Ecological Society of America
Null models have had a long and contentious history in community ecology (Connor and Simberloff 1979, Harvey et al. 1983, Gotelli and Graves 1996, Graves and Rahbek 2005). Much of this debate has arisen because multiple strategies for null models can be used to address a particular question of interest, and the present exchange is no exception. To assess constancy in species richness through time in a desert rodent community, Nichols et al. (2006) have proposed a Markov Chain model as an alternative to the random-walk model we developed (Goheen et al. 2005). While both null models simulate stochastic local extinction and colonization of species from a regional pool, our objectives differ substantially from those of Nichols et al. in ways that influence the choice of models and interpretation of results.
Goheen, J.R., E.P. White, S.K.M. Ernest, J.H. Brown. 2006. Intra-guild compensation regulates species richness in desert rodents: reply. Ecology 87:2121-2125