Ch 10 Biodiversity

What Biodiversity Means Variety of organisms in a given area Genetic variation within a population Variety of species in a community Variety of communities in an ecosystem.

Biodiversity Certain areas contain extraordinary variety of species. Need to understand and preserve biodiversity for our own survival

Biodiversity about 1.7 million spp (species) most of which are insects. Actual number is unknown. Estimate of greater than 10 million total # of species Exist in remote wilderness, deep ocean & even cities

Unknown Diversity

Species Are Connected to Ecosystems Species play an important role in any ecosystem. Every species is dependent on or depended upon by at least 1 other spp. 1 species disappears, a strand in a food web is removed.

keystone species critical to functioning of ecosystem in which it lives Affects survival and abundance of many other species in its community Pacific Coast Kelp →Sea Urchins →Sea Otter Prairie Dogs aerate soil in grasslands

Genetic diversity within populations Critical factor in species survival Increases chances for survival in environmental changes Small and isolated populations are less likely to survive such pressures.

Bottleneck Effect Population decreases, genetic diversity decreases Even if population is able to  again, an inbreeding within a smaller variety of genes will occur. Population members may be more likely to inherit genetic diseases

Benefits of Biodiversity Medical – Drugs Industrial – Chemicals Agricultural Hybrid crops resistant to disease Ethics Aesthetics & recreation Pets, wildlife viewing, nature enjoyment

Biodiversity at Risk Sec. 10-2

Current Extinctions Midst of another mass extinction. Rate is estimated to have  by a multiple of 50 since 1800  25% of all species on Earth becoming extinct 1800 - 2100 Different from past b/c humans are primary cause of extinctions. Amphibians extremely sensitive to environmental change

Species at Risk Migrating spp Those that require large or special habitats Those exploited by humans Not illegal to hunt polar bears in Canada

Endangered species In danger of extinction throughout all or a significant part of its range Is under protection by regulations or conservation measures

Threatened species species that has been identified to be likely to become endangered in the foreseeable future 983 species of plants and animals that are threatened or endangered (2002)

How Do Humans Cause Extinctions? human population growth has accelerated and so has the rate of extinctions Major causes: destruction of habitats Introduction of nonnative species Pollution Overharvesting of species

How Do Humans Cause Extinctions?

Habitat Destruction and Fragmentation Humans build and harvest resources Destroy & fragment habitats of other spp. 75% of extinctions are due to habitat loss Cougars – Florida Panther <80 left east of MI River

Invasive Exotic Species Not native to a particular area Familiar organisms are exotic if brought into area not normally found – cats & rats Non-native: alien, exotic, foreign, non-indigenous, invasive Threaten native spp. Non-native sword fern in Hawaii rainforests – facilitates fire

Imported Species Aggressive & spread over large areas Disrupt ecosystem Interfere with human activity One of the biggest threats to endangered species & biodiversity Bio-Invasion –rapid expansion of species by direct or indirect human activities, to areas where they did not previously exist

Birds Starlings Congregate in large flocks Make lots of noise & mess Drive away song birds by competing for food Some feed on farm crops

Plants Intentional/accidental importation Purple loosestrife Accidentally by a ship from Europe Displacing food supply of many wild animals Reduces carrying capacity (the number of species it can sustain) of wetlands it invades

Plants Water Hyacinth Crabgrass/dandelions/crown vetch Considered a weed – a plant that grows in an unwanted location Turning waterways into wetlands & choking life out of wetlands Crabgrass/dandelions/crown vetch weeds

Plants Kudzu Imported from Japan in 1876 for 100th celebration in Philadelphia Used to help prevent erosion Vines destroy forests by competing for sunlight May take up to 10 yrs to kill

Kudzu Kudzu – introduced to SE United States grows rampant, overtaking trees. In its native China, cold winters cause it to die back in cold weather, and several insects are natural predators

Invertebrates Zebra Mussel Native to Caspian Sea in Soviet Union 1st Spotted in US in 1988 in Lake St. Clair (between Lake Huron/Erie) Accidental arrival on European freighter around ’85 – ’86 caused pop. explosion

Invertebrates Zebra Mussel Colonizing rock bottoms where fish spawn Filter feeders may make water too clean for fish by eating all the algae Clog industries’ intake pipes

Harvesting, Hunting, and Poaching Thousands are harvested & sold as pets, houseplants, wood, food, or herbal medicine. Poaching is the illegal harvesting of fish, game, or other species.

Pollution Pesticides, cleaning agents, drugs, and other chemicals into food webs Long term effects may not be clear for after many years

Pollution Bald eagle was endangered because of a pesticide known as DDT Now illegal to use in the U.S. Still manufactured here & used around world.

Areas of Critical Biodiversity Areas where a large number of endemic species exist native to and only found in a particular place Endemic plant species as indicator species: are sensitive to environmental changes Giant Sand Treader Camel Cricket found in CO, NM & UT

Tropical Rain Forests Home to over half of world’s species Despite covering only 7% of Earth’s land surface Most have never been described Unknown # are disappearing as forests are cleared for farming or cattle grazing

Coral Reefs & Coastal Ecosystem Provide millions of people with food Tourism revenue, Coastal protection Sources of new chemicals Poorly studied Not as well protected by laws as terrestrial areas are

Coral Reefs & Coastal Ecosystem swamps, marshes, shores, and kelp beds Threatening human Activities Pollution Development along waterways Overfishing

Islands Limited # of mainland spp colonize new island In turn evolve into new spp – very distinct & limited Become endangered b/c of invasive spp Hawaiian honeycreeper

Biodiversity Hotspots most threatened areas of high species diversity tropical rainforests, coastal areas, and islands Have lost at least 70% of natural vegetation

Biodiversity Hotspots

The Future of Biodiversity Sec 10-3

Captive-Breeding Programs breeding species in captivity But the question remains whether or not these restored populations will ever reproduce in the wild California Condor

Preserving Genetic Material Germ plasm chromosomes and genes Contained in protoplasm of germ cells Seeds, sperm, eggs, or pure DNA Germ-plasm banks store material in controlled environments for future use in research or species-recovery efforts.

Zoos, Aquariums, Parks, and Gardens are living museums of the world’s biodiversity species’ last hope for survival rarely have enough resources or knowledge to preserve

Preserving Habitats and Ecosystems Small plots of land for single population is usually not enough protecting habitats of endangered and threatened species means preserving or managing large areas

Conservation Strategies Protect entire ecosystem rather than individual species save most species in an ecosystem instead of only ones been identified as endangered

Conservation Strategies identify areas of native habitat that can be preserved, restored, and linked into large networks. promote products that have been harvested with sustainable practices

Legal Protection for Species US Congress – 1973 Endangered Species Act is designed to protect any plant or animal species in danger of extinction

Endangered Species Act, the U.S. Fish and Wildlife Service (USFWS) list of all endangered and threatened species Protection from human harm Prevention of Federal Govt projects that harm Recovery plan for each spp Protect or restore habitat

Habitat Conservation Plans land-use plan attempts to protect threatened or endangered species across a given area Allows some tradeoffs between harm to species and additional conservation commitments among cooperating parties

International Cooperation International Union for the Conservation of Nature and Natural Resources (IUCN) Facilitates efforts to protect species and habitats Red Lists of species in danger of extinction around the world

Private Conservation Efforts advises governments on ways to manage natural resources works with groups like the World Wildlife Fund to sponsor projects attempting to stop poaching in Uganda

CITES-Convention on International Trade in Endangered Species Stop slaughter of African elephants for tusks worldwide ban on all sales, imports, and exports

Private Conservation Efforts World Wildlife Fund encourages the sustainable use of resources and supports wildlife protection The Nature Conservancy helped purchase millions of hectacres of habitat preserves in 29 countries Conservation International ID biodiversity hotspots Greenpeace International Organizes direct and sometimes confrontational actions