AP Environmental Science Unit 2: Biodiversity Study Guide

Vocabulary flashcards covering ecological succession, ecosystem services, natural selection, evolution, and biodiversity metrics from AP Environmental Science Unit 2.

Endemic Species

A species found exclusively in a specific, localized geographic area, such as the golden toad (extinct since 1989 in the Monteverde Cloud Forest Reserve) and the Galapagos tortoise.

Geographic Isolation

The physical separation of populations by geographic barriers that leads to speciation and dramatic differences in traits, such as distinct coloration patterns in poison dart frogs on different islands.

Primary Succession

Ecological succession that begins in an essentially lifeless area lacking soil, starting on exposed bare rock such as a volcanic lava flow.

Secondary Succession

The return and recovery of an ecological community following a disturbance where the soil remains intact, such as after a forest fire or in cut forest areas.

Fitness

A biological measure of an organism's reproductive success within an ecosystem.

Fossil Record

The primary historical source of physical evidence used by scientists to understand the history of life and evolutionary changes on Earth.

Adaptation

Any inheritable trait that improves the ability of an individual organism to survive and reproduce at a higher rate than other individuals in a population under prevailing environmental conditions.

Genetic Resistance

The ability of one or more organisms in a population to tolerate and survive a chemical designed to kill it, such as a mosquito population surviving a pesticide.

Mutation

A random change or alteration in the genes of DNA that introduces new genetic traits into a population.

Herpetologist

A scientist who specializes in the study of amphibians and reptiles, organisms frequently monitored as indicator species.

Functional Diversity

The variety of biological and chemical processes, including energy flow and nutrient cycling, necessary for the survival of species, communities, and entire ecosystems.

Climate Determinants

The two primary long-term atmospheric variables that determine terrestrial climate: precipitation and temperature.

Biodiversity

The variety and variability of life on Earth, encompassing genetic diversity, species richness, and ecological functional diversity.

Anthropogenic

Originating from human activity or caused by the presence and pressures of the human population.

Species Richness

The count of the number of different species represented in an ecological community, landscape, or region, without taking relative abundance into account.

Genetic Diversity

The variety of different genes and genetic characteristics contained within an individual species' gene pool.

Coniferous Trees

Cone-bearing needle-leaved trees that represent the most common plant life found in the Taiga (Boreal Forest).

Island Biogeography

The ecological study of the rates of colonization and extinction of species on islands or isolated habitat patches based on their size, shape, and distance from mainland sources.

Biome

A large terrestrial region spanning the globe, typically aligned with lines of latitude, characterized by a specific regional climate and dominant plant communities.

Pioneer Community

The initial collection of early colonizing organisms, such as lichens and mosses, that first populate bare rock or disturbed terrain in the earliest stage of succession.

Climax Community

The final, relatively stable stage of ecological succession resulting after prolonged time without major environmental disruptions, characterized by mature tree species such as white spruce, balsam fir, and paper birch.

Moss (in Primary Succession)

An early pioneer organism that physically and chemically breaks down bare rock and contributes organic nutrients to form initial soil layers.

Invasive Species

Non-native organisms introduced to a habitat in which they did not evolve, often acting as ecological generalists that outcompete native species (e.g., zebra mussel).

Genetic Drift

A change in the genetic composition and allele frequencies of a population over time resulting from chance events or random mating, particularly impactful in small or shrinking populations.

Generalist Species

A species capable of surviving across a wide range of abiotic and biotic environmental conditions with a broad ecological niche, such as a raccoon or Norway rat.

Specialist Species

A species with a narrow ecological niche, adapted to live in a highly specific habitat or feed on a restricted diet, such as the giant panda.

Provisioning Services

Ecosystem services that deliver tangible material goods obtained directly from nature for human consumption or use, including lumber, fur, meat, crops, fresh water, and fuel.

Regulating Services

Ecosystem services provided by natural systems that balance and stabilize environmental conditions, including climate regulation, flood mitigation, pollination, carbon storage, and pest control.

Cultural Services

Non-material benefits that humans obtain from ecosystems, including aesthetic, spiritual, recreational, and educational enrichment.

Supporting Services

Fundamental natural processes necessary for the production and maintenance of all other ecosystem services, such as nutrient cycling, soil formation, and decomposition.

Adaptive Radiation

The evolutionary process by which ancestral species diversify and develop specialized characteristics in response to limited resources like food and territory.

Indicator Species

Organisms that are exceptionally sensitive to ecological changes and alert scientists to early environmental degradation, such as amphibians, mayflies, lichens, and coral.

Keystone Species

A species that plays an exceptionally critical role in maintaining the structure, stability, and biodiversity of its ecological community, such as the American alligator.

Seral Stage

An intermediate stage of ecological succession that an ecosystem transitions through as soil depth, quality, and community composition develop over time.

Evolution

A change in the genetic makeup and gene pool of a biological population over time across successive generations.

Five Fingers of Evolution

A mnemonic framework representing evolutionary mechanisms: Pinky (small/shrinking populations and genetic drift), Ring finger (non-random mating), Middle finger (mutation), Index finger (gene flow via immigration/emigration), and Thumb (adaptation through natural selection).