Dataset: Macroinvertebrates and environmental variables within submerged macrophyte Ranunculus nipponicus var. submersus patches in a spring-fed river

This dataset provides epiphytic macroinvertebrate community data collected from 17 patches of the submerged macrophyte Ranunculus nipponicus var. submersus in the spring-fed Nishibetsu River, Hokkaido, Japan. The field survey was conducted in October 2025 and May 2026. A total of 6,439 macroinvertebrate individuals belonging to 24 taxa were collected (from 79 box samples). The datasets contain macroinvertebrate community data and environmental measurements collected from 17 submerged macrophyte patches in the Nishibetsu River, Japan, during autumn 2025 and spring 2026. Dataset 1: Macroinvertebrate community metrics and environmental variables This dataset includes taxonomic richness (number of taxa), Shannon diversity index, total macroinvertebrate abundance, total density (individuals per gram of macrophyte dry weight, DW), and abundances of each functional feeding group (FFG) and habit-trait group. Environmental variables include: Macrophyte dry weight (g) Depth to shoots (cm) Canopy height (cm) Number of shoots collected Current velocity above the canopy (m s⁻¹) Current velocity within patches (m s⁻¹) Mean maximum shoot swaying range (cm) Particulate organic matter (POM; mg and mg g⁻¹ DW) Particulate inorganic matter (PIM; g) Dataset 2: Taxonomic composition of macroinvertebrate assemblages This dataset contains the abundance of each macroinvertebrate taxon identified at each intra-patch sampling position, along with total abundance and macrophyte dry weight (g). Dataset 3: Current velocity and water depth around macrophyte patches This dataset contains current velocity (m s⁻¹) and water depth (cm) measured at four locations around each macrophyte patch: 10 cm upstream, downstream, and to the left and right sides. Dataset 4: Raw shoot swaying measurements This dataset contains the maximum horizontal shoot swaying range (cm) measured for five individual shoots at each intra-patch sampling position, together with the mean value calculated from these five measurements.