Soil Organic Carbon Mineralization as Affected by Cyclical Temperature Fluctuations in a Karst Region of Southwestern China

作     者：CI En Mahdi M.AL-KAISI WANG Liange DING Changhuan XIE Deti 

作者机构：College of Resources and Environment Southwest University Department of Agronomy Iowa State University 

出 版 物：《Pedosphere》 (土壤圈（英文版）)

年 卷 期：2015年第25卷第4期

页      面：512-523页

核心收录：

学科分类：0818[工学-地质资源与地质工程] 09[农学] 0903[农学-农业资源与环境] 0901[农学-作物学] 090301[农学-土壤学] 

基　　金：supported by the National Natural Science Foundation of China (No. 41301245) the Strategic Priority Research Program of Chinese Academy of Sciences (No. XDA05050506) the Special Program for National Science & Technology Basic Work of China (No. 2014FY110200A13) the Fundamental Research Funds for the Central Universities of China (No. XDJK2013B043) 

主　　题：西南喀斯特地区 有机碳矿化 周期性波动 土壤温度 温度波动 土壤有机碳 石灰岩土壤 中国 

摘      要：The diurnal fluctuation in soil temperature may influence soil organic carbon(SOC) mineralization, but there is no consensus on SOC mineralization response to the cyclical fluctuation in soil temperature. A 56-d incubation experiment was conducted to investigate the effects of constant and variable temperatures on SOC mineralization. Three soils were collected from the karst region in western Guizhou Province, southwestern China, including a limestone soil under forest, a limestone soil under crops and a yellow soil under crops. According to the World Reference Base(WRB) classification, the two limestone soils were classified as Haplic Luvisols and the yellow soil as a Dystric Luvisol. These soils were incubated at three constant temperatures(15, 20 and 25?C) and cyclically fluctuating temperatures(diurnal cycle between 15 and 25?C). The results showed that the 56-d cumulative SOC mineralized(C56)at the fluctuating temperatures was between those at constant 15 and 25?C, suggesting that the cumulative SOC mineralization was restricted by temperature range. The SOC mineralization responses to the fluctuating temperatures were different among the three soils, especially in contrast to those at constant 20?C. Compared with constant 20?C, significant(P 0.05) decreases and increases in C56 value were found in the limestone soil under forest and yellow soil under crops at the fluctuating temperatures, respectively. At the fluctuating temperatures, the forest soil with lower temperature coefficient Q10(the relative change in SOC mineralization rate as a result of increasing the temperature by 10?C) had a significantly(P 0.05) lower SOC mineralization intensity than the two cropland soils. These indicated that differences in temperature pattern(constant or fluctuating) could significantly influence SOC mineralization, and SOC mineralization responses to the fluctuating temperatures might be affected by soil ***, the warmer temperatures might improve