桉树人工林林龄对土壤团聚体有机碳稳定性的影响  

Soil Organic Carbon Stability in Aggregates as Affected by Stand Age in Eucalyptus SPP.Plantation

作　　者：余平福 朱俊华 吴群升 杜亮 覃伟 何欣欣 YU Pingfu;ZHU Junhua;WU Qunsheng;DU Liang;QIN Wei;HE Xinxin(Guangxi Zhuang Autonomous Region State-owned Dagui Mountain Farm,Guangxi Hezhou 542899;College of Forestry,Guangxi University,Guangxi Nanning 530004)

机构地区：[1]广西壮族自治区国有大桂山林场,广西贺州542899 [2]广西大学林学院,广西南宁530004

出　　处：《林业科技》2023年第6期6-10,共5页Forestry Science & Technology

基　　金：广西国有大桂山林场《桉树人工林地力维持策略研究》(202200100);广西壮族自治区林业局《桂东北桉树中大径材培育关键技术研究与示范》(桂林科研[2022ZC]第15号)。

摘　　要：本研究以广西国有大桂山林场为研究区域,选择传统轮伐期内不同林龄(1 a、2 a和4 a)桉树人工林土壤以及邻近撂荒地土壤(0 a)为研究对象。采集0~20 cm土层原状土样,通过湿筛法将土样分为4个粒级团聚体,包括>2 mm、2~1 mm、1~0.25 mm和<0.25 mm。针对不同粒级土壤团聚体,测定其有机碳、活性碳和惰性碳含量,并计算其有机碳稳定性(由Kos值表征)。结果表明,在不同林龄桉树人工林中,土壤团聚体有机碳(包括活性碳和惰性碳)含量随着团聚体粒级减小而显著升高,从而导致更多的土壤有机碳分布在<0.25 mm粒级团聚体中,表明<0.25 mm粒级团聚体是土壤有机碳的主要载体。在种植桉树过程中,土壤有机碳含量和Kos值呈先升高后降低的变化趋势,在种植桉树2 a时最高,表明该林龄桉树人工林土壤中积累了更多且更稳定的有机碳。因此,种植桉树2 a以后,应注意土壤有机碳的积累与固持,从而维持桉树人工林土壤的碳汇效应。In this study,the state-owned Daguishan forest farm in Guangxi was selected as the research area,and the soil of eucalyptus plantation with different ages(1 a,2 a and 4 a) and nearby abandoned land(0 a)were selected as the research objects.The undisturbed soil samples of 0-20 cm soil layer were collected and divided into 4 aggregate fractions,including >2 mm,2-1 mm,1-0.25 mm and <0.25 mm aggregates,by wet sieve method.The contents of organic carbon,labile carbon and inert carbon in soil aggregates of different grain sizes were determined,and their organic carbon stability(characterized by Kos value) was calculated.The results showed that the content of organic carbon(including labile carbon and inert carbon) in soil aggregates increased significantly with the decrease of aggregate size in eucalyptus plantations of different ages,resulting in more soil organic carbon distributed in <0.25 mm aggregates,indicating that the <0.25 mm aggregates are the main carriers of soil organic carbon.In the process of planting eucalyptus,soil organic carbon content and Kos value showed a trend of first increasing and then decreasing,and the highest values were reached when planting eucalyptus 2 a,indicating that more and more stable organic carbon accumulated in the soil of the aged eucalyptus plantation.Therefore,after planting eucalyptus 2 a,attention should be paid to the accumulation and retention of soil organic carbon,so as to maintain the carbon sink effect of eucalyptus plantation soil.

关 键 词：桉树人工林 土壤团聚体 有机碳含量 有机碳稳定性 

分 类 号：S792[农业科学—林木遗传育种]