Top-down degradation of alpine meadow in the Qinghai-Tibetan Plateau: Gravelization initiate hillside surface aridity and meadow community disappearance

• Published in: Catena (Giessen) 2022-03, Vol.210, p.105933, Article 105933
• Main Authors: Cui, Zeng, Yang, Wen-Shan, Cheng, Zhen, Zhang, Zhenchao, Li, Shixiong, Zhao, Jingxue, López-Vicente, Manuel, Wu, Gao-Lin
• Format: Article
• Language: English
• Subjects: Gravel cover; Gravel erosion; Meadow community; Plant functional group; Soil moisture; Soil temperature
• ISSN: 0341-8162; 1872-6887
• DOI: 10.1016/j.catena.2021.105933

•Alpine gravelization by glacier melting seriously eroded downstream grassland.•Alpine gravelization decreased alpine grassland coverage, biomass density, and diversity.•Alpine gravelization initiated extreme soil aridity of hillside alpine grassland.•Alpine gravelization initiated disappearance of some species and plant functional groups. Alpine gravelization by glacier melting may subsequently cause degradation of downstream vegetation. The thinning rates of glaciers outside ice sheet peripheries in some regions has doubled over the past 20 years.However, no study is available about the effects of alpine gravelization on alpine meadow ecosystem. Here, by investigating and measuring the community characteristics, soil moisture, and soil temperature of alpine meadows under three different gravel coverage levels (No gravel covered meadow, half gravel covered meadow, and fully gravel covered meadow),we examine the response of surface microhabitats and community to gravel cover on a typical hillside alpine meadow. Results showed that gravel cover significantly decreased soil/gravel ratio and topsoil moisture. Topsoil water content of the half-covered and the fully-covered gravel meadow was outstandingly low and reached