Collaborative Research: Above- and Belowground Response of Coniferous Ecosystems to Tree-Fall Gaps

合作研究：针叶林生态系统对树木倒伏间隙的地上和地下响应

• 批准号: 8909037
• 负责人: Jerry Franklin
• 金额: $ 16.63万
• 依托单位: University of Washington
• 依托单位国家: 美国
• 项目类别: Continuing Grant
• 财政年份: 1989
• 资助国家: 美国
• 起止时间: 1989-11-01 至 1993-10-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=8909037&HistoricalAwards=false
• 关键词: Collaborative; Research; Above; Belowground; Response

A collaborative research project will be conducted by the University of Washington, Yale University, and Oregon State University for an experimental study of ecosystem responses to tree-fall gaps and spatial and temporal relationship between above- and belowground gaps. It is hypothesized that mechanisms of community and ecosystem responses to gaps can only be understood if both above- and belowground structures and resources are considered. An experiment to determine the size of aboveground gap needed to form a belowground gap in mature and old-growth coniferous forests will be imposed. The investigators will also measure how above-and belowground structural changes are reflected in resource availability and loss and in vegetative response. To examine the hypotheses, the team will create tree- fall gaps of ranging from small to large in five sizes (0, 2, 8 and 16 and 32 trees removed) in reach of two stand developmental stages: mature (understory reinitiation), and old growth. Above and belowground sampling will be conducted to provide an estimate of the mean of the gap and will consist of root biomass (separated into tree, shrub and herb components), N leaching below the rooting zone, and soil temperature and moisture, light level determinations, shrub and herb biomass, seed germination and monitoring of advanced regeneration. In the old-growth stands, above-and belowground resources (plus net N mineralization) and vegetative biomass will be sampled more intensively to provide not only an estimate of the gap mean but of the within-gap spatial patterns. In addition, trenching experiments will be established in the old-growth stands to test the relative importance of above- and belowground resources on tree establishment and growth and develop predictive models of plant response to resources. The three-institution project team is excellent. Research sites and facilities are first rate. Results should be important to both the fundamental understanding of forest ecology and to forest resource management.

华盛顿大学、耶鲁大学和俄勒冈州立大学将开展一个合作研究项目，对生态系统对树木倒塌间隙以及地上和地下间隙之间的时空关系的反应进行实验研究。 据推测，只有同时考虑地上和地下结构和资源，才能理解群落和生态系统对差距的反应机制。 将进行一项实验，以确定在成熟和古老的针叶林中形成地下间隙所需的地上间隙的大小。 研究人员还将测量地上和地下结构变化如何反映在资源可用性和损失以及植物反应中。 为了检验这些假设，该团队将创建从小到大五种尺寸的树木倒落间隙（移除 0、2、8、16 和 32 棵树），以达到两个林分发育阶段：成熟（林下重新开始）和老生长。 将进行地上和地下采样，以提供间隙平均值的估计，包括根生物量（分为树木、灌木和草本植物部分）、根区以下的氮浸出、土壤温度和湿度、光照水平测定、灌木和草本生物量、种子发芽和高级再生监测。 在老林中，将对地上和地下资源（加上净氮矿化）和植物生物量进行更密集的采样，不仅提供间隙平均值的估计，而且提供间隙内空间模式的估计。 此外，将在老林中进行挖沟实验，以测试地上和地下资源对树木建立和生长的相对重要性，并开发植物对资源响应的预测模型。 三机构项目团队非常优秀。 研究地点和设施都是一流的。 结果对于森林生态学的基本理解和森林资源管理都应该很重要。