Dam inundation simplifies the plant community composition

Jie Zheng; Muhammad Arif; Songlin Zhang; Zhongxun Yuan; Limiao Zhang; Jiajia Li; Dongdong Ding; Changxiao Li

doi:10.1016/j.scitotenv.2021.149827

Dam inundation simplifies the plant community composition

Sci Total Environ. 2021 Dec 20:801:149827. doi: 10.1016/j.scitotenv.2021.149827. Epub 2021 Aug 22.

Authors

Jie Zheng¹, Muhammad Arif², Songlin Zhang³, Zhongxun Yuan⁴, Limiao Zhang⁵, Jiajia Li⁶, Dongdong Ding⁷, Changxiao Li⁸

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. Electronic address: jiezheng@email.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: muhammadarif@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. Electronic address: zhangsonglin@cigit.ac.cn.
⁴ 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.
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: lmzhang@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: ljj133888@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: dingdongdong@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: lichangx@swu.edu.cn.

PMID: 34467924
DOI: 10.1016/j.scitotenv.2021.149827

Abstract

The construction of dams has caused riparian habitat degradation and ecosystem service loss globally. It is critical to assess the response of riparian plant communities to inundation gradients for their conservation. Recent evidence suggests that plant community assemblages are governed by flooding stress, soil nutrient availability, climate (environmental filtering) and dispersal, speciation, local extinction (dispersal filtering), but it remains unclear which dominates the riparian ecosystem regulated by a dam. Thus, this article aims to elucidate the relative importance of environmental and dispersal filtering to variations in plant communities to understand community assembly mechanisms in riparian ecosystems. Here we used plant community data related to four elevations in the riparian zone of the Three Gorges Dam Reservoir in China to show that species richness and diversity, community height, and the cover of total, annual, and exotic plant categories decreased, while the cover of perennial and native plant groups increased under higher flooding stress. Community composition varied substantially with elevation, and species composition tended to converge with increased inundation, characterized by flood-tolerant species. The community composition underwent stronger environmental filtering at low elevations and stronger dispersal filtering at high elevations, with stronger environmental filtering across riparian ecosystems. Therefore, we conclude that dam inundation drives community assemblages of riparian plants by the combined effects of environmental and dispersal filtering. Still, their relative contribution varies between elevations, and environmental filtering is more important in shaping community assembly. This study is the first to confirm that plant community assembly in the dam-regulated riparian area is determined by both niche-based and stochastic processes. Thus, we highlighted the importance of considering inundation intensity, propagule sources, and river connectivity when implementing restoration projects.

Keywords: Ecological restoration; Riparian ecosystems; Three gorges dam reservoir; Water level fluctuation zone.

MeSH terms

Ecosystem*
Floods
Plants*
Rivers
Soil

Substances

Soil