森林生长发育阶段划分方法综述

[Objective]Identifying the growth and development stages of forests is the prerequisite for realizing the full-cycle management of forests.This study systematically sorted out the main methods for dividing the growth and development stages of forests,proposed the advantages and disadvantages of various methods and their application scenarios,and provided scientific basis for the accurate management of the full-cycle of forests and promoted the sustainable development of forest management.The research is divided into two parts:the division of growth and development stage of single tree and the division of growth and development stage of stand.The five main methods are introduced respectively.[Method]Kraft grading,Terazaki grading,Holley grading,Dunning grading and tree grading index are commonly used in the classification of growth and development stages of individual trees.Kraft grading method is the most classic classification method,based on tree growth potential and crown form,trees are divided into five grades,with easy operation and strong applicability,especially suitable for pure forests of the same age.Although it ignores trunk defects,it has become an important tool in forest management because of its simple operation and wide application.Terasaki grading method and Holley grading method are applicable to coniferous pure forest and mixed broad-leaved forest respectively.The former pays more attention to the crown form,while the latter focuses on the competition state of trees in the crown.Dunning grading method is suitable for mixed forests of different ages,which is based on many indexes such as tree age and crown development,but the application is complicated.The law of tree classification index provides quantitative basis for complex stands through quantitative classification model and competition index,which is a relatively innovative classification method.In terms of the division of growth and development stages of stand,the age group division,forest cycle stage division,forward succession stage division,development succession stage division and stage division based on mathematical methods were introduced.Based on the age characteristics of trees,the age group classification method is simple and suitable for artificial forests,but the description of natural forests of different ages is limited.The classification method of forest cycle stage is mainly applicable to natural forest,and the growth stage is divided by the concept of forest dynamic cycle,which is especially suitable for undisturbed virgin forest area.The forward succession stage division method divides multiple stages through the species replacement process in secondary succession.Although it can explain the succession law,its direct application in forest management is limited.This method combines natural succession and forest management.It not only reflects the ecological process,but also provides practical guidance for the multifunctional management of plantation and natural forest.It has high application value.The mathematical method of stage division uses big data and modeling techniques,such as optimal segmentation,cluster analysis,TWINSPAN bidirectional indicator analysis,etc.,to improve the objectivity and accuracy of stage division,but the biological explanation is insufficient and needs further optimization.[Result]In general,the Kraft grading method and the developmental succession stage classification method are more practical in practice and research because of their perfect theory and wide application,but the relevant standard system needs to be further improved.With the development of big data and artificial intelligence technology,the future stage division method can combine mathematical methods with biological theories,improve the applicability and biological significance of stage division,and promote the optimization and popularization and application of forest growth and development stage division method,so as to provide more accurate technical support for sustainable forest management.