科尔沁沙地沙丘固定过程中植物生物量及土壤特性

Plant Biomass and Soil Properties during the Process of Dune Restoration in the Horqin Sandy Land

为了解沙丘固定不同阶段植物群落的生物量特点及土壤理化特性的变化规律,研究比较了科尔沁沙地流动沙丘、半固定沙丘、固定沙丘、沙质草地4种生境的地上、地下生物量,并分4层土壤深度分析了土壤理化特性的演变特征及相关关系。结果表明:(1)植物地上生物量与地下生物量显著正相关,0~10cm土层地下生物量最大,随着沙丘的固定,地下10~20、20~40、40~60cm深度土层的生物量显著增加,植物地上生物量依次增大,分别为2.20、98.10、131.41、190.38g·m-2,地下地上生物量比依次为10.44、1.67、0.81、1.18;(2)随着沙丘的固定,表层土壤容重由1.62g·cm3下降到1.33g·cm3,各土层的粉沙和极细沙的占比依次增加,中沙比例依次减小,土壤碳氮含量、碳氮比、pH值、电导率均逐渐增加;(3)地上、地下生物量均与表层土壤碳氮含量、pH值、电导率显著正相关,土壤碳、氮含量均与pH值、电导率、土壤水分含量显著正相关,与土壤容重显著负相关(p【0.05)。综上所述,沙丘恢复过程中植物生物量的增加与表层土壤颗粒细化、营养物质增多、水分增加密切相关,土壤-植被系统构成了有机的综合体。

To understand the differences of plant biomass characteristics and soil chemical and physical properties from different plant communities in the process of sand dune restoration,this paper examined the above-groundand below-ground biomass of mobile dune,semi-fixed dune,fixed dune,sandy grasslandfour habitats,and analyzed characteristics of soil properties and their relationships by separatingsoil into 4 layers.The results showed that plant aboveground biomass and below-ground biomass had significantly positive correlation,and the 0-10 cm depth soil layer had the largest biomass.With the fixation of sand dune,10-20,20-40,40-60 cm depth belowground biomass increased significantly,and the aboveground biomass increased successively in 2.20,98.10,131.41,190.38 g·m-2;below-aboveground biomass ratio was 10.44,1.67,0.81,1.18 respectively.In the process of sand dune stabilization,soil bulk density in the surface layer dropped from1.62 g·cm3 to 1.33 g·cm3;the percentage of silt sand and very fine sand from each soil layer went up,while medium grained sand went down successively;soil carbon and nitrogen content,pH,EC all accumulated gradually.Below-ground biomass had significantly positive correlation with soil carbon and nitrogen content,pH,EC;both soil carbon and nitrogen content positively related with pH,EC and soil moisture,but negatively correlated with soil bulk density(p<0.05).In conclusion,the augment of plant biomass was strongly linked with the refinement of surface layer soil particle,increase of nutrient substance and water content in the process of dune restoration;soil-vegetation systems are integrated comprehensive units.