Ecological regulation of water level should be combined with seed supplementation for lakeshore Carex community restoration in Yangtze-disconnected lakes

Huili Wang; Xiaoke Zhang; Yawen Xu; Heyin Wang; Mengyi Song; Yongbao Shen

doi:10.1016/j.scitotenv.2023.165358

Ecological regulation of water level should be combined with seed supplementation for lakeshore Carex community restoration in Yangtze-disconnected lakes

Sci Total Environ. 2023 Nov 1:897:165358. doi: 10.1016/j.scitotenv.2023.165358. Epub 2023 Jul 6.

Authors

Huili Wang¹, Xiaoke Zhang², Yawen Xu³, Heyin Wang³, Mengyi Song³, Yongbao Shen⁴

Affiliations

¹ College of Forestry, Nanjing Forestry University, Nanjing 210037, China; Collaborative Innovation Center of Sustainable Forestry in Southern China, Nanjing Forestry University, Nanjing 210037, China; Engineering Technology Research Center for Aquatic Organism Conservation and Water Ecosystem Restoration in University of Anhui Province, College of Life Science, Anqing Normal University, Anqing 246133, China.
² Engineering Technology Research Center for Aquatic Organism Conservation and Water Ecosystem Restoration in University of Anhui Province, College of Life Science, Anqing Normal University, Anqing 246133, China. Electronic address: zxksgsg@163.com.
³ Engineering Technology Research Center for Aquatic Organism Conservation and Water Ecosystem Restoration in University of Anhui Province, College of Life Science, Anqing Normal University, Anqing 246133, China.
⁴ College of Forestry, Nanjing Forestry University, Nanjing 210037, China; Collaborative Innovation Center of Sustainable Forestry in Southern China, Nanjing Forestry University, Nanjing 210037, China. Electronic address: ybshen@njfu.edu.cn.

PMID: 37419353
DOI: 10.1016/j.scitotenv.2023.165358

Abstract

Carex communities in most Yangtze-disconnected lakes have been degraded severely due to alterations in water level fluctuations. To explore the feasibility of restoring the lakeshore Carex communities through ecological regulation of water level, the present study selected the Yangtze-connected Qili Lake (the lakeshore was dominated by Carex) and the Yangtze-disconnected Wuchang Lake (the lakeshore was dominated by Zizania latifolia) as model systems, and analyzed the lakeshore seed bank characteristics and seed-related quantitative, morphological, and germination traits of three representative Carex species. According to the results, although Carex seed density in the Qili Lake seed bank was obviously higher than that in Wuchang Lake, their contribution to the total seed density in both lakes was extremely low, with no significant difference between the two lakes. The results indicate that restoration of the degraded Carex communities using existing seed bank in Yangtze-disconnected lakes exclusively through water level regulation is not feasible. In addition, the seed densities of aboveground parts of Carex cinerascens, Carex dimorpholepis, and Carex argyi in Qili Lake were 6.9 × 10⁴, 45.1 × 10⁴, and 3.6 × 10⁴ seeds/m², respectively, which can provide high numbers of seeds continuously for lakeshore Carex restoration. The results of seed germination experiments showed that light, burial depth, and their interaction had significant effects on seed germination of the three species, whereas water condition had a significant effect only on C. dimorpholepis seed germination. The average germination rates of the three Carex species were 16.63 %, 19.06 %, and 7.78 %, respectively. However, considering the high seed densities in the aboveground parts of the three species, there are considerable numbers of seeds that can be used for Carex restoration. Therefore, the restoration of Carex communities in lakeshore zones of Yangtze-disconnected lakes is still possible if water level regulation can be combined with natural or artificial seed supplementation.

Keywords: Carex communities; Ecological restoration; Seed supplementation; Water level regulation; Yangtze floodplain.

MeSH terms

Carex Plant*
China
Dietary Supplements
Ecosystem
Lakes*
Seeds / physiology
Water

Substances

Water