关键词: 可加性模型, 落叶松人工林, 林分生物量, 非线性似乎不相关回归

Abstract: The monsoon broad-leaved evergreen forests are one of the zonal vegetation types with most complex structure, highest productivity, and most abundant biodiversity. Thus, clarifying the changes in stoichiometric characteristics of forests is critical to understanding nutrient cycling, limiting factors and stability mechanisms of the ecosystem. We analyzed the leaf carbon (C), nitrogen (N), and phosphorous (P) concentrations of 152 wood species from 29 plots (30 m×30 m in size) in Pu’er, Yunnan Province. The results showed that the arithmetic means of leaf C, N and P concentrations of the 152 species were 458.17, 20.88 and 1.42 mg·g^-1, with the coefficients of variation of 7.12%, 34.89%, 51.81% respectively. The arithmetic means of leaf C/N, C/P and N/P were 24.96, 394.74 and 16.50, with the coefficients of variation of 33.46%, 38.79% and 51.44% respectively. Leaf C concentration was significantly negatively correlated with leaf N concentration (P=0.005). Leaf N concentration was significantly positively correlated with leaf P concentration (P<0.001). However, no significant relationship was found between C and P concentration (P=0.078). The variations of leaf N, P and C/N, C/P, N/P in different families were relatively large, compared with that of leaf C. Except for leaf C, significant differences of leaf N, P, C/N, C/P, and N/P were observed between trees and shrubs, and between trees and lianas (P<0.05). N and P concentrations of trees were significantly lower than those of shrubs and lianas. The relatively high N/P ratio (16.50) of the overall 152 woody species implied that P was a limit factor of monsoon evergreen broad-leaved forest in Pu’er, Yunnan Province.

Key words: larch plantation, stand-level biomass, additive system, non-linear seemingly unrelated regression