Estimation of dry deposition and canopy exchange in Chinese fir plantations
Estimation of dry deposition and canopy exchange in Chinese fir plantations
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DOI：
10.1016/s0378-1127(00)00469-2
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发表时间：
2001-06-30
影响因子：
3.7
通讯作者：
Hong, W
中科院分区：
文献类型：
--
作者：
Fan, HB;Hong, W
基于三年的事件降水、径流和茎流化学监测数据，对中国南平郊区距离污染源不同距离的两处杉木人工林的净径流通量（NTF）进行了分析，以评估干沉降和冠层交换的相对重要性。 NTF 分析显示冠层对降雨化学的影响一致，H+、K+、Na+、Ca2+、Mg2+ 和 SO42- 通过树叶添加到降雨中，而 NH4+ 和 NO3- 离子则从降水中吸收。单事件数据的回归分析表明，冠层交换（浸出和吸收）是控制大多数溶质 NTF 的主要过程。然而，干沉降对两个地点的 Na+ 和 Ca2+ 以及靠近排放源的 XQF 地点的 SO42- 和 NO3- 的 NTF 贡献显着。沉淀酸度增加导致Ca2+浸出增加。降水中NH4+浓度对其在冠层中的保留具有显着的正向影响，表明冠层对NH4-的吸收是一个活跃的过程。冠层对氮素的吸收受林龄的强烈控制，在快速生长期（16年生）的FFC站点，冠层年吸收氮量为2.97 kg ha(-1)，而XQF成熟林分（41年生）的年吸收量仅为0.56 kg ha(-1)。 (C) 2001 Elsevier Science B.V. 保留所有权利。
Based on the data from three years of chemical monitoring for incident precipitation, throughfall and stemflow, the net throughfall flux (NTF) was analyzed to evaluate the relative importance of dry deposition and canopy exchange in two Chinese fir (Cunninghamia lanceolata) plantations with different distances from the pollution sources in the suburbs of Nanping, China. NTF analysis showed consistent canopy effects on rainfall chemistry, with H+, K+, Na+, Ca2+, Mg2+ and SO42- added to rainfall by foliage, whereas NH4+ and NO3- ions were absorbed from precipitation. Regression analysis of single-event data showed that canopy exchange (leaching and uptake) was a dominant process in controlling NTF for most solutes. However, dry deposition contributed significantly to NTF for Na+ and Ca2+ at the two sites, and for SO42- and NO3- at XQF site close to emission sources. increased precipitation acidity caused increased leaching of Ca2+. NH4+ concentration in precipitation had a significant positive effect on the retention of it in the canopy, suggesting that uptake of NH4- by canopy is an active process. The uptake of nitrogen by canopy is strongly controlled by the stand ages, with annual uptake of 2.97 kg ha(-1) at FFC site where the stand is in the fast-growing stage (16-year old), but only 0.56 kg ha(-1) in the mature stand (41-year old) at XQF. (C) 2001 Elsevier Science B.V. All rights reserved.