STATISTICAL-ANALYSIS OF FOOD WEBS

The numbers of species in different trophic levels of a food web are m odeled as a trinomial random vector, with cell probabilities potential ly depending on the total number of species in the web. A maximum like lihood method is developed to test the hypothesis that the fractions o f species in different levels are independent of the total number of s pecies. The method is applied to a data set whose properties have been debated in the literature, and it is shown to be a powerful alternati ve to the simple linear regression approach used in previous analyses.