Abstract
Variations in the hydrological regime are among the anthropogenic pressures affecting biological assemblage structure in shallow freshwater lakes. We estimated the effects of the water level fluctuation range on the temporal dissimilarity of the macroinvertebrate community by sampling benthic macroinvertebrate assemblages monthly in 2017 and bimonthly in 2018. Then, we applied a boosted regression trees (BRT) model to quantitatively analyzing the relationship between macroinvertebrate abundance and microhabitat factors in different seasons. To distinguish differences in water level fluctuations at the sample site scale, we proposed a variable, namely, the percentage of water level fluctuation range (PWLFR). The results were as follows. (1) An increased water level fluctuation range would lead to more temporally heterogeneous macroinvertebrate communities. Temporal dissimilarity of macroinvertebrates increased linearly in response to increasing water level fluctuation range. (2) Species abundance presented seasonal characteristics, and the dominant factors affecting species abundance varied with the seasons. PWLFR was the dominant variable explaining macroinvertebrate abundance in summer. Macroinvertebrate abundance showed positive effects with increasing PWLFR. (3) The interaction between chlorophyll a and PWLFR in summer promoted an increase in macroinvertebrate abundance. These findings may provide a basis for the formulation of effective ecological water replenishment management decisions aimed at maintaining the stability of shallow lake ecosystems in arid and semi-arid regions.
Highlights
The regulation of water levels for flood control, water consumption, and irrigation is a major form of anthropogenic disturbance in shallow freshwater ecosystems, leading to declines in biodiversity and ecosystem services [1,2]
This study found that the interaction between percentage of water level fluctuation range (PWLFR) and Chl a in summer had the greatest impact on macroinvertebrate abundance
To increase the understanding of the response of macroinvertebrate community structure to water level fluctuations, this study analyzed the impact of water level fluctuation range on the degree of variations in dissimilarity in the overall community structure at two consecutive sampling events, and used the boosted regression trees (BRT) model to quantitatively analyze the response of macroinvertebrate species abundance to PWLFR and other important microhabitat factors in different seasons at the microhabitat level
Summary
The regulation of water levels for flood control, water consumption, and irrigation is a major form of anthropogenic disturbance in shallow freshwater ecosystems, leading to declines in biodiversity and ecosystem services [1,2]. Implementing ecological water replenishment projects in shallow lakes with degraded ecological structure and function is currently an effective means to restore the health of their ecosystems [3]. As a foundation of the stability of lake ecosystems, macroinvertebrates play an important role in nutrient circulation and energy flow in the freshwater food web [5]. Responses of the community structure and abundance of macroinvertebrates to variations in the hydrological regime are often used to evaluate the impact of human pressure on ecosystems [6,7,8,9]. Understanding the response of macroinvertebrate communities to variations in hydrological regimes in shallow lakes has become critical in the restoration and management of degraded shallow lake ecosystems
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
