适地适树是造林学理论与实践的基本原则。实现树种和立地“配对”即适地适树的传统方法是:首先对有林地目标造林树种的生长指标(通常是树高)和根据经验所选定的立地指标(通常包括气候、地形地貌、土壤、植被等)进行相关分析;然后根据相关结果选定主要立地指标,并依据这些指标对有林和无林地的立地质量进行分类;最后划分该树种的最适宜、较适宜、一般适宜和不适宜生长的立地类型,以用于指导造林生产活动。但基于经验和相关分析对立地质量进行评价的方法中存在其立地指标因人、因地和因树的改变而无法重复的缺陷。为此,提出以土壤钙的供应潜力作为立地质量的统一指标,以树种最大生长对钙的需求作为树种的生物学特性指标,当树种最大生长的钙需求与立地钙供应潜力相吻合时,树种与立地则满足适地适树原则。依此原理,以辽东栎(Quercus liaotungensis Koidz)为例,建立了基于钙供给与需求平衡的理论数学模型。运用该模型计算造林树种的理论生长指数,通过理论生长指数与最大实际生长量的比值得到适钙适树指数。通过对适钙适树指数与实际生长量进行相关分析验证了适钙适树理论模型的可预测性和真实性。结果表明,用土壤钙供应潜力作为立地质量评价指标可以很好地在造林生产活动中贯彻适地适树原则。适地适树的本质即为适钙适树。 Appropriate tree planting is the basic principle of afforestation theory and practice. The traditional method of tree planting and site matching "that is to adapt to the tree is to first measure the growth index (usually the tree height) of afforestation species with the target of afforestation and the site selection index (empirically, including climate, topography Landform, soil, vegetation and so on). Then the main site indexes are selected according to the related results. According to these indexes, the site quality of the forest and non-forest land is classified. Finally, the most suitable, suitable, general suitable And unsuitable growing sites for guiding afforestation production activities. However, based on experience and related analysis, there is a defect that the site index can not be repeated because of the change of people, ground and tree. Therefore, the potential supply of soil calcium is taken as a unified indicator of site quality, and the demand of calcium for the maximum growth of tree species is taken as the biological characteristic index of tree species. When the demand of calcium for maximum tree growth coincides with the supply potential of site calcium, And the site is to meet the appropriate tree principles. Based on this principle, Quercus liaotungensis Koidz was used as an example to establish a theoretical mathematic model based on the balance of calcium supply and demand. The model was used to calculate the theoretical growth index of afforestation tree species, and the suitable Camptotheca acuminata tree index was obtained by the ratio of theoretical growth index and maximum actual growth rate. Through the correlation analysis between suitable tree index and actual growth, the predictability and authenticity of suitable tree model of Ca (superscript 2) The results showed that using the potential of soil calcium supply as a site quality evaluation index can well implement the principle of appropriate tree planting in afforestation production activities. Appropriate to adapt to the nature of the tree is appropriate calcium tree.