Water’s path from moss to soil Vol. 2: How soil-moss combinations affect the soil water balance and soil erosion

Abstract

Mosses are key components of many ecosystems and particularly related to the soil water balance. In principle, the importance of mosses for water-related processes is known; however, their influence is rarely quantified in scientific studies. To fill this research gap, this study concentrates on the influence of mosses of different species on surface runoff, the amount of percolated water, soil erosion, and the temporal dynamics of soil water content. For this purpose, an experimental approach consisting of an ex situ rainfall simulation with infiltration boxes equipped with biocrust wetness probes was applied. On average, mosses significantly reduced surface runoff by 91% and soil erosion by almost 100%, while the amount of percolated water was increased by 85% compared with bare soils. Similarly, the moss treatments tended to have lower water contents in 3 cm soil depth during 30 minutes of rainfall simulations compared to the bare treatments. However, specific effects of moss treatments were superimposed by desiccation cracks as well as soil hydrophobicity, two major factors that clearly override individual species effects. Therefore, it is imperative that further experiments will be conducted to elucidate the apparently underestimated effects of mosses and their specific traits on the soil water balance and sediment transport.