Biology - ch 45 community & ecosystems

Structure of a community

Species composition & species diversity

Species composition

List of every species found in the community

Species diversity

Composition AND number of individuals in each population (demographics)

Ecological niche

Has all necessary pieces for a species to survive → affected by biotic and abiotic factors

Fundamental niche

All abiotic conditions wear a species (theoretically) could survive if no other adverse biotic

Realized niche

Where a species can survive when adverse conditions are present (real life)

Character displacement

Result of competition for resources → resource partitioning → speciation

Ex. Finches in the Galapagos Island, small, large and medium beak, specialized for certain food

Competitive exclusion

Once species can’t out compete the other (hogs all the resources)

Resource partitioning

Decreases competition niche overlap → success for many

Predator – prey interactions

Living organism that eats another living organism, cycling of populations. As the Lynx population goes up, the Snowshoe Hare population goes down vice versa.

Symbiotic relationship relationships

Parasitism

Commensatism

Mutualism

Parasitism

nourishment from host

Commensatism

Two species, one is helped, and one is neutral

Mutualism

Benefits flow back-and-forth between both parties