ecology terms

Community Structure

The way a community is organized and the relationships between different species living together in the same area.

Species Composition

Refers to the identity of each species in a community.

Simpson’s Diversity Index

A measure of species diversity in a habitat based on random samples of organisms.

Ecological Succession

The process of change in the species structure of a community over time.

Competition

Occurs when resources are limited, either within the same species (intraspecific) or between different species (interspecific).

Competitive Exclusion

When two species competing for the same limited resources cannot coexist at constant population values.

Ecological Niches

Describes how an organism uses the resources available in its habitat.

Symbiosis

Close and long-term biological interaction between two different species.

Mutualism

A symbiotic interaction that benefits both species.

Predator-prey

Interaction where one species (predator) feeds on another species (prey).

Trophic Cascade

Negative effect on other trophic levels due to the removal or decrease in population of a key species.

Trophic Cascade

A series of events in an ecosystem where changes in the population of one species can lead to changes in populations of other species.

Quaternary Consumers

Animals at the top of the food chain that feed on tertiary consumers.

Tertiary Consumers

Animals that eat secondary consumers.

Ecosystem

A community of organisms interacting with each other and their physical environment.

Energy Flow

The movement of energy through an ecosystem via organisms acquiring, using, and transferring energy.

Ectotherm

An organism that relies on external sources to regulate its body temperature.

Metabolic Rate

The amount of energy expended by an animal over a specific time period.

Trophic Level

The position an organism occupies in a food chain.

Food Chain

The transfer of energy and nutrients from one organism to another in a linear sequence.

Food Web

A network of interconnected food chains in an ecosystem.

Autotroph

An organism that captures energy from physical or chemical sources in the environment.

Heterotroph

An organism that obtains energy by consuming other organisms or their byproducts.

Ecosystem Structure

The organization and arrangement of species within an ecosystem.

Producer

An organism that can make its own food through photosynthesis or chemosynthesis.

Biodiversity

The variety of different species in an ecosystem.

Keystone Species

A species that has a disproportionately large effect on its environment relative to its abundance.

Abiotic Factors

Non-living factors in an ecosystem that influence its diversity, such as sunlight, water, and climate.

Biotic Factors

Living factors in an ecosystem that influence its diversity, such as producers and predators.

Invasive Species

A species that is not native to an area and causes harm to the ecosystem it invades.

Human Impact

The influence of human activities on ecosystems, including habitat destruction and pollution.

Ecosystem Disruption

Changes in the structure and dynamics of an ecosystem due to various factors like human activity or invasive species.

Global Climate Change

The alteration of Earth's climate patterns due to human activities like the emission of greenhouse gases.

Deforestation

The removal of a forest or area of trees for non-forest use, leading to habitat loss, biodiversity loss, arid environments, climate change acceleration, and species extinction.

Urbanization

The shift from rural to urban areas, which can negatively impact habitats through fragmentation and habitat loss, affecting ecosystems and species differently.

Monocropping

Agricultural practice of growing a single crop repeatedly in the same land, economically efficient but damaging soil ecology and creating a niche for parasitic species like Potato blight.

Geological and meteorological events

Events that affect habitat change and ecosystem distribution, illustrated through biogeographical studies.

Stimulus

An external or internal signal or combination of signals that causes a response from an organism.

Behavioral response

Externally observable muscular activity triggered by a stimulus.

Physiological response

Automatic changes to growth/homeostasis/metabolism in response to a stimulus (e.g. change in heart rate, release of a hormone, fruiting, etc.).

Phototropism

Growth toward light.

Kinesis

Random (non-directional) orientation/movement in response to a stimulus.

Taxis

Directional movement in response to a stimulus.

Nocturnal

Behavior characterized by being active during the night.

Diurnal

Behavior characterized by being active during the day.

Fight-or-flight response

Physiological reaction to a perceived harmful event, attack, or threat to survival.

Pheromones

Chemical signals secreted to trigger a response in another individual of the same species.

Territorial marking

Behavior in mammals to chemically identify their territory for communication and reproductive success.

Coloration in flowers

Coloration/patterns in flowers that attract pollinators for reproductive success.

Dominance hierarchy

Ranking of individuals in a group based on social interactions for reproductive success and fitness.

Camouflage

The ability of an animal to avoid detection by other animals.

Mimicry

An evolved resemblance between an organism and another organism/object.

Batesian Mimicry

A harmless species evolves to mimic the warning signals of a harmful species.

Mullerian Mimicry

Two well-defended species with common predators mimic each other's warning signals.

Innate behavior

Genetically controlled behaviors that can occur without prior experience or training.

Learned behavior

Behaviors that are developed as a result of experience or training.

Parent and offspring interactions

Offspring can learn behaviors through their parents, increasing the fitness of the offspring.

Courtship and mating behaviors

Behaviors/displays used to attract a mate, usually by males.

Foraging behavior

Food-obtaining behavior that natural selection favors to minimize costs and maximize benefits.

Population Ecology

The study of populations in relation to the environment, including environmental influences on population density, distribution, age structure, and variations in population size.

Population

A group of individuals of a single species living in the same general area.

Population Growth Equation

The formula to calculate population growth, ignoring immigration and emigration, represented as dN/dt = B - D, where B is the birth rate, D is the death rate, and N is the population size.

Population Density

Refers to how close individuals within a population live near one another, impacted by resource availability in the environment.

Dispersion Patterns

Refers to the spatial arrangement of individuals within a population, including clumped, uniform, and random dispersion.

Density-Dependent Factors

Abiotic or biotic factors whose effect on population size relies on population density, including competition for resources, territoriality, disease, and predation.

Density-Independent Factors

Abiotic or biotic factors that affect population size regardless of population density.