河西走廊盐碱地4种植物群落物种多样性和土壤理化性质特征OA

[Objective]This study reveals the role of plant communities in improving saline-alkali soils and promoting ecological restoration,and provides a theoretical basis for optimizing soil environments and protecting biodiversity in desert saline-alkali lands.[Methods]Desert saline-alkali soils of the Hexi Corridor were selected as the research object.Four typical plant communities were investigated:a Lycium ruthenicum Murr.monoculture community(LL),a L.ruthenicum Murr.and Phragmites australis community(LP),a L.ruthenicum Murr.and Alhagi camelorum Fisch.community(LA),and a L.ruthenicum Murr.and Tamarix chinensis Lour.community(LT).Three replicate plots were established for each plant community.Vegetation surveys and soil sampling were conducted to determine soil physicochemical properties(water content,pH,bulk density,electrical conductivity,organic carbon,total nitrogen,and total phosphorus),and species diversity indices(Simpson dominance index,Shannon diversity index,Pielou evenness index,and Margalef richness index)under the four plant communities.Variance analysis and redundancy analysis were used to evaluate differences in soil properties and species diversity and to identify their influencing factors.[Results]L.ruthenicum was dominant in all communities(LL,LP,LA,and LT),with importance values ranging from 0.367 to 0.513,reflecting its strong adaptability to saline-alkali conditions.Significant differences in species diversity were observed.The LP community(L.ruthenicum+P.australis)exhibited the highest Shannon diversity index(1.283)and Margalef richness index(0.932),which were 1.24 times and 1.55 times higher,respectively,than those of the LL community(1.035,0.603).Regarding soil physicochemical properties,the LP community had the highest water content(25.57%),which was significantly higher than that of the LL(14.6%)and LA(8.09%)communities.The LT community(L.ruthenicum+Tamarix chinensis)showed the highest soil organic carbon and total nitrogen contents,which were on average 31%and 28%higher,respectively,than those of the other communities.Electrical conductivity showed pronounced surface aggregation,with the highest value(46 mS/cm)recorded in the surface layer of the LA community.No significant variation pattern was detected for total phosphorus.[Conclusion]Different types of plant communities significantly influence physicochemical properties and biodiversity of saline-alkali lands through variations in species composition and structure.L.ruthenicum,as a key constructive species,exhibits broad ecological adaptability.Mixed communities,especially the combination of L.ruthenicum and P.australis,show outstanding performance in enhancing species diversity and soil water-holding capacity,whereas the combination of L.ruthenicum and T.chinensis significantly promotes the accumulation of soil organic carbon and nitrogen nutrients.The findings provide a theoretical basis and practical reference for vegetation restoration and ecological management of saline-alkali lands in the Hexi Corridor.