杉木人工林林分直径结构预测影响因子的研究

Affection Factors for Predicting Stand Diameter Structure of Chinese Fir Plantations

林分直径结构预测能为科学地进行人工林的定向培育提供可靠的理论依据。本文从生长方程等 4方面探讨了产生杉木人工林林分直径结构预测效果好坏的原因 ,并对两种参数估计方法作了实证比较研究 ,对影响预测适合度高低的原因从林分因子的角度进行了进一步的探索 ,得到如下实验结果 :不同的回收模型、建模材料、检验材料、生长方程对检验适合度的影响程度分别为具有极显著影响、显著影响、呈显著影响或极显著影响、无显著影响 ,当回收模型采用最简幂函数时 ,适合度均在 5 0 %以上 ,Richards生长方程预测效果较好 ,其 6种情形下的适合度仅有 1种低于 6 0 % ;参数预测法和参数回收法用于预测时检验适合度均较高 ,此 2种方法各有优劣 ,均具有很好的应用前景 ;林分初植密度不同于年龄、立地指数、间伐等因子 ,不同密度范围下的预测适合度大小总体上存在一定的规律 ,且对适合度具有显著影响 ,按密度因子作分类预测时 ,应考虑密度的这种突出效应。

The prediction of stand diameter structure can provide theoretical foundation for scientifically directive silviculture of plantations. In this paper, the reasons that influence the effects of Chinese Fir stand diameter structure prediction were approached from 4 aspects of growth equation, and so on. And the comparative research of two parameter estimation methods was conducted. The reasons for affecting the prediction adaptation degree were further explored from the angle of stand factors. The results showed that the affection of different recovery models, different material used to build model, different test material and different growth equations on test adaptation degree respectively present greatly obvious, obvious in some times, obvious or greatly obvious and no obviousness. When recovery model adopts the simplest power function, the adaptation degrees all go beyond 50%, the prediction effect of Richards equation is the best, its adaptation degree under six kinds of conditions only have one below 60%. Parameter prediction method and parameter recovery method both have relatively high test adaptation degree when being used to predict, these two methods have their own benefits and shortcomings, and both have good application prospects. Stand planting density is different from age, site index and thinning, its size of testing adaptation degree overall exists regular law, and has obvious affectation on adaptation degree, while predicting according to different density range, the prominent effect of planting density of stand should be considered.