{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2025,8,28]],"date-time":"2025-08-28T06:10:08Z","timestamp":1756361408478,"version":"3.44.0"},"reference-count":40,"publisher":"Wiley","issue":"7","license":[{"start":{"date-parts":[[2025,7,9]],"date-time":"2025-07-09T00:00:00Z","timestamp":1752019200000},"content-version":"vor","delay-in-days":8,"URL":"http:\/\/onlinelibrary.wiley.com\/termsAndConditions#vor"}],"funder":[{"DOI":"10.13039\/501100010681","name":"Research Institute for Humanity and Nature","doi-asserted-by":"publisher","award":["RIHN14200156"],"award-info":[{"award-number":["RIHN14200156"]}],"id":[{"id":"10.13039\/501100010681","id-type":"DOI","asserted-by":"publisher"}]}],"content-domain":{"domain":["onlinelibrary.wiley.com"],"crossmark-restriction":true},"short-container-title":["Water Environment Research"],"published-print":{"date-parts":[[2025,7]]},"abstract":"<jats:title>ABSTRACT<\/jats:title><jats:p>This study investigated the environmental determinants of nitrate (NO<jats:sub>3<\/jats:sub><jats:sup>\u2212<\/jats:sup>) concentrations from undisturbed mountain streams in the southern part of Kyushu Main Island, Japan. Four hundred twenty\u2010seven water samples were collected between April 2021 and December 2022 under the baseflow condition. Random Forest (RF) regression model was used to identify the important environmental factors affecting stream NO<jats:sub>3<\/jats:sub><jats:sup>\u2212<\/jats:sup> concentrations. The RF result revealed that annual precipitation is the most significant determinant, negatively correlation with NO<jats:sub>3<\/jats:sub><jats:sup>\u2212<\/jats:sup> concentrations. This suggests that higher precipitation enhances NO<jats:sub>3<\/jats:sub><jats:sup>\u2212<\/jats:sup> flushing from forest soils, reducing NO<jats:sub>3<\/jats:sub><jats:sup>\u2212<\/jats:sup> availability during subsequent baseflow periods. In contrast, temperature was positively correlated, indicating that higher temperature may increase nitrogen mineralization and nitrification rates, leading to more NO<jats:sub>3<\/jats:sub><jats:sup>\u2212<\/jats:sup> leaching. Atmospheric nitrogen (N) depositions derived from agricultural emissions and fuel combustions are also significantly influenced stream NO<jats:sub>3<\/jats:sub><jats:sup>\u2212<\/jats:sup>. Stream NO<jats:sub>3<\/jats:sub><jats:sup>\u2212<\/jats:sup> concentrations tended to increase when total annual N deposition exceeded approximately 12\u2009kg\u2009N\u2009ha<jats:sup>\u22121<\/jats:sup>\u2009year<jats:sup>\u22121<\/jats:sup>. These findings highlight the importance of climatic variables, particularly precipitation and temperature, and N depositions in determining stream NO<jats:sub>3<\/jats:sub><jats:sup>\u2212<\/jats:sup> concentrations in the wider area, providing a valuable framework for predicting and mitigating N pollution in similar ecosystems globally.<\/jats:p>","DOI":"10.1002\/wer.70131","type":"journal-article","created":{"date-parts":[[2025,7,9]],"date-time":"2025-07-09T14:38:40Z","timestamp":1752071920000},"update-policy":"https:\/\/doi.org\/10.1002\/crossmark_policy","source":"Crossref","is-referenced-by-count":0,"title":["Environmental Determinants of Stream Nitrate Concentrations During Baseflow Conditions in Undisturbed Mountain Streams of Southern Parts of Kyushu, Japan"],"prefix":"10.1002","volume":"97","author":[{"ORCID":"https:\/\/orcid.org\/0009-0000-1884-7275","authenticated-orcid":false,"given":"Nay\u00a0Lin","family":"Maung","sequence":"first","affiliation":[{"name":"Kyoto University  Kyoto Kyoto Japan"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Naoko","family":"Tokuchi","sequence":"additional","affiliation":[{"name":"Kyoto University  Kyoto Kyoto Japan"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Yukio","family":"Komai","sequence":"additional","affiliation":[{"name":"Kyoto University  Kyoto Kyoto Japan"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"ORCID":"https:\/\/orcid.org\/0000-0002-5148-1436","authenticated-orcid":false,"given":"Soyoka","family":"Makino","sequence":"additional","affiliation":[{"name":"Fukui Prefectural University  Awara Fukui Japan"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Hikari","family":"Shimadera","sequence":"additional","affiliation":[{"name":"The University of Osaka  Suita Osaka Japan"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Satoru","family":"Chatani","sequence":"additional","affiliation":[{"name":"National Institute for Environmental Studies  Tsukuba Ibaraki Japan"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Kazuya","family":"Nishina","sequence":"additional","affiliation":[{"name":"National Institute for Environmental Studies  Tsukuba Ibaraki Japan"}],"role":[{"role":"author","vocabulary":"crossref"}]}],"member":"311","published-online":{"date-parts":[[2025,7,9]]},"reference":[{"key":"e_1_2_9_2_1","doi-asserted-by":"publisher","DOI":"10.1080\/02626667909491834"},{"key":"e_1_2_9_3_1","doi-asserted-by":"publisher","DOI":"10.1023\/A:1010933404324"},{"key":"e_1_2_9_4_1","doi-asserted-by":"publisher","DOI":"10.1115\/1.2128636"},{"key":"e_1_2_9_5_1","doi-asserted-by":"publisher","DOI":"10.1007\/s44273\u2010025\u201000052\u20105"},{"key":"e_1_2_9_6_1","doi-asserted-by":"publisher","DOI":"10.1016\/j.envpol.2018.10.054"},{"key":"e_1_2_9_7_1","doi-asserted-by":"publisher","DOI":"10.1016\/j.envpol.2021.117634"},{"key":"e_1_2_9_8_1","doi-asserted-by":"publisher","DOI":"10.1029\/2009JG000944"},{"key":"e_1_2_9_9_1","doi-asserted-by":"publisher","DOI":"10.1029\/98WR01924"},{"key":"e_1_2_9_10_1","doi-asserted-by":"publisher","DOI":"10.1016\/0378\u20101127(94)06092\u2010W"},{"key":"e_1_2_9_11_1","doi-asserted-by":"publisher","DOI":"10.1029\/2004GL020477"},{"key":"e_1_2_9_12_1","doi-asserted-by":"publisher","DOI":"10.1016\/j.atmosenv.2016.08.034"},{"issue":"1","key":"e_1_2_9_13_1","first-page":"31","article-title":"Trends in EU Nitrogen Deposition and Impacts on Ecosystems","volume":"65","author":"Erisman J. 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