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采用室内控制温度(-10、5、15、25、35和40℃)和湿度(29%、58%、85%和170%田间持水量,FWC)培养原状土柱的方法,研究腾格里沙漠东南缘天然植被区藓类结皮土壤氮矿化特征及其对水热因子的响应.结果表明:低温(<15℃)培养时,土壤氮素转化以微生物固持作用为主,>25℃后土壤氮素转化速率显著增加.藓类结皮土壤氮素转化速率及其对温度的敏感性均高于无结皮土壤,且在85%FWC时敏感性最高,表明藓类结皮的存在有利于土壤氮素的转化.随着土壤湿度的增加,土壤氮素转化速率呈先增加后减小的趋势,85%FWC时最大.藓类结皮土壤净氮矿化速率在高温(25~40℃)和中等水分条件下(58%FWC和85%FWC)最大,呈现明显的温湿度交互作用.藓类结皮的繁衍和拓殖能够提高土壤的供氮能力,促进氮素循环,有助于土壤生态系统的修复.
The method of cultivating undisturbed soil columns with indoor temperature control (-10,5,15,25,35 and 40 ℃) and humidity (29%, 58%, 85% and 170% field capacity, FWC) Soil nitrogen mineralization and its responses to hydrothermal factors in moss crusts in the natural vegetation zone of the southeastern margin of the desert. The results showed that soil nitrogen transformation was dominated by microbial retention at temperatures> 25 ℃ The nitrogen conversion rate of soil increased significantly after transplanting, the nitrogen conversion rate and its sensitivity to temperature of moss-crust soil were higher than that of non-skin soil, and the sensitivity was the highest at 85% FWC, indicating the existence of moss crust Which is conducive to the transformation of soil nitrogen.With the increase of soil moisture, soil nitrogen conversion rate first increased and then decreased, the maximum 85% FWC moss crust soil net nitrogen mineralization rate at high temperature (25 ~ 40 ℃) and medium moisture condition (58% FWC and 85% FWC), showing a significant interaction of temperature and humidity. The multiplication and colonization of moss crusts can increase soil nitrogen supply and promote nitrogen cycle, Restoration of soil ecosystems.