Dataset paper: Tree proximity exerts stronger effects than fertilization on spider community structure in managed temperate grasslands

This dataset contains spider community data and associated environmental variables collected from managed temperate grasslands in Uruguay.The study evaluated the effects of grassland fertilization treatments and proximity to trees on spider assemblage structure, including abundance, morphospecies richness, community composition, and functional guild structure.Sampling was conducted using pitfall traps arranged along transects distributed across four management treatments:G = natural grassland,GL = grassland overseeded with legumes,GN060 = grassland with nitrogen fertilization (60 kg N ha−1),GN120 = grassland with nitrogen fertilization (120 kg N ha−1).The dataset includes:1) Community matrices with abundances of spider morphospecies,2) Functional guild classifications,3) Environmental variables associated with each sampling unit,4) R scripts used for statistical analyses and figure generation.Analyses included generalized linear mixed models (GLMM), PERMANOVA, multivariate dispersion analyses, and sample coverage estimation using iNEXT.All adult spider individuals were identified to morphospecies whenever possible and assigned to functional guilds following published classifications.