LTREB: Collaborative Research: Hydrologic-nutrient Cycle Interaction in Small, Undisturbed and Human-manipulated Ecosystems

在这个合作项目中， 生态系统研究和锡拉丘兹大学将继续长期 哈伯德布鲁克实验森林的地球化学研究 （HBEF）在新罕布什尔州评估大气中的趋势 沉积、河水化学和关键营养物的循环 元素 在过去的三十年里， 大气沉降，河流水化学，植被生物量 和土壤化学进行了观察在HBEF。 这些变化 对管理基础薄弱地区的生态影响 森林生态系统，这是遍布各地的 特别是美国东北部， 盐基阳离子增加了森林的敏感性， 水生生态系统持续高输入的酸性沉积物， 以及森林管理做法，例如 皆伐 无论是大气输入的减少， 观测到的森林地面盐基阳离子浓度下降 在此期间，根据现有的知识或 森林生态系统养分循环模型。 值得注意的是， 人为酸化后的恢复模式 表明酸化可能不是一个完全可逆的过程。 %%% 长期致力于生物化学的合成和整合 哈伯德布鲁克的信息将继续。 结果从这个 研究将提高对地球化学通量的认识 美国东北部的森林生态系统中的循环。 此外，长期记录的延续， 哈伯德的降水、河水和土壤水化学 布鲁克将提供一个基础，解释的影响， 改变大气沉降对地球化学过程的影响 陆地和相关的水生生态系统。

In this collaborative project scientists at the Institute of Ecosystem Studies and Syracuse University will continue long-term biogeochemical studies at the Hubbard Brook Experimental Forest (HBEF) in New Hampshire to evaluate trends in atmospheric deposition, streamwater chemistry and cycling of critical nutrient elements. During the past three decades, dramatic changes in atmospheric deposition, streamwater chemistry, vegetation biomass and soil chemistry were observed at the HBEF. These changes have important ecological implications for the management of base-poor forest ecosystems, which are widespread throughout the northeastern U.S. In particular, a decline in atmospheric inputs of base cations has increased the sensitivity of forest and aquatic ecosystems to continuing high inputs of acidic deposition, as well as to forest management practices, such as harvest by clearcutting. Neither the decline in atmospheric inputs nor declines in forest floor concentrations of base cations observed during this period were predicted from existing knowledge or from models of nutrient cycling for forest ecosystems. Significantly, the pattern of recovery following anthropogenic acidification suggests that acidification may not be a fully reversible process. %%% Long-term efforts at synthesis and integration of biogeochemical information at Hubbard Brook will be continued. Results from this research will improve the understanding of biogeochemical flux and cycling in forest ecosystems of the northeastern U.S. In addition, the continuation of the long-term record of precipitation, streamwater and soilwater chemistry at Hubbard Brook will provide a basis for interpreting the effects of changing atmospheric deposition on biogeochemical processes in terrestrial and associated aquatic ecosystems.