基于最大胸径生长率的浙江省杉木人工林立地质量评价

  目的  森林立地质量评价是指对立地的宜林性或潜在的生产力进行判断和预测，目的在于建立浙江省杉木Cunninghamia lanceolata人工林立地质量评价数量化理论模型。  方法  提出1个新的立地质量评价指标:最大胸径生长率指标。以最大胸径生长率指标为立地评价指标，以浙江省1994-2009年国家森林资源清查（NFI）数据为基础，从NFI复位样木时间序列数据中提取529个杉木人工林样地优势木最大胸径生长率；结合易于获取的纬度、海拔、坡位、坡向、坡度、土壤类型等立地因子，基于数量化理论Ⅰ方法，建立杉木人工林立地质量评价模型。  结果  模型统计检验值为14.723，模型复相关系数为0.606，达极显著水平，模型效果较理想。基于NFI的最大胸径生长率是立地质量评价的合适指标；坡向、坡位、土壤类型、坡度、纬度、海拔等立地因子对最大胸径生长率贡献依次减弱。  结论  基于NFI和数量化理论Ⅰ的浙江省杉木人工林立地质量评价模型总体指标合理，克服了传统立地质量评价对年龄的依赖，能有效利用NFI历史数据，适用于同龄林和异龄林；构建以最大胸径生长率为指标的立地质量评价模型，能对研究区立地质量进行有效评价，不仅可对现有杉木人工林生产力进行评价，也可以对无林地的生产潜力进行预测。

Site quality evaluation of Cunninghamia lanceolata plantations in Zhejiang Province based on maximum DBH growth rate

  Objective  Forest site quality evaluation refers to the judgement and prediction of site suitability or potential productivity. The aim is to establish a site quality evaluation model of Cunninghamia lanceolata plantaion.  Method  A new site quality evaluation index, the maximum growth rate index of DBH, was proposed. Taken as the site evaluation index, and based on the National Forest Inventory(NFI) data of Zhejiang Province from 1994 to 2009, the maximum DBH growth rate for 529 permenant plots of C. lanceolata plantations was extracted from the NFI time series data as the site quality evaluation index of C. lanceolata plantations. Integrated with readily available site factors such as latitude, altitude, slope position, slope direction, slope, soil types, etc., and based on the quantitative theory Ⅰ method, a site quality evaluation model of C. lanceolata plantations was established.  Result  The statistical test value of the model is 14.723, and the complex correlation coefficient of the model is 0.606, which reaches a very significant level, and the effect of the model is satisfactory. The maximum DBH growth rate based on NFI is an appropriate index for site quality evaluation. The contribution of site factors such as slope direction, slope position, soil type, slope, latitude and altitude to the maximum growth rate of DBH decreases sequentially.  Conclusion  Based on NFI and quantitative theory Ⅰ, the overall index of site quality evaluation model of C. lanceolata plantations in Zhejiang Province is reasonable. It overcomes the dependence of traditional site quality evaluation on age, and can effectively use NFI historical data, which is suitable for forests of the same age and different age. The site quality evaluation model can effectively evaluate the site quality of the study area. It can not only evaluate the productivity of existing C. lanceolata plantations, but also predict the potential productivity of non-forest land.