Oh. Diserud, Detecting changes in diversity in a fluctuating environment based on simulation of stochastic processes, OCEANOL ACT, 24(5), 2001, pp. 505-517
In this paper, I present a method developed to detect 'extra', or novel, ch
anges in diversity in a naturally fluctuating environment. When comparing s
amples in order to evaluate changes in community structure, the sampling pr
ocedure will inevitably induce randomness in observed species composition a
nd abundance, so two samples may show considerable differences, even if the
y come from exactly the same community. Sometimes the effort put into the s
ampling varies as well, leading to the expectation of a further increase in
difference. Finally, if there were a temporal distance between the samples
, we would like to correct for variations in species abundance occurring na
turally due to fluctuating environmental conditions. The test method presen
ted here includes a model of the sampling procedure, and corrects for diffe
rential sampling efforts. The population dynamics is modelled by a diffusio
n process, its variance mimicking the effect a fluctuating environment has
on species abundances. We are thereby able to test the null hypothesis of n
o unnatural change in diversity, against the alternative of additional chan
ges in community structure due to for example human disturbances. (C) 2001
Ifremer/CNRS/IRD/Editions scientifiques et medicales Elsevier SAS.