Ecosystems and Nutrient Cycling - Chapter 2 (Environmental Science for a Changing World)

Vocabulary review flashcards covering key concepts from the lecture notes on ecosystems, nutrient cycles, population ecology, community ecology, and case studies.

Ecosystem

All the organisms in a given area plus the physical environment in which they interact.

Biotic components

The living components of an ecosystem.

Abiotic components

The nonliving components of an ecosystem.

Biosphere

The total area on Earth where living things are found; the sum of all biomes.

Biome

A distinctive type of ecosystem determined by climate and identified by the predominant vegetation and organisms.

Population

All the individuals of a species living in the same geographic area and able to interbreed.

Community

All the populations living and interacting in an area.

Habitat

The physical environment in which individuals of a species can be found.

Niche

The unique role a species plays in its community, including how it gets energy and nutrients, habitat requirements, and interactions.

Niche specialist

A species with very specific habitat or resource requirements that restrict where it can live.

Niche generalist

A species that uses a wide variety of resources and habitats.

Ecosystem ecology

The study of how ecosystems work, including interactions of abiotic and biotic components.

Energy flow

The one-way passage of energy through an ecosystem.

Matter cycles

The cycling of essential chemicals (carbon, nitrogen, phosphorus) through an ecosystem.

Sinks (reservoirs)

Abiotic or biotic components that store nutrients in nutrient cycles.

Residence time

The amount of time a nutrient spends in a sink.

Photosynthesis

Producers convert solar energy and CO2 into sugars and oxygen.

Cellular respiration

Organisms break down sugars to release energy, producing CO2.

Producers

Organisms that convert solar energy to chemical energy via photosynthesis.

Consumers

Organisms that obtain energy by feeding on other organisms.

Detritivores

Consumers that eat dead organic material.

Decomposers

Bacteria and fungi that break organic matter down to nutrients.

Food chain

A simple, linear path showing who eats whom in a community.

Food web

A network of interconnected food chains showing feeding relationships.

Trophic level

A feeding level in a food chain; TL1 producers, TL2 primary consumers, TL3 secondary, TL4 tertiary, TL5 quaternary.

Energy transfer between trophic levels

Only about 10% of energy is passed to the next level; ~90% is lost as heat.

Keystone species

A species with a disproportionately large effect on ecosystem structure and function; example mangrove trees.

Ecosystem engineers

Keystone species that modify the environment in ways that benefit other species (e.g., alligators).

Indicator species

A species whose status reflects the health of an ecosystem (wood stork in the Everglades).

Edge effect

Different conditions at an ecotone that attract or repel certain species.

Ecotone

The boundary region between two different habitats.

Core species

Species that live mainly in interior habitat away from edges.

Edge species

Species that thrive in edge habitats.

Habitat fragmentation

Breaking up of habitat into smaller patches, increasing edge and reducing core areas.

Restoration ecology

Science of repairing damaged ecosystems; often uses indicator species; Everglades restoration (CERP).

Ecological succession

Progressive replacement of species over time in response to changing conditions; primary vs secondary.

Pioneer species

Early successional species that colonize new or disturbed areas; often r-selected.

Carrying capacity

Maximum population size a given environment can sustain indefinitely (K).

Minimum viable population

Smallest population size that can persist and grow; low genetic diversity risk.

Population density

Number of individuals per unit area.

r-selected

High biotic potential; many offspring; early maturity; little parental care; thrives in unstable environments.

K-selected

Low biotic potential; few offspring; late maturity; high parental care; stable environments.

Biotic potential

Maximum growth rate under ideal conditions, linked to fecundity.

Exponential growth

Growth that is unrestricted, producing a J-shaped curve when plotted.

Logistic growth

Growth that slows as carrying capacity is approached, producing an S-shaped curve.

Density-dependent factors

Factors whose impact increases with population size (predators, disease, competition).

Density-independent factors

Factors whose impact is not related to population size (fire, flood).

Nitrogen cycle

Cycle through air, soil, organisms, and back; includes fixation, nitrification, assimilation, denitrification; human impact increases usable nitrogen.

Phosphorus cycle

Movement of phosphorus through rock, soil, water, and organisms; slow; disrupted by mining and fertilizers.

Carbon cycle

Movement of carbon among atmosphere, biosphere, oceans, and soils; balanced by photosynthesis and respiration; humans disturb balance.

Biosphere 2

A sealed-dome ecosystem study to understand self-contained ecosystems and Earth’s balance; lessons on Earth's irreplaceability.

Yellowstone gray wolf restoration

Reintroduction of wolves in Yellowstone; top-down regulation; monitoring packs; Endangered Species Act context.

Indicator species (Everglades example)

Wood storks indicate ecosystem perturbations in the Everglades; slow-maturing, vulnerable to change.

Ecosystem services

Benefits humans receive from ecosystems, such as pollination, water purification, and flood control.