Bryophyte-dominated biological soil crusts mitigate soil erosion in an early successional Chinese subtropical forest
- 1Soil Science and Geomorphology, Department of Geosciences, University of Tübingen, 72070 Tübingen, Germany
- 2State Museum of Natural History, 70191 Stuttgart, Germany
- 3Nees Institute for Biodiversity of Plants, University of Bonn, 53115 Bonn, Germany
- 4State Key Laboratory of Soil and Sustainable Agriculture, Institute of Soil Science, Chinese Academy of Sciences, Nanjing, 210008, PR China
- 5Department of Geosciences, Federal University of Rio Grande do Sul, Porto Alegre, 90040-060, Brazil
- 6Multiphase Chemistry Department, Max Planck Institute for Chemistry, 55128 Mainz, Germany
Abstract. This study investigated the development of biological soil crusts (biocrusts) in an early successional subtropical forest plantation and their impact on soil erosion. Within a biodiversity and ecosystem functioning experiment in southeast China (biodiversity and ecosystem functioning (BEF) China), the effect of these biocrusts on sediment delivery and runoff was assessed within micro-scale runoff plots under natural rainfall, and biocrust cover was surveyed over a 5-year period.
Results showed that biocrusts occurred widely in the experimental forest ecosystem and developed from initial light cyanobacteria- and algae-dominated crusts to later-stage bryophyte-dominated crusts within only 3 years. Biocrust cover was still increasing after 6 years of tree growth. Within later-stage crusts, 25 bryophyte species were determined. Surrounding vegetation cover and terrain attributes significantly influenced the development of biocrusts. Besides high crown cover and leaf area index, the development of biocrusts was favoured by low slope gradients, slope orientations towards the incident sunlight and the altitude of the research plots. Measurements showed that bryophyte-dominated biocrusts strongly decreased soil erosion, being more effective than abiotic soil surface cover. Hence, their significant role in mitigating sediment delivery and runoff generation in mesic forest environments and their ability to quickly colonise soil surfaces after disturbance are of particular interest for soil erosion control in early-stage forest plantations.