黄土丘陵区不同类型生物结皮下土壤微生物的分布特征

发布时间：2018-04-12 19:21

本文选题：生物结皮 + 发育特征　；参考：《西北农林科技大学学报(自然科学版)》2017年06期

【摘要】：【目的】分析黄土丘陵区不同类型生物结皮的发育特征及土壤微生物的分布特征,以明确生物结皮形成过程对土壤微生物的影响。【方法】采用野外调查和室内分析相结合的方法,调查黄土丘陵区浅色藻结皮、深色藻结皮、藻+少量藓结皮、藓+少量藻结皮及藓结皮5类生物结皮的发育特征,并测定生物结皮层及结皮下0~2cm土层的土壤微生物数量和化学性质,最后分析了不同生物结皮发育特征和土壤化学性质与土壤微生物数量之间的相关性。【结果】研究区浅色藻结皮、深色藻结皮、藻+少量藓结皮、藓+少量藻结皮及藓结皮的结皮厚度分别为1.13,3.26,6.31,8.91,12.61mm,藻盖度分别为100%,98.67%,71.61%,27.33%,7.80%,藓盖度分别为0%,0.80%,24.90%,65.87%,81.30%。不同类型生物结皮土壤细菌数量占微生物总数的比例为53.12%~72.09%,放线菌所占比例为27.49%~46.80%,真菌所占比例为0.08%~0.92%。在生物结皮层,土壤微生物总数和细菌数量从浅色藻结皮到藓结皮总体呈增加趋势,藓结皮土壤细菌、放线菌和真菌数量显著高于其他生物结皮;在结皮下0~2cm土层,土壤微生物总数和放线菌数量表现为藓结皮浅色藻结皮深色藻结皮藓+少量藻结皮藻+少量藓结皮,藓结皮土壤细菌、放线菌和真菌数量显著高于其他生物结皮。在生物结皮层,藓结皮土壤细菌比例较藻结皮有所增加,放线菌比例相应减少,藓结皮真菌比例最高;藓结皮下0~2cm土层真菌比例显著大于其他生物结皮。垂直分布上,生物结皮层土壤细菌数量和比例、真菌数量和比例均大于结皮下0~2cm土层,但放线菌数量和比例小于结皮下0~2cm土层。在生物结皮层和结皮下0~2cm土层,不同类型生物结皮土壤化学性质存在明显差异。生物结皮层微生物总数、细菌数量和比例、真菌数量与藓盖度和结皮厚度呈显著或极显著正相关关系,放线菌比例与藓盖度和结皮厚度呈显著负相关关系。土壤微生物总数、细菌数量和比例、真菌数量和比例与土壤碳氮含量、碳氮比、电导率呈显著或极显著正相关关系,细菌数量和比例、真菌数量和比例与土壤pH值呈显著或极显著负相关关系。【结论】生物结皮对半干旱地区土壤微生物具有重要影响,藓结皮较其他生物结皮可显著提高土壤微生物数量。
[Abstract]:[objective] to analyze the developmental characteristics of different types of biological crusts and the distribution characteristics of soil microorganisms in the loess hilly region.In order to clarify the effect of biological crust formation process on soil microorganism. [methods] A combination of field investigation and laboratory analysis was used to investigate the light algal crust, dark algal crust and a small amount of moss crust in loess hilly region.The developmental characteristics of a few algae crusts and five biological crusts of mosses, and the quantity and chemical properties of soil microbes in the biological crust and subcutaneous 0~2cm soil layer were measured.Finally, the correlation between the development characteristics of different biological crusts and soil chemical properties and the number of soil microbes was analyzed. [results] in the study area, the algal crusts, dark algae crusts, and a few mossy crusts were studied.The proportion of bacteria in the soil of different types of biological crust was 53.120.72.09, the proportion of actinomycetes was 27.4946.80, and the proportion of fungi was 0.080.92.In the biological crust, the total number of microbes and the number of bacteria in the soil increased from algal crust to moss crust. The number of bacteria, actinomycetes and fungi in mossy crust soil was significantly higher than that in other biological crust, and in the subcutaneous 0~2cm soil layer, the number of bacteria, actinomycetes and fungi was significantly higher than that of other organisms.The total number of microorganism and actinomycetes in the soil showed that the number of soil bacteria, actinomycetes and fungi was significantly higher than that of other organisms in moss crust, dark algal crust, dark algal crust, a small amount of phytoderma, a small amount of phytoderma, and the number of soil bacteria, actinomycetes and fungi.The proportion of bacteria in mossy crust soil was higher than that in algal crust, and the proportion of actinomycetes was decreased, and the proportion of fungi in mossy crust was the highest, and the proportion of fungi in 0~2cm soil layer was significantly higher than that in other biological crust.In vertical distribution, the number and proportion of bacteria and fungi in the soil of the biological cortex were higher than those in the soil layer of subcutaneous 0~2cm, but the number and proportion of actinomycetes were smaller than those in the soil of subcutaneous 0~2cm.The chemical properties of different types of biological crusts in the 0~2cm soil layer were significantly different from those in the biological crust layer and the subcutaneous 0~2cm soil layer.The total number of microbes, the number and proportion of bacteria, the number of fungi were positively correlated with moss coverage and crust thickness, while the proportion of actinomycetes was negatively correlated with moss coverage and crust thickness.The total number of microbes, the number and proportion of bacteria, the number and proportion of fungi were positively correlated with soil carbon and nitrogen content, C / N ratio, electrical conductivity, and the number and proportion of bacteria.There was a significant negative correlation between the number and proportion of fungi and soil pH. [conclusion] Biological crust has an important effect on soil microbes in semi-arid areas, and mossy crust can significantly increase the number of soil microbes compared with other biological crusts.
【作者单位】：西北农林科技大学资源环境学院;中国科学院教育部水土保持与生态环境研究中心黄土高原土壤侵蚀与旱地农业国家重点实验室;
【基金】：中国科学院“西部之光”联合学者项目国家自然科学基金项目(41271298,41571268)
【分类号】：S154.3

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