Comparing decadal responses of whole-watershed manipulations at the Bear Brook and Fernow experiments
Comparing decadal responses of whole-watershed manipulations at the Bear Brook and Fernow experiments
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DOI：
10.1007/s10661-010-1524-2
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发表时间：
2010-12-01
影响因子：
3
通讯作者：
Norton, Stephen A.
中科院分区：
文献类型：
--
作者：
Fernandez, Ivan J.;Adams, Mary Beth;Norton, Stephen A.
美国缅因州的熊溪流域和美国西弗吉尼亚州的费诺实验森林代表了独特的、长期的、成对的、整个流域的实验操作，重点是氮(N)和硫(S)沉积对温带森林的影响。两个流域的N和S在倒下时开始以(NH(4))(2)SO(4)的形式在全生态系统中增加N，两个流域都进入了处理流域慢性富集期的第三个十年，而参考流域为评估森林流域对恢复的反应提供了独特的机会。BBWM和Fernow在大气沉积、土壤性质和森林组成历史上的差异，都有助于随着时间的推移对河流化学品出口的不同响应轨迹。这四个流域代表了氮的浓缩和保留的光谱，从缅因州参考流域的大约到98%的N保留，到西弗吉尼亚州经过处理的流域大约20%的N保留。尽管有这些差异，但有证据表明，所有四个流域在盐基阳离子淋溶和其他过程中的反应机制是相似的。在这两种情况下，迄今20年的研究和监测历史为生态系统反应提供了新的见解，这在更传统的短期研究中并不明显。
The Bear Brook Watershed in Maine (BBWM), USA, and the Fernow Experimental Forest in West Virginia, USA, represent unique, long-term, paired, whole watershed, experimental manipulations focusing on the effects of nitrogen (N) and sulfur (S) deposition on temperate forests. Both watersheds began whole-ecosystem additions of N and S as (NH(4))(2)SO(4) in the fall of 1989, and both are entering their third decade of chronic enrichment of the treated watersheds, while the reference watersheds offer unique opportunities to evaluate forest watershed responses to recovery. Differences between BBWM and Fernow in the history of atmospheric deposition, soil properties, and forest composition all contribute to different response trajectories in stream chemical exports over time. The four watersheds represent a spectrum of N enrichment and retention, ranging from approximate to 98% N retention in the reference watershed in Maine, to approximate to 20% N retention in the treated watershed in West Virginia. Despite these differences, there is evidence that mechanisms of response in base cation leaching and other processes are similar among all four watersheds. In both cases, the history to date of two decades of research and monitoring has provided new insights into ecosystem response not evident in more traditional short-term research.