Community Ecology Practice Flashcards

A set of vocabulary-style flashcards covering the foundational concepts of community ecology, including population growth, species interactions, and biodiversity metrics.

Niche

An organism's role within an ecosystem as well as its specific environmental requirements.

Logistic Growth

A type of population growth that starts slowly, increases rapidly, and then levels out as it approaches the carrying capacity.

Carrying Capacity ($k$)

The hypothetical maximum population size that an environment can support based on available resources.

G. F. Gauss

An ecologist who conducted paramecium competition experiments in the early 1900s to study population sizes and extinctions.

Competitive Exclusion Principle

The rule stating that if two species occupy the same niche and require the exact same resources, only one will persist while the other will be driven to extinction.

Niche Differentiation

A process where organisms reduce competition by partitioning resources or separating in space; also known as resource partitioning.

Fundamental Niche

The full range of environmental conditions and resources an organism could potentially occupy in the absence of competition or predation.

Realized Niche

The actual environmental conditions and resources an organism occupies in the presence of competition or other species interactions.

Parasitism

A positive-negative ($+/-$) interaction where one organism benefits at the expense of a host organism.

Ectoparasites

Parasites that live on the outside of a host's body, such as ticks, mosquitoes, and mistletoe.

Endoparasites

Parasites that live inside the body of a host, such as tapeworms.

Brood Parasite

An organism, like the brown-headed cowbird or European cuckoo, that lays its eggs in another species' nest, forcing the other bird to care for its young.

Predation

A positive-negative ($+/-$) interaction where one organism, the predator, kills and eats another organism, the prey.

Keystone Species

A species with a relatively small population size that nevertheless has a disproportionately large and beneficial impact on the biodiversity of its ecosystem.

Mutualism

A positive-positive ($+/+$) interaction where both species involved benefit, such as pollinators and flowers or cleaner fish and their hosts.

Commensalism

A positive-neutral ($+/0$) interaction where one organism benefits while the other is neither helped nor harmed.

Biodiversity

A measure of the variety of life, typically categorized into three levels: genetic diversity, species diversity, and ecosystem diversity.

Species Diversity

The number of different species present in a specific community or ecosystem.

Ecosystem Diversity

The variety of different habitats and ecological communities found within a large geographical area, such as a state's coastline, mountains, and deserts.

Genetic Diversity

The variety of alleles and the size of the gene pool within a population, which provides adaptive potential against diseases and environmental changes.

Food Web

A complex diagram showing the interconnected feeding relationships and energy flow among various organisms in an ecosystem.

Primary Producers

Autotrophic organisms at the base of the food web, such as oak trees or phytoplankton, that provide energy for other levels.

Apex Predator

An organism at the top of a food web that is not eaten by any other species, such as a killer whale.