Community Ecology (Chapter 56)

These flashcards cover key concepts from the lecture notes on Community Ecology, including definitions, examples, and important principles related to species interactions and community dynamics.

What is a community in ecology?

All the different species (populations) living and interacting in the same area.

What is species diversity?

The variety of species in a community.

What is species richness?

Total number of different species

What is relative abundance?

How common each species is.

How can community composition change across a geographic landscape?

It changes due to varying environmental factors (climate, soil, elevation), leading to different species types and numbers in different places.

What is interspecific competition?

When different species compete for the same limited resources.

What is Interference competition?

Directly blocking access to resources (e.g., plants releasing chemicals, animals fighting)

What is a niche?

An organism's role and 'address' in its environment (how it uses resources).

What is resource partitioning?

Species divide up resources to avoid direct competition and coexist.

What is an example of resource partitioning?

Birds eating different parts of a tree

What is a realized niche?

The actual resources a species *does* use due to competition/other limits.

What is a fundamental niche?

The full potential range of resources a species *could* use.

How do other species affect a species' realized niche?

Competitors or predators limit access to resources/habitats, shrinking the realized niche from its fundamental niche.

What is the Principle of Competitive Exclusion?

If two species compete for the exact same resource, one will outcompete the other.

How did Gause's experiment show the Principle of Competitive Exclusion?

It showed one species always eliminated the other when together with limited food.

What is character displacement?

Competing species evolve physical differences where they live together to reduce competition and coexist.

What is an example of character displacement?

Finches on an island evolve different beaks for different seeds.

What is predation?

One organism (predator) kills and eats another (prey).

What effects does predation have on populations?

It controls prey numbers, drives prey defenses (camouflage), and affects prey behavior/location.

What is intraspecific competition?

When 2 of the same species compete for the same limited resources.