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生物结皮在荒漠地区的生态恢复中具有重要的生态学意义,且不同发育演替阶段的结皮具有不同的生态功能.通过野外调查、显微观察结合微生物定量分析对腾格里沙漠东南缘沙坡头地区生物结皮的发育演替进行了研究.结果表明该地区的生物结皮一般按照“藻结皮→地衣结皮→藓结皮”的模式发育演替.随着结皮的发育演替,光合生物生物量逐渐增加,微藻生物量却呈现先增加后减少的趋势.其中,具鞘微鞘藻(Microcoleus vaginatus)作为结皮藻类中的第一优势种,在藻结皮中生物量最大,达到0.33 mm3·g-1,而爪哇伪枝藻(Scytonema javanicum)和(一种)念珠藻(Nostoc sp.)在晚期的地衣结皮中生物量达到最大.另外,研究发现异养微生物生物量在藻结皮中开始增加,但在地衣结皮中呈下降的趋势,最后在藓结皮中异养微生物生物量再次增加并达到最大.其中细菌数量的增加与结皮有机碳、Na+含量的增加显著相关(P<0.05),真菌数量的增加与K+、Na+含量的增加显著相关(P<0.05).本研究观察了沙坡头地区生物结皮发育演替的模式,并从环境适应与功能需求的角度探讨了生物结皮发育演替过程中微生物生物量的变化特征,对于理解结皮的发育演替以及荒漠化地区生态恢复过程中结皮的维护管理具有重要的理论与实践意义.
Biological crusts play an important ecological role in the ecological restoration of desert areas and have different ecological functions in different stages of development and succession.Through the field investigation and microscopic observation combined with quantitative analysis of microorganisms, The developmental succession of the biological crusts in Shapotou area was studied.The results showed that the biological crusts in this area generally developed in succession in the pattern of “algal crusts → lichen crusts → moss crusts” The developmental succession of the crusts and the photosynthetic biomass increased gradually while the biomass of the microalgae increased firstly and then decreased.The micro-algae Microcoleus vaginatus was the first dominant species in the crustacean algae, The biomass of algal crusts was the largest, reaching 0.33 mm3 · g-1, while the biomass of Scytonema javanicum and Nostoc sp. Reached the maximum in the late lichen crust. , It was found that the biomass of heterotrophic microorganisms began to increase in algal crusts but decreased in lichen crusts, and finally the biomass of heterotrophic microorganisms increased again and reached the maximum in moss crusts. The increase of bacterial count and Crust organic carbon (P <0.05), and the increase of fungi was significantly correlated with the increase of K + and Na + contents (P <0.05) .In this study, the patterns of development and development of the biological crusts in the Shapotou area were observed and compared The characteristics of microbial biomass change during the development and succession of the biological crusts were discussed from the perspectives of environmental adaptation and functional requirements. They have important theoretical and practical implications for understanding the development and succession of crusts and the maintenance and management of crusts in the process of ecological restoration in desertified areas. Practical significance.