9705814 Waide The Luquillo Experimental Forest (LEF) Long-Term Ecology Research Program began in 1988 with the goal of integrating studies of disturbance regime and forest structure and dynamics with a landscape perspective. Two central research questions addressed 1) the relative importance of different disturbance types within the four tropical rain forest life zones of the LEF and 2) the importance of the biota in restoring ecosystem productivity after disturbance. The long-term monitoring program initiated as part of the Luquillo LTER was critical to the evaluation of immediate and subsequent effects of Hurricane Hugo, which struck Puerto Rico in 1989. The occurrence of a hurricane soon after the initiation of the LTER program provides an opportunity to study the long-term dynamics of a tropical forest as it recovers from a major disturbance. Integration of the spatial and temporal patterns of the different disturbances affecting the LEF (tree falls, landslides, hurricanes, and human land use) indicated that even the effects of large disturbances are not homogeneous over the forest landscape. A strong gradient in damage from Hurricane Hugo occurs from northeast to southwest in the LEF, corresponding to the direction of the strongest winds. However, even in severely disturbed areas, many forest attributes were approaching their pre-hurricane values within four years of the storm. Forest responses depended both on the successional status of the site at the time of disturbance and the intensity of disturbance. In many areas, the legacy of past human activites was apparent in forest composition and structure even after Hurricane Hugo. The long-term experiments and measurements initiated in 1988 will remain the central focus of the Luquillo LTER as it moves into its second phase. Analysis of the dynamics of recovery after the hurricane and its associated landslides and synthesis of the interaction of multiple disturbances continue to be the primary goals of collaborating invest igators. New initiatives will concentrate on defining the distinctive characteristics of anthropogenic disturbance and on evaluating the importance of pivotal species in shaping the path of succession. As before, a major emphasis of the Luquillo LTER will be to provide information and ideas for cross-site and network-wide syntheses..
