Biodiversity and Ecosystem Stability Review

Genetic biodiversity loss

Cheetahs decreased in number during a period of glaciation and then a second period of overhunting in the early 1900s. Now cheetahs have so many of the same bad genes that they frequently produce weak, sickly offspring.

Ecosystem/Habitat biodiversity loss

The midwestern states used to have numerous small wetlands called prairie potholes, which supported many small amphibians and migrating birds. Most of the prairie potholes have been filled in to make more grazing land to support herds of cattle.

Species biodiversity loss

Large forest areas have often been divided into smaller areas by habitat fragmentation. Most of the large predators requiring a large hunting area have disappeared from these areas.

Estimated species on Earth

Most scientists believe there are 8.7 million species that exist on earth.

Species richness

Species richness is 13.

Simpson biodiversity index

Simpson index is 9.36.

High biodiversity stability

Ecosystems recover better from disruptions because there are more organisms in the food chain and more organisms with similar niches.

Supporting ecosystem service

The death of honeybees has left many plants without pollinators. Bumble bees often use the same plants for food and so the plants continue to be pollinated.

Provisionary ecosystem service

Forests provide us with lumber to build houses.

Regulating ecosystem service

Forests also help remove some of the excess carbon dioxide added to the air by burning fossil fuels.

Cultural ecosystem service

National parks provide many people opportunities to enjoy hiking and peaceful surroundings that help to relieve stress.

Wetlands regulating service

New York city has decreased the amount of money it has to spend on water purification by improving wetlands along the course of its streams. Wetlands filter much of the waste before it enters the stream.

Island biogeography originator

E.O. Wilson.

Factors determining island species number

Size of island and distance from mainland.

Large islands extinction rate

Most species can find a place to live because there are more habitats, and therefore do not go extinct.

Islands colonization rate

Islands far from the mainland have a lower colonization rate because it is less likely colonizing organisms will reach the island.

High species richness characteristics

Largeness and proximity to mainland.

Biogeography application to land areas

It explains fragmented habitats as 'islands' and helps design wildlife preserves.

Tolerance

Limits of environmental conditions an organism can tolerate.

Generalist species

A species that can live in a wide variety of situations (like a roach).

Specialist species

A species that can only live in a specific set of situations (like a koala bear).

Generalists thriving conditions

Wide variety of conditions.

Specialists thriving conditions

Detailed and consistent conditions.

Mass extinctions count

There have been 5 mass extinctions.

Current mass extinction

It is anthropogenic (an environmental change caused by people). Only extinction to be caused by a single species.