Collaborative Research: Hydrologic-Nutrient Cycle Interaction in Small Undisturbed and Man-Manipulated Ecosystems

这项研究将继续调查空气-土地-植物- 在加积和扰动的北方水-人相互作用 阔叶林生态系统 从历史上看，哈伯德布鲁克 生态系统研究结合了生态系统的长期调查 地球化学和森林生长的详细实验， 包括实验室和小区级研究，整个生态系统 操作，以及开发和应用 计算机模型。 降水输入、生态系统研究 水塘及溪涧的流量将会继续。 这一长期 生物地球化学研究将与正在进行的 拟议的通过开发质子 元素周期相互作用的预算和分析。 地块级别 使用（NH 4）2SO 4、H2SO 4、Na 2SO 4和CaSO 4的化学操作 将研究现代的， 在氢离子、硫、氮和金属阳离子循环中。 哈伯德溪北方阔叶林生态系统研究 是一个多调查员/多机构的努力。 大多数工作 将在新罕布什尔州的哈伯德布鲁克实验森林进行， 然而，要研究的概念和过程通常是 适用于多种生态系统。 这项研究将作为 在过去，有助于从根本上理解 森林生态系统和产量的有用信息 管理其宝贵的自然资源。 该项目团队是优秀的，包括证明合作 表演者 美国农业部和林业局的合作是非常积极的。 机构的住宿条件是一流的。 生态系统研究计划自信地建议， 连续四年获奖。

This research will continue investigations of air-land-plant- water-human interactions in aggrading and disturbed northern hardwood forest ecosystems. Historically, the Hubbard Brook Ecosystem Study has coupled long-term investigation of ecosystem biogeochemistry and forest growth with detailed experimentation, including laboratory and plot-level studies, whole ecosystem manipulations, as well as the development and application of computer models. Studies of precipitation inputs, ecosystem pools and stream outflow will be continued. This long-term biogeochemical research will be integrated with ongoing and proposed process-level studies through the development of proton budgets and analysis of element cycle interactions. Plot-level chemical manipulations using (NH4)2SO4, H2SO4, Na2SO4 and CaSO4 will investigate present-day, anthropogenically-induced changes in hydrogen ion, sulfur, nitrogen and metallic cation cycles. Research on northern hardwood forest ecosystems at Hubbard Brook is a multi-investigator-/multi-institutional effort. Most work will be conducted at the Hubbard Brook Experimental Forest, NH, yet the concepts and processes to be investigated are generally applicable to many types of ecosystems. This research will, as in the past, contribute to the fundamental understanding of forest ecosystems and yield information useful to the better management of their valuable natural resources. The project team is excellent and comprises proven collaborative performers. USDA/Forest Service collaboration is quite positive. Institutional accommodations are first-rate. The Ecosystem Studies Program confidently recommends that this collaborative, four-year continuing award be made.