LTER: The Luquillo Experimental Forest II

Luquillo实验森林（LEF）长期生态学研究项目始于1988年，其目标是从景观角度综合研究干扰制度、森林结构和动态。研究的两个核心问题是：1)不同干扰类型在四个热带雨林生活区内的相对重要性；2)生物区系在干扰后恢复生态系统生产力的重要性。作为Luquillo LTER项目的一部分启动的长期监测项目对于评估1989年袭击波多黎各的雨果飓风的即时和后续影响至关重要。在LTER项目启动后不久，飓风的发生为研究热带森林从大扰动中恢复的长期动态提供了机会。综合不同干扰因素（树木倒下、山体滑坡、飓风和人类土地利用）的时空格局表明，即使是大的干扰对森林景观的影响也是不均匀的。飓风“雨果”造成的破坏在左东风中呈现从东北到西南的强烈梯度，与最强风的方向相对应。然而，即使在受到严重干扰的地区，许多森林属性在飓风发生后的四年内已接近飓风前的值。森林的响应取决于扰动发生时立地的演替状态和扰动的强度。在许多地区，即使在雨果飓风之后，过去人类活动的遗产在森林组成和结构中也很明显。在进入第二阶段时，1988年开始的长期实验和测量仍将是Luquillo LTER的中心重点。分析飓风及其相关山体滑坡后的恢复动态和综合多种干扰的相互作用仍然是合作投资者的主要目标。新的倡议将集中于确定人为干扰的独特特征，并评估关键物种在形成演替路径中的重要性。和以前一样，Luquillo LTER的一个主要重点将是为跨站点和网络范围的综合提供信息和想法。

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..