| Under the social background of economic development and the improvement of people's income,tourism has entered a stage of rapid development.With the continuous expansion of the scope and intensity of human activities,it is bound to have a certain negative impact on the ecological environment.Once the development and utilization of tourism resources,the environment around the tourist area may be damaged.A large number of studies show that vegetation and soil bear the main pressure brought by tourism activities in scenic spots.Therefore,it is of great significance to study the impact of tourism disturbance on the vegetation and soil in scenic spots for the protection of ecological environment.In view of this,this study selected the most important human trample factor as the breakthrough point to study the changes of soil condition and root physiological ecology of surface vegetation in Nanjing Zijin Mountain scenic spot.In this study,three experimental plots were selected as the research objects,and five artificial trampling paths were selected in each experimental plot,which were divided into five trampling intensities.The root physiological indexes,root growth indexes and soil permeability of five typical grass shrub layers in three plots of Zijin Mountain were studied to explore the response ability of vegetation roots and soil to human trampling activities.The main results are as follows:(1)With the increase of human trampling,the root activity of vegetation decreased;Plant roots were damaged,resulting in a decreasing trend of SOD activity and a decreasing trend of POD activity after increasing;Compared with the control,the cat activity and MDA content of plant roots increased under trampling;The content of soluble sugar in the roots of Ophiopogon japonicus and Ophiopogon japonicus showed a downward trend,and the content of soluble protein in the roots of P.salicina decreased most significantly.(2)With the increase of human trampling intensity,the growth indexes of plant roots were affected and decreased.(3)With the increase of human trampling intensity,soil bulk density gradually increased,and soil total porosity and non-capillary porosity decreased;The relative indexes of soil permeability showed a decreasing trend,and the infiltration rate gradually decreased from fast to slow,reaching a stable infiltration rate within one hour.(4)With the increase of soil depth,the root growth index showed a decreasing trend.Soil bulk density increased,porosity decreased and soil permeability decreased.(5)Based on the study of plant root growth indexes and soil related indexes in different plots under the same trampling intensity,it was found that among the three plots in Zijin Mountain,toutuoling plot had the lowest root growth indexes,Meihuashan plot had the highest root growth indexes,Meihuashan plot had the lowest soil bulk density,larger total soil porosity and better soil permeability.(6)By analyzing the correlation between plant root growth index and soil index,it was found that there was a negative correlation between root growth index and soil permeability.In summary,with the increase of human trampling degree,vegetation will be damaged,damaged or died under trampling,vegetation coverage will be reduced,root content in soil will be reduced,soil porosity will decrease,bulk density will be increased,soil binding degree will be intensified,soil permeability will also be reduced,which will not be conducive to soil water conservation.In a long time,the vegetation will be damaged or died,The ecological environment will be seriously damaged and the soil and water loss will be serious. |
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