The Research On Leaf Characters And Functional Diversity Of Desert Plants In Hexi Corridor

Desert plants are zonal vegetation that have unique functional characteristics and characterize the use of desert resources in arid regions.Desert plant traits and functional diversity patterns play a key role in its community construction and structural optimization.This paper studies the variation of leaf traits,trade-off strategies and functional diversity of different growth types?shrubs,herbs?and their responses to soil physical and chemical properties under the decreasing gradient of natural precipitation along the Hexi Corridor desert area from southeast to northwest.Discuss the mechanism of community construction in the eastern,central and western sections.Through field sample setting,survey sampling,indoor plant soil test analysis,and data simulation calculation,14 leaf trait values related to leaf resource acquisition and retention,morphology,moisture,and physiology and the community weighted average of corresponding traits were obtained;using the five traits of specific leaf area?SLA?,specific leaf volume?SLV?,leaf nitrogen?N?,phosphorus?P?,and plant height?H?to calculate the functions of single trait and multiple trait combinations Index;analysis and determination of chemical variables,physical composition?divided into gravel,sand,silt,and clay according to particle size?and environmental information data of 0-100cm soil profile.The main results and conclusions are as follows:?1?The leaf nitrogen to phosphorus ratio indicates that the Hexi Corridor area is phosphorus limited;The coefficient of variation of the nitrogen to phosphorus ratio,carbon to phosphorus ratio,phosphorus,bound water free water ratio?BW/FW?,bound water?BW?,free water?FW?are large;principal component analysis shows that the total leaf water content?TWC?,BW,leaf dry matter content?LDMC?,SLV,leaf succulent degree?Suc?is the most representative of desert plant leaves in adversity Characteristics of change;BW is significantly positively correlated with SLV,SLA,LT,Suc,and significantly negatively correlated with FW,LDMC,H;LDMC is significantly negatively correlated with TWC,BW,BW/FW,SLV,SLA,LT,Suc,and C,H showed a significant positive correlation;SLV was significantly positively correlated with TWC,BW;LT was significantly positively correlated with Suc,C:N,and significantly negatively correlated with N,indicating a complex trade-off relationship between traits.Soil organic carbon?SOC?,available phosphorus?AP?,moisture?SW?,pH,altitude,and soil physical composition?except gravel?are important factors that affect the changes in the leaf characteristics of the community.?2?The shrub LDMC is high in the eastern and middle regions,and plants adopt a conservative"slow return"and effective resource storage strategy,while the shrub in the west region has a high SLA,which can quickly obtain resources to achieve a"fast return"investment strategy;except for the eastern region The growth strategy of herb communities in other areas is different from that of shrubs.It indicates that the regional scale plant investment-return strategy theory needs to consider the strategic differences caused by plant community composition,growth type?or functional group?and special landforms?such as desert?.?3?The eastern plant community is characterized by high CWM_LDMC,CWM_C,CWM_P,CWM_SLA,and CWM_H;the middle plant community is mainly dominated by high CWM_N,CWM_N:P,and CWM_FW;the western segment community leaf total water content community weighted mean(CWM_TWC),CWM_BW,CWM_BW/FW is high and CWM_SLA is low.It shows that the mass ratio hypothesis occupies a large proportion in the desert ecosystem function of the Hexi Corridor.The community-weighted mean responded significantly to soil chemical characteristics?total phosphorus TP,AP,conductivity Ec,SW?,physical composition?fine sand,fine powder?,and altitude.?4?The high functional diversity of plants in the eastern section indicates that there is a certain competitive role in community construction;the functional diversity in the central and western sections is low,and community construction may be affected by environmental filtering mechanisms.TP and SOC are important soil chemical factors that determine the functional diversity of desert plant communities.The composition of the sand soil promotes functional diversity,and the smaller soil particle size is related to the decrease of the functional richness and the increase of the functional difference of the desert community.This paper provides a theoretical basis for the study of the relationship between the variation of desert vegetation leaf traits and soil physical and chemical properties at the regional scale,and provides a scientific basis for the three components of functional diversity to indicate the plant community construction in the Hexi Corridor.