AP Bio Unit 8

Organismal Ecology

Subdisciplines of physiological, evolutionary, and behavioral ecology focused on how organisms' structure, physiology, and behavior meet challenges.

Population

Analyzing factors that affect population size and changes over time.

Community

A group of populations of different species in an area, examining interactions like predation and competition.

Ecosystem

A community of organisms in an area along with physical factors interacting with them, emphasizing energy flow and chemical cycling.

Landscape

A mosaic of connected ecosystems focusing on exchanges of energy, materials, and organisms across multiple ecosystems.

Global (Biosphere)

The global ecosystem comprising all of the planet's ecosystems and landscapes.

Biotic Factors

Living components of an environment, including all organisms.

Abiotic Factors

Nonliving chemical and physical components such as temperature, light, water, and nutrients.

Dispersal

The movement of individuals away from their area of origin or centers of high population density.

Photic Zone

Layer of water where there is sufficient light for photosynthesis.

Aphotic Zone

Layer of water where little light penetrates.

Benthic Zone

The bottom of all aquatic biomes, made up of substrate consisting of sand and organic/inorganic sediments.

Detritus

Dead organic matter that falls from the productive surface water of the photic zone and serves as food for benthic species.

Thermocline

A narrow layer in lakes and oceans where there is an abrupt temperature change.

Turnover

Semiannual mixing of waters that changes temperature profiles and redistributes nutrients and oxygen.

Climograph

A plot showing the impact of climate on the distribution of organisms based on temperature and precipitation in a region.

Ecotone

A transitional area between terrestrial biomes that may be wide or narrow.

Population Density

The number of individuals per unit area or volume.

Dispersion

The pattern of spacing among individuals within a population's boundaries.

Mark-Recapture Method

A technique to estimate population size by capturing, marking, and releasing individuals before recapturing them.

Immigration

The influx of new individuals into a population.

Emigration

The movement of individuals out of a population.

Clumped Dispersion

The most common pattern where individuals aggregate in patches.

Uniform Dispersion

An even distribution of individuals that results from direct interactions between them, like territoriality.

Random Dispersion

Positions of individuals are independent of each other, occurring in the absence of strong attractions or repulsions.

Demography

The study of vital statistics of populations including birth and death rates.

Cohort

A group of individuals of the same age, often used to construct life tables.

Semelparity

A reproductive strategy where individuals reproduce only once at a high output.

Iteroparity

A reproductive strategy where individuals reproduce multiple times over their lifespan.

Exponential Reproduction Growth

Population increase under ideal conditions with abundant resources.

Logistic Population Growth

Model that incorporates the carrying capacity and changes in growth rate as population size approaches it.

Carrying Capacity (K)

The maximum population size an environment can sustain.

K-Selected Populations

Species that mature slowly and are adapted to stable environments.

r-Selected Populations

Species that reproduce rapidly in unstable environments.

Density Independent

Birth and death rates that do not change regardless of population density.

Density Dependent

Rates of birth or death that change with population density.

Metapopulation

Local populations linked by immigration and emigration.

Interspecific Interactions

Interactions that occur between individuals of different species, such as competition.

Competitive Exclusion

The principle that two species competing for the same resource cannot coexist.

Ecological Niche

The sum of a species' use of biotic and abiotic resources in its environment.

Resource Partitioning

Differentiation of niches that allows similar species to coexist.

Character Displacement

The tendency for characteristics to diverge in sympatric populations.

Cryptic Coloration

Camouflage that makes prey difficult to spot.

Aposematic Coloration

Bright colors as a warning signal for potential predators by chemically defended species.

Batesian Mimicry

A harmless species mimicking a harmful one to avoid predation.

Mullerian Mimicry

Two unpalatable species resembling each other for predator avoidance.

Herbivory

Interaction where an organism feeds on parts of a plant or alga.

Symbiosis

Close and often long-term interactions between two different species.

Parasitism

One organism benefits at the expense of the other.

Mutualism

Interaction that benefits both species involved.

Obligate Mutualism

One species cannot live without the other in the mutualistic relationship.

Facultative Mutualism

Both species can survive alone.

Commensalism

Interaction that benefits one species while the other is neither helped nor harmed.

Species Richness

The number of different species in a community.

Relative Abundance

The proportion of each species within a community.

Biomass

Total mass of all individuals in a population.

Invasive Species

Non-native species that disrupt local ecosystems.

Keystone Species

Species that have a disproportionately large effect on their environment.

Ecological Succession

Process by which disturbed areas are gradually colonized by various species.

Primary Succession

Succession starting in lifeless areas without soil.

Secondary Succession

Succession that occurs following a disturbance that leaves the soil intact.

Vector

An intermediate species that transfers pathogens.

Ecosystem

The sum of all organisms and abiotic factors within a defined area.

Law of Conservation of Mass

Matter cannot be created nor destroyed, applicable in ecosystems.

Primary Producers

Organisms that produce energy through photosynthesis.

Primary Consumers

Herbivores that consume primary producers.

Secondary Consumers

Carnivores that eat herbivores.

Tertiary Consumers

Carnivores that eat other carnivores.

Detrivores/Decomposers

Organisms that obtain nutrients from detritus.

Gross Primary Production (GPP)

Total amount of energy captured by primary producers.

Net Primary Production (NPP)

GPP minus the energy used by primary producers for respiration.

Limiting Nutrient

Nutrient that, when added, increases production.

Eutrophication

Rapid growth of algae due to nutrient enrichment, leading to oxygen depletion.

Product Efficiency

Percentage of energy stored in food that is not used for respiration.

Trophic Efficiency

Percentage of production transferred between trophic levels.

Turnover Time

Time required for biomass to be produced and consumed.

Green World Hypothesis

Explains why herbivores do not consume most plant production.

Biological Magnification

Accumulation of toxins at higher trophic levels.

Conservation Biology

Integrated study aimed at conserving biodiversity.

Endangered Species

Species at risk of extinction.

Threatened Species

Species likely to become endangered.

Introduced Species

Species brought to new habitats through human activity.

Extinction Vortex

A downward spiral of inbreeding and genetic drift in small populations.

Minimal Viable Population (MVP)

Smallest population size needed for a species to survive.

Effecting Population Size (Ne)

Effective population size used to estimate MVP based on breeding potential.

Movement Corridor

Pathways of habitat connecting isolated patches to facilitate movement.

Biodiversity Hot Spot

Geographically limited area with high levels of endemic species and endangerment.

Zoned Reserve

Areas of human-use surrounding less disturbed regions for conservation.

Bioremediation

Use of organisms to detoxify polluted environments.

Biological Augmentation

Adding essential materials to a degraded ecosystem using organisms.

Sustainable Development

Development that meets present needs without compromising future generations.