宣威市退耕还林柳杉林地土壤有机碳含量及活性组分的林龄变化

发布时间：2018-03-11 04:00

  本文选题：退耕还林　切入点：柳杉林　出处：《林业科学》2017年01期 　论文类型：期刊论文

【摘要】：【目的】探讨云贵高原地区土壤有机碳含量及其活性组分在退耕还林后的变化,为退耕还林后的土壤碳储量变化评价和碳汇管理提供科学依据。【方法】在云南省宣威市选择耕地对照和不同退耕还林年数(4,8,12年生)的柳杉人工林地,在不同土层(0~20,20~40和40~60 cm)采集土壤并收集枯落物和细根样品,测定土壤有机碳及其活性组分含量、土壤密度、土壤全氮含量、枯落物现存量和细根生物量。【结果】与耕地相比,退耕还林4,8和12年生时林地0~60 cm土层土壤有机碳含量分别下降20.07%,19.29%和11.52%,即退耕还林初期土壤有机碳含量显著下降,在退耕还林4年后开始逐渐回升,但在12年后仍未恢复到耕地水平;土壤高活性有机碳含量以造林前的耕地最高(4.46 g·kg~(-1)),4年生时最低(2.67 g·kg~(-1));土壤次高活性有机碳含量以8年生时最高(12.03 g·kg~(-1),4年生时最低(4.61 g·kg~(-1));土壤活性有机碳含量以8年生时最高(20.94 g·kg~(-1)),12年生时最低(9.12 g·kg~(-1));土壤有机碳含量及其活性组分含量均随土层加深而减小,且存在显著的土层差异(P0.05),有机碳含量的最小值(11.14 g·kg~(-1))出现在8年生40~60 cm土层;各林龄柳杉林地0~60 cm土层有机碳含量及其高活性有机碳、次高活性有机碳与土壤全氮含量的相关系数分别为0.894,0.756和0.755,均极显著正相关,与土壤密度的相关系数为-0.664,显著负相关。【结论】退耕还林柳杉林地0~60 cm土层有机碳含量及其活性组分含量随林龄增加先降后升,造林年数和林下枯落物量是影响土壤有机碳含量及其活性组分含量的重要因子,今后在森林碳汇管理中需大力推行封山育林,延长林分林龄,尽量保留林下枯落物。
[Abstract]:[Objective] to investigate the changes of Yunnan Guizhou Plateau, soil organic carbon content and its active components in after returning farmland to forest, to provide a scientific basis for soil carbon storage changes after returning farmland to forest carbon sequestration evaluation and management. [method] in Xuanwei City of Yunnan province to choose farmland control and returning farmland to forest in different years (4,8,12 years) the Cryptomeria Plantation in different soil layers (0~20,20~40 and 40~60 cm) to collect soil and collect litter and fine root samples, determination of soil organic carbon and its active component content, soil density, soil nitrogen content, litter biomass and root biomass. [results] compared with cultivated land conversion of cropland to forest, and 4,8 the 12 year old woodland 0~60 cm soil organic carbon content decreased by 20.07%, 19.29% and 11.52%, the farmland soil organic carbon content in forest stage decreased significantly, a gradual recovery in returning farmland to forest 4 years after the start, but not in 12 years. 澶嶅埌鑰曞湴姘村钩;鍦熷￥楂樻椿鎬ф湁鏈虹⒊鍚�閲忎互椋�

本文编号：1596457