Abstract:

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.

Key words: Chinese Fir plantations, Diameter structure, Prediction, Affection factors, Density