Search results
Results from the WOW.Com Content Network
The species–area relationship or species–area curve describes the relationship between the area of a habitat, or of part of a habitat, and the number of species found within that area. Larger areas tend to contain larger numbers of species, and empirically, the relative numbers seem to follow systematic mathematical relationships. [ 1 ]
n 0 is the number of species in the modal bin (the peak of the curve) n is the number of species in bins R distant from the modal bin a is a constant derived from the data. It is then possible to predict how many species are in the community by calculating the total area under the curve (N): =
When plotted as a histogram of number (or percent) of species on the y-axis vs. abundance on an arithmetic x-axis, the classic hyperbolic J-curve or hollow curve is produced, indicating a few very abundant species and many rare species. [2] The SAD is central prediction of the Unified neutral theory of biodiversity.
The rank abundance curve visually depicts both species richness and species evenness. Species richness can be viewed as the number of different species on the chart i.e., how many species were ranked. Species evenness is reflected in the slope of the line that fits the graph (assuming a linear, i.e. logarithmic series, relationship).
In ecology, rarefaction is a technique to assess species richness from the results of sampling. Rarefaction allows the calculation of species richness for a given number of individual samples, based on the construction of so-called rarefaction curves. This curve is a plot of the number of species as a function of the number of samples.
R – Species observed is "Rare" within the given area. D.A.F.O.R scale: D - Species observed is "Dominant" in a given area. A - Species observed is "Abundant" in a given area. F - Species observed is "Frequent" in a given area. O - Species observed is "Occasional" in a given area. R - Species observed is "Rare" in a given area. These methods ...
Get AOL Mail for FREE! Manage your email like never before with travel, photo & document views. Personalize your inbox with themes & tabs. You've Got Mail!
In the equation, S is the total number of species (species richness) in the dataset, and the proportional abundance of the ith species is . Large values of q lead to smaller gamma diversity than small values of q , because increasing q increases the weight given to those species with the highest proportional abundance, and fewer equally ...