Evaluation of estimation methods for fitting the three-parameter Weibull distribution to European beech forests

iForest: Biogeosciences and Forestry

article

Vasilije Trifković¹  Christian Rosset²  Matija Klopčič¹  Ziva Bončina¹ 

[1] Department of Forestry and Renewable Forest Resources, Biotechnical Faculty, University of Ljubljana;Forest Ecosystem and Management, School of Agricultural, Forest and Food Sciences, HAFL, Bern University of Applied Sciences;Slovenia Forest Service

关键词: Diameter Distribution Fitting;    Weibull Function;    Parameter Estimation;    Inventory Data;    Circular Sample Plots;    Near-natural Forests;    Fagus Sylvatica;    Slovenia;   

DOI  :  10.3832/ifor4145-015

学科分类：社会科学、人文和艺术（综合）

来源: Societa Italiana di Selvicoltura ed Ecologia Forestale (S I S E F)

【 摘 要 】

We evaluated three estimation methods for fitting the three-parameter Weibull distribution to even-aged European beech (Fagus sylvatica) forests by using experimental tree diameter data collected in 3709 sample plots (500 m2 each). The maximum likelihood estimation method (MLE), the method of moments (MOM) and the method of modified moments type 1 (MM1) were applied for fitting the Weibull function. The goodness-of-fit of stand parameters (total tree number, stand basal area, dominant stand diameter and mean quadratic diameter) was tested by MAE and RMSE, and the probability and cumulative density functions of trees per 5 cm diameter classes were additionally tested by the Kolmogorov-Smirnov test and compared with Kolmogorov-Smirnov’s D statistic. All three methods are suitable for estimating stand parameters based on the fitted Weibull function. Fitting the diameter distribution per 5 cm diameter classes at the plot level was less accurate due to the low number of trees or irregular diameter distribution of trees. The MM1 method was found to be the most suitable for fitting the three-parameter Weibull distribution to beech forests represented by data derived from small plots.

【 授权许可】

Unknown