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Chapter 18 Conservation of Biodiversity The th 6 Mass Extinction Extinction- when there are no longer any of the species in the world. We are currently losing approximately 50,000 species per year. Characteristics of organisms that make them susceptible to extinction Specialized feeding or food source Requires a large territory Preys on livestock/people Competes with humans Low reproductive rate Exploited for economic value Large size and slow speed Limited range of tolerance Small population linked to low genetic biodiverstiy Arguments in favor of preserving biodiversity Ecosystem function and/or stability based on organisms role Future medical resources Future food resources Economic potential(ecotourism, future products) Good for recreation (hunting, fishing, hiking) Scenic or aesthetic value Intrinsic value/ethical reasons Provides resources for indigenous people Genetic Diversity Scientists want to conserve genetic diversity so that the species can survive environmental change and inbreeding will not occur. Inbreeding occurs when individuals with similar genotypes, generally relatives, breed with each other. This concentrates harmful genes and leads to harmful defects. Categories of Endangerment Extinct- no known species exist today Threatened- species with a high risk of extinction in the future Near-threatened- species that are likely to become threatened in the future Least concern- species are widespread and abundant HIPPCO H- Habitat Loss I- Invasive Species P- Population Growth P- Pollution C- Climate Change O- Overharvested Habitat Loss For most species the greatest cause of decline and extinction is habitat loss. Most habitat loss is due to human development Invasive Species Alien species (exotic species)- species that live outside their historical range. Invasive species- when alien species spread rapidly across large areas. Ex- Kudzu Vine, Zebra Mussel, Silver Carp Population Growth Habitat Loss, Invasive Species, Pollution, Climate change, and overharvesting are all problems caused by human population which is not declining. Pollution Threats to biodiversity can come from toxic contaminants such as pesticides, heavy metals, acids, and oil spills. Climate Change The concern is how climate change will affect temperature and precipitation around the world, and how this will impact biodiversity. Overharvesting When individuals of a species are removed at a rate faster than the population can replace them. Ex- Dodo, American bison, passenger pigeon. Plant and Animal Trade For some species, legal and illegal trade in plants and animals represent a serious threat to their ability to persist in nature. Lacey Act One of the earliest laws in the U.S. to control the trade of wildlife. First passed in 1900, the act prohibited the transport of illegally harvested game animals, primarily birds and mammals, across state lines. CITES Convention on International Trade in Endangered Species of Wild Fauna and Flora Developed in 1973 to control the international trade of threatened plants and animals. Today, CITIES is an international agreement between 175 countries of the world. Red List The International Union for Conservation of Nature (IUCN) keeps a list of threatened species, known as the Red List. Each country has its own way to monitor and regulate the import and export of animals on the list. Ex. US Fish and Wildlife Service. How to conserve Biodiversity? Single Species Approach: When a species declines to threatened or endangered, the populaiton is encouraged to rebound by improving conditions in which it lives. Ex: remove contaminant or increase habitat. Ecosystem Approach: A type of natural resource planning and management, or treatment that ensures consideration of the relationship between all organisms (including humans) and their environment. Conservation Legislation Marine Mammal Protection Act 1972- prohibits the killing of all marine mammals in the U.S. and prohibits the import or export of any marine mammal body parts. Endangered Species Act Endangered Species Act- first passed in 1973, it authorizes the U.S. Fish and Wildlife Service to determine which species can be listed as threatened or endangered and prohibits the harming of these species. Trading these species is also illegal. The act also authorizes the government to purchase habitat that is critical to the species. Convention on Biological Diversity In 1992, nations came together and made a treaty to protect biodiversity internationally. The treaty had three objectives: conserve biodiversity, sustainably use biodiversity, and equitably share the benefits that emerge from the commercial use of genetic resources such as pharmaceutical drugs. 2002 developed a plan to achieve a substantial reduction in biodiversity loss by 2010. In 2010 they concluded the goal had not been met. Convention on Biological Diversity Trends found from 2002 to 2010:species at risk of extinction have moved On average closer to extinction. ¼ of all plants are still threatened with extinction. Natural habitats are becoming smaller and more fragmented. The genetic diversity of crops and livestock is still declining. There is a widespread loss of ecosystem function The causes of biodiversity loss are the same or increasing. The ecological footprint of humans has increased. Changes in protected land worldwide. Size, Shape and Connectedness Theory of island Biogeography – How the size of a habitat and distance from others affects species richness. When designing and managing protected areas we must consider how close to another area they should be, how large the area is, and the amount of edge habitat the area contains. Edge habitat- the area where two different communities come together, typically forming an abrupt transition. Ex. A grassy field meeting a forest. Biosphere Reserves Protected areas consisting of zones that vary in the amount of permissible human impact.
