Long-term Processes Affecting the Hemlock-hardwoods Mosaic at Sylvania, Michigan

铁杉-阔叶林的长期森林动态 密歇根州北方的美国联邦调查局西尔瓦尼亚荒野地区的马赛克， 将利用森林洞穴中的花粉化石进行研究。 在沉积物中记录的个体森林的历史， 将在以火为主的森林中识别出演替群落， 3000年前铁杉入侵前的森林生态系统， 我们可以看到一些地区的骚乱 特别是侵入性，从而影响铁杉进入和 曾经占据这些地方的铁杉补丁的位置 那以后 通过测定铁杉到达一系列极端地点的时间， 环境，附近的沼泽或湖泊或粗糙的土壤，我们将测试 另一种假设是， 环境对铁杉的位置负责 补丁. 沉积物和时间序列的细尺度分析 对所得数据的分析将探讨以下方面的变化： 林火后扰动机制发生变化时的演替途径 三千年前的风 建模将用于调查 边界位置的动态变化 在森林镶嵌图中的树木之间。 结果会很有用 来展示森林群落对气候的反应， 包括可能伴随的扰动机制的变化， 全球变暖 了解马赛克图案的起源 森林群落对景观的影响可能有助于森林管理者 保护古老森林生物多样性的这一方面 台架.

Long-term forest dynamics in the hemlock-hardwood forest mosaic of the USFS Sylvania Wilderness Area, northern Michigan, will be studies using fossil pollen in small forest hollows. Histories of individual forest stands, recorded in the sediment, will identify successional communities in the fire-dominated forest ecosystem before hemlock invasion 3000 years ago, making it possible to see whether disturbances made some areas particularly invasible, thus influencing hemlock entry and the locations of hemlock patches that have occupied those sites ever since. By dating hemlock arrival at a series of sites in extreme environments, near bogs or lakes or on coarse soils, we will test the alternative hypothesis that differences in the physical environment were responsible for the locations of hemlock patches. Fine-scale analyses of sediment and time-series analyses of the resulting data will explore changes in successional pathways as the disturbance regime changed from fire to wind 3000 years ago. Modeling will be used to investigate the dynamic changes that have occurred in the positions of boundaries between stands in the forest mosaic. The results will be useful for demonstrating the response of forest communities to climate, including changes in disturbance regimes which may accompany Global Warming. Understanding the origin of the mosaic pattern of forest communities on the landscape may help forest mangers to preserve this aspect of the biodiversity of old-growth forest stands.