The Nature of & Changes in Communities

This set of flashcards covers key vocabulary and concepts related to the nature of communities, their structure, dynamics, and effects of changes in species interactions.

Communities

Groups of interacting species that occur together at the same place and time.

Taxonomic Affinity

A subset of species defined by their taxonomic relationships, such as all bird species in a community.

Guild

A group of species that use the same resources.

Functional Group

Species that function in similar ways despite belonging to different taxonomic groups.

Food Webs

Organized species based on trophic or energetic interactions.

Trophic Levels

The different levels in a food web, including primary producers, primary consumers, secondary consumers, and tertiary consumers.

Community Structure

Set of characteristics that shape communities, including species diversity, richness, and evenness.

Shannon Index

A commonly used species diversity index that accounts for the proportion of individuals in each species and the number of species in the community.

Biodiversity

Describes diversity at multiple spatial scales, from genes to species to communities.

Species Composition

The identity of species within a community which affects community structure.

Direct Interactions

Interactions that occur between two species.

Indirect Interactions

Relationships between two species that are mediated by a third species.

Trophic Cascade

A change in species abundance or composition at lower trophic levels due to the rate of consumption at one trophic level.

Trophic Facilitation

When a consumer is indirectly helped by a positive interaction between its prey and another species.

Competitive Networks

Interactions among multiple species where each has a negative effect on all others, allowing coexistence.

Interaction Strength

The magnitude of the effect of one species on the abundance of another.

Foundation Species

Large or abundant species that provide food or habitat for other species.

Keystone Species

Species that have a large effect on the community structure relative to their abundance.

Succession

The change in species composition in communities over time due to biotic and abiotic factors.

Primary Succession

Colonization of habitats devoid of life, which can happen very slowly.

Secondary Succession

Reestablishment of a community where some organisms have been destroyed but the soil and seeds remain.

Ecosystem Engineers

Species that significantly modify their environment, affecting other species.

Invasive Species

Non-native species that spread rapidly and disrupt native species interactions.

Caulerpa taxifolia

An invasive alga that dramatically changed native species interactions in the Mediterranean.

Eradication Plan

A strategy designed to eliminate invasive species and restore native ecosystems.