Zusammenfassung der Ressource
OCR - A-Level -
Biology -
Biodiversity
- Measuring
biodiversity
- Species
richness
- The more different
types of species
present, the richer the
habitat.
- Observations of
species present
- Qualitative
- Species
evenness
- Takes into account the
population size of each
species. Even when most of
the species are abundant,
rather than one dominant.
- Observations of
species and numbers
of each to compare
- Quantitative
- Animals
- Large
- Careful observation of
species and counting
individuals
- Small
- Take samples of
animals present, mark
and capture
- Mark
and
Recapture
- Capture and mark
the organisms
harmlessly.
- The number of
captured organisms
of this species is C1
- Release the
organisms that
have been
captured and
marked.
- Capture organisms
again.
- The number of
captured organisms
the second time
around is C2.
- The number of already
marked organisms in
this sample is C3.
- Total population =
(C1 x C2)/C3
- E.g C1 = 3, C2 = 4, C3 = 2
- (3x4)/2 = 6
- Population is 6
- Simpson's
Diversity Index
- D = 1- [∑(n/N)^2]
- D = Diversity
- ∑ = Sum of all species [(n/N)^2]
- n = Number of a
particular spp of plant
- N = Total number of all
individuals of spp (∑n)
- D will be between 0 and 1