[Ecological stoichiometry of surface soil nutrient and its influencing factors in the wild fruit forest in Yili region, Xinjiang, China.]

Soil samples and environmental factors in 60 plots of 20 communities in the wild fruit forest in Yili valley were investigated, and then the stoichiometric characteristics of soil organic carbon (C), total nitrogen (N), total phosphorus (P) and total potassium (K) in 0-10 cm and 10-20 cm layers and their influencing factors were studied. The results showed that soil C, N, P and K contents in 0-10 cm layer were 73.15, 7.00, 1.14 and 14.74 g·kg ^-1 , respectively. Soil C:N, C:P, C:K, N:P, N:K and P:K were 10.37, 62.73, 5.05, 6.05, 0.48 and 0.08, respectively. Except for K and C:N, the stoichiometric values in 0-10 cm layer were significantly higher than that in 10-20 cm layer. Soil P, K, C:N and P:K presented high stability (CV=8%-24%), while others showed moderate variability (CV=28%-46%). Soil nutrient contents and their stoichiometric ratios differed markedly in different sampling sites, communities and slope aspects. Except the power relationship between C and N, all the soil nutrient contents and their stoichiometric ratios represented quadratic relationships, indicating nonlinear coupling among soil stoichiometric traits. Slope aspect, precipitation and temperature were the main factors influencing soil stoichiometry in the wild fruit forest in Yili region.