AP Environmental Science Unit 1 & 2 Vocabulary: The Living World: Ecosystems and Biodiversity

Unit 1 & 2 of APES

ecosystem

A community of living organisms interacting with their physical environment, including both biotic and abiotic components.

biotic

living components of an ecosystem, including plants, animals, and microorganisms.

abiotic

non-living components of an ecosystem, such as water, soil, air, and sunlight that influence the living organisms within it.

evolution

The process by which different kinds of living organisms develop and diversify from earlier forms over time, typically through natural selection.

phylogenetic tree

a diagram that depicts evolutionary relationships among groups of organisms.

speciation

The evolutionary process by which new biological species arise from existing species, often due to genetic divergence and environmental factors.

species

A group of organisms that can interbreed and produce fertile offspring, sharing similar characteristics and genetic makeup.

evolutionary fitness

The ability of an organism to survive and reproduce in its environment, contributing to the genetic pool of the next generation.

natural selection

The process by which organisms better adapted to their environment tend to survive and produce more offspring. It is a key mechanism of evolution.

selective pressure

Factors that influence survival and reproduction, such as predation, competition, and environmental changes.

gene pool

The total collection of genes and their variants within a population, which can be affected by factors like mutation, selection, and gene flow.

genetic drift

A mechanism of evolution involving random changes in allele frequencies within a population, leading to reduced genetic variation over time.

microevolution

The small-scale evolutionary change within a species over time due to processes like mutation, selection, gene flow, and genetic drift.

macroevolution

The large-scale evolutionary changes that occur over geological time spans, resulting in the emergence of new species and higher taxonomic groups.

extinction

The permanent loss of all members of a species from Earth, often resulting from factors such as habitat loss, climate change, or human activity.

biological extinction

the complete disappearance of a species from Earth, leaving no living individuals behind.

commercial/economic extinction

A reduction in a species' population to the point where it is no longer profitable to harvest or exploit, even if members of the species still exist.

population

The total number of individuals of a particular species living in a specific area at a given time.

community

A group of interacting species that inhabit a common environment.

niche

The role or function of a specific species within an ecosystem, including its habitat, resource use, and relationships with other species.

habitat

The natural environment in which an organism lives, including all biotic and abiotic factors.

specialist

A species that has a narrow ecological niche and requires specific conditions or resources to survive.

generalist(environmental science)

a species that has a broad niche, is highly adaptable and can live in varied habitats

competition

competing for resources in the environment

ecological extinction

occurs when there are so few individuals of a species that this species can no longer perform its ecological function

intraspecific competition

competition within the same species

interspecific competition

competition with different species

competitive exclusion

when two different species ina region compete and the better adapted species win

Gause's principle

states that I two species can occupy the same niche at the same time and that the species that is less fit to live in the environment will relocate, die out, or occupy a smaller niche.

realized niche

when a species occupies a smaller niche that in would in the absence of competition

fundamental niche

niche without competition

resource partitioning

when different species use slightly different parts of the habitat, but rely on the same source

predation

when one species feeds on another

symbiotic relationship

close, prolonged associations between two or more different organisms of different species that may, but do not necessarily, benefit each member

mutualism

both species benefit

commensalism

one organism benefits and the other is neither helped or hurt

parasitism

when one organism benefits but another is harmed

biomes

geographic area of an ecosystem that is based on land

aquatic life zones

geographic area of an ecosystem that is based on aqueous environments

ecotones

the transitional area where 2 ecosystems meet

ecozones/ecoregions

smaller regions within ecosystems that share similar characteristics

deciduous forest

tropical forest

grasslands

coniferous forest/taiga

tundra

chaparral

deserts

temperate rainforest

savanna

epilimnion

in freshwater, the uppermost and thus the most oxygenated layer

hypolimnion

the lower colder, and denser layer

thermocline

demarcation line between the epilimnion and hypolimnion at which the temperature shifts dramatically

littoral zone

limnetic zone

profundal zone

benthic zone

estuary

a site where the “arm” of the sea extends inland to meet the mouth of a river

wetlands

mangrove swamps

barrier islands

coral reef

coastal zone

euphotic zone

bathyal zone

abyssal zone

upwellings

red tide

biogeochemical cycles

reservoir