Communities and Food Webs

Flashcards summarizing key vocabulary and concepts related to communities and food webs in ecological studies.

Ecological Community

A collection of species or populations interacting over time and within a defined space. Communities are not a distinct entity (are continuous with each other). The definition as a group of species ignores the component of space.

Species Richness

The total number of different species present in a community.

Keystone Species

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

Dominant Species

Species that have the highest biomass or abundance in a community and shape its structure.

Community Structure

The organization of a community based on species composition, trophic levels, and temporal interactions. SPECIES: each community has a characteristic set of species in terms of patterns and / or relative abundances. • Temporal – has cycles of activity (e.g. daily / seasonal). • Trophic – patterns of energy transfer.

Indicator Species

Species that serve as a signal for the health of an ecosystem.

Trophic Levels

The hierarchical levels in an ecosystem, where organisms are categorized based on their source of energy.

Primary Producers

Organisms that produce energy available for other organisms, usually through photosynthesis.

Primary Consumers

Herbivores that consume primary producers.

Secondary Consumers

Predators that consume primary consumers.

Carnivorous Plants

Plants that can photosynthesize while also obtaining nutrients by consuming other organisms.

Omnivores

Organisms that consume both plants and animals.

Detritivores

Organisms that consume decomposing organic matter.

Rule of Tens

Only approximately 10% of energy is transferred from one trophic level to the next.

Food Chains

Linear representations of energy flow between species in an ecosystem.

Food Webs

Complex networks of interactions showing how different food chains are interconnected.

Guilds

Groups of species that exploit the same resources in similar ways.

Succession

The process through which ecosystems change and develop over time.

Microhabitats

Small, specific areas within a habitat that provide unique conditions for certain species.

Predation

The relationship where one organism consumes another.

Parasitism

A relationship in which one organism benefits at the expense of another.

Mutualism

An interaction where both organisms benefit.

Energy Transfer

The flow of energy from one trophic level to another within an ecosystem.

Ecological Pyramids

Graphical representations showing the numbers, biomass, or energy at each trophic level.

Chain Shortening

The process by which food chains may shorten due to energy losses and population decreases.

Compartmentalisation

The division of food webs into separate groups with strong interactions within and weak interactions between them.

Biomass

The total mass of living matter in a given area or volume.

Adaptation

The process by which species evolve characteristics that enhance their survival and reproduction in their environment.

Community Dynamics

The interactions and changes that occur within a community over time.

Defining populations (compare plants and animals)

Plant community data looks at numbers of individuals within a species while animal data considers the presence or absence of species. Animals are more mobile and may be active at different times, making accurate abundance assessments challenging.