北京林业大学学报2025，Vol.47Issue(3)：73-82,10.DOI:10.12171/j.1000-1522.20240272
基于广义加性模型的落叶松树冠半径模型研建
Construction of crown radius models for Larix gmelinii based on generalized additive model
摘要
Abstract
[Objective]This study aims to develop crown radius models for Larix gmelinii based on the theory of generalized additive model(GAM),and compares the predictive accuracy with the aggregation for crown radius and crown width,and providing theoretical foundations and practical guidance for predictions of crown radius and crown width in Larix gmelinii.[Method]The research subjects were 3 444 Larix gmelinii trees from 68 natural forest plots in the Greater Khingan Mountains of Heilongjiang Province,northeastern China.From eight crown width-diameter base model fitting results,the model with the smallest Akaike information criterion(AIC)and Bayesian information criterion(BIC)was selected as the base models for each crown radius.Single-tree and stand factors were introduced into the optimal base models to construct the generalized models.Based on the constructed generalized models,the aggregation and GAM theory were used to build a system of compatible models for each crown radius.[Result](1)The base model fitting results indicated that the optimal base models varied for crown radii in different directions.(2)Introducing variables such as height to the crown base,basal area,and quadratic mean DBH into the base models for different crown radius directions all improved the model fitting effects.Subsequently,generalized models containing single-tree size and competition variables were constructed for each crown radius.(3)The comprehensive comparison of compatible models of crown radius and crown width based on the aggregation and GAM methods showed that GAM had better fitting effects and predictive accuracy,and the predictions for both crown radius and crown width was better than that of aggregation method.[Conclusion]Each crown radius of Larix gmelinii exhibits different growth trends.In the crown radius model for Larix gmelinii,the predictive accuracy of GAM is superior to that of aggregation.GAM not only does not require strict model assumption but also simplifies the selection process between predictor and response variables.Therefore,from the perspectives of model assumptions and application convenience,GAM is recommended for predicting crown radius and crown width in this region's Larix gmeliniiforests.关键词
落叶松/冠幅/树冠半径/聚合法/可加性模型Key words
Larix gmelinii/crown width/crown radius/aggregation method/additive model分类
林学引用本文复制引用
姜佟燃,燕云飞,姜立春..基于广义加性模型的落叶松树冠半径模型研建[J].北京林业大学学报,2025,47(3):73-82,10.基金项目
国家自然科学基金项目(32271866). （32271866）
