| 摘要: |
| 【目的】研究陕北黄土区封禁小流域中不同类型生物结皮对土壤微生物量碳和氮含量的影响，为该地区植被恢复和生态重建提供参考。【方法】选取陕北黄土区吴起县合沟流域为研究区，以藻类地衣苔藓结皮、藻类地衣结皮、藻类苔藓结皮和物理结皮（对照）为研究对象，分析不同生物结皮类型对结皮层及其以下土层（2～5 cm和5～10 cm）土壤微生物量碳和氮含量的影响。【结果】与物理结皮相比，3种生物结皮均能显著提高结皮层的土壤微生物量碳和氮含量（P<0.05），改善效果的大小顺序为藻类地衣苔藓结皮>藻类苔藓结皮>藻类地衣结皮>物理结皮。生物结皮对结皮层以下土层土壤微生物量碳、氮含量的影响随土壤深度的加深而减小，其改良效果为藻类地衣苔藓结皮最好，藻类地衣结皮和藻类苔藓结皮次之。生物结皮的不同发育阶段与土壤微生物量碳和氮含量呈极显著正相关关系（P<0.01）。【结论】生物结皮的形成与发育能显著改善结皮层及其以下土层土壤微生物量碳和氮含量，提高表层土壤的生物活性。 |
| 关键词: 生物土壤结皮 生物结皮发育阶段 土壤微生物量碳 土壤微生物量氮 黄土区 |
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| 基金项目:国家林业公益性行业科研专项“黄土丘陵严重侵蚀区植被恢复和重建技术研究”（201104002-2）；“十二五”国家科技支撑计划重大项目“黄土及华北石质山地水土保持林体系构建技术研究与示范”（2011BAD38B06） |
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| Effects of biological soil crusts on soil microbial biomass in grazing banned watershed in Loess area |
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ZHAO Yan-min,ZHU Qing-ke,ZHANG Yan,et al
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| Abstract: |
| 【Objective】The impacts of different biological soil crusts (BSCs) on soil microbial biomass carbon and nitrogen contents in grazing banned small watersheds in Loess area,Northern Shaanxi were researched,to provide a reference for vegetation restoration and ecological reconstruction in this area.【Method】Cyanobacteria-lichen-moss crust,cyanobacteria-lichen crust,cyanobacteria-moss crust,and physical crust (CK) in Hegou catchment of Wuqi County were selected to analyze the effects of different BSCs on soil microbial biomass carbon and nitrogen contents in crust layer and subsoil (2－5 cm and 5－10 cm）.【Result】Compared with physical crust,all of the three studied BSCs significantly increased the soil microbial biomass carbon and nitrogen contents (P<0.05),the improvement effects were in a decreasing order of cyanobacteria-lichen-moss crust>cyanobacteria moss crust>cyanobacteria-lichen crust>physical crust.Effect of BSCs on soil microbial biomass carbon and nitrogen contents decreased as the increase of soil depth.Cyanobacteria-lichen-moss crust had the best improvement,followed by cyanobacteria-lichen and cyanobacteria moss crust.There was extremely significantly positive correlation between developmental stages of BSCs and soil microbial biomass carbon and nitrogen contents (P<0.01).【Conclusion】The formation and development of BSCs could significantly improve soil microbial biomass carbon and nitrogen contents in the crust layer and 2－10 cm soil layer and improve the biological activity of surface soil. |
| Key words: biological soil crust developmental stage of BSCs soil microbial biomass carbon soil microbial biomass nitrogen Loess area |
