describing biodiversity Flashcards
define biodiversity
the variety of life that exists, the genetic material they possess they give them unique characteristics, and the ecosystems in which they survive
five common measures used to describe diversity of species in an ecosystem
species richness, relative species abundance, percentage cover, percentage frequency, Simpson’s diversity index
define relative species abundance
refers to how many of each species are present
what does relative species abundance mean in correlation to ecosystems/biodiversity?
an ecosystem is considered healthier is its species are similar in number. a higher biodiversity - more richness and similar abundance
percentage cover
estimate of what percentage of an area enclosed by a quadrant is occupied by each species
percentage frequency
probability that a species will be found within a single quadrant
percentage frequency formula
(number of quadrants in which the species is found /
total number of quadrants) x 100
simpsons diversity index
represents the probability that two individuals randomly selected from a sample will belong to a different species
what is the simpson diversity value between?
0 and 1
simpson diversity index formula
SDI = 1 - (sum of n(n-1) / N(N-1)
abundance
number of individuals (organisms) of a species living in a particular ecosystem
distribution
the spatial arrangement of members of a population within a given area
3 basic patterns of distribution
uniform (evenly spaced),
random (randomly spaced),
clumped (distributed in clusters)
abiotic
non - living
biotic
living
species interactions
organism interact and show relationships that are both infraspecific and interspecific
infraspecific
between members of the same species
interspecific
between members of a different species
