Water-level fluctuations affect the alpha and beta diversity of macroinvertebrates in Poyang Lake, China

Abstract

Water-level fluctuations (WLFs) are a key influence on aquatic biodiversity in seasonally inundatedfreshwater ecosystems. However, how unregulated WLFs affect macroinvertebrates in lake-floodplain systemsexperiencing considerable annual fluctuations remains unclear. We explored spatial and temporal variability intaxonomic α and β diversity in the largest fluctuating lake in China, Poyang Lake, during two hydrological seasons.We hypothesized that taxa richness (α diversity) is greater in the floodplain than in the lake channel due to greateravailability of trophic resources, and that variability in assemblage composition (β diversity) in the channel isgreater during the high-water season (HWS) than the low-water season (LWS) due to increased habitat heterogeneity.Benthic macroinvertebrate assemblages were sampled, water physicochemical and hydrological variables weremeasured, and geographical coordinates were determined at 34 sites during the HWS (October 2017) and LWS(January and April 2018). A total of 74 taxa were recorded. Macroinvertebrate α diversity was comparable in thefloodplain and the lake channel. Beta diversity in the channel was greater during HWS than LWS. Hydrologicalvariables influenced β diversity during LWS and geographical distance between sites increased β diversity duringHWS, whereas physicochemical variables did not influence β diversity in either hydrological season. Our resultssuggest that extensive WLFs altered macroinvertebrate biodiversity among hydrological seasons by extending waterinto floodplains during HWS and reducing substrate heterogeneity in the lake channel during LWS. We thushighlight the importance of WLFs that maintain such environmental seasonality in supporting the biodiversity ofbenthic macroinvertebrates in naturally dynamic freshwater ecosystems.

Daily water‐level forecasting for multiple polish lakes using multiple data‐driven models

“…Water-level changes play an important role in processes in the lake littoral. Water-level fluctuations are a key factor determining water biodiversity (Tan et al, 2021). The exposure of the littoral zone to atmospheric conditions associated with changes in water levels accelerates small-scale energy and matter cycling, causing secondary water pollution, such as the release of many chemical compounds stored in bottom sediments into the water (Sojka et al, 2020(Sojka et al, , 2021.…”

The effects of water quality parameters, water level changes, and mixing on zooplankton community dynamics in a tropical high-mountain Lake Ardibo, Ethiopia

“…Climate change and rainfall variability will magnify the water level uctuations that (Heinsalu et al, 2008) affect the physicochemical variables and the functioning of an aquatic environment (Liu et al, 2019), potentially altering the biological communities of lake ecosystem (Kobayashi et al, 2020). The diversity and abundance of zooplankton community are largely in uenced by the amplitude of water-level regims (Chaparro et al, 2019;Hu et al, 2019;Wang et al, 2019;Tan et al, 2021;Qiu et al, 2022). How ever, little is known about the effect of water level uctuations in deep tropical lakes.…”