集约经营对山核桃林地土壤腐殖质组分碳含量的影响

[目的]研究并探讨土壤腐殖质各组分碳含量的变化规律,为山核桃林地土壤管理提供理论依据。[方法]采集并分析山核桃林经营历史为5,10,15,20a的土壤样品的土壤腐殖质各组分碳含量,并与天然混交林(0a)进行比较。[结果]与天然山核桃—阔叶混交林(0a)相比,随着经营历史的延长,林地土壤腐殖质各组分碳含量的变化主要发生在表层(0—10cm),胡敏酸碳、富里酸碳和胡敏素碳含量均下降。与0a相比,集约经营5a后胡敏酸碳、富里酸碳和胡敏素碳含量分别下降了42.8%,23.9%和21.2%,而集约经营20a后,分别下降了45.3%,39.0%,32.3%。集约经营20a后,亚表层(10—30cm)土壤胡敏素碳含量上升了94.2%。[结论]集约经营降低了山核桃林地土壤表层和亚表层的胡敏酸碳和富里酸碳含量,同时也降低了表层土壤胡敏素碳含量,而提高了亚表层土壤胡敏素碳含量。

Effects of Intensive Management on Carbon Content of Soil Humus Composition in Carya Cathayensis Forest

[Objective] The objective of this study is to research the variation of soil humus carbon content of Carya cathayensis(Chinese hickory) forest after intensive management, in order to provide theoretical basis for soil management in the forest. [Methods] Based on the long-term investigation, we collected the soil samples from forests that were intensively-managed for 5, 10, 15, and 20 years, respectively. We then analyzed the soil humus of the intensively-managed forests(IMF), and compared with the evergreen and deciduous broadleaf forest(EDBF). [Results] The variation of soil humus carbon content mainly occurred in the surface soil. Soil humus including humic acid carbon(HAC), fulvic acid carbon(FAC), and humin acid carbon(HMC) decreased as an EDBE were converted to an IMF. Compared to the EDBF, there was a decrease in HAC(42.8%), FAC(23.9%), and HMC(21.2%) in the Chinese hickory forests after a 5-year of intensive management. After a 20-year intensive management, HAC, FAC, HMC were decreased by 45.3%, 39.0% and 32.3%, respectively. As to the sub-surface, after 20 years, HMC increased by 94.2%. [Conclusion] Intensive management reduced the content of the soil humic acid and fulvic acid carbon at surface and sub-surface soil.