紫色丘陵区典型旱地土壤有机碳矿化对突发性变温的响应  

Soil Organic Carbon Mineralization Response to Sudden Temperature Change in the Typical Dry Land Distributed in the Purple Hilly Region

作　　者：樊晶晶[1] 慈恩[1,2] 唐江[1] 丁长欢[1] 连茂山 王子芳[1,2] 

机构地区：[1]西南大学资源环境学院,重庆400715 [2]重庆市三峡库区农业面源污染控制工程技术研究中心,重庆400715

出　　处：《水土保持学报》2017年第1期286-290,共5页Journal of Soil and Water Conservation

基　　金：国家自然科学基金项目(41301245);国家科技基础性工作专项(2014FY110200A13);中国科学院战略性先导科技专项(XDA05050506)

摘　　要：以紫色土为供试土壤,采用室内培养的方法,设置恒温20℃(HW)、突发性降温(20℃→10℃)(BW1)和突发性升温(20℃→30℃)(BW2)3个温度处理,研究了突发性变温下紫色丘陵区典型旱地土壤(紫色土)的有机碳矿化特征。其中温度突变的具体设置为:待20℃恒温培养至土壤有机碳矿化(Soil organic carbon,SOC)速率基本平稳且维持在较低水平时(第29天),将培养温度分别突降至10℃和突升至30℃,继续培养47d。结果表明,突发性变温对紫色土SOC矿化有显著影响(P<0.05),在变温当天(第30天),突发性升温(BW2)处理对紫色土SOC矿化有明显促进作用,而突发性降温(BW1)处理则会明显削弱紫色土SOC矿化,二者的SOC矿化速率分别较恒温(HW)处理提高了225.1%,降低了38.5%;变温后的培养初期(第30~44天),各温度处理间的SOC累积矿化量存在显著差异(P<0.05),与HW处理相比,BW2和BW1处理中紫色土SOC累积矿化量的变幅分别为+140.5%(升高)和-55.3%(降低);随培养时间的延续,各处理间的SOC累积矿化量未发现明显差异。表明突发性变温对紫色土SOC矿化的影响具有一定的时限性,其影响时长在2周左右。结合矿化动力学分析可知,同恒温相比,突发性变温主要通过改变土壤易分解有机碳库(C0)大小进而影响紫色土SOC矿化。The purple soil was used as the test soil.An incubation experiment in the laboratory was conducted to explore the effects of sudden temperature change on soil organic carbon mineralization of the typical dry land soil（purple soil）sampled from the purple hilly region.Experiment consisted of three treatments,that was,treatment HW（constant temperature 20 ℃）,treatment BW1（a sudden cooling from 20 ℃ to 10 ℃）and treatment BW2（a sudden warming from 20 ℃ to 30 ℃）.In treatment BW1 and treatment BW2,the sudden temperature change both happened when soil organic carbon（SOC）mineralization rate was basically stable and maintained a relatively lower level at the temperature of 20℃（29th day）.After the sudden temperature change,treatment BW1,treatment BW2 and treatment HW was cultivated for another 47 d.The results showed that sudden temperature change had a notable effect on purple soil SOC mineralization（P〈0.05）.More specifically,treatment BW2 had significantly promoted soil SOC mineralization,however,treatment BW1 dramatically impaired that.Compared with the constant temperature（HW）treatment,the SOC mineralization rates of the two increased by 225.1% and decreased by 38.5%.There was a significant difference in the amount of SOC accumulated mineralization between each temperature treatment（P〈0.05）within initial stage after sudden temperature change（30th—44th day）.And compared to accumulated soil SOC mineralization in treatment HW,that in treatment BW2 and treatment BW1 increased by 40.5% and decreased by 55.3%respectively.But with the extension of the culture time,the amount of SOC accumulation in each treatment did not find a significant difference.Indicated that the effect of sudden temperaturechange on purple soil SOC mineralization was time-bounded,which remained around two weeks.Combined with mineralization kinetic data,the results showed that sudden temperature change affected SOC mineralization by changing the labile SOC pool size.

关 键 词：土壤有机碳 突发性变温 紫色土 矿化动力学 

分 类 号：S153.6[农业科学—土壤学]