Lichens are bioindicators due to their sensitivity to environmental variables. As key constituents of biological soil crusts in gypsum-rich arid ecosystems, their links to abiotic factors offer insights into ecological processes. We studied lichen community responses to environmental variation in gypsum soils in Spain. Sampling was conducted in 35 plots, estimating lichen cover to quantify taxonomic diversity (TD), calculate functional diversity (FD) assessing and measuring qualitative and quantitative traits, and compute phylogenetic diversity (PD) using a community-level phylogenetic tree. A higher diversity (TD, FD, PD) was found in plots with less extreme temperature conditions. Higher TD, total FD, and FD of quantitative traits were observed in plots with greater precipitation. FD of quantitative traits was positively associated with gypsum content. Functional variability was mostly explained by intraspecific variability except in water-related traits. Our findings reinforce the relevance of trait-based approaches in understanding patterns of lichen biodiversity. Keywords: Biological soil crusts; Gypsum; Specific thallus mass; Water holding capacity; Spain; Traits.