FW 104 Terms and Definitions – FALL 2025

ABIOTIC

Nonliving components of the environment.

ADAPTATION

Genetically controlled characteristics that enhance survival and reproduction in an environment.

ADDITIVE MORTALITY

Concept where the effect of one type of mortality adds to other sources of mortality.

AGE STRUCTURE

Distribution of individuals of various ages in a population.

AESTHETIC (esthetics)

Possessing qualities appreciated for beauty or emotional values.

AESTIVATION

Shutting down of metabolic processes during the summer due to hot or dry conditions.

ALLELE

Alternative forms of a gene occupying the same locus on homologous chromosomes.

NON-NATIVE Species

Species that are not native to a particular ecosystem.

ALTRICIAL

Young born relatively undeveloped and remain in the nest for a long period.

AMENSALISM

Relationship where one species is inhibited or harmed while the other is unaffected.

ANADROMOUS

Fish that begin life in freshwater, mature in the sea, and return to reproduce.

ANTHROPOMORPHIC

Describing nonhuman things as having human traits or form.

APHOTIC ZONE

Region of the ocean with no sunlight and no photosynthesis.

AQUIFER

Subterranean layer of porous rock or sand that can contain water.

AUTOTROPHS

Producers that convert solar energy to chemical energy through photosynthesis.

ASEXUAL REPRODUCTION

Reproduction without the union of individuals or gametes.

BAG LIMIT

Maximum number of animals that can be taken in a specified time.

BEFORE-AFTER-CONTROL-IMPACT (BACI) STUDY

Study collecting data before and after an event to determine impact.

BENTHIC

Related to the lowest region of an aquatic system.

BIOACCUMULATION

Increase of a chemical substance in an organism or part of it.

BIOMAGNIFICATION

Increase of a chemical substance in a food chain.

BIODIVERSITY

Variety of life, including genetic, species, community, and ecosystem diversity.

BIOLOGY

Study of living organisms and their vital processes.

BIOGEOCHEMICAL CYCLES

Movement of elements through living organisms and nonliving environments.

BIOMASS

Total quantity of living organisms per unit area.

BIOMES

Large, distinct ecological systems characterized by climate and biodiversity.

BIOSPHERE

Zone of air, land, and water where organisms exist.

BIOTA

All plants and animals within a specified area.

BIOTIC

Related to life or the act of living.

BIOTIC POTENTIAL

Maximum rate at which a population can grow without limiting resources.

BIRTH OR NATALITY RATE

Number of births per individual over a specified time period.

BROOD

A family of young birds from a single mother.

BYCATCH

Non-target marine organisms captured in fishing operations.

CANDIDATE SPECIES

Species that warrant listing but are precluded by higher priority workloads.

CARNIVORES

Organisms that feed on animal tissue.

CARRYING CAPACITY (K)

Maximum population size that a habitat can support.

CATADROMOUS

Fish that grow in fresh water and migrate to the ocean for spawning.

CHROMOSOMES

Structures of DNA wound around proteins.

CLIMATE FORCINGS

Events that change incoming and outgoing energy balance in the climate system.

CLIMAX

Final stage of ecological succession in dynamic equilibrium.

CODON

A series of three base pairs coding for a gene.

COEVOLUTION

Species interaction over time affecting each other's evolution.

COHORT

Group of individuals in a population born during a specific time period.

COMMENSALISM

Interaction where one species benefits and the other is unaffected.

COMMUNITY

Population of different species coexisting and interdependent.

COMPENSATORY MORTALITY

Concept where one kind of mortality replaces another in populations.

COMPETITION

Interaction between individuals for limited resources.

CONSERVATION

Sustained use of a resource.

CONSERVATION BIOLOGY

Approach to the protection and management of biodiversity.

CONSERVATION EASEMENTS

Legal agreements to protect land from being developed.

CONSUMERS OR HETEROTROPHS

Organisms that obtain organic nutrients by consuming other organisms.

COPROPHAGY

Feeding on feces to recover nutrients lost during digestion.

COVER

Structural resources that enhance organism survival.

CREPUSCULAR

Active during twilight.

CRITICAL HABITAT

Areas essential for the conservation of a listed species.

DECIMATING FACTORS

Immediate causes of death in populations.

DENSITY

Number of organisms per unit area.

DENSITY-DEPENDENT FACTORS

Factors affecting mortality as population density increases.

DENSITY-INDEPENDENT FACTORS

Factors operating independently of population density.

DETRITIVORES

Organisms that feed on dead organic matter.

DIPLOID

Having two sets of homologous chromosomes.

DISEASE

Deviation from a normal state of health.

DISPERSAL

Movement of individuals from their birthplace.

DISPERSION

Distribution of organisms within a population.

DISTURBANCE

Periodic change in or destruction of ecosystem components.

DIURNAL

Active during the day.

DNA

Genetic code consisting of four molecular bases.

DISPHOTIC ZONE

Layer with decreasing sunlight and limited photosynthesis.

ECOLOGY

Study of interrelationships among living systems and their environments.

ECOSYSTEM

Biotic community and its abiotic environment functioning as a system.

ECOSYSTEM ENGINEERS

Organisms that modify environments to benefit other species.

ECOSYSTEM MANAGEMENT

Management emphasizing ecological systems for sustainability.

ECOSYSTEM SERVICES

Processes that benefit humans from ecosystems.

ECOTONE

Transition zone between different communities.

EDGE

Area where different vegetation types meet.

EDGE EFFECT

Response of organisms to conditions created by the edge.

EMIGRATION

Movement of individuals leaving a population.

EMIGRATION RATE

Number of animals leaving a population over time.

ENDANGERED

Species at risk of extinction.

ENTROPY

Disorder or randomness in a system.

ENVIRONMENT

Total physical and biological conditions surrounding an organism.

ENVIRONMENTAL DNA (eDNA)

DNA present in the environment.

ENVIRONMENTAL ETHICS

Moral relationship between humans and the environment.

ENVIRONMENTAL JUSTICE

Fair treatment of all people in environmental policy.

ENVIRONMENTAL LITERACY

Understanding and skills for responsible environmental decisions.

ESTUARY

Zone where freshwater and seawater mix.

ETHICS

Moral principles guiding behavior.

EUPHOTIC ZONE

Layer where sunlight penetrates, allowing photosynthesis.

EUTROPHICATION

Nutrient enrichment in aquatic ecosystems.

EVOLUTION

Change in allele frequency due to natural selection over time.

EXOTIC

Native species introduced to a new area.

EXPONENTIAL GROWTH

Constant growth rate applied to a growing population.

EXTINCTION

State of a species with no living individuals remaining.

FEATURED SPECIES

Species emphasized for management due to their value.

FECUNDITY

Potential ability to produce offspring.

FERAL

Previously domestic animals established in the wild.

FERTILITY

Capability of an organism to produce young.

FITNESS

Ability to survive, reproduce, and pass on genetic material.

FOOD CHAIN

Pathways of energy flow through an ecosystem.

FOOD WEBS

Complex networks of feeding relationships.