荒漠灌丛对生物土壤结皮下土壤养分的影响OA北大核心

[Objective]The purposes of this study are to reveal the effect of desert shrubs on soil nutrients under biocrusts,and to provide theoretical basis and scientific basis for the restoration and management of desert ecosystem in arid sandy area.[Methods]Soil samples were collected from 0-10 cm,10-20 cm and 20-30 cm soil layers under non-shrubs biocrusts(control)and biocrusts of four typical shrubs(Atriplex canescens,Caragana korshinskii,Caragana stenophylla and Artemisia ordosica)in Hongwei natural vegetation sand-fixing area in the southeastern margin of Tengger Desert.The contents of soil organic matter(SOM),water content(SWC),pH value,total nitrogen(TN),available nitrogen(AN),total phosphorus(TP),available phosphorus(AP),total potassium(TK)and available potassium(AK)were measured respectively.The effect of interaction between shrubs and biocrusts on soil quality in desert area were characterized by soil nutrient change.[Results](1)Compared with the control plot,the interaction between shrubs and biocrusts affected soil nutrients,increased soil TN,TK,AK,AN,SOM,AP and cyanobacteria-lichen crust TP content,and reduced moss crust TP content.(2)Soil depth change,shrubs and biocrusts type had significant effects on soil nutrients,and the interaction between each two had no significant effect on TP.Except for AN and AP,the interaction between the three had significant effects on other nutrient indexes(p＜0.05).(3)In the same soil layer,the contents of SOM,TN,TP and AK in the soil under the shrubs+moss crust were higher than those under the shrubs+cyanobacteria-lichen crust.(4)The soil nutrients under the four shrubs+biocrusts were enriched in the 0-10 cm soil layer,and the surface accumulation effect was obvious.The interaction between shrubs,biocrusts and soil depth had different enrichment ability for soil nutrients.[Conclusion]The interaction between shrubs and biocrusts can increase soil fertility,improve soil quality,and play an important role in maintaining a stable desert ecosystem.