This is an early access version, the complete PDF, HTML, and XML versions will be available soon.
Spatial–Temporal Dynamics and Co-Occurrence Networks of Zooplankton Community Structure in a Large Shallow Reservoir Under the Background of Ecological Restoration
by
, ,
Ting Yuan
†, 
Jiangqianhui Qi
†,
Mantang Xiong
,
Geng Huang
,
Kui Zhang
,
Lianfeng Zhou
and
Feng Chen
* Key Laboratory of Ecological Impacts of Hydraulic-Projects and Restoration of Aquatic Ecosystem of Ministry of Water Resources, Institute of Hydroecology, Ministry of Water Resources & Chinese Academy of Sciences, Wuhan 430079, China
*
Author to whom correspondence should be addressed.
†
These authors contributed equally to this work.
Animals 2026, 16(13), 2065; https://doi.org/10.3390/ani16132065 (registering DOI)
Submission received: 9 May 2026
/
Revised: 27 June 2026
/
Accepted: 30 June 2026
/
Published: 4 July 2026
Simple Summary
Zooplankton are sensitive indicators of environmental change and food-web regulation in freshwater ecosystems. The Shilianghe Reservoir, which is located in the Huai River Basin, is a typical case demonstrating initial restoration success. However, the response of the zooplankton community to water quality enhancement remains unclear. We investigated zooplankton composition, standing stock, diversity, co-occurrence associations and environmental drivers in this large shallow drinking-water reservoir in eastern China, based on two annual sampling cycles from 2021 to 2024. The results showed that temporal variation explained more community change than spatial zonation, while inflow tributaries supported high species richness and standing stock but relatively loose co-occurrence associations. Compared with the 2021–2022 cycle, the 2023–2024 cycle showed lower density and biomass but higher diversity, which suggested zooplankton community reorganization. These observed changes are temporally aligned with the implementation of restoration measures, though other environmental and stochastic factors may also contribute. Subsequent restoration efforts should focus on controlling external pollution inputs and regulating food-web structure. These findings provide a case-based framework for using zooplankton communities to evaluate ecological change in thousands of reservoirs undergoing ecological restoration in the Huai River Basin.
Abstract
Zooplankton are sensitive indicators of ecological change, but their community reorganization under early-phase restoration remains unclear. This study aims to reveal how their diversity, standing stock, and co-occurrence networks respond to early-phase restoration and identifies key environmental drivers, offering novel insights into restoration–plankton interplay. Shilianghe Reservoir, as the largest reservoir in Jiangsu Province, represents a typical case of restoration in the Huai River Basin that offers transferable insights for numerous eutrophic reservoirs. The study comprised eight surveys representing two annual cycles (July 2021–May 2022 and April 2023–January 2024). The 2023 sampling cycle showed lower zooplankton density and biomass but higher α-diversity than the 2021 sampling cycle. Co-occurrence network density and the size of the largest connected component decreased in spring and summer of the 2023 sampling cycle, suggesting community reorganization. Inflow tributaries supported the highest species richness and standing stock but showed looser interspecific associations. PERMANOVA analysis indicated that season explained the largest proportion of community variation, followed by sampling year and region. Environmental variables including DO, WT, Cond and TN significantly correlated with zooplankton community structure. Zooplankton community reorganization was characterized by reduced standing stock, increased diversity, and altered co-occurrence patterns, providing a mechanistic framework for using zooplankton as bioindicators in reservoir restoration assessments.
