Effects of weir‐induced habitat fragmentation on the diversity and community composition of benthic macroinvertebrates in an agricultural stream

Abstract This research delves into the effects of weir‐induced habitat fragmentation on the diversity and structure of benthic macroinvertebrate communities in Topyeong Stream in the Republic of Korea. Through comprehensive zonation, environmental assessments and analyses of macroinvertebrate populations, the study brings to light the significant impact of physical barriers within aquatic ecosystems. Findings reveal notable differences in macroinvertebrate diversity among various stream zones, with alpha diversity measurements demonstrating the significant influence of habitat conditions on biodiversity. Beta diversity analyses uncovered considerable species turnover, pointing to distinct ecological features within fragmented habitats. Mantel tests solidified a significant link between geographical separation and species composition, highlighting the critical impact of spatial isolation arising from habitat fragmentation. The research also pinpointed environmental factors, including habitat size and depth variation, as critical influences on macroinvertebrate community dynamics. Discussions on conservation tactics centered on habitat restoration and forward‐thinking water management strategies aim to counteract the negative consequences of fragmentation and drought. This study emphasizes the essential need for cohesive conservation initiatives to preserve aquatic biodiversity and the functionality of ecosystems amidst human‐induced challenges.