Response Characteristics Of Growth And Physiology Of Two Shrub Species To Root Damage In Semi-arid Area

The strong wind erosion,water erosion and compound erosion in the semi-arid area are prone to damage such as pulling,shearing,etc.on the above-ground branches,leaves and roots of plants,and seriously affect the normal growth of plants and even the stability of communities.In order to explore the characteristics of plant growth and changes in physiological parameters of the typical shrub roots in the area after damage stress,this study selected 1-to 2-year-old Salix psammophila and Artemisia ordosica as research objects under natural conditions Three levels(mild,moderate,and severe)of the roots of the two shrubs were damaged,and the roots were damaged 1d,3d,4d,6d,7d,8d,9d,20d,28d,44d,75d.Growth characteristics(plant height,crown width and other 4 indicators),photosynthetic physiological characteristics(net photosynthetic rate.stomatal conductance and other 4 indicators)and stress physiological characteristics(superoxide dismutase,peroxidase,catalase)Activity and malondialdehyde content).This study aims to explore the response of two shrub species to root damage in terms of growth,photosynthetic physiology and stress physiological characteristics,to elucidate the self-repairing characteristics of Salix psammophila and Artemisia ordosica roots after damage,and to prevent and control soil erosion in the semi-arid area of Inner Mongolia Provide data support for vegetation restoration construction.The main research conclusions are as follows:(1)The greater the degree of damage to the root systems of the two shrubs,the lower the growth rate of various indicators,including plant height,crown width,branch length,branch diameter growth rate,net photosynthetic rate,stomatal conductance,transpiration rate SOD activity The POD activity and CAT activity are as follows:control group>mild injury>moderate injury>severe injury.(2)The greater the damage to the root systems of the two shrubs,the lower the values of chlorophyll content,net photosynthetic rate,stomatal conductance,and transpiration rate.After the roots of the two plants were damaged,their net photosynthetic rate,stomatal conductance,and transpiration rate increased first and then decreased over time.(3)In terms of physiological characteristics of stress,the total SOD activity,POD activity,and CAT activity of leaves showed a tendency to rise first and then fall after the roots of the two shrubs were damaged.(4)Two kinds of shrubs have self-healing ability after the damaged root system,and the self-healing ability of Artemisia ordosica is better than that of Salix psammophila.Over time,the differences in chlorophyll content,stomatal conductance,transpiration rate,net photosynthetic rate,SOD activity,POD activity,and CAT activity of the two shrubs decreased gradually compared with the values of the parallel control until there was no difference.When the roots of the two shrubs were damaged for 75 days,although some indexes of the damaged plants were still significantly different from those of the control group,the plants had formed a new dynamic balance through the self-repair process.