1.
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
2.
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
3.
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
4.
Papua New Guinea
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Its capital, located along its southeastern coast, is Port Moresby. The western half of New Guinea forms the Indonesian provinces of Papua, Papua New Guinea is one of the most culturally diverse countries in the world. There are 852 known languages in the country, of which 12 have no known living speakers, most of the population of more than 7 million people live in customary communities, which are as diverse as the languages. It is also one of the most rural, as only 18 percent of its live in urban centres. The country is one of the worlds least explored, culturally and geographically and it is known to have numerous groups of uncontacted peoples, and researchers believe there are many undiscovered species of plants and animals in the interior. Papua New Guinea is classified as an economy by the International Monetary Fund. Strong growth in Papua New Guineas mining and resource sector led to the becoming the sixth fastest-growing economy in the world in 2011. Growth was expected to slow once major resource projects came on line in 2015, mining remains a major economic factor, however. Local and national governments are discussing the potential of resuming mining operations in Panguna mine in Bougainville Province, nearly 40 percent of the population lives a self-sustainable natural lifestyle with no access to global capital. Most of the still live in strong traditional social groups based on farming. Their social lives combine traditional religion with modern practices, including primary education, at the national level, after being ruled by three external powers since 1884, Papua New Guinea established its sovereignty in 1975. This followed nearly 60 years of Australian administration, which started during the Great War and it became an independent Commonwealth realm with Queen Elizabeth II as its head of state and became a member of the Commonwealth of Nations in its own right. Archaeological evidence indicates that humans first arrived in Papua New Guinea around 42,000 to 45,000 years ago and they were descendants of migrants out of Africa, in one of the early waves of human migration. Agriculture was independently developed in the New Guinea highlands around 7000 BC, a major migration of Austronesian-speaking peoples to coastal regions of New Guinea took place around 500 BC. This has been correlated with the introduction of pottery, pigs, in the 18th century, traders brought the sweet potato to New Guinea, where it was adopted and became part of the staples. Portuguese traders had obtained it from South America and introduced it to the Moluccas, the far higher crop yields from sweet potato gardens radically transformed traditional agriculture and societies. Sweet potato largely supplanted the previous staple, taro, and resulted in a significant increase in population in the highlands. In 1901, on Goaribari Island in the Gulf of Papua, missionary Harry Dauncey found 10,000 skulls in the islands Long Houses, traders from Southeast Asia had visited New Guinea beginning 5,000 years ago to collect bird of paradise plumes
5.
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
6.
Sarawak
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Sarawak is one of the two Malaysian states on the island of Borneo. The capital city, Kuching, is the centre of the state. Other cities and towns in Sarawak include Miri, Sibu, as of the 2015 census, the total population of Sarawak is 2,636,000. Sarawak has a climate with tropical rainforests and abundant animal. It has several prominent cave systems at Gunung Mulu National Park, Rajang River is the longest river in Malaysia, Bakun Dam, one of the largest dams in Southeast Asia, is located on one of its tributaries, the Balui River. Mount Murud is the highest point in Sarawak, the earliest known human settlement in Sarawak, located at the Niah Caves, dates back to 40,000 years ago. A series of Chinese ceramics dated from the 8th to 13th century AD was uncovered at the site of Santubong. The coastal regions of Sarawak came under the influence of the Bruneian Empire in the 16th century, in 1839, James Brooke, a British explorer, arrived in Sarawak. He, and his descendants, governed the state from 1841 to 1946, during World War II, it was occupied by the Japanese for three years. After the war, the last White Rajah, Charles Vyner Brooke, ceded Sarawak to Britain, on 22 July 1963, Sarawak was granted self-government by the British and subsequently became one of the founding members of the Federation of Malaysia, established on 16 September 1963. However, the federation was opposed by Indonesia leading to a three-year confrontation, the creation of the Federation also resulted in a communist insurgency that lasted until 1990. The head of state is the Governor, also known as the Yang di-Pertua Negeri, Sarawak exhibits notable diversity in ethnicity, culture, and language, major ethnic groups in Sarawak are, Iban, Malay, Chinese, Melanau, Bidayuh and Orang Ulu. English and Malay are the two official languages of the state, there is no official religion. The Gawai Dayak is a festival celebrated on a public holiday. The official explanation of the word Sarawak is that it is derived from the Sarawak Malay word serawak, which means antimony. A popular alternative explanation is that it is a contraction of the four Malay words purportedly uttered by Pangeran Muda Hashim, Saya serah pada awak, James Brooke became the first of the White Rajah dynasty to govern Sarawak. Sarawak is nicknamed Land of the Hornbills and these birds are important cultural symbols for the Dayak people, representing the spirit of God. It is also believed if a hornbill is seen flying over residences
7.
Palm oil
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Palm oil is naturally reddish in color because of a high beta-carotene content. It is not to be confused with palm oil derived from the kernel of the same fruit. The differences are in color, and in saturated fat content, palm oil is 49% saturated, while palm kernel oil and coconut oil are 81% and 86% saturated fats. Along with coconut oil, palm oil is one of the few highly saturated vegetable fats and is semisolid at room temperature, Palm oil is a common cooking ingredient in the tropical belt of Africa, Southeast Asia and parts of Brazil. Its use in the food industry in other parts of the world is widespread because of its lower cost. In 2004, a group called the Roundtable on Sustainable Palm Oil was formed to work with the palm oil industry to address these concerns. It is believed that traders brought the oil palm to Egypt, Palm oil from E. guineensiss has long been recognized in West and Central African countries, and is widely used as a cooking oil. European merchants trading with West Africa occasionally purchased palm oil for use as an oil in Europe. Palm oil became a highly sought-after commodity by British traders, for use as a lubricant for machinery during Britains Industrial Revolution. Palm oil formed the basis of soap products, such as Lever Brothers Sunlight soap, by around 1870, palm oil constituted the primary export of some West African countries, such as Ghana and Nigeria, although this was overtaken by cocoa in the 1880s. Palm oil, like all fats, is composed of fatty acids, Palm oil has an especially high concentration of saturated fat, specifically, of the 16-carbon saturated fatty acid palmitic acid, to which it gives its name. Monounsaturated oleic acid is also a constituent of palm oil. Unrefined palm oil is a significant source of tocotrienol, part of the vitamin E family. The approximate concentration of fatty acids in palm oil is, Red palm oil is rich in carotenes, such as alpha-carotene, beta-carotene and lycopene, many processed foods either contain palm oil or various ingredients derived from it. After milling, various oil products are made using refining processes. First is fractionation, with crystallization and separation processes to obtain solid, then melting and degumming removes impurities. Then the oil is filtered and bleached, RBDPO is the basic palm oil product sold on the worlds commodity markets. Many companies fractionate it further to produce palm olein for cooking oil, since the mid-1990s, red palm oil has been cold-pressed and bottled for use as cooking oil, and blended into mayonnaise and salad oil
8.
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
9.
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
10.
Surface runoff
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Surface runoff is the flow of water that occurs when excess stormwater, meltwater, or other sources flows over the Earths surface. Surface runoff is a component of the water cycle. It is the agent in soil erosion by water. Runoff that occurs on the surface before reaching a channel is also called a nonpoint source. If a nonpoint source contains man-made contaminants, or natural forms of pollution the runoff is called nonpoint source pollution, a land area which produces runoff that drains to a common point is called a drainage basin. When runoff flows along the ground, it can pick up soil contaminants including petroleum, pesticides, surface runoff can be generated either by rainfall, snowfall or by the melting of snow, or glaciers. Snow and glacier melt occur only in areas cold enough for these to form permanently, typically snowmelt will peak in the spring and glacier melt in the summer, leading to pronounced flow maxima in rivers affected by them. The determining factor of the rate of melting of snow or glaciers is both air temperature and the duration of sunlight, in high mountain regions, streams frequently rise on sunny days and fall on cloudy ones for this reason. In areas where there is no snow, runoff will come from rainfall, however, not all rainfall will produce runoff because storage from soils can absorb light showers. This occurs when the rate of rainfall on a surface exceeds the rate at which water can infiltrate the ground and this is called flooding excess overland flow, Hortonian overland flow, or unsaturated overland flow. This more commonly occurs in arid and semi-arid regions, where rainfall intensities are high and this occurs largely in city areas where pavements prevent water from flooding. When the soil is saturated and the depression storage filled, and rain continues to fall, the level of antecedent soil moisture is one factor affecting the time until soil becomes saturated. This runoff is called saturation excess overland flow or saturated overland flow, soil retains a degree of moisture after a rainfall. This residual water moisture affects the soils infiltration capacity, during the next rainfall event, the infiltration capacity will cause the soil to be saturated at a different rate. The higher the level of antecedent soil moisture, the more quickly the soil becomes saturated, once the soil is saturated, runoff occurs. After water infiltrates the soil on a portion of a hill, the water may flow laterally through the soil. This is called subsurface return flow or throughflow, any remaining surface water eventually flows into a receiving water body such as a river, lake, estuary or ocean. Urbanization increases surface runoff by creating more impervious surfaces such as pavement and it is instead forced directly into streams or storm water runoff drains, where erosion and siltation can be major problems, even when flooding is not
11.
Flood
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A flood is an overflow of water that submerges land which is usually dry. The European Union Floods Directive defines a flood as a covering by water of land not normally covered by water, in the sense of flowing water, the word may also be applied to the inflow of the tide. Floods can also occur in rivers when the flow exceeds the capacity of the river channel. Floods often cause damage to homes and businesses if they are in the flood plains of rivers. Some floods develop slowly, while others such as floods, can develop in just a few minutes. Additionally, floods can be local, impacting a neighborhood or community, or very large, the word flood comes from the Old English flod, a word common to Germanic languages. Deluge myths are stories of a great flood sent by a deity or deities to destroy civilization as an act of divine retribution. Floods can happen on flat or low-lying areas when water is supplied by rainfall or snowmelt more rapidly than it can infiltrate or run off. The excess accumulates in place, sometimes to hazardous depths, surface soil can become saturated, which effectively stops infiltration, where the water table is shallow, such as a floodplain, or from intense rain from one or a series of storms. Infiltration also is slow to negligible through frozen ground, rock, concrete, paving, areal flooding begins in flat areas like floodplains and in local depressions not connected to a stream channel, because the velocity of overland flow depends on the surface slope. Endorheic basins may experience flooding during periods when precipitation exceeds evaporation. Floods occur in all types of river and stream channels, from the smallest ephemeral streams in humid zones to normally-dry channels in arid climates to the worlds largest rivers. When overland flow occurs on tilled fields, it can result in a flood where sediments are picked up by run off. Localized flooding may be caused or exacerbated by drainage obstructions such as landslides, ice, debris, slow-rising floods most commonly occur in large rivers with large catchment areas. The increase in flow may be the result of sustained rainfall, rapid snow melt, monsoons, the cause may be localized convective precipitation or sudden release from an upstream impoundment created behind a dam, landslide, or glacier. In one instance, a flood killed eight people enjoying the water on a Sunday afternoon at a popular waterfall in a narrow canyon. Without any observed rainfall, the rate increased from about 50 to 1,500 cubic feet per second in just one minute. Two larger floods occurred at the site within a week
12.
Old-growth forest
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Old-growth features include diverse tree-related structures that provide diverse wildlife habitat that increases the biodiversity of the forested ecosystem. The concept of tree structure includes multi-layered canopies and canopy gaps, greatly varying tree heights and diameters. Old-growth forests are valuable, and logging of these forests has been a point of contention between the logging industry and environmentalists. Old-growth forests tend to have trees and standing dead trees, multi-layered canopies with gaps that result from the deaths of individual trees. Depending on the forest, this may take anywhere from a century to several millennia, hardwood forests of the eastern United States can develop old-growth characteristics in one or two generations of trees, or 150–500 years. In British Columbia, Canada, old growth is defined as 120 to 140 years of age in the interior of the province where fire is a frequent and natural occurrence. In British Columbia’s coastal rainforests, old growth is defined as more than 250 years. In Australia, eucalypt trees rarely exceed 350 years of age due to frequent fire disturbance, Forest types have very different development patterns, natural disturbances and appearances. Levels of biodiversity may be higher or lower in old-growth forests compared to that in second-growth forests, depending on circumstances, environmental variables. Logging in old-growth forests is an issue in many parts of the world. Excessive logging reduces biodiversity, affecting not only the old-growth forest itself, a forest in old-growth stage has a mix of tree ages, due to a distinct regeneration pattern for this stage. New trees regenerate at different times from other, because each one of them has different spatial location relative to the main canopy. The mixed age of the forest is an important criterion in ensuring that the forest is a stable ecosystem in the long term. A climax stand that is uniformly aged becomes senescent and degrades within a relatively short time-period to result in a new cycle of forest succession, thus, uniformly aged stands are a less stable ecosystem. Forest canopy gaps are essential in creating and maintaining mixed-age stands, also, some herbaceous plants only become established in canopy openings, but persist beneath an understory. Openings are a result of death due to small impact disturbances such as wind, low-intensity fires. Because old-growth forest is structurally diverse it provides higher-diversity habitat than forests in other stages, thus, sometimes higher biological diversity can be sustained in old-growth forest, or at least a biodiversity that is different from other forest stages. The characteristic topography of much old-growth forest consists of pits and mounds, mounds are caused by decaying fallen trees, and pits by the roots pulled out of the ground when trees fall due to natural causes, including being pushed over by animals
