Vegetation Response in Simulated Hurricane Experiment at Harvard Forest since 1990

Wind disturbance profoundly shapes temperate forests but few studies have evaluated patterns and mechanisms of long-term forest dynamics following major windthrows. In 1990, a large hurricane simulation experiment was initaited in a 0.8 ha manipulation (pulldown) and 0.6 ha control area of a maturing Quercus rubra/Acer rubrum forest in New England. 276 trees were toppled in the pulldown, using a winch and cable, in the Northwesterly direction of natural treefall from major hurricanes. Eighty percent of canopy trees and two-thirds of all trees greater than 5 cm dbh suffered direct and indirect damage. Twenty years of measurements were used to evaluate the trajectory and mechanisms of forest response after intense disturbance. Based on the patch size and disturbance magnitude, we expected pioneer tree and understory species to drive succession.

风扰（wind disturbance）对温带森林的塑造作用极为显著，但目前鲜有研究针对大规模风倒事件后森林长期动态的格局与机制展开评估。1990年，研究团队在新英格兰地区一片成熟的红栎（Quercus rubra）-红花槭（Acer rubrum）混交林内，设置了0.8公顷的人工伐倒干扰样区与0.6公顷的对照样区，启动了大型飓风模拟实验。研究人员借助绞盘与钢缆，将276株树木沿对应大型飓风自然倒木的西北方向伐倒。该样区内80%的冠层树木，以及胸径（diameter at breast height, dbh）大于5厘米的树木中三分之二均遭受了直接或间接损伤。研究团队依托20年的连续监测数据，评估了该森林在强干扰后的恢复轨迹与响应机制。基于斑块规模与干扰强度，研究团队推测先锋树种与林下物种将主导该区域的群落演替过程。