干旱区流动沙地建植梭梭(Haloxylon ammodendron)林后细粒物质输入对土壤碳氮积累的影响  

Effects of fine particulate matter input on soil carbon and nitrogen accumulation after establishment of Haloxylon ammodendron plantations on shifting sand dunes in arid area

作　　者：安芳娇 苏永中 牛子儒 刘婷娜 An Fangjiao;Su Yongzhong;Niu Ziru;Liu Tingna(Northwest Institute of Eco-Environment and Resources,Chinese Academy of Sciences,Lanzhou 730000;University of Chinese Academy of Sciences,Beijing 100049,China)

机构地区：[1]中国科学院西北生态环境资源研究院,甘肃兰州730000 [2]中国科学院大学,北京100049

出　　处：《中国沙漠》2021年第5期147-156,共10页Journal of Desert Research

基　　金：国家自然科学基金项目(31971730);国家重大研发计划项目(2017YFC0504304)。

摘　　要：在河西走廊中段临泽荒漠绿洲过渡带选择不同建植时间序列(0、3、6、11、19、28、46 a)的固沙梭梭(Haloxylon ammodendron)林,取冠层下和冠层外表层土样(0—10 cm),研究人工固沙梭梭林生长发育过程中土壤粒级组成和碳氮的变化,分析细粒物质变化对碳氮积累的贡献。结果表明:随着梭梭的生长发育土壤碳氮含量显著增加,无机碳(SIC)是有机碳(SOC)的2.7—11.2倍;黏粉粒和碳酸钙含量与土壤可侵蚀因子(EF)显著负相关,与结皮厚度显著正相关,冠层下结皮厚度是冠层外的1.9—2.6倍;土壤各粒级中SOC、SIC和全氮(TN)含量显著增加,黏粉粒中含量显著高于其他粒级,且对SOC、SIC和TN贡献由0 a的25.4%、8.5%和16.1%增至46 a的59.7%、33.9%和51.9%。干旱区土壤黏粉粒和碳酸钙含量的增加共同促进了土壤物理结皮的形成和发育,进而导致沙面的稳定,同时黏粉粒增加也是土壤碳氮固存的主要机制。Different ages(0-,3-,6-,11-,19-,28-and 46-years)of Haloxylon ammodendron plantations in Linze desert-oasis ecotone of northwestern China were selected and surface soil(0-10 cm)under and outside the canopy were sampled,to explore the changes of soil particle size and carbon and nitrogen in particle-size fractions during the development of sand-fixing H.ammodendron plantations,and analyze the contribution of soil fine particles to carbon and nitrogen accumulation.The results showed that soil carbon and nitrogen increased significantly with the growth of H.ammodendron,and inorganic carbon(SIC)was 2.7-11.2 times of organic carbon(SOC).The content of soil fine particles and calcium carbonate(CaCO3)were significantly negatively correlated with soil erodible fraction(EF),and significantly positively correlated with the thickness of soil crust.The thickness of soil crust under the canopy was 1.9-2.6 times that outside canopy.The content of SOC,SIC and total nitrogen(TN)in each particle-size fraction increased significantly,and the content of silt+clay fractions were significantly higher than other fractions.The contribution of silt+clay fractions to SOC,SIC and TN increased from 25.4%,8.5%and 16.1%in year 0 to 59.7%,33.9%and 51.9%in year 46.In arid areas,the increase of silt+clay fractions and CaCO3 content jointly promoted the formation and development of soil physical crusts,which led to the stability of the sand surface.Meanwhile,the increase of silt+clay fractions were also the main mechanism of soil carbon and nitrogen sequestration.

关 键 词：固沙梭梭(Haloxylon ammodendron)林 固沙年限 颗粒组分 土壤碳氮固存 绿洲边缘 

分 类 号：S153.6[农业科学—土壤学]