Biodiversity refers to the variety and variability of life on Earth. Biodiversity is a measure of variation at the genetic and ecosystem level. Terrestrial biodiversity is greater near the equator, the result of the warm climate and high primary productivity. Biodiversity is not distributed evenly on Earth, is richest in the tropics; these tropical forest ecosystems cover less than 10 percent of earth's surface, contain about 90 percent of the world's species. Marine biodiversity is highest along coasts in the Western Pacific, where sea surface temperature is highest, in the mid-latitudinal band in all oceans. There are latitudinal gradients in species diversity. Biodiversity tends to cluster in hotspots, has been increasing through time, but will be to slow in the future. Rapid environmental changes cause mass extinctions. More than 99.9 percent of all species that lived on Earth, amounting to over five billion species, are estimated to be extinct. Estimates on the number of Earth's 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 in May 2016, scientists reported that 1 trillion species are estimated to be on Earth 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 total 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 organisms living on Earth; the age of the Earth is about 4.54 billion years. The earliest undisputed evidence of life on Earth dates at least from 3.5 billion years ago, during the Eoarchean Era after a geological crust started to solidify following the earlier molten Hadean Eon. There are microbial mat fossils found in 3.48 billion-year-old sandstone discovered in Western Australia. Other early physical evidence of a biogenic substance is graphite in 3.7 billion-year-old meta-sedimentary rocks discovered in Western Greenland. More in 2015, "remains of biotic life" were found in 4.1 billion-year-old rocks in Western Australia.
According to one of the researchers, "If life arose quickly on Earth.. it could be common in the universe."Since life began on Earth, five major mass extinctions and several minor events have led to large and sudden drops in biodiversity. The Phanerozoic eon marked a rapid growth in biodiversity via the Cambrian explosion—a period during which the majority of multicellular phyla first appeared; the next 400 million years included repeated, massive biodiversity losses classified as mass extinction events. In the Carboniferous, rainforest collapse led to a great loss of animal life; the Permian–Triassic extinction event, 251 million years ago, was the worst. The most recent, the Cretaceous–Paleogene extinction event, occurred 65 million years ago and has attracted more attention than others because it resulted in the extinction of the dinosaurs; the period since the emergence of humans has displayed an ongoing biodiversity reduction and an accompanying loss of genetic diversity. Named the Holocene extinction, the reduction is caused by human impacts habitat destruction.
Conversely, biodiversity positively impacts human health in a number of ways, although a few negative effects are studied. The United Nations designated 2011–2020 as the United Nations Decade on Biodiversity. 1916 - The term biological diversity was used first by J. Arthur Harris in "The Variable Desert," Scientific American, JSTOR 6182: "The bare statement that the region contains a flora rich in genera and species and of diverse geographic origin or affinity is inadequate as a description of its real biological diversity." 1975 - The term natural diversity was introduced 1980 - Thomas Lovejoy introduced the term biological diversity to the scientific community in a book.. It became used. 1985 -The contracted form biodiversity was coined by W. G. Rosen 1985 - The term "biodiversity" appears in the article, "A New Plan to Conserve the Earth's Biota" by Laura Tangley. 1988 - The term biodiversity first appeared in a publication. The present - the term has achieved widespread use. "Biodiversity" is most used to replace the more defined and long established terms, species diversity and species richness.
Biologists most define biodiversity as the "totality of genes and ecosystems of a region". An advantage of this definition is that it seems to describe most circumstances and presents a unified view of the traditional types of biological variety identified: taxonomic diversity ecological diversity morphological diversity functional diversity This multilevel construct is consistent with Datman and Lovejoy. An explicit definition consistent with this interpretation was first given in a paper by Bruce A. Wilcox commissioned by the International Union for the Conservation of Nature and Natural Resources for the 1982 World National Parks Conference. Wilcox's definition was "Biological diversity is the variety of life forms...at all levels of biologi
Quaternary is the current and most recent of the three periods of the Cenozoic Era in the geologic time scale of the International Commission on Stratigraphy. It follows the Neogene Period and spans from 2.588 ± 0.005 million years ago to the present. The Quaternary Period is divided into two epochs: the Holocene; the informal term "Late Quaternary" refers to the past 0.5–1.0 million years. The Quaternary Period is defined by the cyclic growth and decay of continental ice sheets associated with Milankovitch cycles and the associated climate and environmental changes that occurred. In 1759 Giovanni Arduino proposed that the geological strata of northern Italy could be divided into four successive formations or "orders"; the term "quaternary" was introduced by Jules Desnoyers in 1829 for sediments of France's Seine Basin that seemed to be younger than Tertiary Period rocks. The Quaternary Period extends to the present; the Quaternary covers the time span of glaciations classified as the Pleistocene, includes the present interglacial time-period, the Holocene.
This places the start of the Quaternary at the onset of Northern Hemisphere glaciation 2.6 million years ago. Prior to 2009, the Pleistocene was defined to be from 1.805 million years ago to the present, so the current definition of the Pleistocene includes a portion of what was, prior to 2009, defined as the Pliocene. Quaternary stratigraphers worked with regional subdivisions. From the 1970s, the International Commission on Stratigraphy tried to make a single geologic time scale based on GSSP's, which could be used internationally; the Quaternary subdivisions were defined based on biostratigraphy instead of paleoclimate. This led to the problem that the proposed base of the Pleistocene was at 1.805 Mya, long after the start of the major glaciations of the northern hemisphere. The ICS proposed to abolish use of the name Quaternary altogether, which appeared unacceptable to the International Union for Quaternary Research. In 2009, it was decided to make the Quaternary the youngest period of the Cenozoic Era with its base at 2.588 Mya and including the Gelasian stage, considered part of the Neogene Period and Pliocene Epoch.
The Anthropocene has been proposed as a third epoch as a mark of the anthropogenic impact on the global environment starting with the Industrial Revolution, or about 200 years ago. The Anthropocene is not designated by the ICS, but a working group has been working on a proposal for the creation of an epoch or sub-period; the 2.6 million years of the Quaternary represents the time during which recognizable humans existed. Over this geologically short time period, there has been little change in the distribution of the continents due to plate tectonics; the Quaternary geological record is preserved in greater detail than that for earlier periods. The major geographical changes during this time period included the emergence of the Strait of Bosphorus and Skagerrak during glacial epochs, which turned the Black Sea and Baltic Sea into fresh water, followed by their flooding by rising sea level; the current extent of Hudson Bay, the Great Lakes and other major lakes of North America are a consequence of the Canadian Shield's readjustment since the last ice age.
The climate was one of periodic glaciations with continental glaciers moving as far from the poles as 40 degrees latitude. There was a major extinction of large mammals in Northern areas at the end of the Pleistocene Epoch. Many forms such as saber-toothed cats, mastodons, etc. became extinct worldwide. Others, including horses and American cheetahs became extinct in North America. Glaciation took place during the Quaternary Ice Age – a term coined by Schimper in 1839 that began with the start of the Quaternary about 2.58 Mya and continues to the present day. In 1821, a Swiss engineer, Ignaz Venetz, presented an article in which he suggested the presence of traces of the passage of a glacier at a considerable distance from the Alps; this idea was disputed by another Swiss scientist, Louis Agassiz, but when he undertook to disprove it, he ended up affirming his colleague's hypothesis. A year Agassiz raised the hypothesis of a great glacial period that would have had long-reaching general effects.
This idea led to the establishment of the Glacial Theory. In time, thanks to the refinement of geology, it has been demonstrated that there were several periods of glacial advance and retreat and that past temperatures on Earth were different from today. In particular, the Milankovitch cycles of Milutin Milankovitch are based on the premise that variations in incoming solar radiation are a fundamental factor controlling Earth's climate. During this time, substantial glaciers advanced and retreated over much of North America and Europe, parts of South America and Asia, all of Antarctica; the Great Lakes formed and giant mammals thrived in parts of North America and Eurasia not covered in ice. These mammals became extinct. Modern humans evolved about 315,000 years ago. During the Quaternary Period, flowering plants, insects dominated
An ecotone is a transition area between two biomes. It is where two communities integrate, it may be narrow or wide, it may be local or regional. An ecotone may appear on the ground as a gradual blending of the two communities across a broad area, or it may manifest itself as a sharp boundary line; the word ecotone was coined from a combination of eco plus -tone, from the Greek tonos or tension – in other words, a place where ecologies are in tension. There are several distinguishing features of an ecotone. First, an ecotone can have a sharp vegetation transition, with a distinct line between two communities. For example, a change in colors of grasses or plant life can indicate an ecotone. Second, a change in physiognomy can be a key indicator. Water bodies, such as estuaries, can have a region of transition, the boundary is characterized by the differences in heights of the macrophytes or plant species present in the areas because this distinguishes the two areas' accessibility to light. Scientists look at color changes in plant height.
Third, a change of species can signal an ecotone. There will be specific organisms on one side of the other. Other factors can illustrate or obscure an ecotone, for example and the establishment of new plants; these are known as spatial mass effects, which are noticeable because some organisms will not be able to form self-sustaining populations if they cross the ecotone. If different species can survive in both communities of the two biomes the ecotone is considered to have species richness. Lastly, the abundance of introduced species in an ecotone can reveal the type of biome or efficiency of the two communities sharing space; because an ecotone is the zone in which two communities integrate, many different forms of life have to live together and compete for space. Therefore, an ecotone can create a diverse ecosystem. Changes in the physical environment may produce a sharp boundary, as in the example of the interface between areas of forest and cleared land. Elsewhere, a more blended interface area will be found, where species from each community will be found together as well as unique local species.
Mountain ranges create such ecotones, due to the wide variety of climatic conditions experienced on their slopes. They may provide a boundary between species due to the obstructive nature of their terrain. Mont Ventoux in France is a good example, marking the boundary between the flora and fauna of northern and southern France. Most wetlands are ecotones; the spatial variation of ecotones form due to disturbances, creating patches that separate patches of vegetation. Different intensity of disturbances can cause landslides, land shifts, or movement of sediment that can create these vegetation patches and ecotones. Plants in competition extend themselves on one side of the ecotone as far as their ability to maintain themselves allows. Beyond this competitors of the adjacent community take over; as a result, the ecotone represents a shift in dominance. Ecotones are significant for mobile animals, as they can exploit more than one set of habitats within a short distance; the ecotone contains not only species common to the communities on both sides.
The phenomenon of increased variety of plants as well as animals at the community junction is called the edge effect and is due to a locally broader range of suitable environmental conditions or ecological niches. An ecotone is associated with an ecocline: a "physical transition zone" between two systems; the ecotone and ecocline concepts are sometimes confused: an ecocline can signal an ecotone chemically, or microclimatically between two ecosystems. In contrast: an ecocline is a variation of the physicochemical environment dependent of one or two physico-chemical factors of life, thus presence/absence of certain species. An ecocline can be a thermocline, halocline or pycnocline. Ecocline transitions are less distinct, have more stable conditions within, hence a higher plant species richness. An ecotone describes a variation in species prevalence and is not dependent on a major physical factor separating one ecosystem from another, with resulting habitat variability. An ecotone is unobtrusive and harder to measure.
An ecotone is the area. Ecotones can be identified by distinct change in soil gradient and soil composition between two communities. Ecotone transitions are more clear-cut, conditions are less stable, hence they have a low species richness; the Kra ecotone between 11°N and 13°N latitude just north of the Kra Isthmus that connects the Thai-Malay Peninsula with mainland Asia is an example of a regional scale ecotone. It marks the transition zone between the moist deciduous forest in the mainland Southeast Asia biogeographical region in the north and the wet seasonal dipterocarp forest in the Sundaland region in the south, it has been shown to be the biogeographical transition between Sundaic faunas. 152 species of bird were found to have northern or southern range limits between these latitudes. Population genetics studies have found that the Kra ecotone is the major physical barrier that limits gene flow in the honeybees Apis cerana and Apis dorsata and the stingles
World Wide Fund for Nature
The World Wide Fund for Nature is an international non-governmental organization founded in 1961, working in the field of the wilderness preservation, the reduction of human impact on the environment. It was named the World Wildlife Fund, which remains its official name in Canada and the United States. WWF is the world's largest conservation organization with over five million supporters worldwide, working in more than 100 countries, supporting around 1,300 conservation and environmental projects, they have invested over $1 billion in more than 12,000 conservation initiatives since 1995. WWF is a foundation with 55% of funding from individuals and bequests, 19% from government sources and 8% from corporations in 2014. WWF aims to "stop the degradation of the planet's natural environment and to build a future in which humans live in harmony with nature." The Living Planet Report is published every two years by WWF since 1998. In addition, WWF has launched several notable worldwide campaigns including Earth Hour and Debt-for-Nature Swap, its current work is organized around these six areas: food, freshwater, wildlife and oceans.
WWF has been accused by BuzzFeed News, Kathmandu Post, the Rainforest Foundation Fund and Survival International of protecting paramilitary forces funded by the organization to fight poaching that have engaged in human rights abuses despite an internal report acknowledging them in 2015. They have attacked African and South Asian villages, torturing and killing villagers. Investigators revealed that the WWF engaged in cover ups and lobbied to release rangers when they were arrested; the Conservation Foundation, a precursor to WWF, was founded in 1948 by Fairfield Osborn as an affiliate of the New York Zoological Society with an aim of protecting the world's natural resources. The advisory council included leading scientists such as Charles Sutherland Elton, G. Evelyn Hutchinson, Aldo Leopold, Carl Sauer, Paul Sears, it supported much of the scientific work cited by Rachel Carson's Silent Spring, including that of John L. George, Roger Hale, Robert Rudd, George Woodwell; the idea for a fund on behalf of endangered animals was proposed by Victor Stolan to Sir Julian Huxley in response to articles he published in the British newspaper The Observer.
This proposal led Huxley to put Stolan in contact with Max Nicholson, a person who had had thirty years experience of linking progressive intellectuals with big business interests through the Political and Economic Planning think tank. Nicholson thought up the name of the organization. WWF was conceived on 29 April 1961, under the name of World Wildlife Fund, its first office was opened on 11 September that same year in Morges, Switzerland. WWF was conceived to act as a funding institution for existing conservation groups such as the International Union for the Conservation of Nature and Natural Resources and The Conservation Foundation. Godfrey A. Rockefeller played an important role in its creation, assembling the first staff, its establishment was marked with the signing of the "Morges Manifesto", the founding document that sets out the fund's commitment to assisting worthy organizations struggling to save the world's wildlife: They need above all money, to carry out mercy missions and to meet conservation emergencies by buying land where wildlife treasures are threatened, in many other ways.
Money, for example, to pay guardians of wildlife refuges.... Money for education and propaganda among those who would care and help if only they understood. Money to send out experts to danger spots and to train more local wardens and helpers in Africa and elsewhere. Money to maintain a sort of'war room' at the international headquarters of conservation, showing where the danger spots are and making it possible to ensure that their needs are met before it is too late. Dutch Prince Bernhard of Lippe-Biesterfeld helped found the World Wildlife Fund, becoming its first President in 1961. In 1963, the Foundation held a conference and published a major report warning of anthropogenic global warming, written by Noel Eichhorn based on the work of Frank Fraser Darling, Edward Deevey, Erik Eriksson, Charles Keeling, Gilbert Plass, Lionel Walford, William Garnett. In 1970, along with Duke of Edinburgh and a few associates, Prince Bernhard established the WWF's financial endowment The 1001: A Nature Trust to handle the WWF's administration and fund-raising.
1001 members each contributed $10,000 to the trust. Prince Bernhard resigned his post after being involved in the Lockheed Bribery Scandal. WWF has set up operations around the world, it worked by fundraising and providing grants to existing non-governmental organizations, based on the best-available scientific knowledge and with an initial focus on the protection of endangered species. As more resources became available, its operations expanded into other areas such as the preservation of biological diversity, sustainable use of natural resources, the reduction of pollution, climate change; the organization began to run its own conservation projects and campaigns, by the 1980s started to take a more strategic approach to its conservation activities. In 1986, the organization changed its name to World Wide Fund for Nature, while retaining the WWF initials. However, it continued at that time to operate under the original name in the United States and Canada; that year was the 25th anniversary of WWF's foundation, an event marked by a gathering in Assisi, Italy to which the organization's International President HRH Prince Philip, the Duke of Edinburgh, invited religi
Sud Yungas Province
Sud Yungas or Sur Yungas is a province in the Bolivian department of La Paz. It was created during the presidency of José Manuel Pando on January 12, 1900; the capital of the province is Chulumani. The Cordillera Real traverses the province; the highest peaks of the province is Illimani at 6,438 m above sea level. Other mountains are listed below: The province is divided into five municipalities. Jach'a Quta Laram Quta Pilón Lajas Biosphere Reserve and Communal Lands
Sapote is a term for a soft, edible fruit. The word is incorporated into the common names of several unrelated fruit-bearing plants native to Mexico, Central America and northern parts of South America, it is known in Caribbean English as soapapple. Some but not all sapotes come from the family Sapotaceae: Sapodilla called naseberry is native to Mexico, Nicaragua, El Salvador; the Sapotaceae were named after a synonym of this species. Yellow sapote is native to Central America. Mamey sapote is from southern Mexico to northern South America. Green sapote is native to lowland southern Mexico. Sapotes from the Ebenaceae family include: Black sapote, from eastern Mexico south to Colombia, is the original Aztec tzapotl. Chapote is native to the lower Rio Grande valley region in Texas and Mexico White sapote is native to northern and central Mexico, Costa Rica, El Salvador and Guatemala. South American sapote is native to the Amazon rainforests of Brazil, Colombia and Peru
Endemism is the ecological state of a species being unique to a defined geographic location, such as an island, country or other defined zone, or habitat type. The extreme opposite of endemism is cosmopolitan distribution. An alternative term for a species, endemic is precinctive, which applies to species that are restricted to a defined geographical area; the word endemic is from New Latin endēmicus, from Greek ενδήμος, endēmos, "native". Endēmos is formed of en meaning "in", dēmos meaning "the people"; the term "precinctive" has been suggested by some scientists, was first used in botany by MacCaughey in 1917. It is the equivalent of "endemism". Precinction was first used by Frank and McCoy. Precinctive seems to have been coined by David Sharp when describing the Hawaiian fauna in 1900: "I use the word precinctive in the sense of'confined to the area under discussion'...'precinctive forms' means those forms that are confined to the area specified." That definition excludes artificial confinement of examples by humans in far-off botanical gardens or zoological parks.
Physical 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 hunted, in one jurisdiction but not another. There are two subcategories of endemism: neoendemism. Paleoendemism refers to species that were 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 and polyploidy in plants. Endemic types or species are likely to develop on geographically and biologically isolated areas such as islands and remote island groups, such as Hawaii, the Galápagos Islands, Socotra. Hydrangea hirta is an example of an endemic species found in Japan. Endemics can become endangered or extinct if their restricted habitat changes, particularly—but not only—due to human actions, including the introduction of new organisms.
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 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. Principal causes of habitat degradation and loss in endemistic ecosystems include agriculture, urban growth, surface mining, mineral extraction, logging operations and slash-and-burn agriculture