Leaf Traits And Nutrient Stoichiometry Of Desert Halophytes In Salinization Area Of Shule River Basin

Salinization is a major environmental and agricultural problem in the world, which is relative to food security and ecological sustainability. The problem is more serious in arid and semi-arid regions due to the originally water scarcity and high evaporation-precipitation ratio. Therefore, the study of ecological adaptability of desert halophytes in arid salinization area has significant importance on salinization management and halophyte resources utilization. This study focus on the desert halophytes in the salinization area of Shule River basin, the leaf C:N:P stoichiometry, SLA, LDMC and soil nutrients were examined to address the following questions:(1) what is the plant leaf traits and C, N, P stoichiometry at all plant level and across different functional groups of desert halophytes; (2) what is the relationships between leaf traits and leaf C, N, P stoichiometry under saline environment; (3) whether and how leaf traits and C, N, P stoichiometry of halophytes respond to the salinity gradient; (4) what is the influence of soil nutrient on the variance of plant nutrients. The main results are as follows:1. For all species, the average values of leaf C, N, P, C:N, C:P, N:P were 396.7mg g-1，28.1 mg g-1,1.85 mg g-1,15.7,229.4,15.4 respectively and the average values of SLA and LDMC was 8.6 m2 kg-1,0.28g g-1. The desert halophytes in the study area had a relatively higher N, lower SLA, C, C:N, and C:P, but there were no significant difference of leaf P and N:P compared with other datasets.2. Within the three functional group, succulent woody species has significantly lower C, C:N, C:P and significantly hiher N than herbs and non-succulent woody species, but no significant difference of leaf N:P. The field survey indicate that succulent woody species are more adapted to the high saline environment.3. For all species, leaf C, N, P concentrations have significant liner correlations with leaf traits and there are no significant correlation between SLA and LDMC. However, within the each functional groups, SLA are significantly negatively correlated with LDMC.4. There were no significant differences in the leaf traits and C:N:P stoichiometry within the three functional groups along the increasing salinity gradient. Compared with soil soil salinity, the variance of leaf N, P was mainly influenced by soil available nutrients.