Aims Water is the main limiting factor for revegetation and ecorestrotion in arid sandy areas.Soil available water content directly affects the xylem water transport capacity of plant.However,the differences in xylem hydraulic traits and leaf gas exchange of different shrub species with different ages under varied soil water content are still unclear.Methods The 10-year-old and 30-year-old Caragana korshinskii and C.liouana in the sand-binding area were employed to explore the differences and relationships between their hydraulic traits and photosynthetic traits during the dry and rainy season.Important findings The results showed that the shrub age has no significant effect on xylem hydraulic conductivity,degree of natural embolism,leaf water potential and relative water content of C.korshinskii and C.liouana,while soil water content significantly effects on these functional traits.Both shrub age and soil water content have significant effects on leaf photosynthesis of two shrub species,but the effect of shrub age on them is little significant during the rainy season.In addition,there was a significant positive linear relationship between soil water content with leaf water content and xylem-stem specific hydraulic conductivity.Xylem hydraulic conductivity also had a significant positive correlation with leaf water content and stomatal conductance,whereas net photosynthetic rate was also positive related to xylem hydraulic conductivity and leaf water content.Results indicated that soil water content directly affected leaf water status and the capacity of photosynthetic carbon assimilation by affecting xylem hydraulic conductivity and embolization degree.In conclusion,the change of soil water content significantly affected the xylem hydraulic conductivity and leaf photosynthetic carbon assimilation capacity of C.caragana and C.Liouana.
关键词
固沙灌木/木质部导水率/光合特性/水分效应/干旱区
Key words
sand-binding shrub/xylem hydraulic conductivity/photosynthetic traits/water effect size/arid areas
维普
万方数据