Lecture 26 Flashcards
Biological community
Populations of organisms in a prescribed area or habitat
Species richness
Number or species in a community
Species evenness
Relative abundance or species
Diversity Index- Shannon Wiener Index
H=-£pílnpí
Pí=proportion of species í in total sample
Keystone species
Species with disproportionate effect on diversity relative to biomass
Succession
Replacement of populations of habitat through a stable state
Primary succession
Creation of new habitat
Ex) lava flow, glaciation, sand dunes
Intermediate disturbance hypothesis
Species diversity will be highest at intermediate levels of disturbance
Food web
Community portrait based on feeding relationships
Tropic level
Feeding position within food web
Primary produce-herbivore-primary consumer- 3°consumer
J
Indirect effects
Interaction between 2 species altered by 3rd species