生物土壤结皮是荒漠生态系统的重要组成部分，对荒漠土壤的稳定和功能具有极其重要的作用。本研究以古尔班通古特沙漠两种生物土壤结皮(藻-地衣、藓类)为对象，以裸沙为对照，选取土壤碳氮磷循环相关养分指标，通过平均值法计算土壤多功能指数(SMF)，研究生物土壤结皮对不同土层SMF的影响，并解析其影响因素。结果表明:有机碳(TOC)、全氮(TN)、全磷(TP)、无机氮(IN)和可溶性有机氮(DON)等土壤单一功能指数随结皮的发育而增加，随土层的加深而降低;裸沙SMF在-0。96～0。55，在0～5 cm 土层呈上升趋势，在5～20cm 土层呈下降趋势;藻-地衣混生结皮和藓类结皮SMF分别在-0。53～1。33和-0。43～2。05，在0～20 cm 土层呈现降低趋势;三种类型生物土壤结皮SMF在20～100 cm 土层趋于稳定;SMF在0～20 cm和0～100 cm整体上表现为藓类结皮＞藻-地衣混生结皮＞裸沙;土壤pH、含水量(SWC)和脲酶活性与SMF的垂直变化密切相关，其中pH、SWC与SMF具有显著的负效应，脲酶活性具有显著的正效应;生物土壤结皮土壤粒径大小也是影响SMF的主要因素，中砂含量对SMF具有显著的负效应，粗砂含量对SMF具有显著的正效应;生物土壤结皮的发育显著提高了土壤单一功能和土壤多功能，但结皮对土壤多功能的影响主要集中在表层土壤0～20 cm范围，对更深层土壤的影响较小，生物土壤结皮影响土壤多功能的同时，其他功能亦随之发生改变。
Vertical patterns of soil multifunctionality as affected by biological soil crusts in Gurbantunggut Desert
As an important part of desert ecosystems,biological soil crusts(BSCs)play an extremely important role in the stability and function of desert soils.We analyzed the influence of BSCs on soil multifunctionality(SMF)in different soil layers and main driving factors.This study was carried out in the Gurbantunggut Desert,and two types of BSCs(algal-lichens and mosses)were used as research objects(with bare sand as the control).Soil or-ganic carbon(TOC),total nitrogen(TN),total phosphorus(TP),inorganic nitrogen(IN)and soluble organic nitrogen(DON)were selected to calculate the SMF index by the mean method.Each functionality such as TOC,TN,TP,IN and DON increased with the development of BSCs and decreased with soil depths.The SMF of bare sand ranged from-0.96 to 0.55,showing an increasing trend in the 0-5 cm soil depth and a decreasing trend in 5-20 cm soil depth.The SMF of mixed algal-lichen crusts and moss crusts was at-0.53 to 1.33 and-0.43 to 2.05,respectively,and showed a decreasing trend in the 0-20 cm soil depth.The SMF of the three types of BSCs tended to be stable in the 20-100 cm soil layer.The SMF showed an overall trend of moss crusts＞mixed algal-lichen crusts＞bare sand in the 0-20 cm and 0-100 cm soil layer.Soil pH,soil water content,and soil urease activity were closely related to the vertical changes of SMF.Soil pH and soil water content had significant negative effects on SMF,while soil urease activity had significant positive effects.Soil particle size was one of the main factors affecting SMF,with negative relationship between medium-sized sand contents and SMF,and positive relationship between coarse sand contents and SMF.Therefore,the development of BSCs significantly improved soil single functionality and soil multifunctionality.The influence of BSCs on soil multifunctionality was mainly concentrated in the range of 0-20 cm in the surface soil,with little effect on the deeper soil.While BSCs affected soil multifunctionality,other functions also changed.
万方数据
维普
