How many species?

Abstract

Outlines approaches to estimating what the total number of species on Earth might be, eg extrapolation of past trends; direct assessments based on the overall fraction previously recorded among newly studied groups of tropical insects; indirect assessment derived from recent studies of arthropods in the canopies of tropical trees (giving attention to the question of what fraction of the species found on a given host-tree are likely to be "effectively specialized' on it); and estimates inferred from theoretical and empirical patterns in species-size relations or in food web structure. There is a discussion by R.J.H. Beverton. -from Author