Chapter 11: Biodiversity

Biodiversity

The variety of all forms of life, from genes to species, through the broad scale of ecosystems. Often used as a measure of the health of biological systems.

E.O. Wilson

__ coined the term biodiversity and introduced HIPPO

Ecology

The study of organisms and their interaction with the environment.

Genetic Diversity

The variety of different forms of the same gene within individuals.

Species Diversity

The number (variety) of different species within an ecosystem.

Ecological Diversity

The richness/complexity of a biological community; the more complex the food web, the more __

Soil formation, waste disposal, air and water purification, nutrient cycling, solar energy absorption and hydrological cycles.

Ways we benefit from biodiversity

Composting

Pile of yard waste then different decomposing organisms take over. Little human help can increase the process

Extinction

The elimination of a species; a normal process of the natural world, part of evolutionary change. Humans have greatly increased the rate.

More than 99% of all species to ever exist are now extinct, but new species arise due to mutation and natural selection.

Fossil records indicate __

22-47%, 50 years

At current rates, the UN Environmental Programs projects that __ of all known plant species, and the animals that rely on them, could go extinct in the next __

Habitat loss (conversion of grasslands to crop land)

The most important current threat to species

50%

Forests today cover __ of what was once covered

Invasive Species

A species accidentally or deliberately introduced to a new ecosystem.

Habitat destruction, Invasive species, Pollution, Population (human), and Overharvesting.

HIPPO stands for:

Habitat Destruction (HIPPO)

Humans convert habitat into other uses, forcing native species to small scattered areas that are not sufficient to maintain the population.

Invasive Species (HIPPO)

Colonize new territories and displace native species.

Pollution (HIPPO)

Pesticides, herbicides, other chemicals that don’t degrade well. Accumulated chemical levels in species higher up in food web cause birth defects and death.

Human Population (HIPPO)

Due to consumption needs, as population number grows harvesting will increase in order to meet demands.

Overharvesting (HIPPO)

Harvesting so much of a resource that its existence is threatened.

Hunting Laws

In 1874 State and Federal Governments began regulating wildlife harvest.

Passenger Pigeon

The population crashed in 20 years because of market hunting and habitat loss (fragmentation).

Endangered Species

Considered to be close to extinction.

Threatened Species

Likely to become extinct in the future.

Keystone Species

Major effects on ecological functions of the area.

Indicator Species

Ties to specific biotic communities or successional stages. Oftentimes are first to show stress on the ecosystem.

Umbrella Species

Require large continuous habitat, some may require multiple styles of habitat.

Flagship Species

Those that cause an emotional reaction in people.

1975 Convention on International Trade in Endangered Species (CITES)

Aimed at stopping international trade and black market sales of endangered species.

Spotted Owls

Estimated that preserving habitat for 1,600-2,400 of this species could cost $33 billion in love revenue and 40,000 jobs.

Snail Darter

The Tellico Dam was under construction when an endangered species was found upstream; however, the ‘God-Squad’ decided the benefits of the dam outweigh the cost.