Episodic, seasonal, and annual export of atmospheric and microbial nitrate from a temperate forest
Episodic, seasonal, and annual export of atmospheric and microbial nitrate from a temperate forest
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温带森林大气和微生物硝酸盐的间歇性、季节性和年度出口
DOI：
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发表时间：
2016
期刊：
影响因子：
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通讯作者：
K. N. Eshleman
中科院分区：
文献类型：
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作者：
Robert D. Sabo;D. Nelson;K. N. Eshleman
评估大气沉积的硝酸盐和微生物硝酸盐（分别为 NO3-NAtm 和 NO3-NMicro）到达河流的时间和数量仍然很困难。为了阐明 NO3-NAtm 和 NO3-NMicro 的时间变化，我们在两个水年的一系列水文条件下测量了阿巴拉契亚山脉中部森林覆盖的分水岭的一条溪流中的硝酸盐浓度、δ17O-NO3− 和 δ18O-NO3−。根据同位素数据，我们计算了 Δ17O-NO3− 值，该值用于校准统计负荷模型，以估计 NO3-NAtm 和 NO3-NMicro 的输出。水文过程线分离用于估计通过基流和直接径流路径的 NO3-NAtm 和 NO3-NMicro 损失。 NO3-NAtm 贡献了硝酸盐总产量的 7-11%，并且 NO3-NMicro 的季节性模式与之平行。研究期间，水流中 NO3-NAtm 和 NO3-NMicro 的产量主要由基流输送（分别为 61% 和 85%）决定，这表明基流是该流域两种硝酸盐物种的主要损失途径。
It remains difficult to assess the timing and amount of atmospherically deposited and microbial nitrate (NO3‐NAtm and NO3‐NMicro, respectively) reaching streams. To elucidate temporal variation of NO3‐NAtm and NO3‐NMicro, we measured nitrate concentrations, δ17O‐NO3−, and δ18O‐NO3− in a stream draining a gaged, forested watershed in the central Appalachian Mountains throughout a range of hydrological conditions during two water years. From the isotopic data we calculated Δ17O‐NO3− values, which were used to calibrate a statistical load model to estimate export of NO3‐NAtm and NO3‐NMicro. A hydrograph separation was used to estimate loss of NO3‐NAtm and NO3‐NMicro through base flow and direct runoff pathways. NO3‐NAtm contributed 7–11% of the total nitrate yields and paralleled seasonal patterns of NO3‐NMicro. Yields of NO3‐NAtm and NO3‐NMicro in streamflow during the study period were dominated (61 and 85%, respectively) by base flow transport, suggesting that base flow is a major loss pathway for both nitrate species from this watershed.
影响因子：
7.4
作者：
Kaiser, Jan;Hastings, Meredith G.;Sigman, Daniel M.
通讯作者：
Sigman, Daniel M.