Pt 7 Struggle for existence Flashcards
community ecology - definition
An ecological community consists of all biotic entities within a defined locality.
Differences between communities and ecosystems:
Communities focus on biotic components.
Ecosystems include both biotic and abiotic elements.
Types of Community Studies
Taxonomically-defined communities: Groups of closely related species (e.g., bird communities).
Functionally-defined communities: Groups with similar ecological roles (e.g., soil decomposers).
Guilds: Species sharing functional niches (e.g., insect-eating warblers in spruce forests).
Community Properties
Species richness: Number of species present in a community.
Species diversity: A balance of species richness and evenness of their abundances.
Example: A community with ten equally abundant bird species is more diverse than one with a dominant species.
Metapopulations:
Composed of multiple subpopulations.
Defined by patchy habitats with varying colonization and extinction rates.
How does an ecological community differ from an ecosystem?
A: Communities include only biotic components, while ecosystems include both biotic and abiotic factors.
What are the three main types of community studies?
A: Taxonomically-defined communities, functionally-defined communities, and guilds.
What is species richness?
A: The total number of species present in a community.
What is a dominant species in a community?
A: A species with a disproportionately high abundance or biomass compared to others.
What is the typical pattern of abundance in communities?
A: Few dominant species and many rare species.
What is a guild in community ecology?
A: A group of species that share similar ecological roles or niches (e.g., insect-eating birds).
What happens to p when e>c?
A: The metapopulation collapses because extinction exceeds colonization.
How does the equilibrium proportion formula apply to island ecosystems?
A: It predicts patch occupancy based on isolation and habitat quality
