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,......................................................................................................................................................................... F RAY E 0 SA F E T Y NET S o the Colorado River. Preserve management must also address "edge effects" that can adversely affect communities on the edge of preserves, such as increased wind at the edge of forests, nest parasitism by cowbirds that lay eggs in birds' nests located close to the forest edge, predation by such opportunistic predators as raccoons (Procyon lotor) and domestic cars, increased human presence, and exotic species invasion. These factors (among others) can have significant negative impacts on species dependent upon interior habitats. Conservation plans must contain monitoring of potential edge effects, management prescriptions to ameliorate such effects, and preserve design that delineates adjacent land use and buffer areas. Of the conservation plans analyzed here, the MSCP in San Diego County will be affected most by edge effects. This plan creates a preserve system while allowing development outside the preserve areas and allowing some infrastructure development within the preserves. The plan acknowledges that under this scenario, edge effects are potentially severe. If the MSCP is implemented as intended and funding is suffi- cient, each preserve tract will have a habitat man- agement plan, which will delineate habitat buffers and specifY measures that managers will take to minimize edge effects. Building new roads in preserved areas is likely to be very diffi- cult in the MSCP because any such project would require a major amendment to the plan (a process requiring FWS approval). Moreover, a highly controversial expansion of Route 56 in San Diego County will be completed so that it does not run through sensitive habitat identified in the MSCP planning efforts. In addition, the biological monitoring plan emphasizes detection of changes in habitat quality over time, especial- ly edge effects. Dr. Ted Case at the University of California, San Diego, has proposed an institute that would bring researchers together to perform studies of these increasingly isolated habitat pre- serves. While this institute is not part of the MSCP per se, the emergent studies would be peer-reviewed and published in scientific jour- nals, and the researchers would communicate their results to local management agencies and the broader scientific community. Adaptive Management Management plans should be put into place immediately after preserves are established, but there must also be a method to change manage- ment techniques according to changing condi- tions. Any science-based conservation plan must incorporate techniques of adaptive management, whereby experimental approaches to manage- ment are monitored and changed with informa- tion generated by those experiments (Walters 1986). Plans must also contain the capability for changes in management that take into account new monitoring information, ecological knowl- edge, and/or changing environmental conditions. Decisions regarding management in conservation plans, to be effective, must be explicitly tied to monitoring and biological goals of the plan (Murphy et al. 1997). There are several reasons why conservation plans must include provisions for incorporating changes in management. The plan may have unpredicted consequences for the species; or new .... ... ... ... .......... .... ... ......... ... ................ .............. ........................ ... ....... ............... ... ... ....................................................... .........................................