Articles | Volume 14, issue 24
Research article
22 Dec 2017
Research article |  | 22 Dec 2017

Bryophyte-dominated biological soil crusts mitigate soil erosion in an early successional Chinese subtropical forest

Steffen Seitz, Martin Nebel, Philipp Goebes, Kathrin Käppeler, Karsten Schmidt, Xuezheng Shi, Zhengshan Song, Carla L. Webber, Bettina Weber, and Thomas Scholten

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.

Short summary
This study investigated biological soil crusts (biocrusts, e.g. cyanobacteria and mosses) within an early-stage mesic subtropical forest in China, where they were particularly abundant. Biocrust covers significantly decreased soil erosion and were more effective in erosion reduction than stone cover. Hence, they play an important role in mitigating soil erosion under forest and are of particular interest for erosion control in forest plantations.
Final-revised paper