Biological Diversity and Conservation

Biodiversity The variety of life in an area. The simplest and most common measure of biodiversity is the total number of species that live in a certain area or the biosphere.

Ecosystem diversity – Variety of environments and habitats in the living world. Species Diversity– Number of different species in the biosphere Genetic diversity – sum total of all the different genetic information carried by all organisms living on Earth today. More specifically :

Different continents and areas naturally contain different numbers of indigenous species.

Tropical regions contain 2/3 of all the land species on Earth.

For this reason, conservation biologists have named “hot spots” of biodiversity that are the most important areas to concentrate conservation efforts.

Life depends on life Animals couldn’t exist without green plants. Plants couldn’t exist without pollinators. Plants also must have decomposers to return the nutrients to the earth where they live.

Humans depend on biodiversity Through cross breeding with a wild species, common crops can be made disease resistant.

Living things supply the worlds pharmacy The antibiotic penicillin came from a mold found in nature. Aspirin comes from the bark of a willow tree. What about future drugs? What if there is a cure for a disease in an area being destroyed by cutting down all the trees?

Threatened Species Population of the species is decreasing rapidly. African Elephants Sea turtles Sea otters

Endangered species Numbers of the species are so low that extinction is possible. Black rhinoceros

Threats to Biodiversity Habitat loss Habitat fragmentation – separation of wilderness areas from other wilderness areas.

Edge effect - Different conditions along the boundaries of an ecosystem. Habitat degradation – damage to habitat by pollution. Acid rain – with low pH values

Exotic / Invasive Species Organisms that are not native to a particular area. No natural predators Lack of competition Can take over niches of native species.

Goats When people introduced goats to Santa Catalina Island off the coast of California, 48 plant species disappeared.

Lamprey When the Erie Canal was dug, it created a pathway for sea lamprey to get into the Great Lakes…

Sea Lamprey

Kudzu

Giant Salvia Native to Brazil, this water fern was initially introduced as an aquarium plant and garden pond ornamental. It completely covers waterways, blocking light and oxygen to native fish, plants, insects, etc.

Conservation Biology Studies methods and implements plans to protect biodiversity. President Nixon signed the U.S. Endangered Species Act into law in 1973.

American Bald Eagle Florida Manatee Brown pelican

DDT Widely used pesticide, now banned. Biological magnification – it is nonbiodegradable (doesn’t go away) and as it is picked up by herbivores and then the herbivores are eaten, the DDT magnifies inside the organism eaten, making it like a concentrated DDT pill.

Convention in International Trade in Endangered Species CITES – Established lists of species for which international trade is prohibited or controlled. Roughly 5,000 species of animals and 28,000 species of plants are protected by CITES against over-exploitation through international trade.

Habitat Conservation Best way to conserve species is to preserve entire ecosystems. Habitat corridors for fragmented ecosystems that allow for migration from one area to another.

Reintroduction Programs Animals are raised in captivity until they are old enough to survive and then released into the wild. Animals are relocated to a safer environment. The Red Wolf……

Captivity Some organisms exist only because they were kept in captivity. The Ginkgo tree is an example. Chinese monks planted Ginkgos around their monasteries, which saved the trees from extinction.

Ginkgo

Lonesome George The last Pinta Island Tortoise.

Threats to Biodiversity Ozone depletion: Atmosphere must have an ozone layer to protect the earth from harmful UV rays that can cause sunburn, cancer, and eye damage. In the 1970’s scientists found a hole in the ozone layer over Antarctica that can allow in harmful UV rays.

Chlorofluorocarbons (CFC’s) Once used in aerosol propellants, the coolant “Freon”, and the production of Styrofoam. These items are now banned by many different countries.

Global Warming Some scientists think that human activities will cause the earth to warm up several degrees because the over production of greenhouse gases. If this happens, some of the glaciers near the poles will melt and cause major flooding all over the world.