Ecological Stoichiometric Character Of Major Vegetation Type In The Wumeng National Nature Reserve,Yunnan

Ecological stoichiometry is the study of the ecological system internal balance and energy flow between each element of science,as the study of biology,soil,water and other natural geographical elements carbon（C）,nitrogen（N）,phosphorus（P）provide new idea and method of nutrient cycle.Plant and soil are important components of forest ecosystem.Studying the ecology stoichiometric characteristics of plant and soil is a great significance to reveal the nutrient cycling mechanism of forest ecosystem.In this paper,six planting type in Wumeng Mountain National Nature Reserve of Yunnan Province（hereinafter referred to as the protected area）was treated as the object of studyt,and the vertical distribution feature of soil physical and chemical properties of each vegetation type,the content and ratio characteristics of C,N and P of living plants（roots,stems and leaves）,soil and litter,twenty-one plots were set up,to explore the ecological stoichiometry relationship among soil,living plants and litter.In order to provide reference for the study of biology,ecology,utilization and protection of seed quality resources in this reserve.The conclusions are as follows:（1）In the study area of 6 main vegetation types,the soil moisture content and total porosity of 0～100 cm decreased with the deepening of soil depth,while the bulk density is the opposite.The capillary porosity and mechanical composition had no obvious change with the deepening of soil depth.The soil is acidic,the contents of organic matter,alkali-hydrolyzed nitrogen and available potassium decrease with the depth of the soil layer,while the total potassium is the opposite.The content of available phosphorus does not obvious pattern with the depth of the soil layer.（2）The C content of six vegetation types in 0-40 cm soil layer ranged from 43.57g·kg^-1 to 69.46 g·kg^-1,which was higher than the average soil level in China.The N content ranges from 1.13 g·kg^-1 to 5.40 g·kg^-1.The N content in the soil of the artificial Phyllostachys edulis forest and the Dipentodn sunucus forest is lower than that of the average terrestrial soil in China,and the N content in the Davidia involucrate forest,the evergreen and deciduous broadleaf mixed forest,the humid evergreen broadleaved forest and the natural protist Phyllostachys edulis forest is higher than that of the average terrestrial soil in China.P content ranges from 0.36 g·kg^-1 to 1.31 g·kg^-1,and all vegetation types except Davidia involucrate forest have lower P content than the average terrestrial level in China.The C∶N values of the six planted coverts were the highest in the Dipentodn sunucus forest and the lowest in the Davidia involucrate forest.Except for the Davidia involucrate forest,all the other vegetation types were lower than the global soil values.The soil C∶P in Davidia involucrate forest was the lowest,and the Dipentodn sunucus forest was the highest,except for Davidia involucrate forest,all the other vegetation types were above the average level in China.The soil N∶P of planting cover types were all lower than the national average level.（3）The contents of C,N and P in the roots of the 6 planting covers in Wumeng Mountain National Nature Reserve were lower than the global average level,the contents of C in the stems were higher,and the contents of N and P were similar to those in other areas of the same province.The contents of C in the leaves were higher than the global average level,the contents of N were similar to the global average level,but higher than the national average level,and the contents of P were slightly higher than the national average level,and the contents of C in the litters were higher.N content is similar to that of global woody plants,and P is slightly higher.C∶N and C∶P of roots,stems,leaves and litters of 6 vegetation type were all higher than the global average level,root N∶P was roughly consistent with the global level,stem,leaves and litters were lower than the global average level,and N∶P of all vegetation organs in the study area were all lower than 14,indicating that the growth of vegetation in the study area was mainly restricted by N element.（3）The C,N and P contents in the living,litter and soil of natural protist Phyllostachys edulis forest was 49.00～555.37,2.38～26.85,0.68～2.02 g·kg^-1,those in artificial Phyllostachys edulis forest was 43.57～648.20,1.85～30.43,0.69～2.74 g·kg^-1.46.34-634.87,2.75-11.62,0.36-1.11 g·kg^-1 in humid evergreen broadleaved forest,69.46-587.11,4.34-17.76,0.588-1.46 g·kg^-1 in evergreen and deciduous broadleaf mixed forest,The Davidia involucrate forest ranges from 52.84 to 560.20,5.40 to 17.99,1.31 to 1.43 g·kg^-1,and the Dipentodn sunucus forest ranges from 50.38 to 582.48,1.13to 19.41,0.39 to 1.67 g·kg^-1.There were significant differences in the contents and ratios of C,N and P in living plant-litter-soil of different vegetation type in the study area.The growth of roots,stems and leaves of natural protist Phyllostachys edulis forest and artificial Phyllostachys edulis forest was restricted by N element;the roots of humid evergreen broadleaved forest was restricted by P element;the roots of evergreen and deciduous broadleaf mixed forest was restricted by N and P,and stems,leaves were restricted by N;the roots and stems of Davidia involucrate forest was restricted by P element,the Dipentodon sinicus forest was limited by N element,and the leaves of both plants are restricted by element N.