planning may give rise to noise pollution, since side-by-side industrial and residential buildings can result in noise pollution in the residential areas, documented problems associated with urban noise go back as far as Ancient Rome. Outdoor noise can be caused by machines, construction activities, and music performances, noise-induced hearing loss can be caused by outside or inside noise. High noise levels can contribute to cardiovascular effects in humans and an incidence of coronary artery disease. In animals, noise can increase the risk of death by altering predator or prey detection and avoidance, interfere with reproduction and navigation, Noise pollution affects both health and behavior. Unwanted sound can damage psychological health, Noise pollution can cause hypertension, high stress levels, tinnitus, hearing loss, sleep disturbances, and other harmful effects. Sound becomes unwanted when it interferes with normal activities such as sleeping, conversation. Chronic exposure to noise may cause noise-induced hearing loss, less addressed is how humans adapt to noise subjectively. Indeed, tolerance for noise is frequently independent of decibel levels, however, Murray Schafers soundscape research was groundbreaking in this regard. In his eponymous work, he makes compelling arguments about how humans relate to noise on a subjective level, other key research in this area can be seen in Fongs comparative analysis of soundscape differences between Bangkok, Thailand and Los Angeles, California, US. Acoustic overexposure can lead to temporary or permanent loss of hearing, an impact of noise on wild animal life is the reduction of usable habitat that noisy areas may cause, which in the case of endangered species may be part of the path to extinction. Noise pollution may have caused the death of species of whales that beached themselves after being exposed to the loud sound of military sonar. Noise also makes species communicate more loudly, which is called Lombard vocal response, scientists and researchers have conducted experiments that show whales song length is longer when submarine-detectors are on. If creatures do not speak loudly enough, their voice will be masked by anthropogenic sounds and these unheard voices might be warnings, finding of prey, or preparations of net-bubbling. When one species begins speaking more loudly, it will mask other species voice, marine invertebrates, such as crabs, have also been shown to be negatively affected by ship noise. Larger crabs were noted to be affected more by the sounds than smaller crabs
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Carrying capacity
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In population biology, carrying capacity is defined as the environments maximal load, which is different from the concept of population equilibrium. Its effect on population dynamics may be approximated in a logistic model, Carrying capacity was originally used to determine the number of animals that could graze on a segment of land without destroying it. Later, the idea was expanded to more complex populations, like humans, for the human population, more complex variables such as sanitation and medical care are sometimes considered as part of the necessary establishment. As population density increases, birth rate decreases and death rate typically increases. The difference between the rate and the death rate is the natural increase. The carrying capacity could support a natural increase or could require a negative natural increase. Thus, the capacity is the number of individuals an environment can support without significant negative impacts to the given organism. Below carrying capacity, populations typically increase, while above, they typically decrease, a factor that keeps population size at equilibrium is known as a regulating factor. Population size decreases above carrying capacity due to a range of factors depending on the species concerned, a recent review finds the first use of the term in an 1845 report by the US Secretary of State to the US Senate. Several estimates of the carrying capacity have made with a wide range of population numbers. A2001 UN report said that two-thirds of the fall in the range of 4 billion to 16 billion with unspecified standard errors. More recent estimates are lower, particularly if non-renewable resource depletion. Supporters of the concept argue that the idea of a carrying capacity is just as valid applied to humans as when applied to any other species. Animal population size, living standards, and resource depletion vary, the number of people is not the only factor in the carrying capacity of Earth. Waste and over-consumption, especially by people and nations, is putting more strain on the environment than overpopulation. This has been studied by computer models like World3. Some aspects of a carrying capacity may involve matters such as available supplies of food, water, raw materials. Eradication of, for example, large or critical portions of any system can interrupt essential processes
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Endangered species
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An endangered species is a species which has been categorized as likely to become extinct. In 2012, the IUCN Red List featured 3079 animal and 2655 plant species as endangered worldwide, the figures for 1998 were, respectively,1102 and 1197. Many nations have laws that protect conservation-reliant species, for example, population numbers, trends and species conservation status can be found in the lists of organisms by population. The conservation status of a species indicates the likelihood that it will become extinct, the IUCN Red List of Threatened Species is the best-known worldwide conservation status listing and ranking system. Over 40% of the species are estimated to be at risk of extinction. Internationally,199 countries have signed an accord to create Biodiversity Action Plans that will protect endangered, in the United States, such plans are usually called Species Recovery Plans. Those species of Near Threatened and Least Concern status have been assessed and found to have relatively robust and healthy populations, though these may be in decline. The IUCN categories, with examples of animals classified by them, include, Extinct Extinct in the wild Captive individuals survive, critically endangered Faces an extremely high risk of extinction in the immediate future. Endangered Faces a high risk of extinction in the near future, vulnerable Faces a high risk of endangerment in the medium term. Near-threatened May be considered threatened in the near future, Least concern No immediate threat to species survival. A population size reduction of ≥ 50%, projected or suspected to be met within the next 10 years or three generations, whichever is the longer, based on any of to under A1. E) Quantitative analysis showing the probability of extinction in the wild is at least 20% within 20 years or five generations, there is data from the United States that shows a correlation between human populations and threatened and endangered species. Under the Endangered Species Act in the United States, species may be listed as endangered or threatened, the Salt Creek tiger beetle is an example of an endangered subspecies protected under the ESA. Some endangered species laws are controversial, also lobbying from hunters and various industries like the petroleum industry, construction industry, and logging, has been an obstacle in establishing endangered species laws. The Bush administration lifted a policy that required federal officials to consult an expert before taking actions that could damage endangered species. Under the Obama administration, this policy has been reinstated, being listed as an endangered species can have negative effect since it could make a species more desirable for collectors and poachers. This effect is potentially reducible, such as in China where commercially farmed turtles may be reducing some of the pressure to poach endangered species. Another problem with the species is its effect of inciting the use of the shoot, shovel
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Endemism
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The extreme opposite of endemism is cosmopolitan distribution. An alternative term for a species that is endemic is precinctive, the word endemic is from New Latin endēmicus, from Greek ενδήμος, endēmos, native. Endēmos is formed of en meaning in, and dēmos meaning the people, the term, precinctive, has been suggested by some scientists, and was first used in botany by MacCaughey in 1917. It is the equivalent of endemism, precinction was perhaps first used by Frank and McCoy. That definition excludes artificial confinement of examples by humans in far-off botanical gardens or zoological parks, physical, climatic, and biological factors can contribute to endemism. The orange-breasted sunbird is found in the fynbos vegetation zone of southwestern South Africa. The glacier bear is found only in limited places in Southeast Alaska, political factors can play a part if a species is protected, or actively hunted, in one jurisdiction but not another. There are two subcategories of endemism, paleoendemism and neoendemism, paleoendemism refers to species that were formerly widespread but are now restricted to a smaller area. Neoendemism refers to species that have arisen, such as through divergence and reproductive isolation or through hybridization. Endemics can easily become endangered or extinct if their restricted habitat changes, particularly—but not only—due to human actions, there were millions of both Bermuda petrels and Bermuda cedars in Bermuda when it was settled at the start of the seventeenth century. By the end of the century, the petrels were thought extinct, cedars, already ravaged by centuries of shipbuilding, were driven nearly to extinction in the twentieth century by the introduction of a parasite. Bermuda petrels and cedars are now rare, as are species endemic to Bermuda
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Extinction debt
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In ecology, extinction debt is the future extinction of species due to events in the past. Extinction debt occurs because of delays between impacts on a species, such as destruction of habitat, and the species ultimate disappearance. For instance, long-lived trees may survive for years even after reproduction of new trees has become impossible. Extinction debt may be local or global, but most examples are local as these are easier to observe and it is most likely to be found in long-lived species and species with very specific habitat requirements. Interventions such as habitat restoration may reverse extinction debt, immigration credit is the corollary to extinction debt. It refers to the number of species likely to immigrate to an area after an event such as the restoration of an ecosystem, extinction debt is also known by the terms dead clade walking, and survival without recovery when referring to the species affected. Dead clade walking has since appeared in other writings about the aftermaths of mass extinctions. Similarly, the current extinction may continue long after human impacts on species halt, extinction debt is caused by many of the same drivers as extinction. The most well-known drivers of extinction debt are habitat fragmentation and habitat destruction and these cause extinction debt by reducing the ability of species to persist via immigration to new habitats. Under equilibrium conditions, species may become extinct in one habitat patch, however, as other patches have been destroyed or rendered inaccessible due to fragmentation, this insurance effect is reduced and the species may ultimately become extinct. Pollution may also cause extinction debt by reducing a species birth rate or increasing its death rate so that its population slowly declines, extinction debts may be caused by invasive species or by climate change. Extinction debt may also occur due to the loss of mutualist species, however, as the plant is slow-growing and long-lived, its populations persist. Jablonski found that the rate of marine invertebrates was significantly higher in the stage following a mass extinction than in the stages preceding the mass extinction. His analysis focused on marine molluscs since they constitute the most abundant group of fossils and are therefore the least likely to produce sampling errors, ecosystems that developed after recoveries from mass extinctions may have been less favorable for the dead clades walking. The time to payoff of extinction debt can be very long, islands that lost habitat at the end of the last ice age 10,000 years ago still appear to be losing species as a result. It has been shown that some bryozoans, a type of marine organism. This event cut off the flow of nutrients from the Pacific Ocean to the Caribbean 3–4.5 million years ago, while bryozoan populations dropped severely at this time, extinction of these species took another 1–2 million years. Extinction debts incurred due to human actions have shorter timescales, local extinction of birds from rainforest fragmentation occurs over years or decades, while plants in fragmented grasslands show debts lasting 50 to 100 years
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Giant panda
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The giant panda, also known as panda bear or simply panda, is a bear native to south central China. It is easily recognized by the large, distinctive black patches around its eyes, over the ears, the name giant panda is sometimes used to distinguish it from the unrelated red panda. Though it belongs to the order Carnivora, the giant pandas diet is over 99% bamboo, Giant pandas in the wild will occasionally eat other grasses, wild tubers, or even meat in the form of birds, rodents or carrion. In captivity, they may receive honey, eggs, fish, yams, shrub leaves, oranges, the giant panda lives in a few mountain ranges in central China, mainly in Sichuan province, but also in neighbouring Shaanxi and Gansu. As a result of farming, deforestation, and other development, the giant panda is a conservation reliant vulnerable species. A2007 report showed 239 pandas living in captivity inside China, as of December 2014,49 giant pandas lived in captivity outside China, living in 18 zoos in 13 different countries. Some reports also show that the number of giant pandas in the wild is on the rise, in March 2015, Mongabay stated that the wild giant panda population had increased by 268, or 16. 8%, to 1,864 individuals. In 2016, the IUCN reclassified the species from endangered to vulnerable, while the dragon has often served as Chinas national symbol, internationally the giant panda appears at least as commonly. As such, it is becoming widely used within China in international contexts, for many decades, the precise taxonomic classification of the giant panda was under debate because it shares characteristics with both bears and raccoons. However, molecular studies suggest the giant panda is a bear and part of the family Ursidae. The giant pandas closest extant relative is the bear of South America. The giant panda has been referred to as a living fossil, despite the shared name, habitat type, and diet, as well as a unique enlarged bone called the pseudo thumb the giant panda and red panda are only distantly related. The word panda was borrowed into English from French, but no explanation of the origin of the French word panda has been found. The closest candidate is the Nepali word ponya, possibly referring to the adapted wrist bone of the red panda, the Western world originally applied this name to the red panda. Until 1901, when it was stated to be related to the red panda. Even in 2013, the Encyclopædia Britannica still used giant panda or panda bear for the bear, since the earliest collection of Chinese writings, the Chinese language has given the bear 20 different names, such as huāxióng and zhúxióng. The most popular names in China today is dàxióngmāo, or simply xióngmāo, the name xióngmāo was originally used to describe the red panda, but since giant panda was thought to be closely related to red panda, dàxióngmāo was named relatively. In Taiwan, another name for panda is the inverted dàmāoxióng, though many encyclopediae
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Deforestation
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Deforestation, clearance or clearing is the removal of a forest or stand of trees where the land is thereafter converted to a non-forest use. Examples of deforestation include conversion of forestland to farms, ranches, the most concentrated deforestation occurs in tropical rainforests. About 30% of Earths land surface is covered by forests, Deforestation occurs for multiple reasons, trees are cut down to be used for building or sold as fuel, while cleared land is used as pasture for livestock and plantation. The removal of trees without sufficient reforestation has resulted in damage to habitat, biodiversity loss and it has adverse impacts on biosequestration of atmospheric carbon dioxide. Deforestation has also used in war to deprive the enemy of cover for its forces. Modern examples of this were the use of Agent Orange by the British military in Malaya during the Malayan Emergency, as of 2005, net deforestation rates have ceased to increase in countries with a per capita GDP of at least US$4,600. Deforested regions typically incur significant adverse soil erosion and frequently degrade into wasteland, disregard of ascribed value, lax forest management and deficient environmental laws are some of the factors that allow deforestation to occur on a large scale. In many countries, deforestation, both naturally occurring and human-induced, is an ongoing issue, Deforestation causes extinction, changes to climatic conditions, desertification, and displacement of populations as observed by current conditions and in the past through the fossil record. More than half of all plant and land animal species in the live in tropical forests. Between 2000 and 2012,2.3 million square kilometres of forests around the world were cut down, as a result of deforestation, only 6.2 million square kilometres remain of the original 16 million square kilometres of forest that formerly covered the Earth. According to the United Nations Framework Convention on Climate Change secretariat, subsistence farming is responsible for 48% of deforestation, commercial agriculture is responsible for 32%, logging is responsible for 14%, and fuel wood removals make up 5%. Experts do not agree on whether industrial logging is an important contributor to global deforestation, some argue that poor people are more likely to clear forest because they have no alternatives, others that the poor lack the ability to pay for the materials and labour needed to clear forest. One study found that population increases due to fertility rates were a primary driver of tropical deforestation in only 8% of cases. Other causes of contemporary deforestation may include corruption of government institutions, the distribution of wealth and power, population growth and overpopulation. Globalization is often viewed as another cause of deforestation, though there are cases in which the impacts of globalization have promoted localized forest recovery. The degradation of forest ecosystems has also traced to economic incentives that make forest conversion appear more profitable than forest conservation. Some commentators have noted a shift in the drivers of deforestation over the past 30 years, Deforestation is ongoing and is shaping climate and geography. Deforestation is a contributor to global warming, and is cited as one of the major causes of the enhanced greenhouse effect
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Soybean
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Glycine max, commonly known as soybean in North America or soya bean, is a species of legume native to East Asia, widely grown for its edible bean which has numerous uses. The plant, classed as a rather than a pulse by the UN Food and Agriculture Organization. Fat-free soybean meal is a significant and cheap source of protein for animal feeds, for example, soybean products, such as textured vegetable protein, are ingredients in many meat and dairy substitutes. The beans contain significant amounts of acid, dietary minerals. Soy vegetable oil, used in food and industrial applications, is product of processing the soybean crop. Traditional non-fermented food uses of soybeans include soy milk from which tofu and tofu skin are made, fermented soy foods include soy sauce, fermented bean paste, natto and tempeh. The main countries growing soybeans are the United States, Brazil, the English words soy and soya are ultimately derived from the Japanese pronunciation of shōyu, the Sino-Japanese word for soy sauce, by way of the Dutch adaptation of the same word, soja. The genus Glycine Willd. is divided two subgenera, Glycine and Soja. Includes the cultivated soybean, Glycine max Merr. and the wild soybean, Glycine soja is the wild ancestor of Glycine max, and grows wild in China, Japan, Korea and Russia. The subgenus Glycine consists of at least 25 wild perennial species, for example, Glycine canescens F. J. Herm. and G. tomentella Hayata, perennial soybean originated in Africa and is now a widespread pasture crop in the tropics. Like some other crops of long domestication, the relationship of the soybean to wild-growing species can no longer be traced with any degree of certainty. It is a variety with a very large number of cultivars. Like most plants, soybeans grow in distinct morphological stages as they develop from seeds into fully mature plants, the first stage of growth is germination, a process that first becomes apparent as a seeds radicle emerges. This is the first stage of growth and occurs within the first 48 hours under ideal growing conditions. The first photosynthetic structures, the cotyledons, develop from the hypocotyl and these cotyledons both act as leaves and as a source of nutrients for the immature plant, providing the seedling nutrition for its first 7 to 10 days. The first true leaves develop as a pair of single blades, subsequent to this first pair, mature nodes form compound leaves with three blades. Mature trifoliolate leaves, having three to four leaflets per leaf, are often between 6–15 cm long and 2–7 cm broad, under ideal conditions, stem growth continues, producing new nodes every four days. Before flowering, roots can grow 1.9 cm per day, if rhizobia are present, root nodulation begins by the time the third node appears
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Biodiversity hotspot
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A biodiversity hotspot is a biogeographic region with significant levels of biodiversity that is threatened with destruction. For example forests are considered as biodiversity hotspots, around the world,36 areas qualify under this definition. These sites support nearly 60% of the plant, bird, mammal, reptile. Only a small percentage of the land area within biodiversity hotspots is now protected. Several international organizations are working in ways to conserve biodiversity hotspots. They are chosen for their species richness, endemism, taxonomic uniqueness, unusual ecological or evolutionary phenomena, all biodiversity hotspots contain at least one Global 200 Ecoregion. Birdlife International has identified 218 “Endemic Bird Areas” each of which two or more bird species found nowhere else. Birdlife International has identified more than 11,000 Important Bird Areas all over the world, Plant life International coordinates several the world aiming to identify Important Plant Areas. Alliance for Zero Extinction is an initiative of a number of scientific organizations. They have identified 595 sites, including a number of Birdlife’ s Important Bird Areas. Papers such as Kareiva & Marvier have argued that the biodiversity hotspots, do not adequately represent taxa other than vascular plants. Do not protect smaller scale richness hotspots, do not make allowances for changing land use patterns. Hotspots represent regions that have experienced considerable habitat loss, but this does not mean they are experiencing ongoing habitat loss, on the other hand, regions that are relatively intact have experienced relatively little land loss, but are currently losing habitat at tremendous rates. A recent series of papers has pointed out that biodiversity hotspots do not address the concept of cost, the purpose of biodiversity hotspots is not simply to identify regions that are of high biodiversity value, but to prioritize conservation spending. The regions identified include some in the world, alongside others in the developing world. The cost of land is likely to vary between regions by an order of magnitude or more, but the biodiversity hotspot designations do not consider the conservation importance of this difference. However, the resources for conservation also tend to vary in this way. R. A. Mittermeier, C. G. Mittermeier, G. A. B. da Fonseca, spyros Sfenthourakis, Anastasios Legakis, Hotspots of endemic terrestrial invertebrates in Southern Greece
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Tropics
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The tropics are a region of the Earth surrounding the equator. The tropics are also referred to as the zone and the torrid zone. The tropics include all the areas on the Earth where the Sun is at a point directly overhead at least once during the solar year. The tropics are distinguished from the climatic and biomatic regions of Earth, which are the middle latitudes. Tropical is sometimes used in a sense for a tropical climate to mean warm to hot and moist year-round. Many tropical areas have a dry and wet season, the wet season, rainy season or green season, is the time of year, ranging from one or more months, when most of the average annual rainfall in a region falls. Areas with wet seasons are disseminated across portions of the tropics and subtropics, under the Köppen climate classification, for tropical climates, a wet season month is defined as a month where average precipitation is 60 millimetres or more. Tropical rainforests technically do not have dry or wet seasons, since their rainfall is distributed through the year. When the wet season occurs during the season, or summer, precipitation falls mainly during the late afternoon. The wet season is a time when air quality improves, freshwater quality improves and vegetation grows significantly, floods cause rivers to overflow their banks, and some animals to retreat to higher ground. Soil nutrients diminish and erosion increases, the incidence of malaria increases in areas where the rainy season coincides with high temperatures. Animals have adaptation and survival strategies for the wetter regime, unfortunately, the previous dry season leads to food shortages into the wet season, as the crops have yet to mature. Regions within the tropics may well not have a tropical climate, there are alpine tundra and snow-capped peaks, including Mauna Kea, Mount Kilimanjaro, and the Andes as far south as the northernmost parts of Chile and Argentina. Under the Köppen climate classification, much of the area within the tropics is classed not as tropical but as dry including the Sahara Desert. Tropical plants and animals are those native to the tropics. Tropical ecosystems may consist of rainforests, dry forests, spiny forests, desert. There are often significant areas of biodiversity, and species present, particularly in rainforests. In biogeography, the tropics are divided into Paleotropics and Neotropics, together, they are sometimes referred to as the Pantropic
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Terrestrial animal
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Terrestrial invertebrates include ants, flies, crickets, grasshoppers and snails. The term terrestrial is typically applied for species that live primarily on the ground, in contrast to arboreal species, there are other less common terms that apply to specific groups of terrestrial animals, Saxicolous are rock dwelling creatures. Saxicolus is derived from the Latin word Saxum which means Rocks, arenicolous creatures live in the sand. Terrestrial invasion is one of the most important events in the history of life, Terrestrial lineages evolved in several animal phyla, among which vertebrates, arthropods, and mollusks are representatives of more successful groups of terrestrial animals. Terrestrial animals do not form a clade, rather, they share only the fact that they live on land. The transition from an aquatic to terrestrial life has evolved independently and successfully many times by groups of animals. Most terrestrial lineages originated under a mild or tropical climate during the Paleozoic and Mesozoic, roundworms, tardigrades, and rotifers are microscopic animals that require a film of water to live in, and are not considered truly terrestrial. Flatworms, ribbon worms, velvet worms and annelids all depend on more or less moist habitats, labeling an animal species terrestrial or aquatic is often obscure and becomes a matter of judgment. Many animals considered terrestrial have a life-cycle that is dependent on being in water. Penguins, seals, and walruses sleep on land and feed in the ocean, there are crab species that are completely aquatic, crab species that are amphibious, and crab species that are terrestrial. Fiddler crabs are called semi-terrestrial since they make burrows in the muddy substrate, when the tide is out, fiddler crabs search the beach for food. The same is true in the Mollusca, many hundreds of genera and species live in intermediate situations, such as for example. Some gastropods with gills live on land, and others with a live in the water. As well as the terrestrial and the purely aquatic animals. There are no universally accepted criteria for deciding how to label these species, fossil evidence has shown that sea creatures, likely related to arthropods, first began to make forays on to land around 530 million years ago. There is little reason to believe, however, that animals first began living reliably on land around this time period. A more likely hypothesis is that these early arthropods motivation for venturing on to dry land was to mate or lay out of the reach of predators. As such, they are likely the most recent common ancestor of all modern tetrapods, gastropod mollusks are one of the most successful animals that have diversified in the fully terrestrial habitat
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New Zealand
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New Zealand /njuːˈziːlənd/ is an island nation in the southwestern Pacific Ocean. The country geographically comprises two main landmasses—the North Island, or Te Ika-a-Māui, and the South Island, or Te Waipounamu—and around 600 smaller islands. New Zealand is situated some 1,500 kilometres east of Australia across the Tasman Sea and roughly 1,000 kilometres south of the Pacific island areas of New Caledonia, Fiji, because of its remoteness, it was one of the last lands to be settled by humans. During its long period of isolation, New Zealand developed a distinct biodiversity of animal, fungal, the countrys varied topography and its sharp mountain peaks, such as the Southern Alps, owe much to the tectonic uplift of land and volcanic eruptions. New Zealands capital city is Wellington, while its most populous city is Auckland, sometime between 1250 and 1300 CE, Polynesians settled in the islands that later were named New Zealand and developed a distinctive Māori culture. In 1642, Dutch explorer Abel Tasman became the first European to sight New Zealand, in 1840, representatives of Britain and Māori chiefs signed the Treaty of Waitangi, which declared British sovereignty over the islands. In 1841, New Zealand became a colony within the British Empire, today, the majority of New Zealands population of 4.7 million is of European descent, the indigenous Māori are the largest minority, followed by Asians and Pacific Islanders. Reflecting this, New Zealands culture is derived from Māori and early British settlers. The official languages are English, Māori and New Zealand Sign Language, New Zealand is a developed country and ranks highly in international comparisons of national performance, such as health, education, economic freedom and quality of life. Since the 1980s, New Zealand has transformed from an agrarian, Queen Elizabeth II is the countrys head of state and is represented by a governor-general. In addition, New Zealand is organised into 11 regional councils and 67 territorial authorities for local government purposes, the Realm of New Zealand also includes Tokelau, the Cook Islands and Niue, and the Ross Dependency, which is New Zealands territorial claim in Antarctica. New Zealand is a member of the United Nations, Commonwealth of Nations, ANZUS, Organisation for Economic Co-operation and Development, Pacific Islands Forum, and Asia-Pacific Economic Cooperation. Dutch explorer Abel Tasman sighted New Zealand in 1642 and called it Staten Landt, in 1645, Dutch cartographers renamed the land Nova Zeelandia after the Dutch province of Zeeland. British explorer James Cook subsequently anglicised the name to New Zealand, Aotearoa is the current Māori name for New Zealand. It is unknown whether Māori had a name for the country before the arrival of Europeans. Māori had several names for the two main islands, including Te Ika-a-Māui for the North Island and Te Waipounamu or Te Waka o Aoraki for the South Island. Early European maps labelled the islands North, Middle and South, in 1830, maps began to use North and South to distinguish the two largest islands and by 1907, this was the accepted norm. The New Zealand Geographic Board discovered in 2009 that the names of the North Island and South Island had never been formalised and this set the names as North Island or Te Ika-a-Māui, and South Island or Te Waipounamu
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Madagascar
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Madagascar, officially the Republic of Madagascar, and previously known as the Malagasy Republic, is an island country in the Indian Ocean, off the coast of Southeast Africa. The nation comprises the island of Madagascar, and numerous smaller peripheral islands, consequently, Madagascar is a biodiversity hotspot, over 90% of its wildlife is found nowhere else on Earth. The islands diverse ecosystems and unique wildlife are threatened by the encroachment of the growing human population. The first archaeological evidence for human foraging on Madagascar dates to 2000 BC, human settlement of Madagascar occurred between 350 BC and AD550 by Austronesian peoples arriving on outrigger canoes from Borneo. These were joined around AD1000 by Bantu migrants crossing the Mozambique Channel from East Africa, other groups continued to settle on Madagascar over time, each one making lasting contributions to Malagasy cultural life. The Malagasy ethnic group is divided into 18 or more sub-groups of which the largest are the Merina of the central highlands. Until the late 18th century, the island of Madagascar was ruled by an assortment of shifting sociopolitical alliances. Beginning in the early 19th century, most of the island was united and ruled as the Kingdom of Madagascar by a series of Merina nobles, the monarchy collapsed in 1897 when the island was absorbed into the French colonial empire, from which the island gained independence in 1960. The autonomous state of Madagascar has since undergone four major constitutional periods, since 1992, the nation has officially been governed as a constitutional democracy from its capital at Antananarivo. However, in an uprising in 2009, president Marc Ravalomanana was made to resign. Constitutional governance was restored in January 2014, when Hery Rajaonarimampianina was named president following a 2013 election deemed fair, Madagascar is a member of the United Nations, the Organisation Internationale de la Francophonie and the Southern African Development Community. Madagascar belongs to the group of least developed countries, according to the United Nations, Malagasy and French are both official languages of the state. The majority of the population adheres to traditional beliefs, Christianity, ecotourism and agriculture, paired with greater investments in education, health, and private enterprise, are key elements of Madagascars development strategy. As of 2017, the economy has been weakened by the 2009-2013 political crisis, in the Malagasy language, the island of Madagascar is called Madagasikara and its people are referred to as Malagasy. The islands appellation Madagascar is not of origin, but rather was popularized in the Middle Ages by Europeans. On St. Laurences Day in 1500, Portuguese explorer Diogo Dias landed on the island, polos name was preferred and popularized on Renaissance maps. At 592,800 square kilometres, Madagascar is the worlds 47th largest country, the country lies mostly between latitudes 12°S and 26°S, and longitudes 43°E and 51°E. Neighboring islands include the French territory of Réunion and the country of Mauritius to the east, as well as the state of Comoros, the nearest mainland state is Mozambique, located to the west
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Philippines
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The Philippines, officially the Republic of the Philippines, is a sovereign island country in Southeast Asia situated in the western Pacific Ocean. It consists of about 7,641 islands that are categorized broadly under three main geographical divisions from north to south, Luzon, Visayas, and Mindanao, the capital city of the Philippines is Manila and the most populous city is Quezon City, both part of Metro Manila. The Philippines has an area of 300,000 square kilometers, and it is the eighth-most populated country in Asia and the 12th most populated country in the world. As of 2013, approximately 10 million additional Filipinos lived overseas, multiple ethnicities and cultures are found throughout the islands. In prehistoric times, Negritos were some of the archipelagos earliest inhabitants and they were followed by successive waves of Austronesian peoples. Exchanges with Chinese, Malay, Indian, and Islamic nations occurred, then, various competing maritime states were established under the rule of Datus, Rajahs, Sultans or Lakans. The arrival of Ferdinand Magellan in Homonhon, Eastern Samar in 1521 marked the beginning of Hispanic colonization, in 1543, Spanish explorer Ruy López de Villalobos named the archipelago Las Islas Filipinas in honor of Philip II of Spain. With the arrival of Miguel López de Legazpi from Mexico City, in 1565, the Philippines became part of the Spanish Empire for more than 300 years. This resulted in Roman Catholicism becoming the dominant religion, during this time, Manila became the western hub of the trans-Pacific trade connecting Asia with Acapulco in the Americas using Manila galleons. Aside from the period of Japanese occupation, the United States retained sovereignty over the islands until after World War II, since then, the Philippines has often had a tumultuous experience with democracy, which included the overthrow of a dictatorship by a non-violent revolution. It is a member of the United Nations, World Trade Organization, Association of Southeast Asian Nations, the Asia-Pacific Economic Cooperation forum. It also hosts the headquarters of the Asian Development Bank, the Philippines was named in honor of King Philip II of Spain. Spanish explorer Ruy López de Villalobos, during his expedition in 1542, named the islands of Leyte, eventually the name Las Islas Filipinas would be used to cover all the islands of the archipelago. Before that became commonplace, other such as Islas del Poniente. The official name of the Philippines has changed several times in the course of its history, during the Philippine Revolution, the Malolos Congress proclaimed the establishment of the República Filipina or the Philippine Republic. From the 1898 Treaty of Paris, the name Philippines began to appear, since the end of World War II, the official name of the country has been the Republic of the Philippines. The metatarsal of the Callao Man, reliably dated by uranium-series dating to 67,000 years ago is the oldest human remnant found in the archipelago to date and this distinction previously belonged to the Tabon Man of Palawan, carbon-dated to around 26,500 years ago. Negritos were also among the archipelagos earliest inhabitants, but their first settlement in the Philippines has not been reliably dated, there are several opposing theories regarding the origins of ancient Filipinos
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Japan
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Japan is a sovereign island nation in Eastern Asia. Located in the Pacific Ocean, it lies off the eastern coast of the Asia Mainland and stretches from the Sea of Okhotsk in the north to the East China Sea, the kanji that make up Japans name mean sun origin. 日 can be read as ni and means sun while 本 can be read as hon, or pon, Japan is often referred to by the famous epithet Land of the Rising Sun in reference to its Japanese name. Japan is an archipelago consisting of about 6,852 islands. The four largest are Honshu, Hokkaido, Kyushu and Shikoku, the country is divided into 47 prefectures in eight regions. Hokkaido being the northernmost prefecture and Okinawa being the southernmost one, the population of 127 million is the worlds tenth largest. Japanese people make up 98. 5% of Japans total population, approximately 9.1 million people live in the city of Tokyo, the capital of Japan. Archaeological research indicates that Japan was inhabited as early as the Upper Paleolithic period, the first written mention of Japan is in Chinese history texts from the 1st century AD. Influence from other regions, mainly China, followed by periods of isolation, from the 12th century until 1868, Japan was ruled by successive feudal military shoguns who ruled in the name of the Emperor. Japan entered into a period of isolation in the early 17th century. The Second Sino-Japanese War of 1937 expanded into part of World War II in 1941, which came to an end in 1945 following the bombings of Hiroshima and Nagasaki. Japan is a member of the UN, the OECD, the G7, the G8, the country has the worlds third-largest economy by nominal GDP and the worlds fourth-largest economy by purchasing power parity. It is also the worlds fourth-largest exporter and fourth-largest importer, although Japan has officially renounced its right to declare war, it maintains a modern military with the worlds eighth-largest military budget, used for self-defense and peacekeeping roles. Japan is a country with a very high standard of living. Its population enjoys the highest life expectancy and the third lowest infant mortality rate in the world, in ancient China, Japan was called Wo 倭. It was mentioned in the third century Chinese historical text Records of the Three Kingdoms in the section for the Wei kingdom, Wa became disliked because it has the connotation of the character 矮, meaning dwarf. The 倭 kanji has been replaced with the homophone Wa, meaning harmony, the Japanese word for Japan is 日本, which is pronounced Nippon or Nihon and literally means the origin of the sun. The earliest record of the name Nihon appears in the Chinese historical records of the Tang dynasty, at the start of the seventh century, a delegation from Japan introduced their country as Nihon
30.
China
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China, officially the Peoples Republic of China, is a unitary sovereign state in East Asia and the worlds most populous country, with a population of over 1.381 billion. The state is governed by the Communist Party of China and its capital is Beijing, the countrys major urban areas include Shanghai, Guangzhou, Beijing, Chongqing, Shenzhen, Tianjin and Hong Kong. China is a power and a major regional power within Asia. Chinas landscape is vast and diverse, ranging from forest steppes, the Himalaya, Karakoram, Pamir and Tian Shan mountain ranges separate China from much of South and Central Asia. The Yangtze and Yellow Rivers, the third and sixth longest in the world, respectively, Chinas coastline along the Pacific Ocean is 14,500 kilometers long and is bounded by the Bohai, Yellow, East China and South China seas. China emerged as one of the worlds earliest civilizations in the basin of the Yellow River in the North China Plain. For millennia, Chinas political system was based on hereditary monarchies known as dynasties, in 1912, the Republic of China replaced the last dynasty and ruled the Chinese mainland until 1949, when it was defeated by the communist Peoples Liberation Army in the Chinese Civil War. The Communist Party established the Peoples Republic of China in Beijing on 1 October 1949, both the ROC and PRC continue to claim to be the legitimate government of all China, though the latter has more recognition in the world and controls more territory. China had the largest economy in the world for much of the last two years, during which it has seen cycles of prosperity and decline. Since the introduction of reforms in 1978, China has become one of the worlds fastest-growing major economies. As of 2016, it is the worlds second-largest economy by nominal GDP, China is also the worlds largest exporter and second-largest importer of goods. China is a nuclear weapons state and has the worlds largest standing army. The PRC is a member of the United Nations, as it replaced the ROC as a permanent member of the U. N. Security Council in 1971. China is also a member of numerous formal and informal multilateral organizations, including the WTO, APEC, BRICS, the Shanghai Cooperation Organization, the BCIM, the English name China is first attested in Richard Edens 1555 translation of the 1516 journal of the Portuguese explorer Duarte Barbosa. The demonym, that is, the name for the people, Portuguese China is thought to derive from Persian Chīn, and perhaps ultimately from Sanskrit Cīna. Cīna was first used in early Hindu scripture, including the Mahābhārata, there are, however, other suggestions for the derivation of China. The official name of the state is the Peoples Republic of China. The shorter form is China Zhōngguó, from zhōng and guó and it was then applied to the area around Luoyi during the Eastern Zhou and then to Chinas Central Plain before being used as an occasional synonym for the state under the Qing
31.
India
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India, officially the Republic of India, is a country in South Asia. It is the seventh-largest country by area, the second-most populous country, and it is bounded by the Indian Ocean on the south, the Arabian Sea on the southwest, and the Bay of Bengal on the southeast. It shares land borders with Pakistan to the west, China, Nepal, and Bhutan to the northeast, in the Indian Ocean, India is in the vicinity of Sri Lanka and the Maldives. Indias Andaman and Nicobar Islands share a border with Thailand. The Indian subcontinent was home to the urban Indus Valley Civilisation of the 3rd millennium BCE, in the following millennium, the oldest scriptures associated with Hinduism began to be composed. Social stratification, based on caste, emerged in the first millennium BCE, early political consolidations took place under the Maurya and Gupta empires, the later peninsular Middle Kingdoms influenced cultures as far as southeast Asia. In the medieval era, Judaism, Zoroastrianism, Christianity, and Islam arrived, much of the north fell to the Delhi sultanate, the south was united under the Vijayanagara Empire. The economy expanded in the 17th century in the Mughal empire, in the mid-18th century, the subcontinent came under British East India Company rule, and in the mid-19th under British crown rule. A nationalist movement emerged in the late 19th century, which later, under Mahatma Gandhi, was noted for nonviolent resistance, in 2015, the Indian economy was the worlds seventh largest by nominal GDP and third largest by purchasing power parity. Following market-based economic reforms in 1991, India became one of the major economies and is considered a newly industrialised country. However, it continues to face the challenges of poverty, corruption, malnutrition, a nuclear weapons state and regional power, it has the third largest standing army in the world and ranks sixth in military expenditure among nations. India is a constitutional republic governed under a parliamentary system. It is a pluralistic, multilingual and multi-ethnic society and is home to a diversity of wildlife in a variety of protected habitats. The name India is derived from Indus, which originates from the Old Persian word Hindu, the latter term stems from the Sanskrit word Sindhu, which was the historical local appellation for the Indus River. The ancient Greeks referred to the Indians as Indoi, which translates as The people of the Indus, the geographical term Bharat, which is recognised by the Constitution of India as an official name for the country, is used by many Indian languages in its variations. Scholars believe it to be named after the Vedic tribe of Bharatas in the second millennium B. C. E and it is also traditionally associated with the rule of the legendary emperor Bharata. Gaṇarājya is the Sanskrit/Hindi term for republic dating back to the ancient times, hindustan is a Persian name for India dating back to the 3rd century B. C. E. It was introduced into India by the Mughals and widely used since then and its meaning varied, referring to a region that encompassed northern India and Pakistan or India in its entirety
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Malaysia
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Malaysia is a federal constitutional monarchy located in Southeast Asia. Peninsular Malaysia shares a land and maritime border with Thailand and maritime borders with Singapore, Vietnam, East Malaysia shares land and maritime borders with Brunei and Indonesia and a maritime border with the Philippines and Vietnam. The capital city is Kuala Lumpur, while Putrajaya is the seat of the federal government, with a population of over 30 million, Malaysia is the 44th most populous country. The southernmost point of continental Eurasia, Tanjung Piai, is in Malaysia, located in the tropics, Malaysia is one of 17 megadiverse countries on earth, with large numbers of endemic species. Malaysia has its origins in the Malay kingdoms present in the area which, from the 18th century, the first British territories were known as the Straits Settlements, whose establishment was followed by the Malay kingdoms becoming British protectorates. The territories on Peninsular Malaysia were first unified as the Malayan Union in 1946, Malaya was restructured as the Federation of Malaya in 1948, and achieved independence on 31 August 1957. Malaya united with North Borneo, Sarawak, and Singapore on 16 September 1963 to become Malaysia, less than two years later in 1965, Singapore was expelled from the federation. The country is multi-ethnic and multi-cultural, which plays a role in politics. About half the population is ethnically Malay, with minorities of Malaysian Chinese, Malaysian Indians. The constitution declares Islam the state religion while allowing freedom of religion for non-Muslims, the government system is closely modelled on the Westminster parliamentary system and the legal system is based on common law. The head of state is the king, known as the Yang di-Pertuan Agong and he is an elected monarch chosen from the hereditary rulers of the nine Malay states every five years. The head of government is the prime minister, since its independence, Malaysia has had one of the best economic records in Asia, with its GDP growing at an average of 6. 5% per annum for almost 50 years. The economy has traditionally been fuelled by its resources, but is expanding in the sectors of science, tourism, commerce. Today, Malaysia has a newly industrialised market economy, ranked third largest in Southeast Asia, the name Malaysia is a combination of the word Malay and the Latin-Greek suffix -sia/-σία. The word melayu in Malay may derive from the Tamil words malai and ur meaning mountain and city, land, malayadvipa was the word used by ancient Indian traders when referring to the Malay Peninsula. Whether or not it originated from these roots, the word melayu or mlayu may have used in early Malay/Javanese to mean to steadily accelerate or run. This term was applied to describe the current of the river Melayu in Sumatra. The name was adopted by the Melayu Kingdom that existed in the seventh century on Sumatra
33.
Indonesia
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Indonesia, officially the Republic of Indonesia, is a unitary sovereign state and transcontinental country located mainly in Southeast Asia with some territories in Oceania. Situated between the Indian and Pacific oceans, it is the worlds largest island country, with more than seventeen thousand islands. At 1,904,569 square kilometres, Indonesia is the worlds 14th-largest country in terms of area and worlds 7th-largest country in terms of combined sea. It has an population of over 260 million people and is the worlds fourth most populous country. The worlds most populous island, Java, contains more than half of the countrys population, Indonesias republican form of government includes an elected legislature and president. Indonesia has 34 provinces, of which five have Special Administrative status and its capital and countrys most populous city is Jakarta, which is also the most populous city in Southeast Asia and the second in Asia. The country shares land borders with Papua New Guinea, East Timor, other neighbouring countries include Singapore, Vietnam, the Philippines, Australia, Palau, and the Indian territory of the Andaman and Nicobar Islands. Despite its large population and densely populated regions, Indonesia has vast areas of wilderness that support the second highest level of biodiversity. The country has abundant natural resources like oil and natural gas, tin, copper, agriculture mainly produces rice, palm oil, tea, coffee, cacao, medicinal plants, spices and rubber. Indonesias major trading partners are Japan, United States, China, the Indonesian archipelago has been an important region for trade since at least the 7th century, when Srivijaya and then later Majapahit traded with China and India. Local rulers gradually absorbed foreign cultural, religious and political models from the early centuries CE, Indonesian history has been influenced by foreign powers drawn to its natural resources. Indonesia consists of hundreds of native ethnic and linguistic groups. The largest – and politically dominant – ethnic group are the Javanese, a shared identity has developed, defined by a national language, ethnic diversity, religious pluralism within a Muslim-majority population, and a history of colonialism and rebellion against it. Indonesias national motto, Bhinneka Tunggal Ika, articulates the diversity that shapes the country, Indonesias economy is the worlds 16th largest by nominal GDP and the 8th largest by GDP at PPP, the largest in Southeast Asia, and is considered an emerging market and newly industrialised country. Indonesia has been a member of the United Nations since 1950, Indonesia is a member of the G20 major economies and World Trade Organization. The name Indonesia derives from the Greek name of the Indós, the name dates to the 18th century, far predating the formation of independent Indonesia. In 1850, George Windsor Earl, an English ethnologist, proposed the terms Indunesians—and, his preference, in the same publication, one of his students, James Richardson Logan, used Indonesia as a synonym for Indian Archipelago. However, Dutch academics writing in East Indies publications were reluctant to use Indonesia, they preferred Malay Archipelago, the Netherlands East Indies, popularly Indië, the East, and Insulinde
34.
West Africa
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West Africa, also called Western Africa and the West of Africa, is the westernmost subregion of Africa. Early human settlers from northern Holocene societies arrived in West Africa around 12,000 B. C, sedentary farming began in, or around the fifth millennium B. C, as well as the domestication of cattle. By 1500 B. C, ironworking technology allowed an expansion of productivity. Northern tribes developed walled settlements and non-walled settlements that numbered at 400, in the forest region, Iron Age cultures began to flourish, and an inter-region trade began to appear. The desertification of the Sahara and the change of the coast cause trade with upper Mediterranean peoples to be seen. Local leather, cloth, and gold also contributed to the abundance of prosperity for many of the following empires. Also, based on the archaeology of city of Kumbi Saleh in modern-day Mauritania, three great kingdoms were identified in Bilad al-Sudan by the ninth century. They included Ghana, Gao and Kanem, the Sosso Empire sought to fill the void, but was defeated by the Mandinka forces of Sundiata Keita, founder of the new Mali Empire. In the 15th century, the Songhai would form a new dominant state based on Gao, in the Songhai Empire, under the leadership of Sonni Ali, further east, Oyo arose as the dominant Yoruba state and the Aro Confederacy as a dominant Igbo state in modern-day Nigeria. The Kingdom of Nri was a West African medieval state in the present-day southeastern Nigeria, the Kingdom of Nri was unusual in the history of world government in that its leader exercised no military power over his subjects. The kingdom existed as a sphere of religious and political influence over a third of Igboland, the Eze Nri managed trade and diplomacy on behalf of the Nri people, and possessed divine authority in religious matters. The Oyo Empire was a Yoruba empire of what is today Western, established in the 15th century, the Oyo Empire grew to become one of the largest West African states. It rose through the organizational skills of the Yoruba, wealth gained from trade. The Benin Empire was an empire located in what is now southern Nigeria. Its capital was Edo, now known as Benin City, Edo and it should not be confused with the modern-day country called Benin, formerly called Dahomey. The Benin Empire was one of the oldest and most highly developed states in the hinterland of West Africa. Olfert Dapper, a Dutch writer, describing Benin in his book Description of Africa and its craft was the most adored and treasured bronze casting in the history of Africa. It was annexed by the British Empire in 1897 during the invasion, in the early 19th century, a series of Fulani reformist jihads swept across Western Africa
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Coast
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A coastline or a seashore is the area where land meets the sea or ocean, or a line that forms the boundary between the land and the ocean or a lake. A precise line that can be called a coastline cannot be determined due to the Coastline paradox, the term coastal zone is a region where interaction of the sea and land processes occurs. Both the terms coast and coastal are often used to describe a location or region, for example, New Zealands West Coast. Edinburgh for example is a city on the coast of Scotland, a pelagic coast refers to a coast which fronts the open ocean, as opposed to a more sheltered coast in a gulf or bay. A shore, on the hand, can refer to parts of the land which adjoin any large body of water, including oceans. Similarly, the related term refers to the land alongside or sloping down to a river or to a body of water smaller than a lake. Bank is also used in parts of the world to refer to an artificial ridge of earth intended to retain the water of a river or pond. According to the UN atlas, 44% of people live within 150 kilometres of the sea, tides often determine the range over which sediment is deposited or eroded. Areas with high tidal ranges allow waves to reach farther up the shore, the tidal range is influenced by the size and shape of the coastline. Tides do not typically cause erosion by themselves, however, tidal bores can erode as the waves surge up river estuaries from the ocean. Waves erode coastline as they break on shore releasing their energy, the larger the wave the more energy it releases and the more sediment it moves. Coastlines with longer shores have more room for the waves to disperse their energy, while coasts with cliffs and short shore faces give little room for the wave energy to be dispersed. In these areas the wave energy breaking against the cliffs is higher, sediment deposited by waves comes from eroded cliff faces and is moved along the coastline by the waves. This forms an abrasion or cliffed coast, sediment deposited by rivers is the dominant influence on the amount of sediment located on a coastline. Today riverine deposition at the coast is often blocked by dams and other human regulatory devices, like the ocean which shapes them, coasts are a dynamic environment with constant change. The coast and its adjacent areas on and off shore are an important part of a local ecosystem, Salt marshes and beaches also support a diversity of plants, animals and insects crucial to the food chain. The high level of biodiversity creates a level of biological activity. More and more of the people live in coastal regions
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Coral reef
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Coral reefs are diverse underwater ecosystems held together by calcium carbonate structures secreted by corals. Coral reefs are built by colonies of tiny animals found in waters that contain few nutrients. Most coral reefs are built from stony corals, which in turn consist of polyps that cluster in groups, the polyps belong to a group of animals known as Cnidaria, which also includes sea anemones and jellyfish. Unlike sea anemones, corals secrete hard carbonate exoskeletons which support, most reefs grow best in warm, shallow, clear, sunny and agitated waters. Often called rainforests of the sea, shallow coral reefs form some of the most diverse ecosystems on Earth, paradoxically, coral reefs flourish even though they are surrounded by ocean waters that provide few nutrients. They are most commonly found at depths in tropical waters. Coral reefs deliver ecosystem services to tourism, fisheries and shoreline protection, the annual global economic value of coral reefs is estimated between US$29. 8-375 billion. However, coral reefs are fragile ecosystems, partly because they are sensitive to water temperature. Most of the coral reefs we can see today were formed after the last glacial period when melting ice caused the sea level to rise and this means that most modern coral reefs are less than 10,000 years old. As communities established themselves on the shelves, the reefs grew upwards, Reefs that rose too slowly could become drowned reefs. They are covered by so much water there was insufficient light. Coral reefs are found in the sea away from continental shelves, around oceanic islands. The vast majority of islands are volcanic in origin. The few exceptions have tectonic origins where plate movements have lifted the deep ocean floor on the surface. In 1842 in his first monograph, The Structure and Distribution of Coral Reefs, Charles Darwin set out his theory of the formation of atoll reefs and he theorized uplift and subsidence of the Earths crust under the oceans formed the atolls. Darwin’s theory sets out a sequence of three stages in atoll formation and it starts with a fringing reef forming around an extinct volcanic island as the island and ocean floor subsides. As the subsidence continues, the reef becomes a barrier reef. Darwin predicted that underneath each lagoon would be a bed rock base, where the level of the underlying earth allows, the corals grow around the coast to form what he called fringing reefs, and can eventually grow out from the shore to become a barrier reef
37.
South America
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South America is a continent located in the western hemisphere, mostly in the southern hemisphere, with a relatively small portion in the northern hemisphere. It may also be considered a subcontinent of the Americas, which is the used in nations that speak Romance languages. The reference to South America instead of other regions has increased in the last decades due to changing geopolitical dynamics. It is bordered on the west by the Pacific Ocean and on the north and east by the Atlantic Ocean, North America and it includes twelve sovereign states, a part of France, and a non-sovereign area. In addition to this, the ABC islands of the Kingdom of the Netherlands, Trinidad and Tobago, South America has an area of 17,840,000 square kilometers. Its population as of 2005 has been estimated at more than 371,090,000, South America ranks fourth in area and fifth in population. Brazil is by far the most populous South American country, with more than half of the population, followed by Colombia, Argentina, Venezuela. In recent decades Brazil has also concentrated half of the regions GDP and has become a first regional power, most of the population lives near the continents western or eastern coasts while the interior and the far south are sparsely populated. Most of the continent lies in the tropics, the continents cultural and ethnic outlook has its origin with the interaction of indigenous peoples with European conquerors and immigrants and, more locally, with African slaves. Given a long history of colonialism, the majority of South Americans speak Portuguese or Spanish. South America occupies the portion of the Americas. The continent is delimited on the northwest by the Darién watershed along the Colombia–Panama border. Almost all of mainland South America sits on the South American Plate, South Americas major mineral resources are gold, silver, copper, iron ore, tin, and petroleum. These resources found in South America have brought high income to its countries especially in times of war or of rapid growth by industrialized countries elsewhere. However, the concentration in producing one major export commodity often has hindered the development of diversified economies and this is leading to efforts to diversify production to drive away from staying as economies dedicated to one major export. South America is one of the most biodiverse continents on earth, South America is home to many interesting and unique species of animals including the llama, anaconda, piranha, jaguar, vicuña, and tapir. The Amazon rainforests possess high biodiversity, containing a proportion of the Earths species. Brazil is the largest country in South America, encompassing around half of the land area
38.
Caribbean Sea
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The Caribbean Sea is a sea of the Atlantic Ocean in the tropics of the Western Hemisphere. The entire area of the Caribbean Sea, the islands of the West Indies. The Caribbean Sea is one of the largest seas and has an area of about 2,754,000 km2, the seas deepest point is the Cayman Trough, between the Cayman Islands and Jamaica, at 7,686 m below sea level. The Caribbean coastline has many gulfs and bays, the Gulf of Gonâve, Gulf of Venezuela, Gulf of Darién, Golfo de los Mosquitos, Gulf of Paria, the Caribbean Sea has the worlds second biggest barrier reef, the Mesoamerican Barrier Reef. It runs 1,000 km along the coasts of Mexico, Belize, Guatemala, the name Caribbean derives from the Caribs, one of the regions dominant Native American groups at the time of European contact during the late 15th century. During the first century of development, Spanish dominance in the region remained undisputed, from the 16th century, Europeans visiting the Caribbean region identified the South Sea as opposed to the North Sea. The Caribbean Sea had been unknown to the populations of Eurasia until 1492, at that time the Western Hemisphere in general was unknown to Europeans. Following the discovery of the islands by Columbus, the area was colonised by several Western cultures. As of 2015 the area is home to 22 island territories, the International Hydrographic Organization defines the limits of the Caribbean Sea as follows, On the North. In the Windward Channel – a line joining Caleta Point and Pearl Point in Haïti, in the Mona Passage – a line joining Cape Engano and the extreme of Agujereada in Puerto Rico. From Galera Point through Trinidad to Galeota Point and thence to Baja Point in Venezuela, note that, although Barbados is an island on the same continental shelf, it is considered to be in the Atlantic Ocean rather than the Caribbean Sea. The Caribbean Sea is an oceanic sea largely situated on the Caribbean Plate, the Caribbean Sea is separated from the ocean by several island arcs of various ages. The youngest stretches from the Lesser Antilles to the Virgin Islands to the north east of Trinidad, the larger islands in the northern part of the sea Cuba, Hispaniola, Jamaica and Puerto Rico lie on an older island arc. The geological age of the Caribbean Sea is estimated to be between 160 and 180 million years and was formed by a fracture that split the supercontinent called Pangea in the Mesozoic Era. It is assumed the proto-caribbean basin existed in the Devonian period, in the early Carboniferous movement of Gondwana to the north and its convergence with the Euramerica basin decreased in size. The next stage of the Caribbean Seas formation began in the Triassic, powerful rifting led to the formation of narrow troughs, stretching from modern Newfoundland to the west coast of the Gulf of Mexico which formed siliciclastic sedimentary rocks. In the early Jurassic due to powerful marine transgression, water broke into the present area of the Gulf of Mexico creating a vast shallow pool, the emergence of deep basins in the Caribbean occurred during the Middle Jurassic rifting. The emergence of these marked the beginning of the Atlantic Ocean
39.
Island
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An island or isle is any piece of sub-continental land that is surrounded by water. Very small islands such as emergent land features on atolls can be called islets, skerries, an island in a river or a lake island may be called an eyot or ait, and a small island off the coast may be called a holm. A grouping of geographically or geologically related islands is called an archipelago, an island may be described as such, despite the presence of an artificial land bridge. Example, Singapore and its causeway, or the various Dutch delta islands, there are two main types of islands in the sea, continental and oceanic. The word island derives from Middle English iland, from Old English igland, Old English ieg is actually a cognate of Swedish ö and German Aue, and related to Latin aqua. There is a difference between islands and continents in terms of geology, continents sit on continental lithosphere which is part of tectonic plates floating high on Earths mantle. Oceanic crust is also part of tectonic plates, but it is denser than continental lithosphere, Islands are either extensions of the oceanic crust or geologically they are part of some continent sitting on continental lithosphere. This holds true for Australia, which sits on its own continental lithosphere, continental islands are bodies of land that lie on the continental shelf of a continent. A special type of island is the microcontinental island, which is created when a continent is rifted. Examples are Madagascar and Socotra off Africa, the Kerguelen Islands, New Caledonia, New Zealand, another subtype is an island or bar formed by deposition of tiny rocks where water current loses some of its carrying capacity. While some are transitory and may disappear if the volume or speed of the current changes, others are stable, oceanic islands are islands that do not sit on continental shelves. The vast majority are volcanic in origin, such as Saint Helena in the South Atlantic Ocean, the few oceanic islands that are not volcanic are tectonic in origin and arise where plate movements have lifted up the ocean floor above the surface. Examples are Saint Peter and Paul Rocks in the Atlantic Ocean, one type of volcanic oceanic island is found in a volcanic island arc. These islands arise from volcanoes where the subduction of one plate under another is occurring, examples are the Aleutian Islands, the Mariana Islands, and most of Tonga in the Pacific Ocean. The only examples in the Atlantic Ocean are some of the Lesser Antilles, another type of volcanic oceanic island occurs where an oceanic rift reaches the surface. There are two examples, Iceland, which is the second largest volcanic island, and Jan Mayen. A third type of oceanic island is formed over volcanic hotspots. A hotspot is more or less stationary relative to the tectonic plate above it
40.
Sustainable agriculture
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Sustainable agriculture is farming in sustainable ways based on an understanding of ecosystem services, the study of relationships between organisms and their environment. Wes Jackson is credited with the first publication of the expression in his 1980 book New Roots for Agriculture, the term became popularly used in the late 1980s. Sustainable agriculture can be understood as an approach to agriculture. Practices that can cause damage to soil include excessive tilling of the soil. Long-term experiments have provided some of the best data on how various practices affect soil properties essential to sustainability, the most important factors for an individual site are sun, air, soil, nutrients, and water. Of the five, water and soil quality and quantity are most amenable to human intervention through time, although air and sunlight are available everywhere on Earth, crops also depend on soil nutrients and the availability of water. When farmers grow and harvest crops, they some of these nutrients from the soil. Without replenishment, land suffers from nutrient depletion and becomes either unusable or suffers from reduced yields, sustainable agriculture depends on replenishing the soil while minimizing the use or need of non-renewable resources, such as natural gas, or mineral ores. The last option was proposed in the 1970s, but is recently becoming feasible. Sustainable options for replacing other nutrient inputs are more limited, crops that require high levels of soil nutrients can be cultivated in a more sustainable manner if certain fertilizer management practices are adhered to. Nationwide food producers require vast amounts of land and soil to produce food at an accelerated rate and this diminishes the nutrients in the soil and decimates the idea of sustainable agriculture, which is best built through local, regional agricultural methods. In some areas sufficient rainfall is available for growth. For irrigation systems to be sustainable, they require proper management, otherwise, the water source effectively becomes a non-renewable resource. However, this progress has come at a price, in many areas, such as the Ogallala Aquifer, the water is being used faster than it can be replenished. Several steps must be taken to develop drought-resistant farming systems even in years with average rainfall. Indicators for sustainable water resource development are, Internal renewable water resources and this is the average annual flow of rivers and groundwater generated from endogenous precipitation, after ensuring that there is no double counting. It represents the amount of water resource produced within the boundaries of a country. This value, which is expressed as an average on a basis, is invariant in time
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Central America
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Central America is the southernmost, isthmian portion of the North American continent, which connects with South America on the southeast. Central America is bordered by Mexico to the north, Colombia to the southeast, the Caribbean Sea to the east, Central America consists of seven countries, Belize, Guatemala, El Salvador, Honduras, Nicaragua, Costa Rica and Panama. The combined population of Central America is between 41,739,000 and 42,688,190, Central America is a part of the Mesoamerican biodiversity hotspot, which extends from northern Guatemala through to central Panama. Due to the presence of several active faults and the Central America Volcanic Arc. Volcanic eruptions and earthquakes occur frequently, these disasters have resulted in the loss of many lives. In the Pre-Columbian era, Central America was inhabited by the peoples of Mesoamerica to the north and west. Soon after Christopher Columbuss voyages to the Americas, the Spanish began to colonize the Americas, the seven states finally became independent autonomous states, beginning with Nicaragua, Honduras, Costa Rica, and Guatemala, followed by El Salvador, then Panama, and finally Belize. Middle America is usually thought to comprise Mexico to the north of the 7 states of Central America as well as Colombia, usually the whole of the Caribbean to the north-east and sometimes the Guyanas are also included. According to one source, the term Central America was used as a synonym for Middle America as recently as 1962, in Brazil, Central America comprises all countries between Mexico and Colombia, including those in the Caribbean. Mexico, in whole or in part, is included by British people. For the people living in the 5 countries formerly part of the Federal Republic of Central America there is a distinction between the Spanish language terms América Central and Centroamérica, in the Pre-Columbian era, the northern areas of Central America were inhabited by the indigenous peoples of Mesoamerica. Most notable among these were the Mayans, who had built numerous cities throughout the region, and the Aztecs, following Christopher Columbuss voyages to the Americas, the Spanish sent many expeditions to the region, and they began their conquest of Maya territory in 1523. Soon after the conquest of the Aztec Empire, Spanish conquistador Pedro de Alvarado commenced the conquest of northern Central America for the Spanish Empire. Beginning with his arrival in Soconusco in 1523, Alvarados forces systematically conquered and subjugated most of the major Maya kingdoms, including the Kiche, Tzutujil, Pipil, and the Kaqchikel. By 1528, the conquest of Guatemala was nearly complete, with only the Petén Basin remaining outside the Spanish sphere of influence, the last independent Maya kingdoms – the Kowoj and the Itza people – were finally defeated in 1697, as part of the Spanish conquest of Petén. In 1538, Spain established the Real Audiencia of Panama, which had jurisdiction over all land from the Strait of Magellan to the Gulf of Fonseca. This entity was dissolved in 1543, and most of the territory within Central America then fell under the jurisdiction of the Audiencia Real de Guatemala. This area included the current territories of Costa Rica, El Salvador, Guatemala, Honduras, Nicaragua, and the Mexican state of Chiapas, the president of the Audiencia, which had its seat in Antigua Guatemala, was the governor of the entire area
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Sub-Saharan Africa
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Sub-Saharan Africa is, geographically, the area of the continent of Africa that lies south of the Sahara. According to the UN, it consists of all African countries that are fully or partially located south of the Sahara and it contrasts with North Africa, whose territories are part of the League of Arab states within the Arab world. Somalia, Djibouti, Comoros and Mauritania are geographically in Sub-Saharan Africa, the Sahel is the transitional zone between the Sahara and the tropical savanna and forest-savanna mosaic to the south. The Sahara pump theory explains how flora and fauna left Africa to penetrate the Middle East, African pluvial periods are associated with a wet Sahara phase during which larger lakes and more rivers existed. Geographers historically divided the region into several distinct ethnographic sections based on each areas respective inhabitants, commentators in Arabic in the medieval period used the general term bilâd as-sûdân for the vast Sudan region, or sometimes extending from the coast of West Africa to Western Sudan. Its equivalent in Southeast Africa was Zanj, which was situated in the vicinity of the Great Lakes region. The geographers drew an explicit distinction between the Sudan region and its analogue Zanj, from the area to their extreme east on the Red Sea coast in the Horn of Africa. In modern-day Ethiopia and Eritrea was Al-Habash or Abyssinia, which was inhabited by the Habash or Abyssinians, Sub-Saharan Africa has a wide variety of climate zones or biomes. South Africa and the Democratic Republic of the Congo in particular are considered Megadiverse countries, the Sahel shoots across all of Africa at a latitude of about 10° to 15° N. Countries that include parts of the Sahara Desert proper in their territories and parts of the Sahel in their southern region include Mauritania, Mali, Niger, Chad. The Sahel has a hot semi-arid climate, South of the Sahel, there is a belt of savanna, widening to include most of South Sudan and Ethiopia in the east. The Serengeti ecosystem is located in northwestern Tanzania and extends to southwestern Kenya, the Kalahari Basin includes the Kalahari Desert surrounded by a belt of semi-desert. The Bushveld is a tropical ecoregion of Southern Africa. The Karoo is a semi-desert in western South Africa and this occurred 10 million to 5 million years ago. By 3 million years ago several australopithecine hominid species had developed throughout southern, eastern and they were tool users rather than tool manufacturers. The tools were classed as Oldowan, roughly 1.8 million years ago, Homo ergaster first appeared in the fossil record in Africa. From Homo ergaster, Homo erectus evolved 1.5 million years ago, some of the earlier representatives of this species were small-brained and used primitive stone tools, much like H. habilis. The brain later grew in size, and H. erectus eventually developed a complex stone tool technology called the Acheulean
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Amazon rainforest
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The Amazon rainforest, also known in English as Amazonia or the Amazon Jungle, is a moist broadleaf forest in the Amazon biome that covers most of the Amazon basin of South America. This basin encompasses 7,000,000 square kilometres, of which 5,500,000 square kilometres are covered by the rainforest and this region includes territory belonging to nine nations. States or departments in four nations contain Amazonas in their names, the name Amazon is said to arise from a war Francisco de Orellana fought with the Tapuyas and other tribes. The women of the tribe alongside the men, as was their custom. Orellana derived the name Amazonas from the Amazons of Greek mythology, the rainforest likely formed during the Eocene era. It appeared following a reduction of tropical temperatures when the Atlantic Ocean had widened sufficiently to provide a warm. Following the Cretaceous–Paleogene extinction event, the extinction of the dinosaurs, from 66–34 Mya, the rainforest extended as far south as 45°. Climate fluctuations during the last 34 million years have allowed savanna regions to expand into the tropics, during the Oligocene, for example, the rainforest spanned a relatively narrow band. It expanded again during the Middle Miocene, then retracted to a mostly inland formation at the last glacial maximum, however, the rainforest still managed to thrive during these glacial periods, allowing for the survival and evolution of a broad diversity of species. During the mid-Eocene, it is believed that the basin of the Amazon was split along the middle of the continent by the Purus Arch. Water on the eastern side flowed toward the Atlantic, while to the west water flowed toward the Pacific across the Amazonas Basin, as the Andes Mountains rose, however, a large basin was created that enclosed a lake, now known as the Solimões Basin. Within the last 5–10 million years, this accumulating water broke through the Purus Arch, there is evidence that there have been significant changes in Amazon rainforest vegetation over the last 21,000 years through the Last Glacial Maximum and subsequent deglaciation. There is debate, however, over how extensive this reduction was, more than 56% of the dust fertilizing the Amazon rainforest comes from the Bodélé depression in Northern Chad in the Sahara desert. The dust contains phosphorus, important for plant growth, the yearly Sahara dust replaces the equivalent amount of phosphorus washed away yearly in Amazon soil from rains and floods. Up to 50 million tonnes of Sahara dust per year are blown across the Atlantic Ocean, CALIPSO uses a laser range finder to scan the Earths atmosphere for the vertical distribution of dust and other aerosols. CALIPSO regularly tracks the Sahara-Amazon dust plume, CALIPSO has measured variations in the dust amounts transported— an 86 percent drop between the highest amount of dust transported in 2007 and the lowest in 2011. A possibility causing the variation is the Sahel, a strip of land on the southern border of the Sahara. When rain amounts in the Sahel are higher, the volume of dust is lower, the higher rainfall could make more vegetation grow in the Sahel, leaving less sand exposed to winds to blow away
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Eastern United States
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It is geographically diverse, spanning the Northeast and Southeast as well as the eastern part of the Central United States. In 2011 the 26 states east of the Mississippi had an population of 179,948,346 or 58. 28% of the total U. S. population of 308,745,358. The Southern United States constitutes a region in the south-eastern. In the last few decades, the Southern US has been attracting internal and international migrants, the American South is among the fastest-growing areas in the United States. In one of the earliest English settlements in the New World, English Pilgrims from Europe first settled in New England in 1620, New England produced the first examples of American literature and philosophy and was home to the beginnings of free public education. In the 19th century, it played a prominent role in the movement to abolish slavery in the United States and it was the first region of the United States to be transformed by the Industrial Revolution. The Midwestern United States is one of the four regions within the United States that are recognized by the United States Census Bureau. The region consists of seven states in the central and inland northeastern US, Illinois, Indiana, Iowa, Michigan, Minnesota, Ohio, a 2006 Census Bureau estimate put the population at 66,217,736. Both the geographic center of the contiguous U. S. the United States Census Bureau divides this region into the East North Central States and the West North Central States. Chicago is the largest city in the region, followed by Indianapolis, chicago has the largest metropolitan statistical area, followed by Detroit, and Minneapolis – Saint Paul. Marie, Michigan is the oldest city in the region, having been founded by French missionaries, the term Midwest has been in common use for over 100 years. Another term sometimes applied to the general region is the heartland. Other designations for the region have fallen into disuse, such as the Northwest or Old Northwest, since the book Middletown appeared in 1929, sociologists have often used Midwestern cities as typical of the entire nation. The region has a higher ratio than the Northeast, the West. Four of the associated with the Midwestern United States are traditionally referred to as belonging to the Great Plains region. However, in recent years they are included in the Midwestern region. The following is a list of the 24 largest cities in the East by population, East Coast of the United States Eastern Canada Territories of the United States on stamps
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Midwestern United States
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It was officially named the North Central region by the Census Bureau until 1984. Illinois is the most populous of the states and North Dakota the least, a 2012 report from the United States Census put the population of the Midwest at 65,377,684. The Midwest is divided by the Census Bureau into two divisions, the East North Central Division includes Illinois, Indiana, Michigan, Ohio and Wisconsin, all of which are also part of the Great Lakes region. Major rivers in the include, from east to west, the Ohio River, the Upper Mississippi River. Chicago is the most populated city in the American Midwest and the third most populous in the entire country, other large Midwest cities include, Indianapolis, Columbus, Detroit, Milwaukee, Kansas City, Omaha, Minneapolis, Cleveland, Wichita and St. Louis. Chicago and its suburbs form the largest metropolitan area with 9.8 million people, followed by Metro Detroit. Paul, Greater St. Louis, Greater Cleveland, Greater Cincinnati, Kansas City metro area, the term Midwestern has been in use since the 1880s to refer to portions of the central United States. A variant term, Middle West, has used since the 19th century. Another term sometimes applied to the general region is the heartland. Other designations for the region have fallen out of use, such as the Northwest or Old Northwest, the Northwest Territory was one of the earliest territories of the United States, stretching northwest from the Ohio River to northern Minnesota and upper-Mississippi. The upper-Mississippi watershed including the Missouri and Illinois Rivers was the setting for the earlier French settlements of the Illinois Country, economically the region is balanced between heavy industry and agriculture, with finance and services such as medicine and education becoming increasingly important. Its central location makes it a crossroads for river boats, railroads, autos, trucks. Politically the region swings back and forth between the parties, and thus is heavily contested and often decisive in elections, after the sociological study Middletown, which was based on Muncie, Indiana, commentators used Midwestern cities as typical of the nation. The region has a higher ratio than the Northeast, the West. Traditional definitions of the Midwest include the Northwest Ordinance Old Northwest states, the states of the Old Northwest are also known as Great Lakes states and are east-north central in the United States. The Ohio River runs along the section while the Mississippi River runs north to south near the center. Many of the Louisiana Purchase states in the west-north central United States, are known as Great Plains states. The Midwest lies north of the 36°30′ parallel that the 1820 Missouri Compromise established as the line between future slave and non-slave states
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Tropical rainforest
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True rainforests are typically found between 10 degrees north and south of the equator, they are a sub-set of the tropical forest biome that occurs roughly within the 28 degree latitudes. Within the World Wildlife Funds biome classification, tropical rainforests are a type of tropical moist broadleaf forest that includes the more extensive tropical seasonal forests. Tropical rainforests can be characterized in two words, hot and wet, mean monthly temperatures exceed 18 °C during all months of the year. Average annual rainfall is no less than 1,680 mm and this high level of precipitation often results in poor soils due to leaching of soluble nutrients in the ground. Tropical rainforests exhibit high levels of biodiversity, around 40% to 75% of all biotic species are indigenous to the rainforests. Rainforests are home to half of all the animal and plant species on the planet. Two-thirds of all flowering plants can be found in rainforests, a single hectare of rainforest may contain 42,000 different species of insect, up to 807 trees of 313 species and 1,500 species of higher plants. Tropical rainforests have been called the worlds largest pharmacy, because over one quarter of natural medicines have been discovered within them and it is likely that there may be many millions of species of plants, insects and microorganisms still undiscovered in tropical rainforests. Tropical rainforests are among the most threatened ecosystems globally due to large-scale fragmentation as a result of human activity, habitat fragmentation caused by geological processes such as volcanism and climate change occurred in the past, and have been identified as important drivers of speciation. However, fast human driven habitat destruction is suspected to be one of the causes of species extinction. Tropical rain forests have been subjected to heavy logging and agricultural clearance throughout the 20th century, tropical rainforests have existed on earth for hundreds of millions of years. Most tropical rainforests today are on fragments of the Mesozoic era supercontinent of Gondwana, the separation of the landmass resulted in a great loss of amphibian diversity while at the same time the drier climate spurred the diversification of reptiles. The division left tropical rainforests located in five regions of the world, tropical America, Africa, Southeast Asia, Madagascar. However, the specifics of the origin of rainforests remain uncertain due to a fossil record. Several biomes comprise the general term tropical forest, Lowland equatorial evergreen rain forests are forests which receive rainfall throughout the year. These true rainforests occur in a belt around the equator, with the largest areas in the Amazon basin of South America, the Congo Basin of Central Africa, Borneo, Mindanao, Indonesia, and New Guinea. Moist tropical seasonal forests receive high rainfall with a warm summer wet season. Some trees in these forests drop some or all of their leaves during the dry season
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Ecosystem
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An ecosystem is a community of living organisms in conjunction with the nonliving components of their environment, interacting as a system. These biotic and abiotic components are regarded as linked together through nutrient cycles, as ecosystems are defined by the network of interactions among organisms, and between organisms and their environment, they can be of any size but usually encompass specific, limited spaces. Energy, water, nitrogen and soil minerals are other essential components of an ecosystem. The energy that flows through ecosystems is obtained primarily from the sun and it generally enters the system through photosynthesis, a process that also captures carbon from the atmosphere. By feeding on plants and on one another, animals play an important role in the movement of matter and they also influence the quantity of plant and microbial biomass present. Ecosystems are controlled both by external and internal factors, other external factors include time and potential biota. Ecosystems are dynamic entities—invariably, they are subject to disturbances and are in the process of recovering from some past disturbance. Ecosystems in similar environments that are located in different parts of the world can have different characteristics simply because they contain different species. The introduction of species can cause substantial shifts in ecosystem function. Internal factors not only control ecosystem processes but are controlled by them and are often subject to feedback loops. Other internal factors include disturbance, succession and the types of species present, although humans exist and operate within ecosystems, their cumulative effects are large enough to influence external factors like climate. Biodiversity affects ecosystem function, as do the processes of disturbance, classifying ecosystems into ecologically homogeneous units is an important step towards effective ecosystem management, but there is no single, agreed-upon way to do this. The term ecosystem was first used in 1935 in a publication by British ecologist Arthur Tansley, Tansley devised the concept to draw attention to the importance of transfers of materials between organisms and their environment. He later refined the term, describing it as The whole system, including not only the organism-complex, but also the whole complex of physical factors forming what we call the environment. Tansley regarded ecosystems not simply as natural units, but as mental isolates, Tansley later defined the spatial extent of ecosystems using the term ecotope. G. Raymond Lindeman took these ideas one step further to suggest that the flow of energy through a lake was the driver of the ecosystem. Most mineral nutrients, on the hand, are recycled within ecosystems. Ecosystems are controlled both by external and internal factors, external factors, also called state factors, control the overall structure of an ecosystem and the way things work within it, but are not themselves influenced by the ecosystem
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Rainforest
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The monsoon trough, alternatively known as the intertropical convergence zone, plays a significant role in creating the climatic conditions necessary for the Earths tropical rainforests. Around 40% to 75% of all species are indigenous to the rainforests. It has been estimated there may be many millions of species of plants, insects. Tropical rainforests have been called the jewels of the Earth and the worlds largest pharmacy, the undergrowth in some areas of a rainforest can be restricted by poor penetration of sunlight to ground level. If the leaf canopy is destroyed or thinned, the ground beneath is soon colonized by a dense, tangled growth of vines, shrubs and small trees, the term jungle is also sometimes applied to tropical rainforests generally. Tropical rainforests are characterized by a warm and wet climate with no dry season. Mean monthly temperatures exceed 18 °C during all months of the year, average annual rainfall is no less than 168 cm and can exceed 1,000 cm although it typically lies between 175 cm and 200 cm. Many of the tropical forests are associated with the location of the monsoon trough. The broader category of tropical moist forests are located in the zone between the Tropic of Cancer and Tropic of Capricorn. Tropical forests have been called the Earths lungs, although it is now known that rainforests contribute little net oxygen addition to the atmosphere through photosynthesis, Tropical forests cover a large part of the globe, but temperate rainforests only occur in few regions around the world. Temperate rainforests are rainforests in temperate regions and they occur in North America, in Europe, in East Asia, in South America and also in Australia and New Zealand. A tropical rainforest typically has a number of layers, each with different plants, examples include the emergent, canopy, understorey and forest floor layers. They need to be able to withstand the hot temperatures and strong winds that occur above the canopy in some areas, eagles, butterflies, bats and certain monkeys inhabit this layer. The canopy layer contains the majority of the largest trees, typically 30 metres to 45 metres tall, the densest areas of biodiversity are found in the forest canopy, a more or less continuous cover of foliage formed by adjacent treetops. The canopy, by some estimates, is home to 50 percent of all plant species, epiphytic plants attach to trunks and branches, and obtain water and minerals from rain and debris that collects on the supporting plants. The fauna is similar to found in the emergent layer. A quarter of all species are believed to exist in the rainforest canopy. Scientists have long suspected the richness of the canopy as a habitat, true exploration of this habitat only began in the 1980s, when scientists developed methods to reach the canopy, such as firing ropes into the trees using crossbows
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Temperate broadleaf and mixed forest
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Temperate broadleaf and mixed forest is a temperate climate terrestrial biome, with broadleaf tree ecoregions, and with conifer and broadleaf tree mixed coniferous forest ecoregions. The term Temperate broadleaf and mixed forest is used by the World Wildlife Fund in global biogeography as one of the biome designations under which to organize ecoregions, the typical structure of these forests includes four layers. The uppermost layer is the canopy composed of mature trees ranging from 30 to 61 m high. Below the canopy is the three-layered, shade-tolerant understory that is roughly 9 to 15 m shorter than the canopy, the top layer of the understory is the sub-canopy composed of smaller mature trees, saplings, and suppressed juvenile canopy layer trees awaiting an opening in the canopy. Below the sub-canopy is the layer, composed of low growing woody plants. Typically the lowest growing layer is the cover or herbaceous layer. In the Northern hemisphere, characteristic dominant broadleaf trees in this biome include oaks, beeches, maples, the term mixed forest comes from the inclusion of coniferous trees as a canopy component of some of these forests. Typical coniferous trees include, Pines, firs, and spruces, in some areas of this biome the conifers may be a more important canopy species than the broadleaf species. In the Southern hemisphere, endemic genera such as Nothofagus and Eucalyptus occupy this biome, Temperate broadleaf and mixed forests occur in areas with distinct warm and cool season, which give it a moderate annual average temperature —3 to 15.6 °C. These forests occur in warm and rainy climates, sometimes also with a distinct dry season. A dry season occurs in the winter in East Asia and in summer on the wet fringe of the Mediterranean climate zones. Other areas, as in the central and upper eastern United States and southeastern Canada, have an even distribution of rainfall, annual rainfall is typically over 600 mm
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