Ecosystem Dynamics Flashcards

Vocabulary flashcards for Ecosystem Dynamics.

Ecosystem

Includes all the organisms that live in a particular place, plus the abiotic environment in which they live and interact.

Biogeochemical cycles

Chemicals moving through ecosystems, involving both biotic and abiotic processes, often crossing ecosystem boundaries.

Carbon fixation

Metabolic reactions that make nongaseous compounds from gaseous ones.

Methanogens

Microorganisms that produce methane (CH4) by anaerobic cellular respiration.

Aquifers

Permeable, underground layers of rock, sand, and gravel saturated with water, serving as important freshwater reservoirs.

Nitrogen fixation

Synthesis of nitrogen-containing compounds from N2, carried out by microbes.

Limiting nutrient

The nutrient in shortest supply relative to the needs of organisms, acting as a weak link in the ecosystem.

First Law of Thermodynamics

Energy is neither created nor destroyed; it changes forms.

Second Law of Thermodynamics

Whenever organisms use chemical-bond or light energy, some is converted to heat (entropy).

Greenhouse effect

The accumulation of heat on Earth due to changes in the atmosphere's composition.

Trophic levels

The level at which an organism "feeds" in an ecosystem.

Autotrophs

"Self-feeders" that synthesize organic compounds from inorganic precursors.

Heterotrophs

Organisms that cannot synthesize organic compounds from inorganic precursors and must consume other organisms.

Primary producers

Autotrophs that form the base of the food chain.

Consumers

Heterotrophs that obtain energy by consuming other organisms.

Productivity

The rate at which organisms in a trophic level collectively synthesize new organic matter.

Gross Primary Productivity (GPP)

The raw rate at which primary producers synthesize new organic matter.

Net Primary Productivity (NPP)

The GPP minus the respiration of the primary producers.

Trophic cascade

Process by which effects exerted at an upper trophic level flow down to influence two or more lower levels.

Top-down effects

Effects that flow down through a trophic chain.

Bottom-up effects

Effects that flow up through a trophic chain.

Species richness

The number of species in a community, influenced by ecosystem characteristics like primary productivity and habitat heterogeneity.

Island Biogeography

The study of the factors that affect the species richness and diversity of isolated natural communities.

MacArthur and Wilson equilibrium model

Island species richness is a dynamic equilibrium between colonization and extinction.