Managing surprising ecosystems in southern Florida

Surprises commonly occur in natural resource systems and are manifest as dr amatic shifts in ecosystem structure and processes. Southern Florida ecosys tems have had two such surprises in the last two decades, (1) changes in do minant plant species in freshwater marshes of the Everglades; and (2) massi ve die-offs of seagrass in Florida Bay. Both examples indicate a loss of ec ological resilience and subsequent shifts in controlling processes or stabi lity domains. Techniques of adaptive environmental assessment and managemen t that confront alternative hypotheses of ecosystem change and propose mana gement actions that allow managers to learn have provided robust responses to these surprises. Two predicates for adaptive management are sufficient r esilience in the ecosystem components of a resource system and flexibility in the social system. Ecological resilience provides a buffer in the ecosys tem to the inevitable failure of management actions. Social flexibility thr ough trust and cooperation is needed if ecosystem resilience is exceeded. ( C) 2001 Elsevier Science B.V. All rights reserved.