[R-sig-eco] Diversity on standardised densities in R

[Mario José Marques]

Hi Paris,

excuse-me if I do not understand you. I think that or you standardize 
you effort to less individual in your samples or you extrapolation your 
sample to that more abundant. If you have sample with less individual, 
like you say, it is not recomended to do extrapolation.

If your accumulation curves, for each sample, reaches asymptote, I think 
that you can compare communities without standardize. For zooplancton, 
maybe is possible to reaches asymptote.

I hope have helped you.

Best regards,

Mario

...................................................
Doctoral student in Ecology
Institute of Biology, Dept. Plant Biology, Ecology Lab.
State University of Campinas - UNICAMP
Campinas, São Paulo, Brazil

On 24-10-2013 16:45, Paris wrote:
> Hello all,
>
> I want to calculate classic diversity indexes from my zooplankton samples.
> The problem is that the number of individuals is not the same in all cases
> (some samples were semi-empty) and that is the case for the amount of sample
> I analysed. In order to standardise for effort, I want to do the following:
> a) randomly sample e.g. 50 individuals from each of my sample, so that I
> standardise for effort (that's the difficult part)
> b) then calculate on this newly created matrix all the typical indexes
> (that's the easy part)
> I ll give an example of a dataset in R, where samples are rows and species
> are columns:
>
> 0	0	0	0	0	2	0	0	0	0
> 0	0	0	0	0	0	0	0	0	0
> 0	0	0	0	0	0	0	85	0	0
> 0	0	0	0	0	45	5	57	0	0
> 0	0	0	0	0	13	0	3	0	0
> 0	0	0	0	0	0	0	0	0	0
> 0	0	0	0	0	0	0	7	0	0
> 0	3	0	0	12	8	0	57	0	0
> 0	0	0	0	0	0	0	1	0	0
> 0	0	0	0	0	59	0	0	0	0
> 0	0	0	0	4	0	0	0	0	0
> 0	0	0	0	0	0	0	0	0	0
> 0	0	0	0	0	0	0	0	0	0
> 0	0	0	0	0	0	0	0	0	0
> 0	0	0	0	0	0	0	0	0	0
> 0	105	0	0	0	0	0	0	0	0
> 0	0	0	0	0	0	0	0	0	0
> 0	0	0	0	0	0	0	0	0	0
> 0	0	0	0	0	0	0	0	0	0
> 0	0	0	0	1	0	0	100	0	0
> 0	35	0	55	0	0	0	0	0	0
> 1	4	0	0	0	0	0	0	0	0
> 0	0	0	0	0	34	21	0	0	0
> 0	0	0	0	0	9	17	0	0	0
> 0	54	0	0	0	27	5	0	0	0
> 0	1	0	0	0	1	0	0	0	0
> 0	17	0	0	0	54	3	0	0	0
> 1	0	0	1	0	6	10	0	0	0
> 1	18	0	0	0	1	2	0	6	2
> 0	5	0	0	0	35	57	0	0	0
> 0	3	0	0	0	4	3	0	0	0
> 0	0	0	0	0	6	5	0	0	0
> 0	0	0	0	0	5	4	0	0	0
> 10	5	8	10	0	25	19	0	0	0
> 0	2	7	0	0	6	11	0	0	0
> 15	0	0	0	0	8	7	0	0	0
> 13	2	0	0	0	20	11	0	0	0
> 13	0	0	0	0	0	11	0	0	0
> 8	0	0	0	0	15	10	0	0	0
> 0	1	0	32	1	13	12	0	0	0
>
> Anybody any ideas how to do this in R?
>
>
>
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