Аннотация:Despite the reduction in S and N emissions, acid deposition continues to be a problem for the inland water in Northeast Asia. However, catchment-scale studies on acid deposition in the Asian part of Russia are limited. Based on the long-term data of the Acid Deposition Monitoring Network in East Asia (EANET), we evaluated the effects of acid deposition on the stream water (SW) chemistry in a catchment of the Komarovka River (KMR) located in the Far East of Russia for the period 2005–2019. The SW pH has been decreasing over the last decade, with an increase in acidifying agents, such as SO42– and NO3–. The N/S ratio increased in SW due to a rise in NO3–, which plays a key role in acidification. In contrast, the rainwater pH has been rising at the nearby EANET site. There were transition periods from a decreasing trend to an increasing trend of S and dissolved inorganic nitrogen (DIN) in 2011 and 2014, respectively. Moreover, because of changing precipitation patterns, the contribution of warm season deposition to acidification has increased, which may accelerate the leaching of S and DIN from the forested catchment. The recent increase in S and DIN deposition and increased warm-season precipitation appeared to cause acidification of SW at KMR. The N leaching at KMR was largely influenced by the precipitation patterns, while DIN deposition and forest conditions should be taken into consideration. An interlinkage between air pollution and climate change should be carefully assessed to understand the forested catchment.
