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conservation biology


n.

The branch of biology that deals with the effects of humans on the environment and with the conservation of biological diversity.


 
 
US History Encyclopedia: Conservation Biology

Conservation Biology, an interdisciplinary, mission-oriented science with the goal of alleviating the extinction crisis and fostering biological diversity. Conservation biologists include researchers and managers from fields as varied as ecology, genetics, evolution, biogeography, wildlife biology, forestry, captive species breeding, and restoration ecology. Scientists hope that by studying why species become extinct, they can improve the management of natural areas and endangered species in ways that will prevent further extinctions.

The groundwork for the modern field of conservation biology was laid in the early 1900s with the development of the fields of fisheries, forestry, and wildlife management, along with the first modern formulation of a land ethic, generally credited to Aldo Leopold. Tremendous theoretical progress in community ecology and biogeography during the 1960s and 1970s established a scientific foundation for conservation. At the same time, growing evidence of the massive extinction of species was raising concern within the biological community. Experts estimated that as many as a quarter of all surviving species could be doomed to extinction by the year 2025 if current trends continued. As many as 20,000 species could be lost or doomed every year, most of them unknown to Western science, and virtually all of them victims of human activity.

According to Harvard professor E. O. Wilson, a leader in the field, the current rate of extinction (the number of species lost each year) is between 1,000 and 10,000 times greater than the estimated rate of extinction before the evolution of humans. A species may be vulnerable to extinction for many reasons. Small populations can be wiped out by random local events, social dysfunction, or genetic deterioration. Species that cannot disperse well or that reproduce slowly are in danger. Those exploited by humans are particularly vulnerable because harvesting may drive populations too low, either inadvertently or intentionally. Species dependent on a threatened habitat will suffer the fate of that habitat. Species with large home ranges, such as elk, caribou, bears, and wolves, are also vulnerable because it is difficult for conservationists to protect a land area large enough to support a viable population. (A viable population has a 95 percent probability or better of surviving for more than 100 years.)

From its inception, two core goals of conservation biology have been to preserve functioning samples of all global ecosystems in their natural range and to maintain viable populations of all native species within those ecosystems. Part of the challenge to conservation biologists has been to use scientific principles to select and manage wildlife reserves that meet these two goals. Historically, most parks and other protected areas were chosen for aesthetic or recreational value or because they appeared to have no desirable extractable resources. Conservation biologists now help to choose and redesign protected areas to foster biological diversity.

In practice, this has meant developing a few rules for designing refuges. First, large areas are preferable to small ones because larger areas are more likely to support species with extensive home ranges, and the larger area provides more of a buffer between the refuge and human activities on surrounding lands. Natural disturbances, such as fires and floods, are also less likely to cause extinctions when species can move away from the disturbance yet still remain on protected lands. This is particularly important because some ecosystems require periodic disturbances to maintain their integrity. Some tree species in Yellowstone National Park, for example, require fire to establish seedlings and regenerate the forest. Conversely, periodic fires help maintain midwestern prairie ecosystems where most tree species are not well-adapted to fire. Second, protected zones should have few roads, because they en-courage increased human activities, such as logging, trampling, hunting, and dumping, which may be detrimental to native flora and fauna, and because even the mere presence of roads themselves can affect the suitability of an ecosystem for certain species, especially certain birds. Third, protected zones should be close together and connected. Linkages increase the effective size of protected areas by permitting seasonal movements or migrations, dispersal to prevent inbreeding or to recolonize other sites, and long-distance range shifts in response to climate change.

Because of the sweeping ecological change that has already occurred, in addition to preventing further extinctions, many conservation biologists argue that attempts must be made to restore threatened and endangered ecosystems, populations, and species. Restoration ecology has been the subject of considerable controversy. Questions central to the debate include whether current levels of scientific knowledge and technology make restoration feasible, how scientists can measure the successes and failures of restoration projects, whether preservation is more cost-effective than restoration, and whether it is appropriate to remove preservationist constraints on one site, thus allowing rapid environmental change, on the promise that another site will be restored to a former habitat, a process often fraught with problems, delays, and unforeseen expenses.

While these issues remain unresolved, majority opinions within the world of conservation biology have emerged. First, preservation is generally more cost-effective than restoration. Second, because ecological change and damage are ongoing, restoration projects must be attempted despite failures. Third, it is unwise to allow the possibility of restoration to support the continued expansion of ecologically destructive practices. Fourth, measurement of restoration must include scrutiny of ecosystem function over the long term.

At the start of the twenty-first century, the Society for Conservation Biology (SCB), one of the most prominent organizations in the field of conservation biology, brought together a wide range of interested people, including resource managers, public and private conservation workers, and students and educators from around the world to study—and take action to solve—the problems associated with protecting biological diversity. Because the goals and purposes of conservation biology are political in addition to scientific, research in the field typically is linked to an explicit ecological agenda. Michael Soule, a cofounder of SCB, described conservation biology as a "crisis discipline," in which it is sometimes necessary to make tactical decisions without information. He proposes that in crisis disciplines "the risks of nonaction may be greater than the risks of inappropriate action."

Bibliography

Ehrlich, Paul R., and Anne H. Ehrlich. Extinction. New York: Random House, 1981.

Noss, Reed F. "The Wildlands Project Land Conservation Strategy." Wild Earth (1993): 10–25.

Soule, Michael E. Conservation Biology. Washington, D.C.: Island Press, 2001.

—Susan J. Cooper/C. W.

 
Wikipedia: conservation biology

Conservation biology, or conservation ecology, is the science of analyzing and protecting Earth's biological diversity. Conservation biology draws from the biological, physical and social sciences, economics, and the practice of natural-resource management. 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 application of science to the conservation of genes, populations, species, and ecosystems. Conservation biology is the scientific study of the phenomena that affect the maintenance, loss, and restoration of biological diversity. 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. It was 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.[1] By the 1970s, led primarily by work in the United States under the Endangered Species Act[2] 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.

Threats to biological diversity

Presently the Earth is undergoing the Holocene Mass Extinction, an era of unprecedented number of species extinctions.[3] 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;[4] 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.[5] (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.[4] 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.[6]

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,[7][8] ecosystem stability, and ethics.[9], and today the scientific community "stress[es] the importance" of maintaining biodiversity[10].

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.[11][12][13][14] For example, one segment of North American forests has been assigned an annual value of 250 billion dollars;[15] 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.[16] The value of ecosystem services on one New Zealand island has been imputed to be as great as the GDP of that region.[17]

History

Conservation biologists trace the ethics that guide their work back to early spiritual philosophies, including the Tao, Shinto, Hindu, Islamic and Buddhist traditions.[18] In the West, origins of concern for the destruction of the natural environment by man can be traced to Plato;[19] however, modern roots of conservation biology can be found in the late 18th century Enlightenment period particularly in England and Scotland.[20][21] A number of thinkers, among them notably Lord Monboddo,[21] 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;[22] 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 wildlife refuge), parkland, wilderness, and watersheds. Western Europe was the source of much 19th century progress for conservation biology, particularly the British Empire; however, the United States began making sizable contributions to this field starting with thinking of Thoreau and taking form in the United States Congress passing the Forest Act of 1891, John Muir's work and the founding of the Sierra Club in 1895, founding of the New York Zoological Society in 1895 and establishment of a series of national forests and preserves by Theodore Roosevelt from 1901 to 1909.[23]

In the early 20th century the New York Zoological Society was instrumental in developing concepts of establishing preserves for particular species and conducting the necessary conservation studies to determine the suitability of specific locations that are most appropriate as conservation priorities; the work of Henry Fairfield Osborn Jr., Archie Carr and Archie Carr III is notable in this era.[24][25]

By the early 1970s national and international governmental agencies became more active in the conservation of biodiversity. Notably the United Nations acted to conserve sites of outstanding cultural or natural importance to the common heritage of mankind. The programme was adopted by the General Conference of UNESCO in 1972. As of 2006, a total of 830 sites are listed: 644 cultural, 162 natural. The first country to pursue aggressive biological conservation through national legislation was the USA, which passed back to back legislation in the Endangered Species Act[26] (1966) and National Environmental Policy Act (1970),[27] which together injected major funding and protection measures to large scale habitat protection and threatened species research.

By 1992 most of the countries of the world had become committed to the principles of conservation of biological diversity with the Convention on Biological Diversity;[28] subsequently many countries began programmes of Biodiversity Action Plans to identify and conserve threatened species within their borders, as well as protect associated habitats.

The science of ecology has clarified the workings of the biosphere; i.e., the complex interrelationships among humans, other species, and the physical environment; moreover, the burgeoning human population, and associated agriculture, industry and its ensuing pollution have demonstrated how easily ecological relationships can be disrupted.[29]

See also

Notes

  1. ^ A.R. Rabinowitz, Jaguar: One Man's Battle to Establish the World's First Jaguar Preserve, Arbor House, New York, N.Y. (1986)
  2. ^ U.S. Endangered Species Act (7 U.S.C. § 136, 16 U.S.C. § 1531 et seq.) of 1973, Washington DC, U.S. Government Printing Office
  3. ^ J.H.Lawton and R.M.May, Extinction rates, Oxford University Press, Oxford, UK
  4. ^ a b Paul Ehrlich and Anne Ehrlich, Extinction, Random House, New York (1981) ISBN 0-394-51312-6
  5. ^ IUCN Red-list statistics (2006)
  6. ^ * Chris D. Thomas, Alison Cameron, et al. Extinction risk from climate change Nature 427, 145-148 (8 January 2004) | doi: 10.1038/nature02121
  7. ^ Why preserve endangered species
  8. ^ Endangered Tibetan species with medical uses
  9. ^ Walsh, Bruce. Extinction. Bioscience at University of Arizona. URL accessed July 26 2006.
  10. ^ Committee on Recently Extinct Organisms. "Why Care About Species That Have Gone Extinct?". URL accessed July 30 2006.
  11. ^ World Resources Institute: Valuing ecosystem services (1998)
  12. ^ National Academic Press: Perspectives on Biodiversity: Valuing Its Role in an Everchanging World (1999)
  13. ^ Valuation of Ecosystem services : A Backgrounder
  14. ^ Ecosystem Services: Estimated value in trillions
  15. ^ Canadian Forest Congress: Carbon capture, water filtration, other boreal forest ecoservices worth estimated $250 billion/year
  16. ^ APIS, Volume 10, Number 11, November 1992, M.T. Sanford: Estimated value of honey bee pollination
  17. ^ Regional council, Waikato: The hidden economy
  18. ^ Primack, Richard B. (2004). A Primer of Conservation Biology, 3rd ed.. Sinauer Associates, 320pp.. ISBN 0-87893-728-5 (pbk). 
  19. ^ Plato, The Republic, Penguin Classics, ISBN 9780140449143
  20. ^ David Evans, A History of Nature Conservation in Britain, Routledge, UK ISBN 9780415144919 (1997)
  21. ^ a b Cloyd, E.L., James Burnett, Lord Monboddo (1972)
  22. ^ Short history of biogeography and conservation biology
  23. ^ Environmental timeline 1890-1920
  24. ^ Carr, Archie (Marjorie Carr Ed.), A Naturalist in Florida ISBN 0-300-05589-7
  25. ^ Henry Fairfield Osborn Jr. Biographical summary
  26. ^ U.S. Endangered Species Act of 1966 with subsequent amendments
  27. ^ 42 USC 4321 National Environmental Policy Act (2000): full text of the law
  28. ^ Convention on Biological Diversity Official Page
  29. ^ Al Gore, Earth in the Balance: Ecology and the Human Spirit, (1992) 407 pages

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Dictionary. The American Heritage® Dictionary of the English Language, Fourth Edition Copyright © 2007, 2000 by Houghton Mifflin Company. Updated in 2007. Published by Houghton Mifflin Company. All rights reserved.  Read more
US History Encyclopedia. © 2006 through a partnership of Answers Corporation. All rights reserved.  Read more
Wikipedia. This article is licensed under the GNU Free Documentation License. It uses material from the Wikipedia article "Conservation biology".  Read more

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