文献类型：期刊文献

英文题名：Two subject specific modelling approaches to construcbase-age invariant polymorphic site index curves with varying asymptotes

作者：Sprengel, Lars[1] Spiecker, Heinrich[1] Wu, Shuirong[2]

第一作者：Sprengel, Lars

机构：[1] Albert-Ludwigs-University Freiburg, Tennenbacher Str. 4, Freiburg, 79106, Germany; [2] Research Institute of Forest Policy and Informa-tion, Chinese Academy of Forestry, No. 1 Dongxiaofu, Haidian District, Beijing, 100091, China

年份：2022

卷号：56

期号：1

外文期刊名：Silva Fennica

收录：EI(收录号：20220411520902);Scopus(收录号：2-s2.0-85123321080)

基金：This research was funded by the German Federal Ministry of Education and Research (BMBF) within the project Lin4Future, grant number 01LZ1701A, and the German Federal Ministry of Food and Agriculture (BMEL) within the project Chinawald, grant number 28I-010-01, and supported by the special fund for basic scientific research of central level public welfare scientific research institutes (CAFYBB2020MC002), National Natural Science Foundation of China (31270681). The article processing charge was funded by the Baden-Wuerttemberg Ministry of Science, Research and Art and the University of Freiburg in the funding program Open Access Publishing. The funders had no role in the design of the study; in the collection, analyses, or interpretation of data; in the writing of the manuscript, or in the decision to publish the results.

语种：英文

外文关键词：Algebra - Forestry - Mean square error - Nonlinear analysis

摘要：For constructing growth and yield models the concept of site index as measure of productivity is crucial. Here, we use nonlinear mixed-effects models (NLME) with random individual effects and nonlinear models with dummy variables as fixed individual effects (NLFE) to fit mechanis-tic growth functions to stem analysis data of the economically most important tree species in Zhongtiaoshan forest region, China. The Richards and Lundqvist function are formulated into five dynamic equations (R1, R2, L1, L2 and L3) applying the generalized algebraic difference approach (GADA), which inherit polymorphism, varying asymptotes and base-age invariance. According to Akaike information criterion the R1 model as NLFE fits height growth data of Pinus tabuliformis Carrière, Pinus armandii Franch., Quercus liaotungensis Koidz., Quercus aliena Blume and Betula platyphylla Sukaczev best, while for Quercus variabilis Blume R2 as NLFE fits height growth data best. For Larix principis-rupprechtii Mayr L1 as NLME has been selected as best model, as R1 and R2 both as NLFE and NLME are not extrapolating the comparably short length of height growth data well enough. However, according to the root mean square error and bias differences between model fits of both the selected equation and the chosen model fitting approach are not so clear. Presented families of height growth curves serve as planning tools to identify site index and therefore assess productivity of forest stands in the studied region. A direct comparison of the productivity of forest stands of the same tree species is possible due to base-age invariance of the selected models. ? 2022, Finnish Society of Forest Science. All rights reserved.