clusion has implications for the future of the NPS program. One way to strengthen the NPS science program will be to strengthen cooperative research elements.

By itself, an adequate research program will not eliminate the many, complex threats faced by the national parks. But it will allow faster identification of human perturbations, greater understanding of cause and effect, better insights into prevention, and more appropriate strategies for mitigation so that managers can maintain systems in a desirable condition or restore them where necessary. Virtually all parks have a backlog of unaddressed research questions. This is noted in NPS's own assessment of threats to the parks (NPS, 1980), and it is illustrated clearly in the long lists that typically appear in the "research needs" sections of park resource management plans. Science must be a permanent fixture within the NPS and that research must be an ongoing, iterative process.