APES Review

Conservation

Allowing the use of resources in a responsible manner.

Preservation

Setting aside areas and protecting them from human activities.

Keystone species

Species whose role in an ecosystem is more important than others.

Indicator species

Species that serve as early warnings that an ecosystem is being damaged.

Endangered species

A group of organisms in danger of becoming extinct; population numbers have dropped below the critical level.

Invasive species

Non-native species that thrive and disrupt the ecosystem balance.

Hydrologic cycle

The cycle of water movement through evaporation, condensation, precipitation, and runoff.

Nitrogen fixing

The process of converting atmospheric N2 into ammonia (NH3) by bacteria.

Nitrification

The process where ammonia (NH3) is converted into nitrate ions (NO3-).

Denitrification

The process where bacteria convert nitrate (NO3-) back into N2 gas.

Photosynthesis

The process by which plants convert atmospheric carbon (CO2) into glucose and release oxygen.

Aerobic respiration

The process where organisms break down organic compounds using oxygen.

Mutualism

A symbiotic relationship where both partners benefit.

Commensalism

A symbiotic relationship where one partner benefits and the other is unaffected.

Parasitism

A relationship in which one partner obtains nutrients at the expense of the host.

Sustainability

The ability to meet current needs without compromising future generations' ability to meet theirs.

Natural selection

The process where organisms with favorable adaptations survive and pass traits to the next generation.

Producer/Autotroph

Organisms that can produce their own food through photosynthesis or chemosynthesis.

Primary succession

The development of communities in a lifeless area not previously inhabited by life.

Secondary succession

Life progresses in an area where soil remains after a disturbance.

Carrying capacity

The maximum number of individuals an environment can sustain.

R strategist

Species that reproduce early with many unprotected offspring.

K strategist

Species that reproduce late in life with fewer offspring and care for them.

Point source pollution

Pollution that originates from a specific location.

Non-point source pollution

Pollution that comes from multiple diffuse sources.

Eutrophication

Rapid algal growth caused by excess nutrients in water.

Biological oxygen demand (BOD)

The amount of dissolved oxygen needed by aerobic decomposers to break down organic materials.

Hypoxia

When dissolved oxygen (DO) levels drop too low to support aquatic life.

LD50

The lethal dose of a substance that kills 50% of a test population.

Aquifer

A water-bearing layer in the ground.

Subsidence

Land sinking due to over-pumping of an aquifer.

Cone of depression

The lowering of the water table around a pumping well.

Salinization

The accumulation of salts in soil due to evaporation of water.

Urbanization

The process of making an area more urban or city-like.

Capacity of ecosystems

The ability of ecosystems to support various forms of life and human activities.

Greenhouse gases

Gases that trap heat in the atmosphere, contributing to global warming.

Ozone depletion

The reduction of the ozone layer caused by chemicals such as CFCs.

Montreal Protocol

An international treaty aimed at reducing substances that deplete the ozone layer.

Clean Water Act

Legislation aimed at regulating pollutants in U.S. waters.

Endangered Species Act

U.S. law aimed at protecting threatened and endangered species.