10.2 Community Composition Flashcards
ecological succession
the process by which an ecological community undergoes changes over time
primary succession
ecological succession that starts with barren rock
secondary succession
ecological succession that starts with a climax community
pioneer species
first colonizers in ecological succession
(lichens, mosses, ferns, bacteria)
seral stages
stages between pioneer community and climax community
climax community
stable community
species richness
number of species
species evenness
proportion of species relative to each other
genetic diversity
genetic variation between individuals in the population
species richness formula
R = s
s
number of species
Shannon Wiener Index
H = -∑(Piln[Pi])
Pi
ni/N
ni
individuals in species i
N
total indiviuals
species evenness formula
E = H/ln(R)
higher R, H, and E
more diverse
primary
starts with barren rock (retreating glacier, volcanic eruption) and ends with a climax community
secondary
starts with a climax community, experience destructive event (forest fire, logging, flooding, etc.,), and ends with a climax community
