Long-term succession characteristics and driving factors of zooplankton communities in a typical subtropical shallow lake, central China

Abstract

Zooplankton community could be affected by aquatic environment, land use patterns, and climate factors. However, few studies have evaluated the relative importance of these factors to the zooplankton community succession on a long-term scale. In this study, long-term data were used to analyze the succession characteristics and drivers of zooplankton communities in Honghu Lake, a large-scale shallow lake in central China. Results showed that zooplankton community structure changed greatly in 1959-2021. In general, the species number decreased, abundance and biomass increased, and the number and proportion of pollution tolerant species among dominant species increased during the past ~ 60 years. For the driving factors of zooplankton from 1992 to 2021, redundancy analysis showed that nutrients, wind speed, and aquaculture enclosure and pond were the main drivers of Protozoa and Rotifera, while phytoplankton abundance, wind speed, dissolved oxygen, and farmland were the main drivers of Cladocera and Copepoda. Generalized additive model showed that the aquatic environment had the highest direct explanation (mean is 60.2%) to zooplankton variation, followed by land use (mean is 35.6%) and climate factors (mean is 33.1%). Variance partitioning analysis showed that the effects of human activities (32.9-43.1%) associated with land use, water quality, and phytoplankton on the zooplankton succession are stronger than that of climate factors (19.9-29.2%). Additionally, lake eutrophication is an important factor for the decline in the richness index (p = 0.0017, r = - 0.8411) and Shannon index (p = 0.0301, r = - 0.8020) of zooplankton from 2019 to 2021. Our results highlighted that anthropogenic activity has stronger driving effects on zooplankton succession in the long term than climate changes in the lake. These findings can provide insights into zooplankton conservation in response to global climate change and complex anthropogenic actions.

Keywords: Climate change; Driving factors; Human activities; Lake; Zooplankton.