Response Of Plant Leaf Functional Traits And Their Functional Diversity Under Water-salt Gradients In The Lakeshore Zone Of Bosten Lake

Lake Bosten is a typical mountain front lake oasis.Arid climatic desert conditions and human disturbance have resulted in a monoculture of lakeside wetland vegetation on the western shore of Lake Constance.The ecosystem structure is simple.Leaf blades as the main organ of photosynthesis and material production in plants.It is more sensitive to changes in the external environment.Leaves play an important role in the growth and development of plants.Analysis of the functional traits and leaf ecological stoichiometry of lakeshore wetland plants is important for understanding plant growth rates and the efficiency of plant uptake and use of soil nutrients.The dominant plants of the region are therefore the subject of study.Using a field survey approach.The collection of plant functional trait samples and soil samples was combined with indoor determination of plant functional trait indicators and soil physical and chemical indicators.The differences in functional traits,ecological chemometric characteristics and functional diversity of plant leaves under water-salt gradients in the lakeshore zone of Lake Constance were analysed using data statistics,one-way analysis of variance and regression analysis.Exploring the effects of environmental factors on plant functional traits and functional diversity under water-salt gradients.Elucidating the response strategies of different plants to environmental factors.This is important for the conservation of the environment as well as the plants in the area.The results are as follows.(1)In 3 different seasons,spring,summer and autumn.Analysis of plant species and soil samples surveyed and collected in 24 sample plots set up in the study area.Survey and collection within the 24 sample plots set up in the study area.A total of 24 species of plants were surveyed,including 8 species of shrubs and 16 species of herbs.The plant communities in the sample plots were classified into six plant community types based on importance values and the Chinese Vegetation Types.An increasing trend in soil water content with increasing salt content.Soil total phosphorus,effective phosphorus and moisture showed significant differences in all three seasons,while total potassium and p H did not differ significantly in the three seasons.The magnitude of variation in water and salt content was not significant in spring and summer,with a range of 80.06 to 277.75 g kg^-1and 90.06 to 299.75 g kg^-1,respectively,and a range of 1.21 to 57.67%and 0.39 to 43.18%,respectively.(2)Significant differences in leaf functional traits of plants in the lakeshore zone of Bosten Lake at different water-salt gradients.And with increasing water and salt content,the plants showed an irregular trend in functional traits.There is significant variation in leaf functional traits between plant species.The mean values of leaf nitrogen(N)contents of all six plants Tamarix hispida,Nitraria tangutorum,Lycium ruthenicum,Halostachys caspica,Suaeda salsa and Phragmites australis were higher than those in summer and autumn.Leaf N content of reed,bristle tamarisk and black-fruited wolfberry was significantly different in spring and summer compared to autumn.The mean phosphorus(P)content of leaves was higher and significantly different in autumn than in spring and summer.The carbon(C)to N values of the leaves of the six species were not significantly different in spring and summer,while autumn was significantly different from spring and summer.Leaf dry matter content(LDMC)was highly significantly and positively correlated with leaf dry weight(LDW)in spring,summer and autumn.Chlorophyll content(SPAD)was positively and significantly correlated with specific leaf area(SLA),leaf water content(LWC),LDMC and LDW in spring and autumn.LWC was positively and significantly correlated with LDMC and LDW in both spring and autumn,and LDMC was significantly and positively correlated with C in both spring and autumn.In spring,SPAD was significantly and positively correlated with leaf thickness(LT),N and P,while SLA was significantly negatively correlated with LDMC and LDW with P.In summer,LT was significantly and negatively correlated with SLA and LWC.SLA is negatively and significantly correlated with LWC,C.In autumn,SPAD was significantly positively correlated with C,LT with LDW and LDW with C,while SPAD was significantly negatively correlated with P,LT with C,LWC and PLDW with P.(3)The change in the functional diversity index of plant community species under different soil water-salinity gradients can be seen by analysing.The functional richness index FRic,the functional evenness index FEve,the functional dispersion index FDis and the quadratic entropy index Rao Q of plant community species tended to increase as the soil water-salt gradient increased.However,the functional differentiation index FDiv tends to decrease with increasing soil water and salt content.The variation in functional diversity indices varies between plants.The functional richness index FRic and the functional evenness index FEve vary significantly.The secondary entropy index Rao Q,the functional dispersion index FDiv and the functional dispersion index FDis relatively stable.It was found that the functional richness index FRic was significantly and positively correlated with leaf C content in summer.The functional differentiation index FDiv was significantly and positively correlated with chlorophyll content SPAD and highly significantly and positively correlated with specific leaf area SLA in spring.Other functional diversity indices were not significantly related to plant functional traits.The functional diversity index of community species does not change equally with the seasons,with the functional richness index FRic being autumn>summer>spring,with the least plant richness in spring.FDiv and FDve are larger in spring and smallest in summer.The community species functional dispersion index FDis and the quadratic entropy index Rao Q are greatest in summer.A one-way ANOVA on the functional diversity indices of species in different seasons showed that there were no significant differences in the functional diversity indices of plants across the seasons.(4)Analysis of the correlation between soil environmental factors shows that total nitrogen(TN)and soil organic matter(SOM)show a highly significant positive correlation.Fast-acting potassium(AK)shows a highly significant positive correlation with total phosphorus(TP).Water content(WC)showed a highly significant positive correlation with SOM and TN.WC showed a highly significant negative correlation with fast-acting phosphorus(AP),with a correlation coefficient of 0.456.Total salt(Salt)was significantly correlated with SOM,AP and AK.Analysis of the effects of environmental factors on the functional traits of leaves of the six dominant species revealed that leaf water content of reed was highly significantly and positively correlated with fast-acting phosphorus,and specific leaf area was significantly and negatively correlated with total nitrogen,leaf dry matter content and leaf dry weight with soil water content.The specific leaf area and leaf water content of bristle tamarisk were highly significantly positively correlated with total potassium,and the leaf dry matter content and leaf dry weight were highly significantly positively correlated with fast-acting phosphorus.Chlorophyll content of saline alkali ponies was highly significantly and positively correlated with total salt,and leaf water content was highly and positively correlated with total potassium.The leaf water content of Tangut white spurge was highly significantly and positively correlated with total potassium.The leaf dry matter content and leaf dry weight of Lycium barbarum were both highly significantly and positively correlated with fast-acting phosphorus and total salt.The analysis of the correlation between the plant functional diversity index and the environment revealed a positive correlation between FRic and TN and a positive correlation between FEve and AP.In summary,the range of variation in soil water salinity varies from season to season.Significant differences in functional traits of plant leaves.Plant functional diversity showed different trends in response to changes in soil water and salt content,while the plant functional diversity index did not differ significantly from season to season.Soil environmental factors that affect the functional traits of different plants differ.