Process-level Investigations of Weathering Inputs to Base-poor Forest Ecosystems

在许多森林生态系统中，Ca和其他元素的释放速率 通过化学风化作用吸收的矿物质养分远远超过 从大气中输入的速率。 因此，风化是 河水中无机营养盐流失的主要机制 浸出或从森林采伐被取代。 最近的研究 已经将注意力集中在Ca和其他碱性阳离子的作用上 (CB)淡水酸化，生态系统恢复， 酸化、长期森林生产力、鱼类死亡率和 山地森林中红云杉的减少。 我们可怜 了解风化释放的机制和速率 CB限制了我们批判性地评估观察到的和 预测元素周期的变化。 本研究旨在 确定两个基地的风化机制和速率- 新罕布什尔州的贫瘠森林流域。 该项目乃设计 为了研究单个矿物的风化作用， 轮廓和分水岭。 几种估算方法 风化率将被使用和比较，包括地球化学 物质平衡，矿物耗竭估计，流域要素 Sr同位素分析。 通过评估 单矿物对流域风化作用的贡献 研究土壤中的风化模式 我们预测CB循环和森林变化的能力 未来大气条件下的生产力将是 提高

In many forest ecosystems, the rate of release of Ca and other mineral nutrients through chemical weathering far exceeds the rate of input from the atmosphere. Thus, weathering is the primary mechanism by which mineral nutrient losses in streamwater leaching or from forest harvesting are replaced. Recent research has focused attention on the role of Ca and other basic cations (CB) in the acidification of freshwaters, ecosystem recovery from acidification, long-term forest productivity, fish mortality and the decline of red spruce in montane forests. Our poor understanding of the mechanisms and rates of weathering release of CB limits our ability to critically evaluate observed and predicted changes in element cycles. This study is aimed at determining the mechanisms and rates of weathering in two base- poor forest watersheds in New Hampshire. The project is designed to study weathering on the scale of individual minerals, the soil profile and the watershed. Several methods of estimating weathering rates will be used and compared, including geochemical mass balances, mineral depletion estimates, watershed element balances and Sr isotope analysis. By evaluating the contributions of individual minerals to watershed weathering rates and studying the patterns of weathering within the soil profile, our ability to predict changes in CB cycling and forest productivity under future atmospheric conditions will be improved.