Supporting dataset: Alpine slopes are protected against erosion by functionally diverse and dense plant communities associated with specific microbial communities
Soil erosion is a severe threat for ecosystems and anthropogenic infrastructure. Glaciers are retreating rapidly due to global warming and the receding ice leaves unvegetated depositions of sediment, which are prone to mobilisation during precipitation events. Steep slopes in glacier forelands are therefore particularly vulnerable to erosion processes. Vegetation is known to serve as erosion protection, but how above-and belowground plant traits, vegetation cover and plant diversity on community level are interrelatedly affecting erosion is unclear. Vegetation is also linked to soil microbial communities, which together play important roles for soil functions with possible implications for slope stability. We measured sediment transport on 30 plots of 2 x 3 m size on proglacial slopes of the Gepatschferner glacier (Kaunertal, Austria) over three consecutive years in a natural pristine high alpine environment. Vegetation cover, species abundances and relevant above- and belowground traits were measured for each occurring plant species on community level. A weather station was installed at a maximum distance of 1.6 km from the measurement sites, collecting precipitation data once per minute. A path model was applied to detangle the relationships between plant cover, species (functional) diversity, traits, and soil erosion. Further, we used next generation amplicon sequencing to investigate how bacterial and fungal communities in the soil are related to the plant community characteristics. We found that the most effective property of a plant community for decreasing sediment transport was a dense overall plant cover, which was facilitated by plant species richness, which was in turn facilitated by functional diversity of plant communities. Plant cover, species composition and functional diversity were also closely linked to the composition of soil microorganisms, which may facilitate soil formation and further enhance the plants’ soil stabilising properties. Included datasets: - Precipitation data - Plant community composition - Monthly erosion measurements - Plant trait measurements Bacterial and fungal sequences associated with this study can be accessed in fastq files deposited in the European Nucleotide Archive (ENA) under the accession number ERP133205.