Environmental Correlates of Tardigrade Community Structure in Mosses and Lichens in the Great Smoky Mountains National Park (Tennessee and North Carolina, USA)

A major inventory of tardigrades in the Great Smoky Mountains National Park was conducted and we compared tardigrade species composition in moss and lichen samples and analysed environmental correlates of tardigrade community structure. We also compared these tardigrades with those collected from soil. The basic dataset from tree mosses and lichens consisted of 336 samples, 9200 individuals and 43 species. The supplemental dataset from rock mosses and lichens consisted of 29 samples, 811 individuals, and 41 species. Collectively, there were 57 species present in mosses and lichens. Eleven species were found uniquely on rock habitats. Two-way ANOVAs for various community metrics showed no significant differences between substrate (moss versus lichen) or height (ground level versus breast height); however, there were significant differences between ATBI plots. Tardigrade communities were not significantly different between mosses and lichens, but soil tardigrade communities were quite distinct from these moss/lichen communities. We analysed the impact of 17 environmental variables on community structure using partition tree analyses. SOx deposition explained most of the variation in species richness and evenness in moss tardigrades. Forest disturbance regime had the greatest impact on abundance in lichen tardigrades. Other environmental factors influencing community structure are discussed