Successional stages of biological soil crusts and their microstructure variability in Shapotou region（China）
会议名称：《中国藻类学会第八次会员大会暨第十六次学术讨论会》
会议日期：2011年
学科分类：07[理学] 09[农学] 0903[农学-农业资源与环境] 0713[理学-生态学]
关 键 词：Biological soil crusts Succession Vertical stratification Cementing Phototrophic organisms
摘 要：正In order to investigate succession of biological soil crusts（BSCs） and their microstructure variability,we conducted this work in Shapotou revegetation region at the southeast edge of Tengger *** results showed that BSCs generally succeeded as a pathway of Algae crusts,algae - lichen crusts,lichen crusts,lichen-moss crusts and moss crusts.Occasionally mosses directly occurred on algae crusts,and BSCs succeeded from algae crusts to moss *** vertical stratification was a common phe-nomenon,from top to bottom an inorganic layer,algae-dense layer and algae-sparse layer were divided in algae crusts;a thallus layer,rhizoid layer and sub-rhizoid layer in lichen crusts;a ’ ’stem-leaf ’ layer,rhizoid layer and sub-rhizoid layer in moss crusts,*** main crust binding organisms varied from filamental cyanobacteria（dominated by Microcoleus） in algae crusts to lichen rhi-zoids,free-living cyanobacterial filaments and fungal hyphaes in lichen crusts, and to moss rhizoids and fungal hyphaes in moss *** dominant phototrophic organisms varied from Microcoleus（algae） in algae crusts to Col lema（lichens） in lichen crusts,and to Bryum（or Didymodon and Tortula;mosses） in moss *** phototrophic biomass increased while the free-living algal biomass decreased with the succession of *** addition,exopolysaccharides and fine particles accumulated in the course of development and succession of BSCs,all of which lead to a gradual increase in crust thickness and porosity,while decrease in the bulk density.