Conservation Biology Chapter 50

Conservation Biology 2Outline Conservation Biology & Biodiversity  Extinction Rates Value of Biodiversity  Direct Value  Indirect Value Causes of Extinction  Habitat Loss  Alien Species  Pollution  Overexploitation Conservation Techniques

Conservation Biology 3 Conservation Biology and Biodiversity Considers all aspects of biodiversity  General goal is conserving natural resources for this and future generations  Primary goal is the management of biodiversity for sustainable use by humans

Conservation Biology 4 Conservation Biology and Biodiversity Conservation biology supports certain ethical principles  Biodiversity is desirable for the biosphere  Extinctions due to human actions are undesirable  Ecosystem interactions supporting biodiversity are desirable  Biodiversity brought about by evolutionary change has value in and of itself

Conservation Biology 5Biodiversity At its simplest level, biodiversity is the variety of species on Earth  Estimated that between 5 and 15 million species currently exist Genetic diversity refers to variations among the members of a population Community diversity increases biodiversity Landscape diversity involves a group of interacting ecosystems

6 Number of Described Species

Conservation Biology 7Biodiversity Biodiversity hotspots  Contain about 20% of earth’s species  Represent only about 1% of earth’s land area

8 Eagles and Bears Feed on Spawning Salmon

Conservation Biology 9 Value of Biodiversity Direct Value  Medicinal Value  Agricultural Value ­Crops ­Biological Pest Controls ­Pollinators  Consumptive Use Value ­Wood ­Skins

10 Direct Value of Wildlife

Conservation Biology 11 Value of Biodiversity Indirect Value  Biogeochemical Cycles  Waste Disposal  Provision of Fresh Water  Prevention of Soil Erosion  Regulation of Climate  Ecotourism

12 Indirect Value of Ecosystems

Conservation Biology 13 Causes of Extinction Habitat Loss  Occurs in all ecosystems  Recent concern focused on tropical rain forests and coral reefs Habitat Fragmentation

14 Habitat Loss

Conservation Biology 15 Alien Species Nonnative species that move, or are moved, into a new ecosystem  Often have competitive edge against native species  Avenues of Human Introduction ­Colonization ­Horticulture and Agriculture ­Accidental Transport

16 Alien Species

Conservation Biology 17Pollution Any environmental change that adversely affects living things  Acid Deposition  Eutrophication  Ozone Depletion  Organic Chemicals  Global Warming

18 Global Warming

Conservation Biology 19Overexploitation When the harvest is so great that the population becomes severely reduced in numbers The market forces driving the harvest:  Exotic Pets  Hunting / Poaching  Over-Harvesting Fisheries

20 Trawling

Conservation Biology 21 Conservation Techniques Habitat Preservation  Keystone Species Metapopulations  Small populations isolated because of habitat fragmentation ­Source Populations ­Sink Populations

22 Habitat Preservation

Conservation Biology 23 Conservation Techniques Landscape Preservation Landscape protection for one species benefits other wildlife in the same space Edge Effect  The edge around a patch of habitat has conditions different from the patch interior  Edge does not count as effective habitat for species requiring the conditions of the interior

24 Edge Effect

Conservation Biology 25 Conservation Techniques Computer Analyses  Gap Analysis ­Find gaps in preservation efforts ­Try to identify areas where biodiversity is high outside of currently preserved areas  Population Viability Analysis ­Determine how much habitat a species requires to maintain itself

Conservation Biology 26 Conservation Techniques Habitat Restoration - Three Principles  Begin as soon as possible before remaining fragments are lost  Once natural history is understood, use biological techniques to mimic natural processes  Goal is sustainable usage

27 Restoration of the Everglades

Conservation Biology 28Review Conservation Biology & Biodiversity  Extinction Rates Value of Biodiversity  Direct Value  Indirect Value Causes of Extinction  Habitat Loss  Alien Species  Pollution  Overexploitation Conservation Techniques

Conservation Biology Ending Slide Chapter 50