Conservation Planning Loopholes Threaten Imperiled Species, Researchers Say

Habitat conservation plans are intended to achieve a balance between development and the long-term conservation of species listed as endangered or threatened under the Endangered Species Act. Developers seeking permits for the incidental take of listed species often include multiple species in their plans, both listed and nonlisted, because if a species not in the plan is subsequently listed under the act, the continued activities of the permittee could be jeopardized.

The BioScience article, by Matthew E. Rahn of San Diego State University and two colleagues, analyzed 22 multispecies plans approved by the US Fish and Wildlife Service before 2005. On average, 41 percent of the species covered in the plans had not been confirmed as present in the planning area, a finding the authors describe as "alarming." Furthermore, most of these unconfirmed species lacked any species-specific conservation measures, which means that a multispecies habitat conservation plan could represent a danger.

Rahn and colleagues argue that "assumptions of occurrence should be justified" in multispecies conservation plans. They suggest that the US Fish and Wildlife Service has been inclined to issue permits for multispecies conservation plans in the absence of data, relying instead on professional judgment. Rahn and colleagues call that a "dangerous practice" and suggest that it may help explain why species in multispecies habitat conservation plans fare poorly compared with species with dedicated plans.

The complete list of research articles in the July 2006 issue of BioScience is as follows:

* The Implications of Niche Construction and Ecosystem Engineering for Conservation Biology. Neeltje J. Boogert, David M. Paterson, and Kevin N. Laland

* A Framework for Exploring the Determinants of Savanna and Grassland Distribution. Anthony J. Mills, Kevin H. Rogers, Marc Stalmans, and Ed T. F. Witkowski

* Linking Scales in Stream Ecology. Winsor H. Lowe, Gene E. Likens, and Mary E. Power

* Carbon Storage in Landscapes with Stand-replacing Fires. Daniel M. Kashian, William H. Romme, Daniel B. Tinker, Monica G. Turner, and Michael G. Ryan

* Statistical Power, Sample Sizes, and the Software to Calculate Them Easily. Keith P. Lewis

* Species Coverage in Multispecies Habitat Conservation Plans: Where's the Science? Matthew E. Rahn, Holly Doremus, and James Diffendorfer