AP Environmental Science Unit 1 Ecosystems Vocabulary

Vocabulary flashcards covering core concepts, biogeochemical cycles, primary productivity equations, and ecological interactions from AP Environmental Science Unit 1.

Ecosystem

The interaction of living and non-living things in a specific region.

Environment

Refers to the entire natural world.

Habitat

The given environmental conditions that a certain species needs in order to survive.

Symbiosis

A relationship where organisms live in close proximity to each other.

Mutualism

A symbiotic relationship that benefits both species involved.

Biome

A region on Earth that shares a consistent yearly average temperature and precipitation pattern.

Salinity

The saltiness level of an aquatic biome.

Estuaries

Unique aquatic biomes located where the mouth of a river empties into the ocean, characterized by high nutrient levels and brackish water.

Brackish

Water that is a mixture of fresh water and salt water.

Law of Conservation of Matter

The principle stating that matter is never created or destroyed, only changing forms.

Reservoirs

Components or locations in biogeochemical cycles that temporarily store matter.

Sources

Processes that move matter between reservoirs in biogeochemical cycles.

Sinks

Reservoirs that take in increasing amounts of matter over time because they absorb more matter than they release.

Nitrogen Fixation

The process of converting unusable atmospheric nitrogen gas ($N_2$) into a biologically usable solid form like ammonia or nitrate.

Rhizobacteria

Symbiotic bacteria living in the root nodules of legumes that possess specialized enzymes to fix atmospheric nitrogen.

Weathering

The breakdown of rocks by physical and chemical processes such as wind, rain, and the freezing and thawing of water.

Erosion

The transport of sediments and stored nutrients from one location to another by wind or runoff.

Limiting Nutrient

A nutrient that is scarce in an ecosystem, restricting plant growth even when all other required nutrients are available.

Infiltration

The process of precipitation or surface water seeping into or sinking down through soil layers into groundwater.

Transpiration

The process of water vapor leaving plant leaves through stomata and entering the atmosphere as a gas.

Primary Productivity

The rate at which producers in a given area convert solar energy into glucose or other organic matter over a specific period of time.

Respiration Loss

The energy harvested by plants through photosynthesis that is used up for cellular respiration and body upkeep.

Gross Primary Productivity (GPP)

The total amount of organic energy produced by plants through photosynthesis.

Net Primary Productivity (NPP)

The amount of energy plants store after subtracting respiration loss, calculated as $NPP = GPP - RL$.

Trophic Pyramid

A model representing the flow of energy from organism to organism across different trophic levels in an ecosystem.

10% Rule

The ecological principle stating that only $10\%$ of energy is passed from one trophic level to the next, while $90\%$ is lost to the environment as heat or unconsumed biomass.

Trophic Cascades

The powerful indirect ecological effects caused by the addition or removal of top predators, altering populations across multiple trophic levels down the food web.