Biology Chapter 30/31 - Ecology Vocab

Abiotic factors

Non-living components of an ecosystem.

Age structure diagram

Diagrams based on the distribution of each age group (Three possible: Prereproductive, Reproductive, Post-reproductive). 

Autotroph

Require only inorganic nutrients and an outside energy source to produce organic nutrients.

Biosphere

All communities on Earth whose members exist in air and water and on land.  

Biotic factors

Living components of an ecosystem.

Biotic potential

The maximum rate of natural increase for a population that can occur when resources are unlimited and depends on: Offspring survival to reproductive age, population competition, reproductive opportunities age + number, and disease and predators' presence.  

Camouflage

Blending in for the sake of protection.

Carnivore

Feed on other animals.

Carrying capacity (K)

Maximum number of individuals of a species that can be supported by the environment.

Character displacement

Characteristics become more divergent when populations belong to the same community than when they are isolated.  

Cohort

Composed of all the members of a population born at the same time.

Community

Various populations of multiple species interacting with each other.

Competition

Occurs when members of different species try to utilize a limited resource.  

Competitive exclusion principle

No two species can indefinitely occupy the same niche at the same time.

Consumer

Consume food generated by a producer.

Deceleration phase

Growth slows down during logistic growth curve phases.

Decomposer

Break down dead organic matter.

Demography

Statistical study of a population. 

Density-dependent factor

Populations are affected by the number of organisms present.

Density-independent factor

The number of organisms present does not affect the influence of the factor (abiotic). 

Descriptive Ecology

Used to observe and define ecosystems and their members.  

Detritivore

Feed on decomposing organic matter.

Ecological niche

The role a species plays in its community (Includes habitat and its interactions with other organisms).

Ecological pyramid

Depict the flow of energy with large losses between successive trophic levels.  

Ecology

The study of the interactions of organisms with other organisms and the physical environment.

Ecosystem

Community interacting with the environment.

Exponential growth

The number of individuals added each generation increases as the number of females increases.

Food chain

A diagram showing a single path of energy flow in an ecosystem.

Food web

Represents interconnecting paths of energy flow within ecosystems.

Habitat

Place where an organism lives.  

Herbivore

Feed on plants.

Heterotroph

Need a preformed source of organic nutrients as their food source. 

K-selection

Species that hold their populations near the carrying capacity.

Limiting factor

Environmental aspects that particularly determine where an organism lives.  

Logistic growth

Occurs when limiting environmental factors oppose growth.

Mimicry

One species resembles another species that possesses an antipredator defense.

Omnivore

Feed on plants and animals. 

Population

All the individuals of a species within a particular space.  

Population density

Number of individuals per unit area.  

Population distribution

Pattern of dispersal of individuals across an area of interest.

Predation

One living organism, the predator, feeds on another, the prey.

Predator

Feeds on prey and is larger. 

Prey

Predator feeds on and is usually entirely consumed. 

Producer

Generate food necessary for the ecosystem.  

Rate of natural increase (r)

Dependent on the number of individuals that are born and die every year. Immigration and emigration are assumed equal.  

Resource

Living and nonliving components of an environment that support organisms.  

Resource partitioning

Decreases competition and leads to specialized niche and less niche overlap.  

R-selection

Species that maximize their rate of natural increase.  

Species diversity

Includes both species richness and the abundance of different species.  

Species richness

Also known as species composition. It is the listing of various species in the community with no information on abundance.  

Survivorship

The probability that newborn individuals of a cohort will survive to a particular age.  

Symbiosis

Prolonged association between two or more different biological species.

Trophic level

A level of nourishment within a food web or chain, composed of all the organisms that feed at the same level in a food chain.