Wu Li, Zhang Gao-Ke, Chen Xiao-Guo, Lan Shu-Bin, Zhang De-Lu, Hu Chun-Xiang
Huan Jing Ke Xue. 2014 Apr;35(4):1479-85.
Biological soil crusts (BSCs) play important ecological roles in vegetation and ecological restoration in desert regions, and different crust developmental and successional stages have different ecological functions. In this experiment, the BSCs in Shapotou region (at southeast edge of Tengger Desert) were investigated to study crust development and succession through field investigation, microscopic observation combined with quantitative analysis of microbial biomasses. The results showed that BSCs in this region generally developed and succeeded from algal crusts, lichen crusts to moss crusts. With the development and succession of BSCs, crust photosynthetic biomass gradually increased, while microalgal biomass showed a first increasing and then decreasing trend. Among the crust algae (cyanobacteia), Microcoleus vaginatus, as the first dominant species, occupied the most algal biomass and reached a maximum of 0.33 mm3 x g(-1) crusts in algal crusts; while Scytonema javanicum and Nostoc sp. have their maximal biomasses in the later lichen crusts. In addition, it was found that the heterotrophic microbial biomass began to increase in algal crusts, and then decreased in lichen crusts; followed by another increase and the increase achieved the maximum at last in moss crusts. Through the correlation analysis, it was found that bacterial biomass significantly positively correlated with crust organic carbon and Na+ content, while fungal biomass positively correlated with K+ and Na+ content (P < 0.05). In conclusion, this study investigated the developmental and successional patterns of BSCs in Shapotou region, and discussed the effects of crust development and succession on several microbial biomasses from the point of view of environmental adaptation and functional requirement, which may be helpful for us to understand crust development and succession, and provide theoretical and practical significances for crust maintenance and management in ecological restoration of desertification regions.
生物土壤结皮（BSCs）在沙漠地区植被和生态恢复中发挥着重要的生态作用，不同的结皮发育和演替阶段具有不同的生态功能。本实验对沙坡头地区（腾格里沙漠东南边缘）的生物土壤结皮进行了调查，通过野外调查、显微镜观察并结合微生物生物量的定量分析来研究结皮的发育和演替。结果表明，该地区的生物土壤结皮一般从藻类结皮、地衣结皮发展到苔藓结皮。随着生物土壤结皮的发育和演替，结皮光合生物量逐渐增加，而微藻生物量呈先增加后减少趋势。在结皮藻类（蓝细菌）中，鞘丝藻作为第一优势种，占据了最多的藻类生物量，在藻类结皮中达到最大值0.33 mm³×g⁻¹结皮；而爪哇伪枝藻和念珠藻属在后期的地衣结皮中生物量最大。此外，发现异养微生物生物量在藻类结皮中开始增加，在地衣结皮中减少；随后再次增加，并最终在苔藓结皮中达到最大值。通过相关性分析发现，细菌生物量与结皮有机碳和Na⁺含量显著正相关，而真菌生物量与K⁺和Na⁺含量正相关（P < 0.05）。总之，本研究调查了沙坡头地区生物土壤结皮的发育和演替模式，并从环境适应和功能需求的角度探讨了结皮发育和演替对几种微生物生物量的影响，这可能有助于我们理解结皮的发育和演替，并为荒漠化地区生态恢复中结皮的维护和管理提供理论和实践意义。
