# Impacts of Land Use and Water Quality on Macroinvertebrate Diversity Under Human Disturbance in the Lake Chaohu Basin, China

## TL;DR

The study shows how human activities affect macroinvertebrate diversity in Lake Chaohu, China, by changing land use and water quality, with different species dominating based on disturbance levels.

## Contribution

This study reveals the combined effects of land use and water quality on macroinvertebrate diversity and identifies specific taxa responses to disturbance levels.

## Key findings

- Macroinvertebrate biodiversity increases as human disturbance decreases, with sensitive species in low disturbance areas.
- Built-up land has the strongest negative impact on diversity, both directly and indirectly through water quality deterioration.
- Water quality factors like ammonia nitrogen and total nitrogen strongly inhibit diversity in high and moderate disturbance areas.

## Abstract

Freshwater ecosystems play a critical role in sustaining biodiversity, but with increasing anthropogenic disturbances in recent years, issues such as water degradation and biotic community decline have become increasingly severe. Although existing research has explored the impact of water quality factors and land use on macroinvertebrate communities, the specific mechanisms by which human activities indirectly influence macroinvertebrate diversity by altering the aquatic environment are still underexplored. Therefore, this study, on the basis of land use, aquatic environmental, and macroinvertebrate survey data, employed a Partial Least Squares Path Model (PLS‐SEM) to elucidate the mechanisms by which land use and water quality factors jointly drive changes in macroinvertebrate communities. Our results demonstrate that macroinvertebrate community structure varied significantly among disturbance levels, with biodiversity indices increasing progressively as disturbance intensity lessened. Specifically, pollution‐tolerant taxa dominated in high disturbance areas, Bellamya and Alocinma were predominant in moderate disturbance areas, whereas sensitive species were dominant in low disturbance areas. Land use explained 11.1% of the variation in diversity, about 2.6 times that of water quality factors (4.3%), indicating clear differences in their driving effects on macroinvertebrate diversity, as shown by variance partitioning analysis (VPA). According to the PLS‐SEM results, built‐up land, as the main negative factor, exerted combined effects on diversity both directly and indirectly by causing water quality deterioration. Water quality factors exhibited spatially differentiated effects: ammonia nitrogen and total nitrogen strongly inhibited diversity in high and moderate disturbance areas, whereas in low disturbance areas, total hardness and water temperature emerged as the primary positive drivers. This study elucidates the dynamic response mechanisms of macroinvertebrate communities to changes in land use and water quality, offering new perspectives for freshwater ecosystem health assessments and biodiversity conservation.

Our study revealed that human activities drive changes in macroinvertebrate diversity through the combined effects of land use and water quality. The results showed that sensitive taxa (Semisulcospira cancelata) dominated in low disturbance areas, Bellamya (Bellamya aeruginosa) and Alocinma (Alocinma longicornis) were predominant in moderate disturbance areas, whereas tolerant taxa (
Physa acuta
) dominated in high disturbance areas. Our study reveals the mechanism by which human disturbances influence community diversity through the combined effects of land use and water quality, providing a reference for freshwater ecosystem health assessment and biodiversity conservation.