Unit B - Ch.4 Ecology Terminology

Vocabulary practice flashcards covering all terms listed in Unit B - Ch.4 sections 4.1 through 4.5.

ecology

The scientific study of interactions between organisms and their living and non-living environment.

abiotic factor

A non-living physical or chemical component of an environment, such as temperature, water, sunlight, or soil.

biotic factor

A living organism or a factor related to living organisms that influences an ecosystem.

ecotone

A transition region between two different ecosystems or ecological communities that contains species from both.

artificial ecosystem

A biological community created and maintained by humans, such as a farm, fish tank, or urban park.

natural ecosystem

A community of plants, animals, and microorganisms interacting in a naturally occurring environment without human intervention.

ecological niche

An organism's role and position in its ecosystem, including its habitat, resource use, and interactions with other species.

biome

A large geographical area defined by its climate, vegetation, and distinctive animal communities.

canopy

The top layer of a forest formed by the upper branches and leaves of mature trees.

permafrost

A layer of soil or rock that remains completely frozen continuously for two or more years.

muskeg

A type of northern wetland characterized by acidic soil, sphagnum moss, and stagnant water.

understorey

The layer of vegetation growing beneath the forest canopy, including young trees, shrubs, and shade-tolerant plants.

litoral zone

The shallow area of a body of water near the shore where sunlight penetrates to the bottom, supporting rooted plant life.

limnetic zone

The open-water surface layer of a lake where light reaches sufficiently to drive photosynthesis.

plankton

Microscopic aquatic organisms that float or drift in water, serving as a primary food source in aquatic food webs.

profundal zone

The deep zone of an inland body of water located below the level of effective light penetration.

litter

The uppermost layer of soil composed of freshly fallen organic matter, such as dead leaves and twigs.

topsoil

The dark, nutrient-rich upper layer of soil consisting of rich organic material and humus.

humus

Dark, fully decomposed organic material in soil that supplies essential nutrients to plants.

subsoil

The layer of soil beneath topsoil containing mineral deposits and light organic matter.

bedrock

The solid, continuous layer of rock underlying soil and subsoil.

groundwater

Water located below the earth's surface within soil pore spaces and rock fractures.

epilimnion

The warm, well-oxygenated upper thermal layer of a stratified lake.

hypolimnion

The cold, dense, lower thermal layer of a stratified lake beneath the thermocline.

thermocline

The middle layer of a stratified body of water where temperature changes rapidly with depth.

biotic potential

The theoretical maximum capacity of a population to reproduce under optimal environmental conditions.

carrying capacity

The maximum population size of a species that an ecosystem can sustainably support over time.

law of the minimum

The rule stating that population growth or distribution is controlled by the single resource that is in shortest supply.

law of tolerance

The principle stating that an organism's survival and distribution depend on environmental factors remaining within specific minimum and maximum limits.

density-dependent factor

An environmental limiting factor whose effect on population growth varies based on population density, such as disease or competition.

density-independent factor

An environmental limiting factor that affects population size regardless of population density, such as flood or fire.

slash and burn

An agricultural or forestry clearing technique involving cutting down plants and burning the remaining debris.

clear cutting

A forestry practice in which all trees in a given area are harvested at once.

selective cutting

A forest management technique where only specific mature or diseased trees are cut down while leaving others intact.

prescribed burn

A controlled, intentionally set fire managed by forestry experts to restore forest health and minimize wildland fire risks.

oligotrophic

A lake or body of water characterized by low nutrient levels, high clarity, and low biological activity.

eutrophic

A body of water rich in plant nutrients, leading to dense plant growth and potential oxygen depletion.

coliform bacteria

Bacteria present in the intestinal tracts of humans and warm-blooded animals used as an indicator of water fecal contamination.

biological oxygen demand (BOD)

The amount of dissolved oxygen required by aerobic microorganisms to break down organic material in a water sample.

watershed

An area or ridge of land that drains all surface water and precipitation into a shared body of water.