Abstract: Malus sieversiiis a Tertiary relict tree species and valuable resource of wild fruit tree. In recent years, M. sieversii community is undergoing serious degradation. Whether the degradation of plant community would lead to change in soil stoichiometry is still unclear. This study explored the spatial characteristics of nutrients in the topsoil in M. sieversii communities in response to variation of environmental factors such as elevation in Yili Valley and Tacheng regions. Within the two regions, a total of 60 soil samples (0-10 cm depth) in M. sieversii communities were taken from six counties. The contents of soil organic carbon (C), total nitrogen (N), total phosphorus (P), total potassium (K), available nitrogen (AN), available phosphorus (AP) and available potassium (AP) were measured and their stoichiometric ratios being calculated. Environmental factors including slope, latitude, altitude and precipitation were investigated to study their relationships with soil stoichiometric characteristics. Our results showed that soil C, N, P, and K concentrations of M. sieversiicommunities in Yili were 68.66, 6.64, 1.14, 20.92 g·kg^-1, respectively. The AN, AP, AK concentrations were 562.10, 10.02, 474.50 mg·kg^-1, respectively. Soil C∶N, C∶P, C∶K, N∶P, N∶K, P∶K, AN∶AP, AN∶AK and AP∶AK were 10.22, 59.83, 3.32, 5.80, 0.32, 0.05, 62.00, 1.31 and 0.02, respectively. Except for the values of K, AP, AK and N∶P, stoichiometric values in Yili region were significantly higher than those in Tacheng region, while Tacheng region had a lower coefficient of variation. Soil nutrient contents and their stoichiometric ratios differed significantly among the six counties. Significant linear correlations were found between C and N content, and between C and P content, and significant nonlinear correlations were observed between N and P content, AP and AK content. Canonical Correlation Analysis (CCA) results showed that slope, latitude, altitude and precipitation were the main factors driving the stoichiometric characteristics of soil nutrients in M. sieversii communities.

Key words: hedgerow, ecological benefit, runoff, soil erosion, non-point source pollution.