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1.
Tropical mountains are areas of high species richness and endemism. Two historical phenomena may have contributed to this: (i) fragmentation and isolation of habitats may have promoted the genetic differentiation of populations and increased the possibility of allopatric divergence and speciation and (ii) the mountain areas may have allowed long‐term population persistence during global climate fluctuations. These two phenomena have been studied using either species occurrence data or estimating species divergence times. However, only few studies have used intraspecific genetic data to analyse the mechanisms by which endemism may emerge at the microevolutionary scale. Here, we use landscape analysis of genomic SNP data sampled from two high‐elevation plant species from an archipelago of tropical sky islands (the Trans‐Mexican Volcanic Belt) to test for population genetic differentiation, synchronous demographic changes and habitat persistence. We show that genetic differentiation can be explained by the degree of glacial habitat connectivity among mountains and that mountains have facilitated the persistence of populations throughout glacial/interglacial cycles. Our results support the ongoing role of tropical mountains as cradles for biodiversity by uncovering cryptic differentiation and limits to gene flow.  相似文献   

2.
成年太行山猕猴(Macaca mulatta tcheliensis)肩关节变量的研究   总被引:6,自引:0,他引:6  
本项研究对成年太行山猕猴肩关节变量进行了测量和统计,作了异速生长分析,并对太行山猕猴(M.mulatta tcheliensis)、滇南猕猴(M.mulatta mulatta)、川西猕猴(M.mulatta lasiotis)、湘鄂猕猴(M.mulatta littoralis)肩关节变量进行了比较和聚类分析。与上述3个亚种相比,太行山猕猴较短的肩胛骨、较小的锁肱指数、较大的三角肌止点指数和较小的摆荡指数,表明太行山猕猴肩关节形态结构更适应于地面上的活动,说明其在地面上活动较多,在树上活动较少。  相似文献   

3.

Mountain regions are important places for biodiversity, where organisms could persist throughout prolonged periods and accumulate genetic divergence as well as promote speciation. Roles of mountains for biodiversity have been exclusively discussed in regions that have specifically diverse species or covered with ice-sheets during the Pleistocene glacial periods, whereas the importance of mountainous regions in East Asia has been less disputed. High mountains in the Japanese Archipelago, located at the eastern edge of the Eurasia continent, have one of southernmost populations of alpine and arctic-alpine plants that are also distributed in the northern Pacific and/or the circumarctic regions. Phylogeographic studies on the Japanese alpine plants have excluded their possible ephemeral occurrence during the current warm period, and rather, suggest persistence of alpine plants throughout several cycles of climate changes in the Pleistocene on high mountains in central Honshu, the main island of the Japanese Archipelago. In this review, I look through decade long phylogeographic studies and show complicated patterns of range dynamics of Japanese alpine plants. In addition, I note recent findings of genetic relationships of Japanese populations of alpine and/or arctic-alpine plants with those in northern regions and their possible ecological divergence in the Japanese Archipelago. Taken together, I provide several issues for understanding historical processes that established distribution of alpine plants following climate changes as well as their diversification and propose importance of Japanese populations of alpine plants on biodiversity in alpine communities across broader range, especially in the northern Pacific region.

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4.
中国东北主要植被类型的分布与气候的关系   总被引:38,自引:0,他引:38       下载免费PDF全文
本文根据吉良的热量指标和作者提出的湿度指数,研究了我国东北主要植被类型的分布与气候之间的关系:1.确定了东北地区10个水平地带性植被类型的热量分布范围和水热指标的平均值。2.研究了东北山地垂直地带性植被类型的水热指标分布特点,并用定量指标讨论了东北东部山地岳桦林带的分布、大兴安岭存在山地冻原和东北植被区域的分界线问题。  相似文献   

5.
1  Distribution data were assembled for non-volant small mammals along elevational gradients on mountain ranges in the western U.S.A. Elevational distributions in the species-rich Uinta Mountains were compared to those on smaller mountain ranges with varying degrees of historical isolation from the Uintas.
2  For mountain ranges supporting the richest faunas, species richness is highest over a broad low- to mid-elevation zone and declines at both lower and higher elevations. Patterns on other mountain ranges are similar but reflect lower overall species richness.
3  A basic relationship between elevational and geographical distribution is apparent in the occurrence patterns of mammals on regional mountains. Faunas on mountains that have had low levels of historical isolation appear to be influenced by immigration rather than extinction. Species restricted to high elevations in the Uintas are poorly represented on historically isolated mountains and form a portion of local faunas shaped by extinction. Species occurring at lower elevations in the Uintas have better representation on isolated mountains and apparently maintain populations through immigration.
4  Several widespread species show substantial variation in maximum elevation records on different mountain ranges. This involves (1) an upward shift in habitat zones on small, isolated mountain ranges, allowing greater access by low-elevation species, and (2) expansion of certain low- and mid-elevation species into habitats normally occupied by absent high-elevation taxa.
5  Results indicate that montane mammal faunas of the intermountain region have been shaped by broad-scale historical processes, unique regional geography and local ecological dynamics. Parallel examples among mammals of the Philippine Islands suggest that such patterns may characterize many insular faunas.  相似文献   

6.
A population of rhesus macaques in the Taihang mountains on the Henan-Shanxi border is probably the northernmost population of the species. A more northerly population north of Beijing was locally extirpated in 1988. In the Taihang mountains, 26 natural groups, with >2000 monkeys, have been found. Six of them have been studied for 8 years. They live in a deciduous forest with temperate climate and cold snowy winters. The average group size is 82 individuals, and the population density is 3.1–7.2 individuals per km2. Home rangs are very large, varying from 11 to 22 km2. A natural reserve for the rhesus was established at Jiyuan in 1982, and one group, monitored and provisioned since 1984, has increased from 47 to 83 individuals, an increase of 76.5%.  相似文献   

7.
秦岭山地碳中和空间服务范围及其模拟预测   总被引:1,自引:0,他引:1  
马新萍  李晶  余玉洋  邓晨晖 《生态学报》2022,42(23):9431-9441
在当前碳中和背景下,秦岭山地碳中和的量化及其空间服务范围的测算对于碳中和合理规划和快速实现具有重要意义。采用IUEMS (Intelligent Urban Ecosystem Management System)系统对秦岭山地的固碳量进行核算,利用DMSP/OLS (Defense Meteorological Satellite Program/Operational Linescan System)和NPP-VIIRS (Net Primary Productivity-Visible infrared Imaging Radiometer)夜间灯光数据和各地市的能源消耗数据通过模型拟合对秦岭山地碳排放量进行空间量化,基于固碳量和碳排放量得到秦岭山地空间碳中和量。利用PLUS (Patch-generating Land Use Simulation Model)模型模拟了2030和2050年的碳中和空间分布,结合常见气体扩散系数计算得到常温常压下秦岭山地碳中和对周边区域的服务范围。结果表明:2000-2020年秦岭山地固碳量呈现上升的趋势,大部分区域不同时间尺度上的固碳速率呈正向趋势,空间上秦岭山地中西部区域固碳量整体较大;对秦岭固碳量影响较大的地形特征为海拔1200m左右、斜坡、半阳坡和半阴坡;研究区内碳排放量空间上整体较低,碳排放低值区面积占到了秦岭总面积的90%,碳排放较大区域主要位于秦岭北坡的城区区域,时间上碳排放量最大值为先增加后减少的变化趋势;2000-2050年秦岭山地碳汇服务范围为174-262.63km,服务范围在空间上呈逐渐扩大趋势,2030年后其扩大程度将略有减少。  相似文献   

8.
As mountains have been hypothesized as harboring important Quaternary refugia for plants, one would expect high within-population genetic variation and low or moderate among-population differentiation for those species occurring there. We selected Kirengeshoma koreana and Parasenecio pseudotaimingasa, endemic to mountains of Korea to test the scenario that the main mountain ranges of the Peninsula would also have acted as refugia. We undertook a population genetic analysis using 15 and 12 putative allozyme loci of K. koreana and P. pseudotaimingasa, respectively. We found contrasting levels of genetic diversity in the two species; extremely low within-population genetic variation and high among-population divergence in K. koreana and high within-population genetic variation and moderate among-population divergence in P. pseudotaimingasa. We can conclude that, whereas Korean mountains would have provided large refugial areas (i.e., ‘macrorefugia’) for P. pseudotaimingasa, K. koreana would have endured the Quaternary climate oscillations in small, isolated populations (i.e., ‘microrefugia’). Given the lack of genetic diversity and the extremely low number of populations and individuals of K. koreana, a comprehensive conservation program is urgently needed for this rare and critically endangered species.  相似文献   

9.
罗格平  周成虎  陈曦 《生态学报》2005,25(9):2197-2205
根据三工河流域1978、1987年航片和1998年TM影像,利用GIS、RS和景观生态的研究方法,主要从绿洲景观格局分析了人为驱动的绿洲变化,包括景观多样性与人类活动的复杂多样性、景观斑块形状与绿洲扩张、斑块破碎化程度与人类活动的强度等。结果表明:(1)绿洲景观多样性总体呈现下降趋势,区域差异性较为明显。人类活动可以显著地改变绿洲景观的多样性。(2)绿洲景观斑块形状总体趋向不规则性和复杂性,但趋势减弱。人类一方面尽力在扩张绿洲外围,增加外围斑快形状的不规则性和复杂性,增加分维数,另一方面也在尽量规划绿洲内部,又使斑块形状趋向规则,降低其复杂性;但近20a,绿洲总体上以外围扩张为主。(3)人类活动强度和支配程度较大的绿洲区域,其景观的破碎化程度总体较高,绿洲中部人类活动强度最大,其景观破碎化程度总体高于人类活动强度较弱的绿洲下部和上部;绿洲斑块密度和景观破碎化程度随时间总体呈下降的趋势;人为引入斑块的破碎化程度普遍高于环境资源斑块的破碎化程度。  相似文献   

10.
Aim To assess the geological evolution and biogeographical implications of low mountain passes. In particular, we question the common biogeographical belief that major mountain belts form impervious physical barriers to biological dispersal, and that related taxa found on opposites sides of mountains are necessarily a result of vicariant tectonic processes. Location The Southern Alps of New Zealand form a long (500 km) narrow mountain belt at the oblique collisional Pacific–Australian tectonic plate boundary. High mountains were uplifted during the Pliocene (2–5 Ma) and uplift has continued to the present day. Methods We integrate previous work from several disciplines to obtain an overview of inter‐relationships between plate tectonic processes, geomorphology and biogeography along the main mountain barrier in New Zealand, and then extend this approach to other major mountain belts. Results The Southern Alps initially formed a barrier to at least some biological dispersal, including vicariant formation of separate species of freshwater non‐migratory galaxiid fish on either side. However, the high mountain barrier was breached in several places when passive transport of topography occurred, from the low‐erosion rain shadow on the eastern side towards the high‐erosion, high‐rainfall western side. This tectonic transport resulted in the capture of eastern rivers by west‐draining rivers, leaving low passes at the topographic divide. These low‐elevation corridors permitted biological dispersal across the mountains, although continued uplift raises these passes. A new set of passes has formed in the northern part of the mountains where younger faults are cutting across the older mountain topography. These potential dispersal corridors are becoming lower with continued erosion, and more common as the defining structures migrate southwards. Main conclusions Biological dispersal across the Southern Alps may be facilitated by numerous mountain passes, especially via the new passes formed by cross‐cutting faults. More low‐lying corridors existed than is readily apparent now, as old river capture‐related passes have been blocked by ongoing uplift. The dynamic mountain‐building and erosional environment typified by the Southern Alps occurs in all the world’s collisional mountain belts, such as the Andes, Himalayas, European Alps and North American Cordillera. Sister taxa occurring across mountain belts are not necessarily a result of vicariance driven by the rise of the mountains, as numerous passes may have permitted intermittent dispersal. The evolution of low passes may have been more prevalent than is currently appreciated, suggesting that topographically complex mountain ranges might be more effectively viewed as dynamic filters within a probability landscape rather than as static and impervious high‐altitude barriers to all but the rarest of biological dispersal events. In some cases, the biological disjunctions observed across mountains may more directly reflect habitat differentiation driven by orographic mountain development that has limited the probability of trans‐alpine dispersal success.  相似文献   

11.
The three sections of this paper report on i) new species, ii) new records for the Flora Zambesiaca region and for Mozambique and iii) expansion of distributions of species previously thought to be endemic to particular mountains. Specimens have been collected from three mountains in north-central Mozambique visited during a collecting programme from 2006 to 2008 investigating the conservation value of the biodiversity of currently unprotected areas. Three new species: Crotalaria namuliensis, Isoglossa namuliensis and Helixanthera schizocalyx are described. Five taxa not previously recorded from the Flora Zambesiaca region are here recorded as new records for the region and 31 taxa are listed from Mozambique for the first time, including five taxa previously thought to be Malawi mountain endemics. The number of range extensions recorded from these Mozambican mountains is evidence of the paucity of specimens collected from this part of Mozambique and shows the need for continued collection in order to clarify the distributions of this region’s rarest species.  相似文献   

12.
A species list of oribatid mites collected from the summit of Yes Tor, Dartmoor, is given, together with notes on their distribution. Yes Tor lies south of latitude 51° in that part of Britain which remained ice free during the Pleistocene. The species found on Yes Tor are compared with the species recorded from the summits of 11 mountains lying north of latitude 53°, which were all ice-covered at the period of maximum glaciation. In the case of Yes Tor and these 11 northern montane sites, three similar faunal elements have been identified arctic-alpine species, European-alpine species and a group of British montane species that are also common in the lowlands. The view is advanced that the similarity of the montane oribatid fauna of Yes Tor with that of the mountains to the north of latitude 53° has resulted from the probable movements of the mites during Quaternary and postglacial times over an area extending from the Arctic Circle to the Mediterranean. It is suggested that these movements, while being largely spontaneous, have also been aided by transportation agents, both physical and biological.  相似文献   

13.
浙江省珍稀濒危植物物种多样性保护的关键区域   总被引:29,自引:0,他引:29  
浙江省植物资源丰富,有野生维管植物215科1196属3283种,其中包含了我国特有属49个,浙江省特有植物约200余种,许多物种十分稀少,并受到严重威胁,亟待保护。但浙江省需优先保护的植物物种的分布并不是均匀的,有些地区的重要保护对象比较集中,对这些地区我们应该给予更多的保护。本文根据维管植物物种多样性、珍稀濒危植物的物种数量及个体数量特征、受威胁状况以及浙江省特有植物的分布情况,提出了浙江省珍稀濒危植物保护的7个关键区域:以西天目山为中心的浙西北山区,以古田山为中心的浙西山区,以九龙山为中心的浙西南山区,以凤阳山-百山祖为中心的浙南山区,以括苍山为中心的浙东山区,以天台山为中心的浙东丘陵,以普陀山为中心的舟山群岛。最后提出了浙江省植物物种多样性保护的几点建议。  相似文献   

14.
The hormonally induced stresses have been studied for their effect on higher nervous activity (HNA) of rats under conditions of low-(1760 m above the sea level) and highland (3200 m above the sea level). Hydrocortisone-induced stress (HIS) in mountains decreases to an optimal degree the latent period (LP) of conditioned reflex of active avoidance (CRAA) and strengthens differentiating inhibition (DI). In mountains and on plain it impedes appearance of extinctive inhibition (EI). DOCA-induced stress (DIS) has the same effect though in the emergency period of adaptation it sharply (unlike GIS) increases the number of cases of CRAA amnesia manifestation and prolongs their LP. ACTH-induced stress (AIS) makes the appearance of amnesia cases more frequent and prolongs LP of realized CRAA, unlike DIS, over all the periods of Alpine adaptation. However, DI strengthens, while EI is hindered irrespective of the altitude level. Injection stress in mountains occurs with deviations of HNA; the number of cases of the CRAA amnesia increases as well as differentiation disinhibition. DI fails rapidly being tested for strength. Adaptation of intact rats to highland occurs faithfully without essential changes of LP but with impeded development of EI.  相似文献   

15.
秦岭的珍稀特有植物及其区系特征   总被引:7,自引:0,他引:7  
本文论迹了秦岭地区珍稀、特有植物的种类组成,历史成因,及其区系特征和与邻近地区植物的关系,并分析了它们的分布特点。1.秦岭是我国南北植物的分界线,有珍稀植物66种,特有植物169种。2.秦岭珍稀植物具有相对的古老性,它们与华中亚热带区系的历史渊源较深。而秦岭特有植物却具有相对的年青性,表现出明显的温带性特点和剧烈的分化作用,大部分为分化较晚的新特有种。3.秦岭地区地史上和现在的南北地质、气候条件的分异,决定了其珍稀植物的特点,也使其本身成为我国大多数亚热带珍稀植物分布的北界。而复杂的地形造成不同气候条件的交错和变化,及明显的新构造运动引起垂直气候带谱的变化,导致了秦岭植物的强烈变异和分化,以及大量新特有种的形成。4.秦岭珍稀植物具有多种区系成分,与邻近地区有着广泛的联系,尤其与川东-鄂西地区联系最为密切。我们认为从这里经大巴山东端到秦岭中部,再向西扩展,是秦岭与华中亚热带植物区系相互渗透的一条主要路线。  相似文献   

16.
Saussurea gossypiphora D. Don growing above 4200–4700 m altitude on mountains so far have been not reported. We have first isolated 6 components from it. They are identified as (Ⅰ) umbelliferone, (Ⅱ) scopoletin, (Ⅲ) β-sitosterol, (Ⅳ) apigenin, (Ⅴ) apigenin 7-0-β-D-glucoside, (Ⅵ) umbelliferone 7-O-β-D-plucoside.  相似文献   

17.
The eastern arc mountains (EAMs) are a chain of isolated mountains (534,000 ha) in Kenya and Tanzania surrounded by arid woodlands and influenced by the Indian Ocean. In 1900 there was three times the amount of forest cover there is today. Much of the original forests have been converted into agricultural crops. These mountains are recognized as a globally important ‘hot spot’ by World Wide Fund for Nature (WWF) and World Conservation of Union (IUCN) for forest biodiversity and are major national, regional and local sources of hydropower, water and wide array of forest‐based benefits and agricultural production. In February 2000 we began a 3‐year evaluation of forest health, land‐use change and information sharing in the EAMs. Permanent sample plots were used to evaluate forest health. This paper summarizes the baseline data from eighteen permanent sample plots in the east Usambara's and nine in Ulugurus. The eastern arc web site ( http://www.easternarc.org ) was established, continues to expand and contains some detailed information on the project. Information gathered will assist land managers, planners, policy makers, interested communities (villages) and individuals in decision‐making. These data can also provide an early warning system of stresses on forest catchments.  相似文献   

18.
Aim This paper seeks to investigate whether alpine floras on isolated mountains in boreal forest show nestedness, and, if that is the case, to determine whether selective extinction or colonization is the likely cause of the observed patterns. Location Isolated mountains in the boreal coniferous forests of northern Sweden (province of Norrbotten, c. 66°N; 18°E). The timberline in the region probably has been 300–400 m above the present some thousands of years before present, potentially covering these mountains. Methods A data matrix of twenty‐seven alpine plant species on twenty‐seven isolated mountains was subjected to nested subsets analysis. Extinction probability was assumed to increase with decreasing area, and colonization probability was assumed to decrease with increasing isolation. By sorting the data matrix by these factors and sequentially computing the degree of nestedness, we were able to determine whether the alpine floras were structured mainly by selective extinction or mainly by differential colonization. Results When ordered by decreasing area the data matrix was significantly more nested than random, but that was not the case when ordered by decreasing isolation. Ordering by maximum altitude also produced significant nestedness. Main conclusions Contrary to the conventional view that isolated mountains were completely covered with boreal forest some thousands of years ago, the nestedness patterns of alpine plants indicate that many of them survived the forest period on the isolated mountains, probably on cliffs and slopes too steep for the formation of closed forest.  相似文献   

19.
Ultrastructural peculiarities of blood plates and state of the thrombocytic line of hemostasis have been studied in yaks (Bos grunniens), the Tibet subspecies, living in the Kirghiz mountains at the altitude more than 3.200 m. As a control 6 cows (Bos taurus), constantly living at the altitude of 760 m, have been taken. Stereological analysis of the volume of thrombocytic alpha-granules and of the volume of blood plates in the yaks has been performed. Ultrastructure of thrombocytes in the yaks possesses certain essential peculiarities (polymorphism of mitochondria, difference in the structure of alpha-granules). A conclusion is made on adaptive specificity of thrombocytes in animals living at high altitude.  相似文献   

20.
新疆科古琴山高山流石坡植被的特征   总被引:5,自引:1,他引:4  
研究对新疆科古琴山高山流石坡植被的植物区系特点、植物群落特征和生物-生态学特性进行了论述。初步查明该地有种子植物17科27属34种、藓类5种、地衣9种。说明该地种子植物种类贫乏,特有种少,植物区纱成人年轻,温带特点突出。植物生长稀疏,盖度小,植物群落结构简单,层次分化不明显、季相单调。植被因坡度,坡向的不同存在明显差异。其植物具有株矮、叶小,根系发达,丛生、莲痤状、体被茸毛、生长期短,以营养繁殖为主,多年生、耐寒等特性。应加强对高山流石坡植被及其野生药用植物资源的保护。  相似文献   

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