Study On Drought Resistance Of Dominant Shrubs And Mineral Elements Of Dominant Shrubs In Arid Valley Of The Minjiang River

In this paper,the dominant shrubs distributed along the banks of the valley in the typical area of the arid valley of the Minjiang River are studied,dominant shrubs including Ajania achillloides ? Rabdosia pseudoirrirata ? Campylotropis polyantha?Campylotropis wilsonii?Ceratostigma minus,the leaf water potential ?total chlorophyll content and mineral element(contains major mineral element P?K?Ca?Mg,trace mineral element Na?Fe?Zn?Mn)content of these five shrubs were detected,analysis of the effects of species?slope direction?soil mineral element content?water and chlorophyll on the mineral element content of shrubs,according to the leaf water potential and the total chlorophyll,the drought resistance of these dominant shrubs is ranked,and it was found that the shrubs with small changes in the major mineral elements due to the change in the slope were more drought-resistant.Thus,the ecological strategies of the shrubs in the arid valley of the Minjiang River to deal with the drought stress were deduced.The results show that:(1)The shrub species is the main influencing factor of the difference of mineral element content in the arid valley of the Minjiang River,shrub species with higher content of mineral elements in the body still maintain a high level of mineral elements under the influence of various environmental factors,and environmental factors have limited impact on the total amount of shrub mineral elements.Shrub species with low mineral content are more resistant to drought,arid valley soil is arid and barren,and drought-tolerant for shrub species with low mineral nutrient demand.(2)Leguminosae and Compositae have more advantages in the arid valley of the Minjiang River.(3)The mineral elements of shrubs are closely related to its drought resistance,shrubs adapt to drought stress by regulating the content of mineral elements.Dominant shrubs mainly adapt to drought stress in two ways: one is the reconfigure the mineral elements in the organs of shrubs,second is to accumulate some mineral elements that help the shrubs to resist drought,the accumulated mineral elements are mainly osmotic adjustment ions.(4)Trace mineral elements in shrubs are not sensitive to environmental changes caused by different slope directions,and the effects of major mineral elements on shrub drought resistance are more obvious.(5)The slope direction and soil mineral elements have obvious effects on the content of shrub mineral elements.(6)The leaf water potential of the shrub reflects the water condition of the environment in which the shrub is located,and the leaf water potential is significantly correlated with the major mineral elements of shrubs,It can be inferred that the influence of on the major mineral elements of shrubs.The soil water potential data prove that the sunny slope is more arid,it can be found that there were significant changes in the major mineral element in shrubs growing on the more arid sunny slope compare with those on the shady shrubs,and it was found that the shrubs with small changes in the major mineral elements due to the change in the slope were more drought-resistant.(7)The effect of chlorophyll on shrub mineral elements varies with shrub species and mineral elements.(8)From the perspective of major mineral element content of shrubs,the drought resistance of five dominant shrubs in the arid valley of the Minjiang River is from strong to weak: Ajania achillloides>Rabdosia pseudoirrirata C.Y.Wu>Campylotropis polyantha>Campylotropis wilsonii>Ceratostigma minus.