【作者】 倪瑞强；

【导师】 赵秀海；

【作者基本信息】 北京林业大学 ， 生态学， 2014， 博士

【摘要】 原始阔叶红松林是长白山地区的地带性顶级植被类型。近代以来,长白山原始阔叶红松林资源遭到严重破坏,形成了大面积次生林群落。原始阔叶红松林的保护以及退化次生林群落的恢复任务迫在眉睫。本研究基于已经在长白山地区建立起的3块永久性动态监测大样地,通过对长白山原始阔叶红松林及其次生林在不同演替阶段群落结构及种群动态的研究,比较其不同演替阶段的森林群落结构的区别及其动态变化规律,从时间和空间尺度上探讨可能影响森林结构与种群动态变化的因子,试揭示阔叶红松林的演替规律和物种共存机制,为长白山地区退化阔叶红松林的经营和恢复提供理论与数据支持。次生杨桦林、次生针阔混交林及椴树红松林中在物种组成和空间结构上具有显著差异。分别监测到dbh≥1cm木本植物19673株(15科26属45种)、14662株(12科21属38种)和11526株(10科,13属22种),平均胸径分别为5.6cm,7.4cm,10.1cm。总胸高断面积分别为23.95m2/hm2、32.15m2/hm2和55.47m2/hm2。次生杨桦林、次生针阔混交林及椴树红松林中全部个体的径级结构呈反“J”型分布。由次生杨桦林经次生针阔混交林阶段向椴树红松林演替过程中,红松(Pinus koraiensis)、紫椴(Tilia amurensis)、色木槭(Acer mono)等林中主要树种以及两个代表先锋喜光树种山杨(Populus davidiana)和白桦(Betula platyphylla)的径级分布均呈现出向大径级方向偏移的趋势。3块样地中绝大多数物种在小尺度上(1～20m)呈聚集分布格局,且具有一定的生境偏好性。对于每个样地中6个优势树种组成的个15种对双变量空间关系分析表明,表明生态位相似的物种相互间接竞争性更大。相同的物种对在不同的样地也也可能有不同的种间关系,如红松与臭松(Abies nephrolepis)在次生针阔混交林中主要为正相关或者空间独立,而在椴树红松林中则主要为空间负相关。这可能是因为在该样地中,随着两个树种径级的增大,对于资源的需求类似而导致竞争加剧。生境异质性和竞争强度的不同是大多数物种在3块样地中具有不同空间分布格局的主要原因。不同取样方法对种-面积关系构建有显著影响。在两种取样方法下,最小面积大小顺序皆为：次生杨桦林<次生针阔混交林<椴树红松林。根据AIC值可知,随机样方法建立的逻辑斯蒂模型是拟合长白山地区3块5.2hm2针阔混交林样地种-面积关系的最优模型。尤其对处于演替初级阶段的次生杨桦林的拟合效果最好,其次为次生针阔混交林和椴树红松林。说明森林处于不同的演替阶段对于种面积关系的影响也极为显著。在5年复查中,次生杨桦林中DBH≥1cm的个体数由19673增加到22399,物种数增加了13种。而在次生针阔混交林中,DBH≥1cm的个体数由14662增加到15074,物种数增加了10种。椴树红松林中,DBH≥1cm的个体数由11526降低到9800,物种数增加了3种。次生杨桦林初次调查的45个种中,有29个种的个体数增多,在次生针阔混交林初次调查的38个种里,只有7个种的种群增长。而在椴树红松在2007年调查的树种中,仅有青楷槭(Acer tegmentosum)和裂叶榆(Ulmus laciniata)2个树种种群有所增长,有8个种的多度没有变化。随着树木胸径的增大,三块样地的种群表现为胸径增长加快和死亡率降低,然后在大径级上胸径增长增速降低和死亡率上升的趋势。对于死亡个体的径级分布显示,死亡个体的径级结构总体呈倒“J”型,大多数的死亡树木都是DBH在4cm以下的个体,占到次生杨桦林、次生针阔混交林和椴树红松林死亡总数的88.6%、72.8%和68.3%。负密度制约效应和邻体竞争是导致大多数树木个体尤其是小径级个体死亡的主要机制。次生杨桦林的胸径增长、更新和种群增长都显著强于次生针阔混交林和椴树红松林。椴树红松林具有最高的死亡率,种群数量也呈现负增长,开始呈现衰退的迹象。次生针阔混交林整个森林的增长率和死亡率基本都较低,是三个样地中最稳定的群落。随着森林群落演替,红松、紫椴和臭松种群在群落中的重要性增大；蒙古栎(Quercus mongolica)、水曲柳(Fraxinus mandschurica)、山杨、白桦和色木槭等树种在森林群落中的重要性减小。根据次生演替理论,阔叶红松林中的优势种(如红松、紫椴等)将在竞争过程中逐渐取代山杨和白桦等阳性树种,随着先锋种的死亡,以及阔叶红松林主要树种的更新与发育,次生林在不远的将来将达到稳定性更高的阶段。更多还原

【Abstract】 The original broad-leaved Korean pine forest is the zonal climax vegetation type in the Changbai Mountain. Since the20th century, the resource of original broad-leaved Korean pine forest has been seriously damaged in Changbai Mountain, resulting in a large area of secondary forest communities. The conservation of original broad-leaved Korean pine forest and restoration of degraded secondary forest community is extremely urgent. Based on three large permanent forest dynamics plots in the Changbai Mountain region, the community structure and dynamics of the original broad-leaved Korean pine forest and secondary forests at different successional stages in Changbai Mountain were studied, the differences between the variations of community structure and dynamics between the forests were compared at the temporal and spatial scales to explore the possible factors which influence the forest structure and population dynamics, and try to reveal the succession laws and broad-leaved species coexistence mechanisms.The number of woody plants with DBH≥1cm in secondary poplar-birch forest(PBF), secondary mixed conifer and broad-leaved forest(CBF) and Tilia-Korean pine forest(TPF) were19673(15families,26genera,45species),14662(12families,21genera,38species) and11526(10families,13genera,22species), with an average diameter of5.6cm,7.4cm,10.1cm, respectively. The total basal areas were23.95m2/hm2,32.15m2/hm2and55.47m2/hm2. The size structure distribution showed inversely J-shape. In the process of secondary forests succeeding to the climax community, the DBH class structure of the Pinus koraiensis, Tilia amurensis, Acer mono and the main pioneer species Populus davidiana and Betula platyphylla had a tendency to the larger sizes.The majority of species showed aggregated distribution at small scales(1～20m)in all three plots. Acer barbinerve and Acer mono are positively correlated at all scales, which provd that the two maple trees can coexist in the community. The Tilia amurensis and Populus davidiana were good companion tree species, but Betula platyphylla is negatively correlated with most major trees, thus it gradually withdraw from the community in the succession process. The species with similar niche compete stronger because of similar demand for the resource. And the same species may have different interspecies associations in different sites. Habitat heterogeneity and different competitive pressure may be the reasons why most of species showed distinct spatial patterns in three plots.Different sampling designs had a significant impact on species-area relationship. In both sampling methods, the minimum area size order was:secondary poplar-birch forest<secondary mixed conifer and broadleaved forest<Tilia-Korean pine forest. According to AIC values, the logistic model based on random sampling method is the optimal model to fit the species-area relationship of mixed conifer and broadleaved forest in the three5.2hm2plots in Changbai Mountain, especially fit best for secondary poplar-birch forest at the initial stage of succession, followed by secondary mixed conifer and broadleaved forest and Tilia-Korean pine forest.From the recensus in five years, the second poplar-birch forest had the number of individuals with DBH≥1cm from19673to22399, the number of species increased13species. Accordingly, the secondary mixed conifer and broad-leaved forest had14662to15074individuals and the species added by10, while the original broad-leaved Korean pine forest reduced the number of individuals from the11526to9800.29of45,7of38and2of22species in the three corresponding forests plots had increased the individuals by the end of recensus.With the increase of DBH, the populations increased the radial growth and decreased the mortality, and the reversed the tendency across the larger size class. The size distribution of dead trees after the recensus showed a reverse J shape to, as well as the overall size distribution in the plots. Most of the dead individuals are less than4cm DBH, taking a percentage of88.6%,72.8%and68.3%of all dead individuals in respective forests. Negative density dependence and neighborhood competition were the main mechanisms that influenced the mortality of individuals, especially the small ones.The second poplar-birch forest is more dynamic than the other two forests, with a faster radial growth, recruitment and population growth. The original broad-leaved Korean pine forest has the highest mortality rate, and the population growth declined and showed regression. While the secondary mixed conifer and broad-leaved forest has the low population growth and mortality, and was the most stable communities among the three plots. As the succession of forests, the importance of Pinus koraiensis, Tilia amurensis and Abies nephrolepis enhanced; the importance of species, for example, Quercus mogolica, Populus davidiana and Betula platyphylla, and so on, decreased in the forests. According to the secondary succession theory, the Pinus koraiensis and Tilia amurensis will replace the light demanding species of Populus davidiana and Betula platyphylla in the forests as the death of pioneer species and development of dominant species. The secondary forests will get to more stable stage in the future.更多还原