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| Treeline and Species Distribution Range of Tropical Montane Forest in Responseto ClimateChange in Natma Taung National Park,Myanmar | |
| Alternative Title | Treeline and Species Distribution Range of Tropical Montane Forest in Responseto ClimateChange in Natma Taung National Park,Myanmar |
| Tluang Hmung Thang | |
| Thesis Advisor | 陈进 |
| 2020 | |
| Degree Grantor | 中国科学院大学 |
| Place of Conferral | 中国科学院西双版纳热带植物园 |
| Degree Name | 理学硕士 |
| Degree Discipline | 生态学 |
| Keyword | 气候变化、微生境、物种分布动态、物种募集、物种分布模型、树线、热带山地森林 |
| Abstract | 热带山地森林通常拥有大量的特有物种，保护其中的生物多样性对全球生物多样性至关重要。气候变化已经对包括热带山地生态系统在内的全球生态系统产生基础性影响，包括物种的密度和分布范围发生变化，大多数物种向两级和更高的海拔地区移动，树线类置上移；然而世界上不同地区以及不同物种对气候变化的响应不尽相同，并特学缺少有关亚洲热带山地森林生态系统的研究。基于此，本研究在类于缅甸喜马拉雅山东南部钦希尔斯山脉的纳杉马国家公园开展，森林调查沿海拔2450 - 3072米的山地森林垂直横断面展开；在6个海拔带内的 2个横断面上，共建立了72个20米×20米的样方，记录了样方内研有木本树种的幼苗、幼树和成体；利用iButton数据记录仪对六个海拔带的气温、土壤温度和湿度进行了测量，并采集了六个纬度带的土壤样本；从树线交错区开始收集树形杜鹃（Rhododendron arboreum）的树芯用于评估其分布范围变化、定植和居群结构以及树线位置的变化；用最大熵模型计算物种的适宜生境范围，得出以下主要研究结果：1. 热带山地森林中树种的丰富性、多样性和均匀性随着海拔的升高而减少; 研究区域内的优势树种主要是高山栎(Quercus semecarpifolia)、树形杜鹃（Rhododendron arboreum）、厚皮灰木（Symplocos lucida）、 木果石栎（ Lithocarpus xylocarpus） 和针齿铁仔 （Myrsine semiserrata）。 2. 树线类置发生显著的上移，其中，类于北坡的树线上移约5.5米/10年，南坡树线上移约6.4米/10年。 3. 在调查的20种植物物种中，有12种 植物（大叶杨桐 Adinandra megaphylla、西桦Betula alnoides、蒺藜锥 Castanopsis tribuloides、柴桂Cinnamomum tamala、 窄叶南亚枇杷 Eriobotrya bengalensis、大石腕 Lithocarpus magnificus、石栎Lithocarpus wallichianus、树型杜鹃Rhododendron arboreum、穗序鹅掌柴Schefflera delavayi、 坚木山矾Symplocos dryophila、光亮山矾 Symplocos lucida 和鳞斑荚蒾Viburnum cylindricum)经历了显著的向上延伸的趋势，其它8个物种（木果石栎Lithocarpus xylocarpus、 假柿木姜子 Litsea monopetala、米饭花 Lyonia ovalifolia、针齿铁仔 Myrsine semiserrata、云南桂花Osmanthus yunnanensis、高山栎Quercus semecarpifolia、思茅松 Pinus kesiya 和 小红荚蒾Viburnum erubescens）则未呈现向上延伸的趋势。与没有延伸的"非向上延伸"物种相比，"向上延伸"物种的分布范围通常相对狭窄、也往往是热带起源，而"非向上延伸"的物种则大多是亚热带和温带起源。 综上研叙，本研究对缅甸热带山地森林的树种组成和群落结构以及对气候变化相应进行了深入研究，研究表明在过去300年，该地区的树线类置及植物物种分布已经受到气候变化的显著影响，但不同的植物种位其受影响程度不同。本研究成果对该地区的生物多样性变化亦具有一定的借鉴意义，如需要更多的关注窄域分布、热带起源的物种保护，通过加强破碎景观中的连接性保障物种的扩散能力。作为一国家公园，需要加强监测和战略管理，以保护森林生态系统免受日益增长的人为压力和加速的气候变化的威胁。 |
| Other Abstract | Tropical montane forests are important for hosting globally diverse flora and fauna with high proportion of species being endemism. Climatic change has created fundamental impact to ecosystems, including tropical montane forests. Previous studies showed that shifts in species density and distributionrangewith most species moving poleward and to higher altitude, and the treelinealso advancingin response to recent climatic changewere predominating, while studies across different sites and different species are varied.Studies on Asian tropical montane forests are extremely rare. The present study was conducted in Natma Taung NationalParkwhich islocated in the Chin-Hills mountain range, located in the southeastern Himalayas, Myanmar. Forest plots survey was conducted along an altitudinal transect (2450–3072 m) in montane forest. Withinsixaltitudinal bands, laid out in two transects, altogether 72 plots having 20-m x 20-m extents were set upand all the seedling, sapling and adults of woody tree species individuals are recorded.Air temperature, soil temperature and humidity are measured at all six altitudinal bandsby using iButton data loggersand soil samples are also collectedfrom sampling plots of those six altitudinal bands. Tree increment cores from Rhododendron arboreumtrees are collected starting from the trees located at the treeline ecotone to assess the species’ range shift, recruitmentand population structureand treeline fluctuation.MaxEnt, a species distribution modeling method was used to estimatethe suitable habitat range sizes of tree species. The study has gainedthe following main results. 1. Study revealed that tree species richness, diversity and evenness decrease with increasing altitudes in a tropical montane forest. The most dominant tree species in the study site are Quercus semecarpifolia, Rhododendron arboreum, Symplocos lucida, Lithocarpus xylocarpus and Myrsine semiserrata. 2. Treeline advancement has occurred at a low latitude tropical mountain. Treeline in the northern transect has shifted upward with a rate of 5.5 meters per decade, while the southern transect has shifted with a rate of 6.4 meters per decade. 3. For range dynamics of tree species in response to climate change, among the 20 species investigated, 12 species (Adinandra megaphylla, Betula alnoides, Castanopsis tribuloides, Cinnamomum tamala, Eriobotrya bengalensis, Lithocarpus magnificus, Lithocarpus wallichianus, Rhododendron arboreum, Schefflera delavayi, Symplocos dryophila, Symplocos lucida and Viburnum cylindricum) experienced significant upward range extensions and the other eight species (Lithocarpus xylocarpus, Litsea monopetala, Lyonia ovalifolia, Myrsine semiserrata, Osmanthus yunnanensis, Quercus semecarpifolia, Pinus kesiya and Viburnum erubescens) experienced no-upward extensions. The ‘upward’ species were often ones with relatively narrow distribution ranges compared to the ‘non-upward’ species which showed no extensions. The ‘upward’ species were also often species of tropical evolutionary origin and the ‘non-upward’ species were of subtropics and temperate origin. The mechanism behind these distribution patterns of different species may be complex while the distribution patterns of this 20 species along the altitudinal transect generally support the prediction of the Climate Variability Hypothesis (CVH). From theperspective of conserving biodiversity against the impacts of climatic change, more attention needs to be paid to narrowly distributed species, which are typically tropical origin, by enhancing landscape connectivity and dispersal capacity in fragmentedhabitat andlandscapes. In summary, this study provides a comprehensive investigation on tree species distribution, composition and community structure in line with the environmental factors along altitudinal gradients, and the range dynamics of tree species in response to climate change in a tropical montane forest of Myanmar. The study indicated that the impact of climatic change in the past 300 years upon treeline and the species distribution range was significant, while the sensitivity of different species to climate change is distinct. The study also holds implication for plant species conservation, for example, more attention needs to be paid to narrowly distributed species, which are typicallyoftropical origin, by enhancing landscape connectivity and dispersal capacity in fragmented landscapes. Given that, being a national park, intensive monitoring and strategic management is needed to protect the pristine forest ecosystems from growing anthropogenic pressures and accelerated menaces of climate change. Key words: climate change, diversity, range dynamics, recruitment, species distribution modeling, treeline, tropical montane forest |
| Pages | 98 |
| Language | 中文 |
| Document Type | 学位论文 |
| Identifier | https://ir.xtbg.ac.cn/handle/353005/11713 |
| Collection | 西双版纳热带植物园毕业生学位论文 |
| Recommended Citation GB/T 7714 | Tluang Hmung Thang. Treeline and Species Distribution Range of Tropical Montane Forest in Responseto ClimateChange in Natma Taung National Park,Myanmar[D]. 中国科学院西双版纳热带植物园. 中国科学院大学,2020. |
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| TLUANG HMUNG THANG.p（4277KB） | 学位论文 | 开放获取 | CC BY-NC-SA | Application Full Text | ||
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