滇西北玉龙雪山沿海拔梯度森林群落构建和转换机制研究

发布时间：2018-06-05 17:32

本文选题：系统发育 + 功能性状　；参考：《云南大学》2016年博士论文

【摘要】：群落构建和群落转换机制是群落生态学的核心论题。将系统发育(进化历史)信息和功能性状信息整合到群落生态学研究中,为探讨群落构建机制等科学问题提供了崭新的视角和思路。综合利用系统发育信息、功能性状和环境因子研究沿海拔梯度森林群落构建及其对气候变化的响应是群落生态学研究的热点。滇西北玉龙雪山位于全球生物多样性热点地区“中国西南山地”的核心区,也是对气候变化最为敏感的区域之一。本研究在玉龙雪山建立19个0.1 ha(20 m×50 m)沿海拔梯度的固定监测森林样方,从3个维度(物种,系统发育和功能)的多样性对玉龙雪山海拔梯度亚高山森林群落和暖温性针叶林—硬叶常绿阔叶林群落交错区开展多样性格局、群落物种组成和转换机制研究,探讨了群落构建机制及其对环境变量的响应等科学问题。主要结果和结论如下：1.物种多样性沿海拔梯度分布格局在19个0.1 ha样方中共采集到65科190属335种种子植物。总的物种丰富度沿海拔梯度呈下降分布格局,乔木多样性沿海拔梯度呈单峰分布格局,但灌木和草本多样性随海拔上升呈下降的趋势,幼苗的多样性沿海拔梯度的分布格局不显著。空间变量和环境变量显著影响群落物种的丰富度和物种组成。不同海拔间的物种组成差异大,随着海拔距离的增大,p多样性呈显著上升的趋势,且物种置换成分主要驱动了物种的p多样性。环境和空间距离显著影响物种p多样性,且空间距离对物种p多样性的解释度要高于环境距离。2.系统发育多样性沿海拔梯度分布格局基于DNA条形码数据构建了高支持率和高解析度的群落系统发育树。乔木群落的系统发育结构(净亲缘关系指数和最近亲缘关系指数)在低海拔和高海拔地区聚集,在中海拔地区则呈离散结构。林下的灌木和草本,在中低海拔群落系统发育结构均为离散,而在高海拔呈聚集结构。幼苗的群落系统发育结构在高海拔呈离散结构。环境变量和空间变量同样对系统发育结构有显著的影响。系统发育p多样性随海拔距离的增大而增大,系统发育置换和内嵌成分共同驱动系统发育p多样性的变化。系统发育p多样性与空间距离和环境距离显著相关,且空间距离对系统发育β多样性解释度大于环境距离。3.功能多样性沿海拔梯度分布格局通过对乔木6个常用的性状(植株高度、叶厚度、比叶面积、叶片碳,氮,磷含量)的变异的分析,发现叶片形态性状(叶厚度,比叶面积)变异主要来自种间变异,而植株高度和叶片元素含量(叶氮含量和叶磷含量)的种内变异对总变异的贡献率大于种间变异。群落的比叶面积、叶片碳含量与海拔呈显著正相关。考虑种内的变异有利于更好地检测群落内物种间性状的生态位分化过程,因此基于性状探讨群落构建机制的研究中需考虑种内的性状变异。木本植物的性状具有显著的系统发育信号,而草本植物性状的系统发育信号较弱。在低海拔和高海拔地区,乔木的功能结构(标准化的平均功能配对距离和最近功能距离)表现为聚集,在中海拔则呈离散结构。林下的灌木,草本和幼苗层的功能结构在中低海拔离散,而在高海拔地区呈聚集结构。空间和环境变量共同影响群落的功能结构,同时系统发育结构对功能结构有一定的影响。功能p多样性沿海拔距离的增大而增大,置换和内嵌成分共同驱动功能p多样性。空间距离和环境距离与乔木、草本和幼苗功能p多样性相关,且空间距离对功能p多样性的解释度更大。4.结合物种、系统发育和功能多样性推断海拔梯度群落构建和转换机制结合物种多样性、功能多样性和系统发育多样性的研究发现,在低海拔地区,乔木群落呈系统发育和功能聚集结构,推断环境过滤可能起主导作用,这可能与低海拔的干扰密切相关；在中海拔地区群落表现为离散,暗示竞争排斥可能起主导作用；而在高海拔地区,环境过滤作用(如低温)可能驱动群落功能和系统发育聚集。林下的植物(灌木和草本)群落,在低海拔和中海拔地区系统发育和功能离散,推断物种之间的竞争排斥作用在中低海拔林下的物种共存机制中发挥重要作用；在高海拔地区,群落系统发育和功能聚集,环境过滤可能起主导作用。本研究发现群落垂直结构中不同生活型植物的群落构建机制不同,揭示了生态位过程在亚高山森林群落构建中的重要性。同时,空间距离能显著影响多样性的分布格局,我们推断种子散布限制可能扮演重要的角色。因此,生态位分化和种子散布限制可能共同驱动玉龙雪山亚高山森林群落沿海拔梯度的分布格局。本研究对理解群落构建及其对气候变化的响应规律具有重要的启示意义。5.暖温性针叶林—硬叶常绿阔叶林交错区群落构建和转换机制在300 m海拔跨度的暧温性针叶林一硬叶常绿阔叶林群落交错区,植被从针叶林渐变为常绿阔叶林。随着海拔的上升,云南松的相对多度逐渐减少,帽斗栎的相对多度逐渐增加,在高海拔变成川滇高山栎林。样地中物种的功能性状具有显著的系统发育信号,性状在进化上是保守的。在云南松林中,从低海拔到高海拔群落系统发育和功能结构由离散变成聚集,表明构建机制从竞争转变成环境过滤。川滇高山栎林群落的系统发育和功能结构离散,表明竞争排斥可能在群落构建和生物多样性维持中起主导作用。在云南松-帽斗栎林交错区群落的系统发育和功能结构呈离散结构,推测竞争排斥可能在群落交错区域起主导作用。群落中物种的距离与系统发育距离和功能距离之间存在显著正相关。郁闭度对物种丰富度和功能结构有显著影响。旱季土壤的含水量显著影响群落系统发育结构和功能结构。环境和空间变量并不能解释系统发育和功能性状的转换,我们推测,与环境变量相比,物种之间的竞争在暖温性针叶林-硬叶常绿阔叶林交错区物种构建中可能起更重要的作用。
[Abstract]:Community construction and community transformation mechanism are the core topics of community ecology. The information and functional characteristics of phylogenetic (evolutionary history) information and functional traits are integrated into the study of community ecology, and a new perspective and ideas are provided for the discussion of scientific problems such as the community construction mechanism. The comprehensive utilization of system development information, functional traits and environmental factors is studied. The construction of the coastal drawing gradient forest community and its response to climate change are the hot spots of community ecology. The Jade Dragon Snow Mountain in northwestern Yunnan is located in the core area of the global biodiversity hot area "Southwest China Mountain", and is one of the most sensitive areas for climate change. This study established 19 0.1 ha (20 m * 50 m) along the Jade Dragon Snow Mountain. Based on the diversity of 3 dimensions (species, phylogeny and function), the diversity of 3 dimensions (species, phylogeny and function) was used to study the diversity of the sub alpine forest community and the warm temperate coniferous forest community ecotone of the warm temperate coniferous evergreen broad-leaved forest, and the species composition and transformation mechanism of the community, and the mechanism of community construction and its mechanism were discussed. The main results and conclusions are as follows: 1. species diversity in 65 families and 190 genera and 335 species of seed plants were collected along the elevation gradient distribution pattern in 19 0.1 ha samples. The total species richness showed a decline distribution pattern along the elevation gradient, and the tree diversity along the coast was a single peak distribution pattern, but shrubs were shrubs. And the diversity of herbaceous species decreased with the elevation, and the diversity of the seedlings was not significant along the elevation gradient. The spatial and environmental variables significantly affected the species richness and species composition. The diversity of species among different altitudes was large. With the increase of altitude, the diversity of P showed a significant rising trend. Species replacement components mainly drive species P diversity. Environment and spatial distance significantly affect species P diversity, and the spatial distance to species diversity of species P diversity is higher than the environmental distance.2. phylogenetic diversity along the elevation gradient distribution pattern based on DNA barcode data to build high support and high resolution community system development. The phylogenetic structure of the tree. The phylogenetic structure of the tree community (the net relative index and the nearest relative index) gathered at low and high altitudes, and the discrete structure in the middle altitudes. The undergrowth shrubs and herbs were dispersed in the middle and low altitude communities, but at high altitudes. The environmental variables and spatial variables also have a significant influence on the phylogenetic structure. The diversity of phylogenetic P increases with the increase of altitude, and the phylogenetic and embedded components are co driven by the system development of P diversity. The diversity of phylogenetic P is significantly different from space distance and environmental distance. The interpretation of phylogenetic beta diversity was greater than that of the environmental distance.3. diversity. The variation of 6 common traits (plant height, leaf thickness, leaf area, leaf carbon, nitrogen, phosphorus content) was analyzed by the altitudinal gradient distribution pattern, and the variation of leaf morphological traits (leaf thickness, leaf area) was mainly derived from the variation of the environmental distance diversity along the altitudinal gradient. Interspecific variation, and the contribution rate of intraspecific variation of plant height and leaf element content (leaf nitrogen content and leaf phosphorus content) to total variation is greater than interspecific variation. The specific leaf area, leaf carbon content and elevation are significantly positively correlated. In this study, the characteristics of the community construction mechanism should be considered in the study of intraspecific variation. The traits of woody plants have significant phylogenetic signals, while the phylogenetic signals of herbaceous traits are weak. At low altitudes and high altitudes, the functional structure of trees (the normalized mean functional pairing distance and the nearest functional distance) The functional structure of the undergrowth shrubs, herbaceous and seedling layers is discrete at the middle and low altitudes, and the structure of the functional structure of the community is influenced by the spatial and environmental variables, while the phylogenetic structure has a certain influence on the functional structure. The functional P diversity along the elevation range is along the altitudinal distance. Increasing and increasing, replacement and embedded components jointly drive functional P diversity. Space distance and environmental distance are related to the diversity of trees, herbaceous and seedling functions, and the spatial distance has a greater interpretation of functional P diversity,.4. binding species, phylogenetic and functional diversity, and the construction and transformation mechanism of elevation gradient communities combined with species. The study of diversity, functional diversity and phylogenetic diversity found that the tree community showed a phylogenetic and functional aggregation structure in low altitude areas, and that environmental filtration might play a leading role, which may be closely related to the low altitude interference; the community in the middle elevation area is discrete, suggesting that competitive exclusion may play a leading role. In high altitude areas, environmental filtration (such as low temperature) may drive community function and phylogenetic aggregation. The undergrowth plants (shrubs and herbaceous) communities, at low and middle altitudes, are systematic and functional discreteness and infer that the competitive exclusion between species plays an important role in the mechanism of species coexistence under the middle and low altitudes. In the high altitude areas, the community system development and functional aggregation, environmental filtration may play a leading role. This study found that the community construction mechanism of different living plants in the vertical structure of the community is different, which reveals the importance of the niche process in the construction of subalpine forest communities. We infer that seed dispersal restrictions may play an important role. Therefore, niche differentiation and seed dispersal restrictions may jointly drive the distribution pattern of subalpine forest communities along the elevation gradient in Jade Dragon Snow Mountain. This study has important implications for understanding community construction and its response to climate change.5. warm temperature needles. The construction and transformation mechanism of the ecotone in the ecotone of the leaf forest - the evergreen broad-leaved forest was in the interlocking area of the warm temperate coniferous forest and evergreen broad-leaved forest in the warm temperate coniferous forest of 300 m. The vegetation changed from the coniferous forest to evergreen broad-leaved forest. With the elevation, the relative abundance of Yunnan pine gradually decreased, the relative abundance of the cap and bucket oak increased gradually, at the high altitude. In the Yunnan pine forest, the system development and functional structure from the low to the high altitudes from the discrete to the aggregation in the Yunnan pine forest show that the construction mechanism from the competition to the environmental filtration. The development and functional structure are discrete, indicating that competitive exclusion may play a leading role in community construction and biodiversity maintenance. The phylogenetic and functional structure of the community in the Yunnan pine cap and Dou oak forest interlaced area is discrete, and the competitive exclusion may play a leading role in the ecotone. The distance and phylogeny of the species in the community There is a significant positive correlation between distance and functional distance. Canopy density has a significant impact on species richness and functional structure. Soil water content in the dry season has a significant influence on the phylogenetic and functional structure of the community. Environmental and spatial variables do not explain the transformation of phylogenetic and functional traits. We speculate that species are compared with environmental variables. Competition may play a more important role in species selection in warm temperate coniferous forest hardwood evergreen broad-leaved forest interlaced area.
【学位授予单位】：云南大学
【学位级别】：博士
【学位授予年份】：2016
【分类号】：S718.54

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