Effects of plant type, size of geographical range and taxonomic isolation on number of insect species associated with British plants

Abstract

IN this communication we analyse the insects associated with higher plants other than trees, which have already received attention1–5. We are concerned with two basic problems. First, we ask how various types of higher plants differ in the numbers of species of insects which they support; we do this by comparing standard species–area curves1,3,6,7 for five different sorts of plants. Then we consider how the “taxonomic isolation” of a plant, measured simply as the number of related species in the same genus and geographical region, might also influence the total number of insect species to be found on it. We find that while plant type and geographical range have a considerable effect, taxonomic isolation does not, except in the case of monocotyledonous herbs.