Yucang Wang , Hao Wu , Zheqi Pan , Longdan Ma , Yu Zhang , Jia Zhou , Minpeng Hu , Zhihan Cheng , Xin Zheng , Dingjiang Chen
{"title":"中国东部典型流域土地利用与景观格局对遗留氮污染的影响","authors":"Yucang Wang , Hao Wu , Zheqi Pan , Longdan Ma , Yu Zhang , Jia Zhou , Minpeng Hu , Zhihan Cheng , Xin Zheng , Dingjiang Chen","doi":"10.1016/j.catena.2025.109129","DOIUrl":null,"url":null,"abstract":"<div><div>Legacy effects from nonpoint source nutrient pollution reduce the effectiveness of nitrogen remediation strategies in watersheds, yet spatial landscape variations and their influence on the legacy effects remain unclear. This study addressed spatial differences in legacy nitrogen pollution within the Yongan watershed in eastern China using detrended fluctuation analysis (where H > 0.5 indicates a legacy effect). Results revealed strong legacy effects for total nitrogen (TN) and nitrate nitrogen (NO<sub>3</sub><sup>–</sup>-N) at the watershed outlet, with H values of 0.70 and 0.87, respectively, primarily influenced by soil nitrogen contributions (40 ± 8 %), as revealed by isotopic source apportionment. Significant spatial variation in the legacy effect was observed across different catchments, with H-index ranging from 0.42 to 0.85 for TN and from 0.58 to 0.91 for NO<sub>3</sub><sup>–</sup>-N. Land use explained 90 % of this variation, predominantly driven by<!--> <!-->grasslands (48 %), impervious surfaces (16 %), and orchards (14 %). Grasslands were found to reduce legacy effects by reducing nitrogen inputs from soil and groundwater, whereas impervious surfaces reduced the legacy effect by increasing domestic wastewater contributions. Conversely, agricultural lands (orchards, paddy fields and drylands) exacerbated the legacy effect through elevated soil nitrogen contributions. Threshold values for key landscape metrics were identified that effectively mitigated the legacy effect: increasing grassland edge density (ED) to 0.16 km/km<sup>2</sup>, orchard connectivity (CONNECT) to 32 %, and impervious surface aggregation (AI) to 91 %. The integration of stable isotopes and landscape data provides a robust framework for identifying dominant nitrogen sources and uncovering the spatial mechanisms underlying legacy pollution. These findings can guide landscape management strategies and support targeted interventions for nonpoint source nitrogen control at the watershed scale.</div></div>","PeriodicalId":9801,"journal":{"name":"Catena","volume":"256 ","pages":"Article 109129"},"PeriodicalIF":5.4000,"publicationDate":"2025-05-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":"0","resultStr":"{\"title\":\"Influence of land use and landscape pattern on legacy nitrogen pollution in a typical watershed in eastern China\",\"authors\":\"Yucang Wang , Hao Wu , Zheqi Pan , Longdan Ma , Yu Zhang , Jia Zhou , Minpeng Hu , Zhihan Cheng , Xin Zheng , Dingjiang Chen\",\"doi\":\"10.1016/j.catena.2025.109129\",\"DOIUrl\":null,\"url\":null,\"abstract\":\"<div><div>Legacy effects from nonpoint source nutrient pollution reduce the effectiveness of nitrogen remediation strategies in watersheds, yet spatial landscape variations and their influence on the legacy effects remain unclear. This study addressed spatial differences in legacy nitrogen pollution within the Yongan watershed in eastern China using detrended fluctuation analysis (where H > 0.5 indicates a legacy effect). Results revealed strong legacy effects for total nitrogen (TN) and nitrate nitrogen (NO<sub>3</sub><sup>–</sup>-N) at the watershed outlet, with H values of 0.70 and 0.87, respectively, primarily influenced by soil nitrogen contributions (40 ± 8 %), as revealed by isotopic source apportionment. Significant spatial variation in the legacy effect was observed across different catchments, with H-index ranging from 0.42 to 0.85 for TN and from 0.58 to 0.91 for NO<sub>3</sub><sup>–</sup>-N. Land use explained 90 % of this variation, predominantly driven by<!--> <!-->grasslands (48 %), impervious surfaces (16 %), and orchards (14 %). Grasslands were found to reduce legacy effects by reducing nitrogen inputs from soil and groundwater, whereas impervious surfaces reduced the legacy effect by increasing domestic wastewater contributions. Conversely, agricultural lands (orchards, paddy fields and drylands) exacerbated the legacy effect through elevated soil nitrogen contributions. Threshold values for key landscape metrics were identified that effectively mitigated the legacy effect: increasing grassland edge density (ED) to 0.16 km/km<sup>2</sup>, orchard connectivity (CONNECT) to 32 %, and impervious surface aggregation (AI) to 91 %. The integration of stable isotopes and landscape data provides a robust framework for identifying dominant nitrogen sources and uncovering the spatial mechanisms underlying legacy pollution. These findings can guide landscape management strategies and support targeted interventions for nonpoint source nitrogen control at the watershed scale.</div></div>\",\"PeriodicalId\":9801,\"journal\":{\"name\":\"Catena\",\"volume\":\"256 \",\"pages\":\"Article 109129\"},\"PeriodicalIF\":5.4000,\"publicationDate\":\"2025-05-08\",\"publicationTypes\":\"Journal Article\",\"fieldsOfStudy\":null,\"isOpenAccess\":false,\"openAccessPdf\":\"\",\"citationCount\":\"0\",\"resultStr\":null,\"platform\":\"Semanticscholar\",\"paperid\":null,\"PeriodicalName\":\"Catena\",\"FirstCategoryId\":\"97\",\"ListUrlMain\":\"https://www.sciencedirect.com/science/article/pii/S034181622500431X\",\"RegionNum\":1,\"RegionCategory\":\"农林科学\",\"ArticlePicture\":[],\"TitleCN\":null,\"AbstractTextCN\":null,\"PMCID\":null,\"EPubDate\":\"\",\"PubModel\":\"\",\"JCR\":\"Q1\",\"JCRName\":\"GEOSCIENCES, MULTIDISCIPLINARY\",\"Score\":null,\"Total\":0}","platform":"Semanticscholar","paperid":null,"PeriodicalName":"Catena","FirstCategoryId":"97","ListUrlMain":"https://www.sciencedirect.com/science/article/pii/S034181622500431X","RegionNum":1,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":null,"EPubDate":"","PubModel":"","JCR":"Q1","JCRName":"GEOSCIENCES, MULTIDISCIPLINARY","Score":null,"Total":0}
Influence of land use and landscape pattern on legacy nitrogen pollution in a typical watershed in eastern China
Legacy effects from nonpoint source nutrient pollution reduce the effectiveness of nitrogen remediation strategies in watersheds, yet spatial landscape variations and their influence on the legacy effects remain unclear. This study addressed spatial differences in legacy nitrogen pollution within the Yongan watershed in eastern China using detrended fluctuation analysis (where H > 0.5 indicates a legacy effect). Results revealed strong legacy effects for total nitrogen (TN) and nitrate nitrogen (NO3–-N) at the watershed outlet, with H values of 0.70 and 0.87, respectively, primarily influenced by soil nitrogen contributions (40 ± 8 %), as revealed by isotopic source apportionment. Significant spatial variation in the legacy effect was observed across different catchments, with H-index ranging from 0.42 to 0.85 for TN and from 0.58 to 0.91 for NO3–-N. Land use explained 90 % of this variation, predominantly driven by grasslands (48 %), impervious surfaces (16 %), and orchards (14 %). Grasslands were found to reduce legacy effects by reducing nitrogen inputs from soil and groundwater, whereas impervious surfaces reduced the legacy effect by increasing domestic wastewater contributions. Conversely, agricultural lands (orchards, paddy fields and drylands) exacerbated the legacy effect through elevated soil nitrogen contributions. Threshold values for key landscape metrics were identified that effectively mitigated the legacy effect: increasing grassland edge density (ED) to 0.16 km/km2, orchard connectivity (CONNECT) to 32 %, and impervious surface aggregation (AI) to 91 %. The integration of stable isotopes and landscape data provides a robust framework for identifying dominant nitrogen sources and uncovering the spatial mechanisms underlying legacy pollution. These findings can guide landscape management strategies and support targeted interventions for nonpoint source nitrogen control at the watershed scale.
期刊介绍:
Catena publishes papers describing original field and laboratory investigations and reviews on geoecology and landscape evolution with emphasis on interdisciplinary aspects of soil science, hydrology and geomorphology. It aims to disseminate new knowledge and foster better understanding of the physical environment, of evolutionary sequences that have resulted in past and current landscapes, and of the natural processes that are likely to determine the fate of our terrestrial environment.
Papers within any one of the above topics are welcome provided they are of sufficiently wide interest and relevance.