Managing critical transition zones

Ecosystems that function as critical transition zones (CTZs) among terrestr ial, freshwater, and marine habitats are closely connected to the ecosystem s adjacent to them and are characterized by a rapid flux of materials and o rganisms. CTZs play various roles, including mediating water flows, accumul ating sediments and organic matter, processing nutrients, and providing opp ortunities for recreation. They are particularly difficult to manage becaus e they tend to be small, albeit important, components of large watersheds, and managers may not have control over the entire landscape. Moreover, they are often the focus of intensive human activity. Consequently, CTZs are cr itically important zones, and their preservation and protection are likely to require unique collaboration among scientists, managers, and stakeholder s. Scientists can learn a great deal from the study of these ecosystems, ta king advantage of small size and the importance of fluxes, but a good under standing of adaptive management strategies is needed to establish a dialogu e with managers and stakeholders on technical and management issues. An und erstanding of risk analysis is also important to help set meaningful goals and establish logical strategies that include all of the interested parties . Successful restoration of a CTZ is the best test of the quality of knowle dge about its structure and function. Much has already been learned about c oastal CTZs through restoration projects, and the large number of such proj ects involving riparian CTZs in particular suggests that there is considera ble opportunity for fruitful collaborations between scientists and managers .