REU: Long-Term Processes Affecting the Hemlock-Hardwood Mosaic at Sylvania, Michigan

REU：影响密歇根州西尔瓦尼亚铁杉-硬木马赛克的长期过程

• 批准号: 8916503
• 负责人: Margaret Davis
• 金额: $ 41.76万
• 依托单位: University of Minnesota-Twin Cities
• 依托单位国家: 美国
• 项目类别: Continuing Grant
• 财政年份: 1990
• 资助国家: 美国
• 起止时间: 1990-03-01 至 1993-08-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=8916503&HistoricalAwards=false
• 关键词: REU; Long; Term; Processes; Affecting

Processes responsible for the mosaic of hemlock stands and hardwood stands in the old-growth forest at Sylvania, Michigan will be studied with retrospective techniques. These approaches include reconstruction of disturbance history over the last two centuries from tree-rings, windstorms, fire and the consequent changes in forest composition over the last five millennia from pollen deposits in small forest hollows. The mosaic of stands and soil textures will be studied in three permanent plots established on different soil types. The ways in which the mosaic changed through time in response to climatic change, to changes in disturbance regimes and to the invasion of hemlock beginning three thousand years ago, will be monitored by pollen diagrams from closely spaced spatial arrays of hollows, approximately one per hectare, within each of the plots. Mosaic changes on a large spatial scale will be shown in pollen diagrams from seven additional hollows scattered throughout Sylvania in stand types not represented in the plots. Modeling and studies of pollen representation will develop needed techniques for accurate interpretation of pollen assemblages from heterogeneous vegetation.

负责镶嵌铁杉立场的进程， 密歇根州西尔瓦尼亚的古老森林中，一棵硬木屹立不倒 将采用回顾性技术进行研究。 这些方法 包括重建过去两年的扰动历史， 几个世纪以来，树木年轮，风暴，火灾以及随之而来的 在过去的五千年里， 花粉沉积在森林的小洼地里。 林分的镶嵌 和土壤质地将在三个永久性地块进行研究 建立在不同的土壤类型上。 的途径 马赛克随着时间的推移而变化，以应对气候变化， 干扰机制的变化和铁杉的入侵 从三千年前开始， 图中显示的是密集排列的空洞， 大约每公顷一个，在每个地块内。 马赛克 大空间尺度上的变化将在花粉图中显示出来 从散布在西尔瓦尼亚的另外七个空洞中 林分类型未在图中表示。 建模和研究 花粉代表性将开发所需的技术， 花粉组合的准确解释 植被