Characteristics of Soil Nutrients in Davidia involucrata Communities at Different Altitudes in Ya'an

The elevations of 1 000 m~1 500 m,1 500 m~2 000 m and 2 000 m~2 500 m were selected in order to explore the soil stoichiometric characteristics and the response regularity of Davidia involucrata communities in different altitndes in Ya'an City by measuring Soil pH and nutrient contents,calculating and analyzing soil C:N,C:P,C:K,N:P,N:K and P:K.The results were as follows:(1) the soil organic carbon,nitrogen,phosphorus and potassium were 7.08 g·kg^-1~86.26 g·kg^-1,0.73 g·kg^-1~5.74 g·kg^-1,0.27 g·kg^-1~1.77 g·kg^-1 and 20.56 g·kg^-1~70.37 g·kg^-1 respectively,and these contents increased with the increase in elevation.(2) Soil C:N,C:P,C:K,N:P,N:K and P:K ranged between 8.91~33.98,22.25~78.06,0.17~3.53,1.47~5.80,0.02~0.23,and 0.17~3.53 respectively.With the increase in elevation,the changes of C:N,C:P and N:P were similar in soil.The soil C:K and N:K increased with the increase in elevation,the change trend of soil P:K was not significant under different elevation gradients.