Species Richness
S = s / √N
s = total number of different species in the sample
N = total number of individual organisms in the sample
Evenness (relative species abundance)
Evenness = number of individuals from one species / total number of individuals from all species
Simpson’s Index
D= ∑n(n-1) / N(N-1)
n = total number of individuals of a particular species
N = total number of organisms of all species
Simpson’s Diversity Index
SDI = 1 - D
D = Simpson’s Diversity
Population Density
Population density = population size / size of the area
Population growth rate
r = (b + i) - (d + e)
b = number of births
i = number of immigrants
d = number of deaths
e = number of emigrants
Population size (Lincoln’s Index)
Size of population (N) = M × n / m
M = number originally marked
n = total number captured in the second sample
m = number of recaptured (marked) individuals in the second sample
Percentage cover (foliage, ground cover of soil, grasses, leaf litter, etc.)
% cover = ∑coverage / total area × 100
Needed for Specht’s classification system
Estimating height of a tree
tan 45° = side opposite (height) / side adjacent (horizontal distance) + height of observer
Needed for Specht’s classification system
Average
Average = ∑of values / total number of values observed × 100
What does Simpson’s Index mean?
It is the probability that two individuals randomly selected from a sample will belong to the same species. Lower the better- closer to 0.
What does Simpson’s Diversity Index mean?
It is the probability that two individuals randomly selected from a sample will belong to different species. High = good = biodiverse. Number between 1-0 - closer to 1 the better.
