Biodiversity

What is Biodiversity? Biological Diversity –Number and variety of species in a given area Complex relationships difficult to study –Often not understood until a species is extinct Some areas more diverse than others –Rain forests vs. deserts

Unknown Diversity Need to catalog Earth’s species to study biodiversity –# of known species 1.7 million (mostly insects) –Actual number Unknown –Probably at least 10 million –As many as 100 million New ones are being discovered

Levels of Diversity Species diversity –Differences between populations of species Ecosystem diversity –Variety of habitats, communities, and ecological processes within an ecosystem Genetic diversity –All of the different genes contained among all members within a population

Benefits of Biodiversity We depend on healthy ecosystems –Each species helps to balance various cycles Carbon, nitrogen, oxygen –Removing a species = removing a thread from the food web Collapse? –Keystone species One that is critical to the functioning of an ecosystem –Ex. Sea otters

Population Survival Greater genetic diversity = better chances of survival –A shrinking population experiences a loss of variation  bottleneck If it recovers there is still little variation  inbreeding  genetic diseases

Uses Food Clothing Shelter Medicine –¼ of drugs prescribed in US come from plants We know of about 1,800 while >400,000 are thought to exist –Almost all antibiotics come from chemicals found in fungi (~1,000 unknown species) Camptotheca acuminata

Other Reasons Ethical –Ecosystems and species have a right to exist regardless of economic value Cultural and/or religious value Aesthetic Recreational –Personal enjoyment Ecotourism –Supports the conservation and sustainable development of ecologically unique areas

Biodiversity at Risk Major extinction events –5 in Earth’s history Last one was the Dinosaurs (6.5 ma) –We are in the middle of one right now 1800 until now the extinction rate has doubled –Cause? »WE ARE – a single species By 2100, 25% to 50% of all species could go extinct

Species Prone to Extinction Small populations in limited areas Those that migrate Need large or special habitats Those exploited by humans –Or those whose habitats are exploited

Species Prone to Extinction Endangered species –One who will likely become extinct if immediate action is not taken Threatened species –Numbers are declining and likely to become extinct if it is not protected

How Do We Cause Extinctions? Human population growth rate goes up  the rate of extinctions go up –Habitat destruction and fragmentation Responsible for ~70% of current extinctions –Invasive exotic species Includes pets –Harvesting, hunting, and poaching Pets, houseplants, wood, food, medicine –Pollution Pesticides, cleaners, drugs, human-made chemicals

Areas of Critical Biodiversity Endemic species –Species found only in that particular limited area # of endemic species indicator of overall biodiversity –Flagship species – well known by public Tropical rainforests, coral reefs and coastal areas, and islands Ocean – important but poorly understood

Areas of Critical Biodiversity Biodiversity “hotspots” –The most threatened areas with a great level of biodiversity Most have lost >70% of their native vegetation Include areas in the US –California, Florida, and Hawaii –

Future of Biodiversity Captive breeding programs –Eventual release back into wild Preserving genetic material –Germ plasm – any form of genetic material Samples saved for future recovery efforts Zoos, aquariums, parks, gardens –Living biodiversity museums

Conservation Strategy Save the habitat or the species? –Saving the habitat saves the species All of them, not just the endangered one –Focus on hotspots –Preservation networks of habitats

Protection U.S. Law –Endangered Species Act (1973) Endangered and threatened species list Habitat conservation plans –Cooperative agreements that protect species and habitat

Protection Internationally –International Union for the Conservation of Nature and Natural Resources (IUCN) Red List –CITES treaty Bans trade related to endangered species –Earth Summit Biodiversity treaty –Fair use of genetic resources in all countries