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土壤温度对作物生长发育、土壤水盐运移、生物的数量与活性、土壤碳平衡等均有较大的影响。为了研究毛乌素沙地生物结皮区和裸沙区土壤温度的差异,于2010年9～11月在陕北毛乌素沙地东南缘神木县圪丑沟地区,选择晴朗天气进行定位观测试验。结果表明:①同一剖面深度,生物结皮样地土壤温度的日变化趋势同裸沙样地一致;且从6:00～21:00时每隔3 h,土壤垂直剖面的温度沿着“”型、微“(”型、明显“(”型、“/”型、微“)”型、“”型进行周期性变化。②生物结皮的覆盖极显著降低了地表的土壤温度(P<0.01)。③生物结皮样地和裸沙样地表层土壤温度变幅最大,随剖面深度的增加土壤温度变化趋缓。当气温和土壤含水量较低时,生物结皮对同一深度土壤温度变化幅度的影响更明显。从垂直剖面角度看,生物结皮降低了土壤温度及其变幅。④生物结皮提高了0～25 cm深度土壤温度对气温的敏感程度。表明土壤温度的变化是多因素作用的结果,前人仅根据生物结皮的颜色来判断其对土壤温度的影响是不够的。生物结皮对土壤温度造成影响的主要原因,可能是其改变了土壤表层结构及土壤水分状况。在今后相关研究中如水分蒸发、土壤化学性状的改变等,要特别注意生物结皮的温度效应对这些过程的影响,从而使分析更加客观深入。
Soil temperature has great influence on crop growth and development, soil water and salt transport, biomass quantity and activity, soil carbon balance and so on. In order to study the difference of soil temperature between the biological crusts and the bare sandy areas in Mu Us sandy land, we selected the sunny weather for the observation and observation from October to November in 2010 in the Yuhugou area, Shenmu County, southeastern margin of Mu Us sandy land in northern Shaanxi Province. The results showed as follows: ①The diurnal variation trend of soil temperature in the same crust and bio-crust was the same as that in the bare sand plots; and the temperature of the vertical section of the soil changed from “ Periodic changes are made in the type ”“, ”“ and ”“, ”“ and ”" The coverage of biological crust significantly reduced the soil temperature (P <0.01). (3) The soil temperature in the bio-crust and the bare sand soil surface fluctuated the most, with the increase of the profile depth, the soil temperature changed slowly. And the soil water content is low, the influence of biological crust on the soil temperature in the same depth is more obvious.From the vertical section, the biological crust reduces the soil temperature and its amplitude.④The biological crust increases 0 ~ 25 cm depth of soil temperature on the temperature sensitivity.It shows that the change of soil temperature is the result of multi-factorial effects, the former only according to the color of the biological crust to determine its impact on soil temperature is not enough .Biological crust on the soil temperature caused The main reason may be that it changed the soil surface structure and soil moisture status in the future related research Studies such as water evaporation, changes in soil chemical properties, pay special attention to the temperature effect of biological crust on these processes, so that the analysis more objective and in-depth.