Rosenzweig-1- Applying Species-area Relationships to the Conservation of Species Diversity

The time has come to ride our horse. Ecology has studied species-area relationships (SPARs) for two centuries. It has collected data at all sorts of spatial scales. It has hammered at them, analyzed them and debated them. The result is a pretty useful set of biogeographical tools. We need them and should use them wherever it makes sense to. I believe this horse will carry us a long way. It will be especially useful on the road to preserving species from extinction. In this chapter, I will show several examples of such use. One, the SLOSS controversy, has already been brought well in hand (although you may not have thought before reading this chapter). Another, the impact of exotic species on diversity, is moving along nicely. The other three (which I will soon describe) will open the doors to a large amount of research and application. There are four types of species-area curves (Rosenzweig, 1995). The four correspond to different scales, partly of space, largely of time (Rosenzweig, 1999). To use them effectively we must understand each of them. Rosenzweig-2-1) The point scale. At this scale, time and space vanish. SPARs result, not from biology