Ecology vocab

Individual

Single living organism

Population

Group of organisms in the same species that live together

Community

Groups of different species living and interacting together

Ecosystem

Community and the nonliving things around it

Biome

Groups of ecosystems with similar biotic and abiotic factors

Biosphere

All of the biomes together

Kinesis

Random fast movement

Taxis

Movement in a specific direction in response to environmental stimuli

Phototropism

Type of taxis in which plants orient themselves in the direction of sunlight

Circadian clock

24 hour clock in organisms that regulates internal activities, such as knowing when to sleep and eat

Innate behavior

Behavior that is performed without any previous experience and is largely determined by genes

Learned behavior

Behavior informed by an individual’s experience in its environment

Habituation

Form of learned behavior in which animals learn to ignore a stimulus

Operant conditioning

Form of learned behavior in which animals are rewarded or punished for their behavior

Imitation

Form of learned behavior in which individuals learn a behavior from watching other individuals perform

Imprinting

Form of learned behavior in which young animals follow the lead of their parents

Cooperative behaviors

Members of the same species exhibit behaviors that improve one another’s fitness

Homeostasis

Process in which cells or organisms maintain stable conditions

Thermoregulation

Process of an organism controlling its body temperature

Endotherm

Organism that regulates its body temperature internally

Hypothalamus

Brain part in birds and mammals that sens a signal to shiver when the organism is too cold

Ectotherm

Organism that generates small amounts of heat and whose body temperature is strongly impacted by external conditions

Metabolic rate

Number of calories that an organism burns over time while at rest

Chemosynthesis

Use of chemical compounds to build sugar where sunlight isn’t available

Autotroph/producer

Organism that gains energy through photosynthesis or chemosynthesis

Heterotroph/consumer

Organism that gains energy by eating other organisms

Food chain

Model that shows how energy flows between organisms

Biomass

Total mass of living matter at each trophic level, the measure of energy in an ecosystem

Food web

Model that shows interconnected food chains and pathways in which energy flows through a group of organisms

Scavenger

Organism that eats dead animals

Detrivore

Organism that breaks down organic and waste products into smaller particles

Decomposer

Organism that converts dead organic matter into molecules and elements that can recycled by producers

Transpiration

Evaporation from the leaves of plants

Surface water

Water in the form of streams, rivers, lakes, etc. that is readily available for use

Calcium carbonate

Bicarbonate combined with calcium, found in marine organism shells and limestone rock

Population density

Number of individuals in an area divided by its size

Geographic range

Area over which a population is spread

Population distribution

Measure of how clumped individuals are within their geographic range

Random distribution

No pattern to the clumping of organisms

Uniform distribution

Individuals are evenly spaced apart

Clumped distribution

Individuals aggregate together in clusters

Population sex ratio

Ratio of males to females

Population age structure

Number of individuals in different age groups

Exponential growth model

Population increases exponentially because there are ideal conditions and unlimited resources

Type I survivorship curve

Individuals experience high survival throughout most of their life and then their survival declines sharply later in life

Type II survivorship curve

Individuals experience steadily declining survival throughout their life

Type III survivorship curve

Individuals experience a sharp drop in survival early in life and then a slower decline throughout the rest of their life, with only a few reaching adulthood

K-selected species

Species that has relatively slow reproduction and remain near the environment’s carrying capacity

r-selected species

Species that reproduces rapidly and has large fluctuations in population size over time

Density-independent factor

Factor that causes a decline in population in which its size has no effect of the individual’s probability of survival

Density-dependent factor

Factor that limits the growth of a population as its size increases

Carrying capacity

Maximum number of organisms that an ecosystem can maintain

Species richness

Number of species in a community

Species evenness

Number of individuals in each species in a community

Simpson’s Diversity Index

Numerical method to determine the biodiversity of a community

Habitat

Physical setting where a species lives

Niche

Complete description of the role a species plays in its environments and the abiotic and biotic requirements that allow them to survive, grow, and reproduce

Fundamental niche

All the abiotic conditions that allow a species to survive, grow, and reproduce

Realized niche

Combination of abiotic and biotic conditions under which a species survives, grows, and reproduces

Niche generalist

Species that can live under a wide range of abiotic and biotic conditions

Niche specialist

Species that lives under a very narrow range of conditions

Parasitism

Interaction in which one species live in or on a host organism

Pathogen

Parasite that causes disease in the host

Herbivory

Interaction in which an animal eats a plant

Competition

Interactions between species that require the same limited resource

Intraspecific competition

Competition among individuals in the same species

Interspecific competition

Competition between individuals in different species

Niche partitioning

Evolution in favor of individuals with phenotypes that reduce the amount of competition

Symbiosis

When two species live in close association

Mutualism

Form of symbiosis in which both species benefit

Commensalism

Form of symbiosis in which one species benefits and the other is neither harmed nor helped

Keystone species

Species that has a large impact on other species in a community despite existing in a small number

Direct effect

One species affects the abundance of another with no other species involved

Indirect effect

Presence of one species affects the abundance of another with other species involved in-between

Trophic cascade

Indirect effect initiated by the presence of a predator

Sucession

Recreation of a community following a disaster event

Primary succession

Succession that occurs on bare rock surfaces where no soil exists

Pioneer species

First species to emerge during primary succession

Secondary succession

Succession that occurs after a disturbance changes the community without removing the soil

Genetic diversity

Variety of genotypes in a given population or species

Ecosystem diversity

Variety of ecosystems in a region, such as a mix of adjacent aquatic and terrestrial ecosystems

Ecosystem productivity

Amount of biomass of producers in a year

Resistance

An ecosystem’s ability to not be impacted by an environmental disturbance

Resilience

An ecosystem’s ability to bounce back from an enviro

Endemic species

Species found in only one location

Biodiversity hotspot

Areas with at least 1500 endemic plant species and experiencing at least 70% vegetation removal from human activity

Continental drift

Movement of plates that broke up Pangea

Laurasia

Continent formed due to continental drift, later broke up into North America, Europe, and Asia

Gondwana

Continent formed due to continental drift, later broke up into South America, Africa, Antarctica, and Australia

Native species

Species that lives in its historic range

Non-native species

Species that lives outside its historic range

Invasive species

Non-native species that spreads throughout a new area and causes economic or ecological harm

Greenhouse gas

Gases able to absorb and release infrared radiation

Greenhouse effect

Sunlight energy gets converted into infrared radiation, which are absorbed by greenhouse gases and then released back into Earth