近自然森林经营是达到持续发挥生态服务功能目标的一个重要途径,对目标林分进行近自然状态分析是开展科学森林经营活动的前提.以豫西山区4种典型林分(栎类纯林、阔杂林、松栎混交林和油松纯林)为研究对象,在构建近自然状态评价指标体系的基础上,采用PCoA(Principal coordinates analysis)坐标分析法对林分之间的相异关系和林分近自然状态进行了分析.研究结果表明,从林分上层结构特征、林分下层结构特征和林分地表根系结构特征3方面构建的近自然状态评价指标体系能够很好反映林分之间的差异信息;PCoA坐标排序轴前2轴解释的方差占总方差94.79％;排序图显示,松栎混交林与阔杂林较接近,阔杂林与栎类纯林较接近,而栎类纯林与油松纯林较接近.将研究区油松纯林、阔杂林、松栎混交林和栎类纯林4个30年生的中龄林分近自然状态分别划分为人工、天然、近天然和半天然,对各林分类型从林木竞争、林分结构、林分生长、林下更新能力和地表根系发育等方面进行了描述,并提出了近自然林森林经营策略.林分近自然状态评价对于制定科学合理的抚育经营措施具有重要意义.%In its origins around the world,forestry was an entity focused on producing wood products such as fuel wood or timber.Silvicultural practices were developed to manage the forest in ways that were sustainable,although primarily focused on sustainability of wood production.Close to nature forestry is a theory and practice that takes the forest as an ecosystem and manages it as such.It is based on reduced human intervention that should be directed to accelerate the processes that nature would do by itself more slowly.Close to nature forest management method was known as an appropriate way to gain this approach.However suitable evaluation on particular stand should be done prior to carry our close-to-nature forest management practice.In this present study,A survey of sixteen plots representing four types of stands (Oak pure stand Broadleaf mixed stand,pine and Oak mixed stand,Pinus pure stand) was conducted in mountainous area of western Henan province.The dissimilarities and stages of close to nature between different stand types were evaluated based on the evaluation index system and Principal Coordinates Analysis (PCoA) method.The overstory structure characteristics,the understory structure characteristics and the surface root structure characteristics were introduced to establish the evaluation index system on the stage of close to nature.Results indicated that most of the dissimilar information between different stand types were measured based on the evaluation index system,so it is reasonable to use the evaluation index system to assess the stage of close to nature.The two main axis accounted for 94.79％ of the total variance in the original data set.The observed changes in stand structure were constant for Bray-Curtis distance matrices.Pine and Oak mixed stand plots were more similar to broadleaf stand plots than other stand types,broadleaf stand plots were more similar to Oak pure stand plots than other stand types,and Oak pure stand plots were similar than other stand types.The stages of close to nature of Oak pure stand,Broadleaf mixed stand,pine and Oak mixed stand,Pinus pure stand were classed and named as artificial,nature,close to nature,and semi nature respectively.The condition of tree competition,stand structure,stand growth,regeneration ability and surface root growth were described,the measures were introduced based on theory of close to nature to different stand types.The simplicity and efficiency of the evaluation of stages of close to nature on particular stand make it a useful tool for multiparty monitoring.
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