LETTERS TO THE EDITORS
To the Editors:
"Conserving Biodiversity Coldspots" (July-August) by Kareiva and Marvier provides a much-needed, critical assessment of biodiversity hotspots. However, the authors neglected a notable point that would have bolstered their position—the temporal component. As we have shown (Rutledge et al. 2001. Conservation Biology 15:475–
487), global biodiversity hotspots change in number and rank over time because additional species are being discovered every year, thereby increasing the diversity and "hotness" of the region where they live. Also, the rate of species discovery is tied to several variables—the amount of time spent searching, the taxa being investigated, the geographic locale—meaning that many unidentified hotspots still exist.
Hotspot analyses are useful in conservation planning, but we concur with the authors that focusing on biodiversity hotspots could prompt declines in other areas—or worse yet, the misconception that "coldspots" or "warmspots" are somehow expendable.
Christopher A. Lepczyk
Department of Forest Ecology and Management
University of Wisconsin-Madison
Daniel T. Rutledge
Manaaki Whenua Landcare Research NZ Ltd
Hamilton, New Zealand