title: Analysis of environmental factors determining development and succession in biological soil crusts.
abstract: Biological soil crusts play important ecological functions in arid and semi-arid regions, while different crust successional patterns appeared in different regions. Therefore in this study, the environmental conditions between Shapotou (with cyanobacterial, lichen and moss crusts) and Dalate Banner (with only cyanobacterial and moss crusts) regions of China were compared to investigate why lichen crusts only appeared in Shapotou; at the same time, artificial moss inoculation was conducted to find out the environmental factors promoting crust succession to moss stage. The results showed lichen crusts always developed from cyanobacterial crusts, which provide not only the stable soil surface, but also the biomass basis for lichen formation; furthermore, addition of crust physicochemical characteristics (primarily silt content) play a facilitating effect on lichen emergence (R(2)=0.53). The inoculation experiment demonstrated early crust soil surface and enough water holding content (>4%) provided the essential guarantee for moss germination. Our results show that there is heterogeneity in crust succession in different regions, which may be mainly affected by the ambient soil microenvironments. It is concluded that a positive feedback mechanism is expected between crust succession and ambient soil microenvironments; while a negative feedback mechanism forms between crust succession and free living cyanobacteria and algae.
authors: Key Laboratory of Algal Biology, Institute of Hydrobiology, Chinese Academy of Sciences, Wuhan 430072, China.
authors: Shubin
authors: S
authors: Lan
authors: School of Resources and Environmental Engineering, Wuhan University of Technology, Wuhan 430072, China.
authors: Li
authors: L
authors: Wu
authors: School of Chemistry, Chemical Engineering and Life Sciences, Wuhan University of Technology, Wuhan 430070, China.
authors: Delu
authors: D
authors: Zhang
authors: Key Laboratory of Algal Biology, Institute of Hydrobiology, Chinese Academy of Sciences, Wuhan 430072, China. Electronic address: cxhu@ihb.ac.cn.
authors: Chunxiang
authors: C
authors: Hu
mesh_terms: D044002:Bryophyta / Q000254:growth & development*; D002681:China; D000458:Cyanobacteria / Q000254:growth & development*; D003889:Desert Climate; D017753:Ecosystem; D004784:Environmental Monitoring; D008011:Lichens / Q000254:growth & development*; D012987:Soil / Q000737:chemistry; D012988:Soil Microbiology
chemical_list: D012987:Soil
keywords: Cyanobacteria; Dalate Banner; Inoculation; Lichen; Moss; Shapotou