What Biodiversity Is Not

Abstract

To help demarcate the boundaries of Chap. 3’s definition of biodiversity, this chapter considers proposals to define biodiversity in ways that head off in various wrong directions. On the one hand (Sect. 4.1) are category mistakes that typically reduce biodiversity to, and confuse it with, the biological identity of some one or another of the entities that contribute to diversity – such as individual organisms or particular species. These reductive slides are evident in such serious and seriously common misstatements as that biodiversity (as opposed to a particular population of flying insects) provides a pollination service. Another kind of slide – from some thing to some measure of that thing – is ensconced in the commonly used ecological definition of biodiversity as some combination of species richness and the even distribution of individuals amongst existing species. Beyond the category mistakes are various “accretive” conceptions (Sect. 4.2), which try to bulk up biodiversity in order to give it some (more) value muscle. The bulk-producing supplements tend to apply (once again) to the particular identity of the things that are diverse, not diversity itself. They include such properties as rarity (defined either non-relationally, as low abundance within some system or relationally, as uniqueness), distinctiveness (a comparative property), endemism (geographical rarity – a place-related property), the species/area ratio (a kind of biodiversity density or place-related efficiency), endangerment (a risk-related property), and viability (also risk-related). Some of these properties will be familiar from the well-known concept of “biodiversity hotspot”, which is also scrutinized.