Biodiversity

Biography

Biography: Daan Vreugdenhil

Abstract

The terms biodiversity and ecosystems have been used in many different ways while for a long time, concise reproducible definitions have remained elusive. As both terms are used in a variety of political objectives, clarity, field identification and mapping are paramount. For a long time, vegetation mapping has been possible from aerial photographs but interpretation was slow while photographs were expensive and national sets were often incomplete. In the 1990s satellite images had become available to scientists and the first detailed vegetation map base on satellite images was produced by Iremonger in 1993. This article demonstrated that identifiable vegetation types can serve as proxies for terrestrial ecosystems while aquatic ecosystems can be distinguished on the bases of a limited number of physical characteristics thus opening the way for full ecosystem mapping and identification. While biodiversity in its purest sense refers to the number of species per area unit, hence a numeric equation, it has more commonly been used as sets of species belonging to an area. However, the identification of all species in any given area is usually impossible. The author argues why ecosystems represent partially distinct sets of species, thus allowing for proxy identification and mapping of species or “biodiversity” in the field. The current article reviews commonly used methods to geographically distinguish biodiversity such as biomes, ecoregions and hotspots, demonstrating that those methods either lack a useful scale, a scientifically definable set of parameters, a practically identifiable set of paramaters or all of the above.