Chemistry of Dissolved Organic Carbon at Bear Brook Watershed, Maine: Stream Water Response to (NH4)2SO4 Additions
Chemistry of Dissolved Organic Carbon at Bear Brook Watershed, Maine: Stream Water Response to (NH4)2SO4 Additions
复制标题
缅因州 Bear Brook 流域溶解有机碳的化学性质：溪流水对 (NH4)2SO4 添加的响应
DOI：
10.1023/a:1006150525494
复制
发表时间：
1999
影响因子：
3
通讯作者：
J. Kahl
中科院分区：
文献类型：
--
作者：
M. David;G. Vance;J. Kahl
本研究的目的是确定流水DOC和有机酸的反应，以增加硫酸铵的输入到整个流域。降水，穿透，土壤溶液（从灰壤）和流沃茨的DOC浓度和馏分（疏水性酸和中性，亲水性酸，碱，和中性）的控制（东熊）和治疗（西熊）集水区的熊溪流域，缅因州（BBWM），北方硬木林。在除降水外的所有溶液中，DOC主要由有机酸组成，疏水性酸在森林地面淋滤液（5000 μmol C L-1）中占主导地位（> 60%），在深层B层和溪流沃茨（约150 μmol C L-1）中占平衡。流沃茨有较高浓度的DOC在风暴或融雪事件（高流量），往往达到300至400 μmol C L-1。森林地面渗滤液C迅速衰减的矿质土壤在所有的流量条件下，表明如何重要的矿质土壤吸附DOC是减少C通过地表水从BBWM的损失。由于1989年至1994年的治疗，控制和治疗流DOC的浓度或组成之间没有差异。1995年，西熊溪的DOC浓度首次低于东熊溪。然而，这发生在一个创纪录的低径流年，表明水文可能影响了C。DOC从集水区的年均出口量相似（1000至2000摩尔C公顷-1年-1）。在高流量事件期间，河水中的有机阴离子略有增加（例如，1995年，East Bear在基流和高排放期间的有机阴离子平均值为15和19 μeq L-1）。西熊的治疗导致有机阴离子的减少，无论是在浓度和贡献的整体阴离子组合物（有机阴离子在高放电作为总阴离子的百分比下降，从约8%至4%，1987-89年和1993-95年的样本，分别）。这可能是由于溶液pH值降低（有机物的质子化程度更高）和无机阴离子浓度更高。总体而言，有没有明确的，可检测到的变化，在流水DOC，有机阴离子只有轻微的变化，作为与硫酸铵处理的结果。
This study was conducted to determine the response of stream water DOC and organic acidity to increased inputs of ammonium sulfate to a whole catchment. Precipitation, throughfall, soil solutions (from Spodosols) and stream waters were characterized for DOC concentrations and fractions (hydrophobic acids and neutrals, hydrophilic acids, bases, and neutrals) in both the control (East Bear) and the treatment (West Bear) catchments of Bear Brook Watershed, Maine (BBWM), a northern hardwood forest. In all solutions except precipitation, DOC was composed primarily of organic acids, with hydrophobic acids dominating (> 60% of DOC) in forest floor leachates (5000 μmol C L-1), and a balance of hydrophobic and hydrophilic acids in deep B horizons and stream waters (∼ 150 μmol C L-1). Stream waters had higher concentrations of DOC during storm or snowmelt events (high discharge), often reaching 300 to 400 μmol C L-1. Forest floor leachate C was rapidly attenuated by the mineral soils under all flow conditions, indicating how important mineral soil sorption of DOC was in reducing the loss of C via surface water from BBWM. No differences occurred between control and treatment streams for concentration or composition of DOC due to treatment from 1989 through 1994. In 1995, West Bear Brook had much lower concentrations of DOC than East Bear for the first time. However, this occurred during a year of record low runoff, suggesting that hydrology may have affected export of C. Average annual export of DOC from the catchments was similar (1000 to 2000 mol C ha-1 yr-1). Organic anions in streamwaters increased slightly during high flow events (e.g., East Bear had means of 15 and 19 μeq L-1 organic anions during base flow and high discharge in 1995). Treatment of West Bear caused a decrease in organic anions, both in concentration and contribution to overall anion composition (organic anions during high discharge as a percentage of total anions decreased from about 8 to 4% for 1987-89 and 1993-95 samples, respectively). This was probably due to decreased solution pH (greater protonation of organics) and higher concentrations of inorganic anions. Overall, there were no clear, detectable changes in stream water DOC, with only minor changes in organic anions, as a result of treatment with ammonium sulfate.