After preservation: Philisophical and practical problems of change

Abstract

Even after land is legally protected, ecological change continues to affect species and ecosystems. Changes vary from natural to human-caused, from beneficial to detremental, and from manageable to impossible to manage. Management can be approached on two levels: (1) an ecosystem-community (‘process-oriented’) level and (2) a species-population (‘species-oriented’) level. Management on these two levels sometimes conflicts. Key changes in reserves include: natural and human disturbance, manipulation of fire regimes, succession, imbalance of animal populations (e.g., elemination of large predators and population fluctuation of grazers), population and genetic change of rare species, introduction of exotics, pollution of air and water, interference with hydrologic regimes, and increased visitor pressure. Man-caused changes and poor management are still the greates threats to nature reserva systems. A preservationist ‘hands-off’ legacy, while idealistic and philosophically attractive, may contribute to lack of firm leadership in reserves by biologists and managers, Because the effects of human are now omnipresent, some form of management (if only to regulate visitor impact) usually is necessary. Dealing with ecological change requires statement of preservation goals, priorities, and clear policy on key issues; in addition, resource inventory, monitoring, and management-oriented research are required.