Community Structure and Composition

These flashcards cover important vocabulary and concepts related to community structure and ecological interactions.

Species Richness

The number of different species present in a community.

Species Evenness

The relative abundance of individuals among different species in a community.

Shannon-Weiner Diversity Index

A mathematical formula used to quantify biodiversity, accounting for species richness and evenness.

Keystone Species

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

Facilitation

When one species increases the probability of a second species becoming established by changing environmental conditions.

Inhibition

When one species decreases the probability of another species becoming established by changing environmental conditions.

Ecological Succession

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

Primary Succession

Succession that occurs in lifeless areas where soil has not yet formed.

Secondary Succession

Succession that occurs in areas where a disturbance has destroyed an existing community but left the soil intact.

Intermediate Disturbance Hypothesis

The concept that moderate levels of disturbance can create conditions that foster greater species diversity.

Island Biogeography

A field of study that examines the ecological relationships and distributions of organisms on islands.

Species-Area Hypothesis

The idea that larger areas tend to support more species than smaller areas.

Heterogeneity

The variation and diversity in habitat types within an ecosystem, contributing to species diversity.

Functional Redundancy

The phenomenon where multiple species perform similar ecological functions, providing a buffer against species loss.

Pioneer Species

The first species to colonize previously disrupted or damaged ecosystems.

Climax Community

A stable community that undergoes little or no change in species over time.

Commensalism

A type of species interaction where one species benefits while the other is not significantly affected.

Predation

An interaction where one organism, the predator, kills and eats another organism, the prey.

Interspecific Competition

Competition between different species for a shared resource, such as food or habitat.

Amensalism

A relationship between two species in which one is harmed and the other is neither helped nor harmed.

Ecological Productivity

The rate at which energy is converted by photosynthetic and chemosynthetic autotrophs to organic substances.

Disturbance

An event that disrupts community structure and function, often changing resource availability.

Ecosystem Size

The physical size of an ecosystem, which can affect species richness and diversity.

Successional Stages

The series of stages through which an ecological community progresses over time during succession.

Relative Abundance

The proportion of individuals of a species in relation to the total number of individuals of all species in a community.

Climate's role in Productivity

The influence of temperature and precipitation on the productivity of an ecosystem.

Island Isolation Effects

The impact of distance from a mainland source population on immigration rates, extinction, and species richness.