Effects of different land use types on the trophic structure of macroinvertebrate communities—a case study in the Yiluo River Basin

The Yiluo River, as the largest tributary downstream of the Xiaolangdi Reservoir in the middle reaches of the Yellow River, is a critical water conservation area within the Yellow River Basin. Understanding the trophic structure of macroinvertebrate communities across different land use types in this basin is essential for maintaining ecological balance and promoting sustainable development. In October 2020 and April 2021, field investigations were conducted in the Yiluo River Basin, collecting 11,894 macroinvertebrate specimens from river sections with varying land use types. These specimens represented 143 species across 4 phyla, 7 classes, 22 orders, and 75 families. The study revealed significant variations in aquatic environments among different land use types. Macroinvertebrate density and biomass were highest in agricultural land reach, followed by forest land reach, and lowest in building land reach. Dry plant weight was the most significant environmental factor influencing the structure of functional feeding groups, followed by land use types at both near- and far-affected areas. Building land reach had the most pronounced impact on functional feeding groups at near-affected areas, while forest land reach was most influential at far-affected areas. The trophic structure of macroinvertebrate communities was most complex in agricultural land reach, followed by forest land reach, and least complex in building land reach. This study provides scientific insights for land use planning and ecological conservation in the Yiluo River Basin.