Assessing riparian zone changes under the influence of stress factors in higher-order streams and tributaries: Implications for the management of massive dams and reservoirs

Muhammad Arif; Zheng Jie; Charles Wokadala; Zhang Songlin; Yuan Zhongxun; Chen Zhangting; Dong Zhi; He Xinrui; Li Changxiao

doi:10.1016/j.scitotenv.2021.146011

Assessing riparian zone changes under the influence of stress factors in higher-order streams and tributaries: Implications for the management of massive dams and reservoirs

Sci Total Environ. 2021 Jul 1:776:146011. doi: 10.1016/j.scitotenv.2021.146011. Epub 2021 Feb 23.

Authors

Muhammad Arif¹, Zheng Jie², Charles Wokadala³, Zhang Songlin⁴, Yuan Zhongxun⁵, Chen Zhangting⁶, Dong Zhi⁷, He Xinrui⁸, Li Changxiao⁹

Affiliations

¹ Key Laboratory of Eco-Environments in the Three Gorges Reservoir Region (Ministry of Education), Chongqing Key Laboratory of Plant Ecology and Resources Research in the Three Gorges Reservoir Region, College of Life Sciences, Southwest University, Chongqing 400715, China; Punjab Forest Department, Government of Punjab, Lahore 54000, Pakistan. Electronic address: muhammadarif@swu.edu.cn.
² Key Laboratory of Eco-Environments in the Three Gorges Reservoir Region (Ministry of Education), Chongqing Key Laboratory of Plant Ecology and Resources Research in the Three Gorges Reservoir Region, College of Life Sciences, Southwest University, Chongqing 400715, China. Electronic address: jiezheng@email.swu.edu.cn.
³ Key Laboratory of Eco-Environments in the Three Gorges Reservoir Region (Ministry of Education), Chongqing Key Laboratory of Plant Ecology and Resources Research in the Three Gorges Reservoir Region, College of Life Sciences, Southwest University, Chongqing 400715, China.
⁴ Key Laboratory of Reservoir Aquatic Environment, Chongqing Institute of Green and Intelligent Technology, Chinese Academy of Sciences, Chongqing 400714, China. Electronic address: zhangsonglin@cigit.ac.cn.
⁵ Key Laboratory of Eco-Environments in the Three Gorges Reservoir Region (Ministry of Education), Chongqing Key Laboratory of Plant Ecology and Resources Research in the Three Gorges Reservoir Region, College of Life Sciences, Southwest University, Chongqing 400715, China. Electronic address: yuanzhongxun@email.swu.edu.cn.
⁶ Key Laboratory of Eco-Environments in the Three Gorges Reservoir Region (Ministry of Education), Chongqing Key Laboratory of Plant Ecology and Resources Research in the Three Gorges Reservoir Region, College of Life Sciences, Southwest University, Chongqing 400715, China. Electronic address: hmilutell@email.swu.edu.cn.
⁷ Key Laboratory of Eco-Environments in the Three Gorges Reservoir Region (Ministry of Education), Chongqing Key Laboratory of Plant Ecology and Resources Research in the Three Gorges Reservoir Region, College of Life Sciences, Southwest University, Chongqing 400715, China. Electronic address: zhidong@email.swu.edu.cn.
⁸ Key Laboratory of Eco-Environments in the Three Gorges Reservoir Region (Ministry of Education), Chongqing Key Laboratory of Plant Ecology and Resources Research in the Three Gorges Reservoir Region, College of Life Sciences, Southwest University, Chongqing 400715, China. Electronic address: hxr2018@email.swu.edu.cn.
⁹ Key Laboratory of Eco-Environments in the Three Gorges Reservoir Region (Ministry of Education), Chongqing Key Laboratory of Plant Ecology and Resources Research in the Three Gorges Reservoir Region, College of Life Sciences, Southwest University, Chongqing 400715, China. Electronic address: lichangx@swu.edu.cn.

PMID: 33647660
DOI: 10.1016/j.scitotenv.2021.146011

Abstract

Riparian ecosystem services along higher-order streams and connected tributaries may change over time as disturbances continuously increase, resulting in diverse deterioration of buffer zones. How habitat, plant cover, regeneration, erosion, and exotic parameters (riparian health conditions) change within huge dams and reservoirs worldwide is an unanswered question. We used multivariate statistical techniques to assess changes in riparian health parameters affected by disturbances identified in 304 transects within the Three Gorges Dam Reservoir, China, and associated tributaries. Kruskal-Wallis tests (p < 0.01) revealed high diversity in habitat, plant cover, regeneration, erosion, and overall stream condition. There was also notable variance relating to exotic and pressure parameters. The critical variables of riparian health indicators and stress factors identified by principal component analysis explained 58.40% and 74.6% (in the main waterway) and 53.23% and 71.0% (in the tributaries) of the total variance. Among riparian health indicators, one habitat parameter (riparian vegetation width) in the main waterway and one regeneration parameter (tree size classes) in tributaries contributed greatly, along with other specified parameters. Furthermore, stress factors such as farming systems, land-use types, and pollutant activity variables had the highest impact on these water bodies. In comparison, counting stress factors alone showed more deterioration in the main waterway with a range of (r = -0.527- 0.493), as determined using Pearson correlation (p < 0.05). Furthermore, after indexing, the parameters exhibited weaker coefficient values in tributaries, where exotic correlated negatively with other indexed values. These findings are relevant for managers of massive dam and reservoir ecosystems seeking to mitigate environmental and socioeconomic losses.

Keywords: Main river; Pressure indicators; Rapid appraisal; Riparian health condition; Three Gorges Dam Reservoir; Tributary.