Atmospheric deposition of nitrogen and sulfur and preferential canopy consumption of nitrate in forests of the Pacific Northwest, USA
Atmospheric deposition of nitrogen and sulfur and preferential canopy consumption of nitrate in forests of the Pacific Northwest, USA
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DOI：
10.1016/j.foreco.2013.03.042
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发表时间：
2013-08-15
影响因子：
3.7
通讯作者：
Lofgren, Rebecca A.
中科院分区：
文献类型：
--
作者：
Fenn, Mark E.;Ross, Christopher S.;Lofgren, Rebecca A.
在华盛顿州的三个国家公园：奥林匹克公园、雷尼尔山公园和北喀斯喀特山公园，对N和S的湿、干和穿透降水沉降进行了为期2年的测量。使用离子交换树脂（IER）收集器测量压降。这项研究的一个主要目标是评估IER穿透降雨测量的有效性，以监测国家公园和其他保护区森林的沉积输入，包括云水沉积。三个公园无机氮的湿沉降（0.9-2.0 kg N ha（-1）yr（-1））和穿透雨（0.5-1.2 kg N ha（-1）yr（-1））沉降量相对较低。硫的湿沉降（1.0-3.2 kg ha（-1）yr（-1））与无机氮的湿沉降相似，但在OLYM，由于SO 4-S的海洋来源，硫的湿沉降高于氮。秋季氮沉降低于湿沉降的N，因为强大的优惠冠层消耗的硝酸盐（NO3-N），特别是在潮湿的冬季期间。这一现象以前曾在该区域的森林中报告过，但其在该区域几乎普遍存在的现象尚未得到承认。本文给出了西北太平洋38个林分的NO_3-N优先林冠滞留量数据，其中21个是新报道的数据。NO3-N在莫拉和NOCA的穿透雨的沉积减少了87%和93%相比，湿沉降在2年。与此相反，湿沉降的NH 4-N一般增加通过冠层。这种强有力的优惠冠层保留湿沉积NO3-N限制了穿透雨测量的有用性，作为一个N沉积监测方法在森林中的太平洋西北地区的北美和其他一些地区的低至中度N沉积。作为一个潜在的补救措施，这一限制，提出了一个简单的方法来估计总氮沉降在研究地点的湿沉降和穿透S沉降的S/N比的基础上。由爱思唯尔公司出版
Wet, dry and throughfall deposition of N and S were measured for 2 years in three national parks in Washington State: Olympic, Mount Rainier, and North Cascades. Throughfall was measured using ion exchange resin (IER) collectors. A major objective of the study was to evaluate the effectiveness of IER throughfall measurements for monitoring deposition inputs, including cloudwater deposition, to forest stands in national parks and other protected areas. Wet deposition (0.9-2.0 kg N ha(-1) yr(-1)) and through-fall (0.5-1.2 kg N ha(-1) yr(-1)) deposition of inorganic N in the three parks were relatively low. Wet deposition of sulfur (1.0-3.2 kg ha(-1) yr(-1)) was similar to wet deposition of inorganic nitrogen except at OLYM where wet deposition of S was higher than for N because of marine sources of SO4-S. Throughfall N deposition was lower than wet deposition of N because of strong preferential canopy consumption of nitrate (NO3-N), particularly during the wet winter periods. This phenomenon was previously reported for forests in this region, but its apparent near ubiquity in the region had not been recognized. Data on preferential canopy retention of NO3-N from wet-deposited N is shown for 38 stands in the Pacific Northwest of which 21 are newly-reported data. Deposition of NO3-N in throughfall at MORA and NOCA was reduced by 87% and 93% compared to wet deposition over the 2 years. In contrast, wet deposition of NH4-N was generally increased by passage through the canopy. This strong preferential canopy retention of wet-deposited NO3-N limits the usefulness of throughfall measurements as a N deposition monitoring approach in forests of the Pacific Northwest region of North America and in some other regions with low to moderate N deposition. As a potential remedy to this limitation, a simple method is proposed for estimating total N deposition in the study sites based on S/N ratios in wet deposition and throughfall S deposition. Published by Elsevier B.V.