林业科学2016，Vol.52Issue(5)：1-8,8.DOI:10.11707/j.1001-7488.20160501
天然混交林最优林分状态的π值法则
A New Rule of πValue of Natural Mixed Forest Optimal Stand State
摘要
Abstract
[Objective]The reasonableness of the stand state concerns the necessity and urgency of forest management, and the quality of evaluation of stand state directly affects the quality of management decision. Only by knowing the exact optimal stand state will it be possible to make an assessment of the reasonableness of the real forest stand,after which it is viable to manage forest with targeted operating adjustment.[Method]The forest is a complex ecosystem,the multi-index evaluation method is usually used to assess it. Following the principles of multi-indicators comprehensive evaluation,a new stand state reasonableness evaluation method based on unit circle has been presented in this paper. [Result]The research shows that the stand state depends on the size of closed chart area composed of real stand state indicators. This chart area as a proportion of the best stand state value( expected value) is the most appropriate measurement of real stand quality. Meanwhile,the best stand state value( expected value) always equals to the unit circle area π,namely the rule ofπ value of the best stand state. The method of unit circle has an essential difference from the usual multi-index system of radar chart in that the expectation of optimal stand state can be directly derived by the new method. The formula given by the research is able to calculate the real stand state which can be divided into five grades. The stand state can be described by stand spatial structure( stand vertical and horizontal structure) ,stand age structure,stand composition( tree species diversity and species composition) ,stand density,stand growth,climax tree species group or main tree species competition,stand regeneration,tree health and etc. This 8 aspects can characterize the major natural attributes of stand, and the corresponding value to each indicator can be assessed easily. To highlight the advancement and practicality of the indicators,most indicators mentioned in this paper use the latest research results and optional measure methods are given. Normalization processing of stand state indicators is crucial to the stand state evaluation. Applying this method to the stand state of natural Korean pine ( Pinus koraiensis) broad-leaved forest and sharp tooth oak( Quercus aliena var. acuteserrata) mixed forest in China has shown visual and reliable evaluation results in accordance with real stand situation.[Conclusion]The stand state evaluation method based on the unit circle,especially the rule of π value of the optimal stand state,that has been put forward in this paper,lays a scientific foundation for forest management decision and provides an analysis method to evaluate the quality of different types of forest health in different areas.关键词
天然混交林/林分状态/π值法则/单位圆Key words
natural mixed forest/stand state/rule of π value/unit circle分类
农业科技引用本文复制引用
惠刚盈,张弓乔,赵中华,胡艳波,刘文桢,张宋智,白超..天然混交林最优林分状态的π值法则[J].林业科学,2016,52(5):1-8,8.基金项目
“十二五”国家科技支撑课题“西北华北森林可持续经营技术研究与示范”(2012BAD22B03)。 （2012BAD22B03）
