Conservation biology
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Conservation biology, or conservation ecology, is the science of analyzing and protecting Earth's biological diversity. Conservation biology is an interdisciplinary subject drawing on biological, physical and social sciences, economics, and the practice of natural-resource management. The rapid decline of biological systems around the world means that conservation biology is often referred to as a "Discipline with a deadline"[1]. Conservation ecology addresses population dynamics issues associated with the small population sizes of rare species (e.g., minimum viable populations). The term "conservation biology" refers to the Conservation biology is the scientific study of the phenomena that affect the maintenance, loss, and restoration of biological diversity and the application of science to the conservation of genes, populations, species, and ecosystems. For the history of biodiversity conservation and volunteer activity, see conservation movement.
In the 19th century actions in the United Kingdom, the United States and certain other western countries emphasized the protection of habitat areas pursuant to visions of such people as John Muir and Theodore Roosevelt. Not until the mid 20th century did efforts arise to target individual species for conservation, notably efforts in big cat conservation in South America led by the New York Zoological Society.[2] By the 1970s, led primarily by work in the United States under the Endangered Species Act[3] along with Biodiversity Action Plans developed in Australia, Sweden, the United Kingdom, hundreds of specific species protection plans ensued. The Society for Conservation Biology is a global community of conservation professionals dedicated to advancing the science and practice of conserving Earth's biological diversity.
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[edit] Threats to biological diversity
Presently the Earth is undergoing the Holocene Mass Extinction, an era of unprecedented number of species extinctions.[4] Human influence over the Earth's ecosystems has been so extensive within the last 10,000 years, that scientists have difficulty estimating the total number of species lost in this era;[5] that is to say the rates of deforestation, reef destruction, wetlands filling and other human acts are proceeding much faster than human assessment of the Earth's species. The matter of ongoing species loss is made more complex by the fact that most of the Earth's species have not been described or evaluated for endangerment. The IUCN has found that 23 percent of vertebrates, 53 percent of invertebrates and 70 percent of plants that have been evaluated are designated as endangered or threatened.[6] (The IUCN does not disaggregate endangered from critically endangered or threatened for the purpose of these statistics.)
Historically the main threat to biodiversity has been a set of threats generated from the overpopulation of humans: mass agriculture, deforestation, overgrazing, slash-and-burn, urban development, pesticide use.[5] Worldwide, the effects of global warming add a potentially catastrophic threat to global biological diversity; a 2004 study by Chris Thomas, Lee Hannah, et al. estimated that 15 to 37 percent of all species would become extinct by 2050.[7]
[edit] Importance of biological diversity
- See also: Benefits of biodiversity
Biologist Bruce Walsh of the University of Arizona states three reasons for scientific interest in the preservation of species; genetic or medical resources,[8][9] ecosystem stability, and ethics.[10], and today the scientific community "stress[es] the importance" of maintaining biodiversity[11].
Biodiversity provides many ecosystem services that are often not readily visible. It plays an essential part in regulating the chemistry of our atmosphere, pollinating crops and generating water supply. Biodiversity is directly involved in recycling nutrients and providing fertile soils. Experiments with controlled environments have shown that humans cannot easily build ecosystems to support human needs; for example insect pollination cannot be mimicked by man-made construction. The total value of ecosystem services may amount to trillions of dollars in ecosystem services per annum to mankind.[12][13][14][15] For example, one segment of North American forests has been assigned an annual value of 250 billion dollars;[16] as another example, honey-bee pollination, a small segment of ecosystem services, is estimated to provide between 10 and 18 billion dollars of value per annum.[17] The value of ecosystem services on one New Zealand island has been imputed to be as great as the GDP of that region.[18]
[edit] History
Conservation biologists trace the ethics that guide their work back to early spiritual philosophies, including the Tao, Shinto, Hindu, Islamic and Buddhist traditions.[19] In the West, origins of concern for the destruction of the natural environment by man can be traced to Plato;[20][original research?] however, modern roots of conservation biology can be found in the late 18th century Enlightenment period particularly in England and Scotland.[21][22] A number of thinkers, among them notably Lord Monboddo,[22] described the importance of "preserving nature"; much of this early emphasis had its origins in Christian theology. By the early 1800s biogeography was ignited through efforts of Von Humboldt, DeCandolle, Lyell and Darwin;[23] their efforts, while important in relating species to their environments, fell short of actual conservation.
The term conservation came into use in the late 19th century and referred to the management, mainly for economic reasons, of such natural resources as timber, fish, game, topsoil, pastureland, and minerals, and also to the preservation of forests (see forestry), wildlife (see w