Transboundary air pollution reduction rapidly reflected in stream water chemistry in forested catchment on the sea of Japan coast in central Japan
Transboundary air pollution reduction rapidly reflected in stream water chemistry in forested catchment on the sea of Japan coast in central Japan
复制标题
DOI：
10.1016/j.atmosenv.2021.118223
复制
发表时间：
2021-03
影响因子：
5
通讯作者：
H. Sase;Tatsuyoshi Saito;M. Takahashi;M. Morohashi;N. Yamashita;Y. Inomata;T. Ohizumi;M. Nakata
中科院分区：
文献类型：
--
作者：
H. Sase;Tatsuyoshi Saito;M. Takahashi;M. Morohashi;N. Yamashita;Y. Inomata;T. Ohizumi;M. Nakata
自20世纪80年代以来，由于冬季的西北季节性风，日本一直受到来自亚洲大陆的跨境空气污染的影响。然而，在2006年和2011/2012年达到峰值后，二氧化硫（SO2）和氮氧化物（NOx）的排放量分别开始下降。为了评估森林生态系统对大气沉降变化的生物地球化学响应，在日本中部日本海沿岸的香川（KJK）杉木人工林进行了林冠外降水（RF）、穿透流和茎流（TF+ SF）和溪流水（SW）化学的通量观测。在2002-2018年的观测期内，KJK的RF和TF+ SF对S和N的通量显著降低。非海盐硫酸盐（SO4 2）通量在2006/2007年达到峰值，此后逐渐下降，这可能反映了S排放的趋势。因此，KJK处SW中so42浓度随碱度的增加而降低。从2006年、2007年和2008年开始，日本8个监测湖泊的二氧化硫浓度也出现了类似的下降。因此，KJK和日本湖泊的SW化学对大气S沉降减少非常敏感。然而，最近KJK的净出口一直在增加，在2014/2015年和2017/2018年出现预算差异。硫同位素分析表明，大气中沉积的S在森林中被保留/循环，然后逐渐排放到西南。因此，由于前几年的内部周期和残余影响，产出的反应略有减弱，可能导致预算差异。的硝酸
Since the 1980s, Japan has been affected by transboundary air pollution from the Asian continent due to northwesterly seasonal winds in the winter. However, after peaks in 2006 and 2011/2012, sulfur dioxide (SO2) and nitrogen oxide (NOx) emissions began decreasing, respectively. To assess the biogeochemical response of forest ecosystems to the changing atmospheric deposition, flux observations of rainfall outside forest canopies (RF), throughfall and stemflow (TF+ SF), and stream water (SW) chemistry were conducted in a Japanese cedar plantation in Kajikawa (KJK) on the Sea of Japan coast in central Japan. Fluxes of S and N by RF and TF+ SF at KJK significantly decreased during the observation period (2002–2018). The non-sea salt sulfate (SO4 2) flux by TF+ SF peaked in 2006/2007 and decreased thereafter, which likely reflected the S emission trends. Accordingly, SO4 2 concentrations in SW at KJK decreased with increasing alkalinity. Similar decreases in SO4 2 concentrations beginning in 2006, 2007, and 2008 were observed at eight monitoring lakes in Japan. Thus, the SW chemistry at KJK and possibly that of Japanese lakes were sensitive to atmospheric S deposition reductions. However, as of late, the net S export at KJK has been increasing, exhibiting budget discrepancies in 2014/2015 and 2017/2018. Sulfur isotopic analysis suggested that the S deposited from the atmosphere was retained/cycled in the forest before it was gradually discharged into SW. Thus, a slightly weakened reaction of the output due to the internal cycle and residual effects of previous years may have caused the S budget discrepancies. The nitrate