Study On Dominant Plant Nutrients And Soil Physico-chemical Properties In Desertification Land Of Poyang Lake

The desertification land of Poyang Lake area is the typical southern desertification of China.Exploring the physical and chemical properties of forest soil of desertification land vegetation and the stoichiometric characteristics of plants,provide reference data for ecological control and recovery,It is have great significance for the ecological restoration and reconstruction of desertified land in subtropical regions of China.Use five dominant species?Cynodon dactylon,Vetiveria zizanioides,Vitex trifolia Linn var.simplicifolia Cham,Glochidion wilsonii,and Pinus elliottii?in different desertification areas?slight,moderate,and severe desertification areas?of Poyang Lake typical desertification land as research objects,analysis the sand size,soil moisture content and stoichiometry of forest soil and the stoichiometric characteristics of the plant components?leaves,stems,litter,roots?.The main results as follows:?1?The soil particle size of the Poyang Lake desertification land is mainly concentrated in the middle sand between 0.50-0.25 mm,accounting for about 70%;the coarse and medium sand content:herb>tree>shrub,and the order of fine sand content:shrub>arbor>herb;the coarse and medium sand of surface soil are larger,while the fine sand is mainly in the deep soil;the heavy desertification area have the lagerest coarse sand content,and the middle sand content have little difference in each desertification area,The fine sand content decreased gradually from mild desertification area to heavy desertification area,and the coarse sand decreased from26.94%to 22.78%.?2?The soil moisture content of the surface soil of Poyang Lake is 4.44%,followed by 4.07%of trees and 3.99%of herbs.The average of soil moisture content in the severe,moderate,and mild desertification area respectively 3.89%,3.80%and4.98%.The arbor forest soil water storage was 26.33 mm,which was less than 26.43mm for the herb and 28.26 mm for the shrub.?3?The average content of carbon,nitrogen and phosphorus in desertification soil area of Poyang Lake was respectively 5.77,0.35 and 0.47 mg.g^-1.With the increase of soil depth and the severity of desertification,the C content decreased gradually,and the C content in shrub and arbor soil was higher than that in herbs.The N content of soil increased gradually from severe desertification area to mild desertification area.The content of N in shrub and arbor soil was higher than that in herb,and the surface soil content was higher than that in deep soil.The content of P in each desertification area is not much different.?4?Among the five dominant plants,the average contents of carbon,nitrogen and phosphorus in leaves were 394.29,11.07 and 1.14 mg.g^-1 reapctively;the average contents of carbon,phosphorus and phosphorus in stem were 369.39,6.51 and 1.09mg.g^-1 respectively;The average contents of nitrogen and phosphorus in litter carbon were 364.36,6.76 and 0.94 mg.g^-1 respectively.The average contents of carbon,nitrogen and phosphorus in roots were 353.24,6.61 and 1.61 mg.g^-1 respectively.There was a significant correlation between the leaf and the N content of each component?P<0.05?,and there was a significant negative correlation between leaf C:P,N:P and stem N and N:P?P<0.01?.The water content and fine sand have a strong influence on the stoichiometry of soil and plant organs,followed by coarse sand and pH value;medium sand and bulk density have the weakest contact with it.