摘要
【目的】探寻三峡库首不同地貌区柑橘园的土壤有机碳(SOC)分布特征和驱动因子,促进科学制定碳固存策略。【方法】对三峡库首宜昌市夷陵区(平原地貌,31个样地)和秭归县(丘陵地貌,63个样地)的柑橘园,分析0~10 cm(表土层)、10~20 cm(中土层)和20~40 cm(底土层)土层SOC含量的分布特征及驱动因素,并通过层次分割量化地貌、土层养分因子对SOC含量的贡献。【结果】丘陵区表土层和中土层的SOC含量均显著高于平原区对应土层的SOC含量(P<0.05)。2种地貌区的表土层SOC含量均显著高于中土层和底土层SOC含量(P<0.05)。2类地貌区内不同土层的SOC含量均与同一土层的全氮(TN)含量显著正相关(P<0.05)。平原区表土层和底土层的碱解氮均驱动相应土层的SOC积累(P<0.05)。丘陵区各土层的SOC含量均与相同土层的SOC/TN显著正相关(P<0.05)。平原区和丘陵区表土层的SOC是中土层SOC的主要来源,贡献分别为34.5%和41.3%;中土层的SOC是底土层SOC的主要来源,贡献分别为30.8%和34.2%。在2种地貌区,表土层养分因子不仅对中土层的SOC贡献近50%,而且和中土层的养分因子共同贡献底土层SOC约50%。【结论】平原区和丘陵区柑橘园可分别通过调控土层间养分有效性和SOC/TN以提高SOC积累。
【Objective】Exploring the distribution characteristics and driving mechanism of soil organic carbon(SOC)pools in citrus orchards with different topographies at the Head Part of Three Gorges Reservoir is helpful to formulate carbon sequestration strategies.【Method】The SOC distribution characteristics and driving factors of 0~10 cm(top soil layer),10~20 cm(middle soil layer)and 20~40 cm(bottom soil layer)were analyzed in citrus orchards of Yiling District(plain area,31 sample sites)and Zigui County(hill area,63 sample sites)in Yichang City,the Head Part of Three Gorges Reservoir.The contribution of different topographic and soil layer nutrient factors to SOC was analyzed by hierarchical partitioning.【Result】The SOC contents of topsoil and middle soil layer in hills were significantly higher than those in plains(P<0.05).The SOC content in the topsoil layer was significantly higher than that in the middle and bottom soil layers(P<0.05).There was a significant positive correlation between SOC content and total nitrogen(TN)content in different soil layers in both topographies(P<0.05).In the plain,alkali-hydrolyzale nitrogen in the topsoil and bottom soil layers drove SOC accumulation in the corresponding soil layers(P<0.05).The SOC contents of different soil layers in the hill were positively correlated with the ratio of SOC to total nitrogen(SOC/TN)in the same soil layer(P<0.05).The topsoil SOC in the plain and hill was the main source of SOC in the middle soil layer,contributing 34.5%and 41.3%,respectively.SOC in the middle soil layer was the main source of SOC in the bottom soil layer,contributing 30.8%and 34.2%,respectively.In the two topography areas,the nutrient factors of the topsoil layer not only contribute nearly 50%of the SOC of the middle soil layer,but also contribute about 50%of the SOC of the bottom soil layer together with the nutrient factors of the middle soil layer.【Conclusion】Citrus orchards in plain and hilly areas can improve soil carbon sequestration by regulating soil nutrient availability and SOC/TN,respectively.
作者
胡建文
刘常富
勾蒙蒙
曾立雄
雷蕾
陈会玲
肖文发
Hu Jianwen;Liu Changfu;Gou Mengmeng;Zeng Lixiong;Lei Lei;Chen Huiling;Xiao Wenfa(Key Laboratory of Forest Ecology and Environment of National Forestry and Grassland Administration,Ecology and Nature Conservation Institute,Chinese Academy of Forestry,Beijing 100091,China;Co-Innovation Center for Sustainable Forestry in Southern China,Nanjing Forestry University,Nanjing 210037,China)
出处
《陆地生态系统与保护学报》
2023年第6期1-9,共9页
Terrestrial Ecosystem and Conservation
基金
国家自然科学基金项目(32172671,32301670,32130074)。
关键词
土壤有机碳
柑橘园
地貌
土层
soil organic carbon
citrus orchards
topography
soil layers
