Embedded Files
ENV CHAPTER 10-1: WHAT IS BIODIVERSITY?
Biodiversity – the number and variety of species in a given area The study of biodiversity starts with cataloging all the species that exist on earth- Known species – collected and described scientifically- Unknown species – exist in remote wilderness, deep oceans, cities. Some types of species are harder to study and get less attention than large, familiar species Biodiversity can be studied and described at 3 levels:1. species diversity – all the differences between populations of species2. ecosystem diversity – the different habitats, communities, and ecological processes within and between ecosystems3. genetic diversity – all the different genes contained within all members of a population’s gene pool – DNA that codes for a specific trait Benefits of biodiversity1. everything is connected – the presence of different species keeps things in balance. The species depends on things and things depend on it. If one species is removed, multiple other species are affected. Things are thrown out of balance. Keystone species – species that are critical to an ecosystem2. genetic diversity – the more genetic diversity there is the better the chance that a species will do well. Genetic bottlenecks are bad – reduced genetic variation3. medical, industrial, and agricultural uses. Medicines come from plants, potential new products for industry, food and new crop varieties. The Irish potato famine happened b/c of lack of biodiversity.4. ethics (b/c it’s the right thing to do), aesthetics (personal enjoyment), recreation (ecotourism)ENV CHAPTER 10-2: BIODIVERSITY AT RISK
Mass extinction – extinction of many species in a short period of time (ex: the dinosaurs)We may be in a mass extinction – but it’s different from before, b/c this time humans are the primary cause Certain species are prone to extinction- Roaches and rats are not – they are large pops that adapt easily to many different habitats- Species with small populations in limited areas are more prone to extinction Endangered species – likely to become extinct if protective measures are not taken immediately Threatened species – species with a declining population that is likely to become endangered if it is not protected 4 main ways humans cause extinctions: 1. habitat destruction – as human pops grow we use more land to build homes and use resources. In the process we destroy and break up the habitats of other species 2. introduction of non-native species – exotic species = species that is not native to a particular place. Exotic species can threaten native species that have no natural defenses against them. 3. over-harvesting and hunting – can push the species to such low numbers that they go extinct. Many countries have laws to regulate it. Poaching – when it continues illegally. 4. pollution – pesticides, cleaners, drugs, chemicals made by humans are making their way into food webs. Areas of critical biodiversity have endemic species.endemic species = species that are native to and found only within a limited area3 areas of critical biodiversity:1. tropical rain forests – cover only 7% of the world but over half the world’s species live there2. coral reefs and coastal ecosystems – contain the majority of marine biodiversity3. islands – have limited but distinct sets of species since islands are isolated biodiversity hotspot – the most threatened areas of high species diversitythey have high numbers of endemic species but are threatened by human activities Biodiversity in the US – we have hotspots tooFlorida everglades, California coastal region, Hawaii, Midwestern prairies, forests in the pacific northwest.We have a lot of freshwater fish, mussels, crayfish, pine trees, sunflowersENV CHAPTER 10-3: THE FUTURE OF BIODIVERSITY
We are making efforts to slow the loss of species and conserve the ecosystem 4 ways we are trying to save species (one species at a time):1. Captive breeding programsbreeding species in captivity with the hope of re-introducing populations to their natural habitats. The big question is whether restored populations will ever reproduce in the wild2. Preserving genetic materialsaving the essence of a species – the essence of a species is its genes. They do it by making germ plasm banks (germ plasm = genetic material from the reproductive cells of animals – seeds, sperm, eggs, or pure DNA). They store it so it can be used in the future.3. Zoos, aquariums, parks, gardensLiving museums of biodiversity. These started as a way to display exotic species… now places like these house the few remaining members of a species and could be the species last hope for survival.4. Making protective laws Problems – captive species may not reproduce in the wild. Small populations are susceptible to infectious disease and genetic disorders from inbreeding. The best thing to do is preserve whole habitats and ecosystems – not just single species.- Since everything is connected – Protecting entire ecosystems may help save many more species and will maintain ecosystem functions.- How – identify native habitats that can be preserved, restored and linked to large networks. - Promote products that have been harvested/produced with sustainable practices Legal protections:US has some of the strongest laws to protect species from becoming extinct Endangered Species Act of 1973 has 4 main parts: - US fish and wildlife service has to make a list of all the endangered and threatened species - Endangered/threatened sp may not be caught/killed. Endangered/threatened plants may not be uprooted. Endangered/threatened sp may not be sold/traded - The federal government may not carry out any project that jeopardizes endangered species - The USFWS must make a species recovery plan for each endangered/threatened species.A. Species recovery plans often propose to protect or restore habitatB. Controversial to restrict human use of land (when developers are restricted from building on their own land b/c such species live there)C. Habitat conservation plan – attempts to protect species and areas of land through trade-offs and cooperative agreements
International cooperation- International Union for the Conservation of Nature and Natural Resources (IUCN) Makes “red lists” of species in trouble and advises governments on ways to manage their national resources and works with wildlife groups- CITES treaty – Convention on International Trade in Endangered Species Started to stop elephant killing and ivory trade- Private conservation efforts like World Wildlife Fund and Greenpeace- Biodiversity treaty – has the goal to preserve biodiversity and ensure the sustainable and fair use of genetic resources in all countries There’s all this we want to do and still keep in balance with human needs. And we want more people to understand the importance of biodiversity
Google Sites
Report abuse