Analysis on the environmental property of Picea asperata stand through four mathematical methods

11 environmental factors including distribution, physiognomy, soil and vegetation type, etc. and four productivity indicators of status index, stand volume, biomass of tall trees and stand biomass are compared quantitatively through four mathematical methods of multi-linear regression analysis, stepwise regression, principal components analysis and the quantitative theory. All of the four mathematical methods can be applied in eliminating the environmental factors, but the quantitative theory is more visual. It shows not only the contribution of environmental factors to productivity but also the contribution difference of productivity due to the classification of sub-items within environmental factors. The criteria of sub-items classification combined with system clustering or Fuzzy clustering can also be directly applied in the ranking measures between sub-items, which forms the complete system of the environmental classification methods.