Spatial and Temporal Patterns of Tropical Forest Recovery in an Agricultural Landscape

本研究将在广泛的时间和空间尺度上回答有关生态系统恢复的理论和应用问题，特别关注哥斯达黎加南部热带山地雨林的恢复。这项研究是一项长期研究的第一阶段，该研究测试了一种新的恢复方法，即种植树木岛屿作为恢复的核心，并评估接近现有雨林斑块对恢复的重要性。为了解决这些问题，将在哥斯达黎加南部100平方公里的废弃农业用地上建立12个0.25公顷的地块。地块将接受以下三种处理之一：(1)控制-不种植；(2)在地块上种植三种大小的本地树木“核”；(3)在整个地块上种植本地树种。这些街区将被“低”和“高”森林覆盖的区域分开。我们将对这些样地和6个剩余样地的树种树苗建立情况进行监测。在第三年，将在选定的样地测量种子雨量、小气候条件、土壤水势、土壤磷和种子/幼苗食草性，以评估幼苗建立的替代机制和模式。这项研究是科学家和对农业生产与生物保护相结合感兴趣的农民之间的创新合作研究成果，因此将产生生态、社会和教育效益。这项工作的结果将有助于改善当地和区域的热带森林恢复工作，这对保护生物多样性和生态系统服务具有重要影响。

This research will answer theoretical and applied questions about ecosystem recovery across broad temporal and spatial scales, specifically focusing on the recovery of tropical montane rain forest in southern Costa Rica. The research is the first stage in a long-term study testing a novel restoration approach, planting islands of trees to serve as nuclei for recovery, and evaluating the importance of proximity to existing rain forest patches for recovery. To address these questions 12 replicate blocks of three 0.25-ha plots will be established in abandoned agricultural lands over a 100 km2 area in southern Costa Rica. Plots will receive one of three treatments: (1) control - no planting, (2) planting the plot with native tree "nuclei" of three sizes, and (3) planting the entire plot with native tree species. These blocks will be split between areas surrounded by "low" and "high" forest cover. We will monitor tree seedling establishment of forest species in these plots, as well as in six remnant forest plots. In the third year, seed rain, microclimatic conditions, soil water potential, soil phosphorus, and seed/seedling herbivory will be measured in selected plots to evaluate alternative mechanisms underlying patterns of seedling establishment. This research constitutes an innovative collaborative research effort between scientists and farmers interested in integrating agricultural production and biological conservation, and consequently will yield ecological, social, and educational benefits. The results of this work will help improve tropical forest restoration efforts both locally and regionally, which has important consequences for conservation of biodiversity and ecosystem services.