Spatial associations between tree regeneration and soil nutrient in secondary Picea forest in Guandi Mountains, Shanxi, China.

According to the technical specifications of CTFS (Center for Tropical Forest Science), 190 sampling points of 4-hm2 plot (GDS plot) in Guandi Mountains of Shanxi Province, China were investigated to examine the spatial distribution pattern of seedlings and 14 soil indicators, including pH value and nutrient indicators. We analyzed the spatial associations between tree regeneration and soil nutrients, explored the mechanism of tree regeneration pattern of secon-dary Picea forest. The results showed that more seedlings survived in the patches with low contents of available N, available K, available Cu, available Fe, available Mn, available Ni and available Zn. Besides available K, the negative correlation between the other six soil nutrient factors and the number of regeneration seedlings of the Ⅱ (2.5 cm