preston: Preston diagram of an ecosystem In untb: ecological drift under the UNTB

Description

Gives a standard Preston diagram for an ecosystem.

Usage

 `1` ```preston(x,n=NULL,original=FALSE) ```

Arguments

 `x` Ecosystem vector that is coerced to class `count`, or a matrix whose rows are species counts `n` An integer specifying the number of species abundance classes to use, with default `NULL` meaning to use 1+log2(J). Must be greater than 1 if specified. If `x` is a vector, `NULL` is not acceptable as the program does not try to guess what is required `original` Boolean, with default `FALSE` meaning to use the nonoverlapping technique discussed below, and `TRUE` meaning to use Preston's original formulation.

Details

The Preston diagram is a table showing the number of species having abundances in specified abundance classes. Consider the following Preston diagram, created with `original = FALSE`:

 ```1 2``` ``` 1 2 3-4 5-8 9-16 17-32 33-64 65-Inf number of species 10 5 7 5 1 5 4 0 ```

This shows that there are 10 species with abundance 1 (that is, singletons); 5 species with abundance 2; 7 species with abudance 3-4; 5 species with abundance 5-8, and so on. This method is used by Hubbell (2001), and Chisholm and Burgman (2004).

Setting argument `original` to `TRUE` means to follow Preston (1948) and count any species with an abundance on the boundary between two adjacent abundance classes as being split 50-50 between the classes. Thus the fourth class would be phi_4/2+phi_5+phi_6+phi_7+phi_8/2 where phi_i is the number of species with abundance i (given by `phi(x)`).

Value

Function `preston()` returns an object of class “`preston`”.

Author(s)

Robin K. S. Hankin

References

• F. W. Preston 1948. “The Commonness, and Rarity, of Species”. Ecology 29(3):254-283

• R. A. Chisholm and M. A. Burgman 2004. “The unified neutral theory of biodiversity and biogeography: comment”. Ecology 85(11): 3172-3174

• S. P. Hubbell 2001. “The Unified Neutral Theory of Biodiversity”. Princeton University Press

`phi`

Examples

 ```1 2 3 4 5 6 7 8``` ```preston(untb(start=rep(1,100), prob=0.01, gens=1000, keep=FALSE)) data(butterflies) preston(butterflies) preston(butterflies,original=TRUE) data(copepod) preston(copepod) ```

untb documentation built on May 30, 2017, 8:29 a.m.