短期降水控制对鼎湖山南亚热带季风林土壤有机碳及官能团碳组分的影响  

Effects of short–term precipitation manipulation on soil organic carbon and organic carbon groups in the south subtropical monsoon forest of Dinghushan

作　　者：许展颖 陈小梅 张雪莹 刘慕瑛 高玉娟 XU Zhanying;CHEN Xiaomei;ZHANG Xueying;LIU Muying;GAO Yujuan(School of Geography and Remote Sensing,Guangzhou University,Guangzhou 510006,China)

机构地区：[1]广州大学地理科学与遥感学院,广州510006

出　　处：《生态科学》2023年第5期223-230,共8页Ecological Science

基　　金：广东省自然科学基金项目(2017A030313153);广州市科技计划项目(201804010159);广州大学校内科研项目(YG2020018)。

摘　　要：区域降水特征变化影响森林土壤有机碳积累。2013年6月—2017年1月,设置年降水量减少50%(DP)、年降水总量不变而降水次数增加(IF)、自然降水(CK)3种降水处理,利用^(13)C NMR技术研究鼎湖山南亚热带季风林土壤总有机碳及其官能团碳组分对降水变化的响应。结果表明:DP处理显著提高了20—40 cm土壤易氧化有机碳,IF处理显著提高了0—10 cm土壤总有机碳和易氧化有机碳;鼎湖山季风林土壤官能团碳结构以烷氧碳为主;DP处理显著提高了20—40 cm土壤烷氧碳和芳香碳含量,IF处理显著提高了0—10 cm土壤的烷氧碳、芳香碳与羰基碳含量;在土壤总有机碳和易氧化有机碳显著变化的土层中惰性指数趋于降低。短期降水控制增加了鼎湖山南亚热带季风林土壤总有机碳和易氧化有机碳,其官能团组分也发生改变,土壤碳结构稳定性下降,不利于季风林土壤有机碳的积累。Changes of precipitation characteristics affect the accumulation of soil organic carbon in the forest.From June 2013 to January 2017,we set up three precipitation manipulation treatments in a subtropical climax forest,monsoon evergreen broadleaved forest of Dinghushan.The manipulation treatments were included:decreasing amount of precipitation by 50%(DP),increasing precipitation frequency with total precipitation amount unaltered(IF)and ambient precipitation(CK).It explored the influence of precipitation manipulation on total organic carbon and organic carbon groups which were characterized by ^(13)C nuclear magnetic resonance spectroscopy.The results showed that DP treatment significantly increased the concentration of ROC in 20-40 cm soil.IF treatment significantly increased the concentrations of TOC and ROC in 0-10 cm soil.O-alkly carbon was the main component of soil carbon in Dinghushan monsoon forest.DP treatment significantly increased concentrations of O-alkly carbon and aromatic carbon.IF treatment significantly increased concentrations of O-alkly carbon,aromatic carbon and carbonyl carbon.Recalcitrance indexes decreased in the soil layers in which the concentrations of TOC and ROC were significantly increased.Our results suggest that short-term precipitation manipulation increases the concentrations of TOC and ROC.The fraction of organic carbon groups is changed and soil carbon tends to be unstable.Therefore,precipitation changes cannot promote the accumulation of carbon of monsoon forest.

关 键 词：降水控制 土壤有机碳 ^(13)C核磁共振 南亚热带森林 

分 类 号：S714[农业科学—林学]