| Rocky desertification in karst areas results in severe ecological and environmental issues including decreased land carrying capacity,increased potential for natural disasters and serious decline in biodiversity.This paper is represented by the study of different rocky desertification levels in the region.This study addresses both the diversity and soil chemical characteristics of vegetation,including mosses,herbs,shrubs and trees,explore its response mechanism to the process of rocky desertification,screening of species more conducive to the restoration of rocky desertification,in areas of rocky desertification,in order to provide a scientific basis for recovery and restoration.The results show that?1?Species diversity:a total of 84 taxa in 29 genera of 14families of mosses were found in study area,including 2 taxa in 2 genera of 2 families of liverworts.25 herbaceous taxa in 24 genera,14 families,6 shrub taxa in 6 genera,6families and just 5 tree species in 5 genera,5 families,were recorded in the study area.?2?The order of species diversity of mosses index are as follows:Severe>Moderate>Slight>Extreme>Nil,and the order of evenness index are as follows:Moderate>Slight>Severe>Extreme>Nil.The order of species diversity of vascular plants index are as follows:Nil Slight>Moderate>Severe>Extreme,and the order of evenness index are as follows:Nil Slight>Moderate>Severe>Extreme.?3?With the deepening of rocky desertification,the proportion of moss wefts showed a downward trend,and the proportion of turfs increased.The total nitrogen in soil associated with mosses and herbs was found to be more readily leached from the soil than total nitrogen associated with soils under shrubs and trees.Total phosphorus in soil associated with mosses was found to be greater than that of soil associated with herbs,shrubs,and trees,but the available phosphorus in soil under vascular plants?herbs,shrubs and trees?was much greater than that found in soil underlying mosses,where it is less easily absorbed and utilized.The capacity of mosses to release and transform potassium in soil to produce available potassium was found to be greater than that of herbs,shrubs or trees.?4?The mosses Homomallium plagiangium,Cyrto-hypnum pygmaeum,Bryum dichotomum and Brachythecium perminusculum were found to be considered pioneer plant species suitable for cultivation and use in restoration of regions of rocky desertification.Through the study of the four species of mosses,it was found that there was a significant difference in water holding between different mosses?P<0.05?.?1?The empirical result shows that the Cyrto-hypnum pygmaeum has the smallest biomass(22.71g·m-2),while the Eurohypnum leptothallum has the largest value(34.83 g·m-2).For saturated water absorptions,mosses with the lowest and highest value are the Cyrto-hypnum pygmaeum(150.01±2.43 g·m-2)and the Brachymenium exile(563.86±2.59g·m-2)separately.?2?Evaporation rates of mosses decrease to 0-30h and gradually approach to 0 g/kg·h around 30h.The Bryum dichotomum is more likely to lose water,whereas the Eurohypnum leptothallum is less likely to lose water among all mosses.?3?There was a positive correlation between the anti erosion ability with rhizoid root length density,root heavy density,biomass of mosses.Eurohypnum leptothallum showed strong resistance to scour in each scour experiment,which could effectively reduce soil loss.All four mosses can effectively improve soil enzyme activity.There was a positive correlation between the biomass,moss erosion resistance enhancement value,root density with soil dehydrogenase and urease.Eurohypnum leptothallum can improve the soil quality rapidly. |
PDF Full Text Request