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在野外调查的基础上,采集不同侵蚀类型区内发育至稳定阶段的生物结皮,分析水分和温度变化对生物结皮固氮活性的影响.结果表明:水蚀区、水蚀风蚀交错区、风蚀区生物结皮固氮活性表现为水蚀区(127.7μmol.m-2.h-1)>水蚀风蚀交错区(34.6μmol.m-2.h-1)>风蚀区(6.0μmol.m-2.h-1);3个侵蚀类型区生物结皮固氮的最适温度分别为35、25和15℃.在最适温度条件下,水蚀区及水蚀风蚀交错区生物结皮固氮活性在100%～40%田间持水量时差异不显著;风蚀区生物结皮固氮活性对水分变化较为敏感,当含水量降至80%田间持水量时固氮活性开始显著降低,降至20%田间持水量时,生物结皮固氮作用停止.3个侵蚀类型区生物结皮固氮活性及其对水分与温度变化响应的差异与不同侵蚀类型区的气候、环境及生物结皮物种组成有关.
Based on the field investigation, the biological crusts, which developed to the stable stage in different erosion types, were collected to analyze the effects of water and temperature on the nitrogen fixation activity of the biological crusts. The results showed that the water erosion zones, The nitrogen fixation activity of the crust was as follows: water erosion (127.7μmol.m-2.h-1)> water erosion and wind erosion (34.6μmol.m-2.h-1)> wind erosion (6.0μmol.m- 1) .The optimum nitrogen fixation temperature for the biological crusts was 35, 25 and 15 ℃ for the three erosion types, respectively.The biocatalytic activity of bio-crust was 100% -40% at the optimum temperature, When the water content decreased to 80% field capacity, the nitrogen fixation activity began to decrease remarkably. When the water holding capacity decreased to 20%, the bio-crust Nitrogen fixation stopped.Nitrogenous activity of the biological crusts in the three erosion types and their differences in response to water and temperature were related to climate, environmental and biological crust species composition in different erosion types.