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 (NO_x) 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 (SO₄²⁻) flux by TF + SF peaked in 2006/2007 and decreased thereafter, which likely reflected the S emission trends. Accordingly, SO₄²⁻ concentrations in SW at KJK decreased with increasing alkalinity. Similar decreases in SO₄²⁻ 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 (NO₃⁻) concentration in the SW at KJK has also been continuously increasing. N deposition and other factors, such as the maturation of the planted trees, may play an important role in NO₃⁻ leaching in plantations.

自1980年代以来，由于冬季西北风，日本受到亚洲大陆跨界空气污染的影响。但是，在2006年和2011/2012年达到峰值之后，二氧化硫（SO ₂）和氮氧化物（NO _x）的排放量分别开始减少。为了评估森林生态系统对大气沉积物变化的生物地球化学反应，在Kajikawa的日本雪松人工林中进行了森林冠层外部雨量（RF），穿透和茎流（TF + SF）以及溪流水（SW）化学的通量观测。 （KJK）在日本中部的日本海海岸。在观测期间（2002-2018年），KJK的RF和TF + SF引起的S和N通量显着下降。非海盐硫酸盐（SO ₄ ^2-）TF + SF的通量在2006/2007年达到峰值，此后下降，这很可能反映了S排放趋势。因此，随着碱度的升高，钾盐钾在西南地区的SO ₄ ^2-浓度降低。SO ₄ ^2-的下降相似从2006年，2007年和2008年开始，在日本的八个监测湖中观测到了高浓度水。因此，KJK以及日本湖泊的SW化学对大气中S沉积物的减少很敏感。但是，最近，KJK的净S出口一直在增加，2014/2015年和2017/2018年的预算差异很大。硫同位素分析表明，从大气中沉积出来的硫在逐步排放到西南部之前，一直在森林中保留/循环。因此，由于内部周期和前几年的剩余影响而导致的产出反应略微减弱，可能导致S预算差异。硝酸盐（NO ₃ ^-）在KJK的西南部集中度也在不断提高。N沉降和其他因素，如种植的树木的成熟，可以以NO发挥重要的作用₃ ^-在种植园浸出。