<正>以典型样地调查资料为依据，选择与喀斯特环境脆弱性紧密相关的6个因子构成评价指标体系，用欧氏距离公式建立了喀斯特环境生态脆弱度（SFD）计算模型。用层次分析法计算了显性和隐性两大喀斯特类型中各指标的权重值。6个因子中，植被因子和岩石裸露率影响最大，权重最高。根据64个样地的脆弱度计算结果。对样地环境的生态脆弱性进行了评价。将其划分为5个等级，即微度（≤0.2）、轻度（0.21～0.4）、中度（0.41～0.60）、强度（0.61～0.80）和极强度（>0.80）。研究结果表明：地质背景是喀斯特环境脆弱性的根源，同等条件下，植被状态对其环境的脆弱程度起决定作用。

In the forest research,many tree growth models are nonlinear ones. The classical method dealing with these nonlinear models is linear approximation using the approximate value of parameter, due to the difference of nonlinearity among different nonlinear models, in which the nonlinear models cannot be linearized. This paper introduces a method to measure nonlinearity of nonlinear models and presents the intrinsic nonlinearity and parameter-effects nonlinearity of nonlinear models. Forestry resources’s surveying sample data is tested by use of this method. The result shows that this method has many useful characteristics for the tree growth models.