土壤呼吸对季节性冻融干扰的响应

Soil Respiration Response to Seasonal Freezing-Thawing Interference

在全球气温上升的背景下,了解高纬度高寒区季节性冻融对土壤呼吸的影响是全面解析高寒区土壤碳循环不可或缺的重要环节,也是进一步研究生态系统如何响应和适应全球变化机制的重要前提。季节性冻融交替通过改变土壤结构、水热性质和生物性状来影响土壤呼吸,同时土壤冻融格局(交替次数、冻融极端温度)和不同冻融时期均对土壤呼吸具有较为显著的影响。在冻融的最初循环阶段土壤呼吸会增强(秋冬冻融交替期),最后下降至较为稳定的水平(冬季冻结期),随后土壤呼吸再度增强(冬春冻融交替期)。土壤呼吸作为全球碳循环最主要的途径之一,其微小的变化都会引起大气CO_2浓度的较大变化,其动态变化规律受多种因素共同影响,研究冻融干扰对土壤呼吸的影响,有助于了解土壤碳变化的速率和趋势,对预测温室效应导致的全球变化具有重要意义。

Under the background of global warming,understand the high latitude Gao Han District seasonal freezingand thawing effects on soil respiration is the indispensable important link of comprehensive analytic Gao Han District soilcarbon cycle,is also the important premise to further study how to respond and adapt to the global ecological systemchange mechanism. Seasonal freezing and thawing alternation by changing the soil structure,water thermal properties andbiological properties to affect soil respiration,at the same time soil freezing-thawing pattern(freezing-thawing alternationfrequencies,freezing-thawing extreme temperature)and different freezing-thawing period have more significant effect onsoil respiration. And soil respiration increased in the first cycle of freezing and thawing(autumn and winter freezing-thawingperiod),then fell to a relatively stable level(winter freezing period),then soil respiration increased again(winter andspring freezing-thawing period). Soil respiration,as one of the most important way to the global carbon cycle,the smallchanges will lead to large variation of the atmospheric CO2 concentration,the dynamic change law is influenced by manyfactors,study the influence of the freeze-thaw disturbance to soil respiration,help to understand the rate and the trend of thechange of soil carbon,for predicting global changes caused by the greenhouse effect is of great significance.