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1.
Geographical barriers and distance can reduce gene exchange among animals, resulting in genetic divergence of geographically isolated populations. The Tibetan antelope (Pantholops hodgsonii) has a geographical range of approximately 1600 km across the Qinghai–Tibet Plateau, which comprises a series of tall mountains and big rivers. However, previous studies indicate that there is little genetic differentiation among their geographically delineated populations. To better understand the genetic structure of P. hodgsonii populations, we collected 145 samples from the 3 major calving regions, taking into consideration their various calving grounds and migration routes. We used a combination of mitochondrial sequences (Cyt b, ATPase, D‐loop and COX I) to investigate the genetic structure and the evolutionary divergence of the populations. Significant, albeit weak, genetic differentiation was detected among the 3 geographical populations. Analysis of the genetic divergence process revealed that the animals gradually entered a period of rapid genetic differentiation approximately 60 000 years ago. The calving migration of P. hodgsonii cannot be the main cause of their weak genetic structure because this cannot fully homogenize the genetic pool. Instead, the geological and climatic events as well as the coupling vegetation succession process during this period have been suggested to greatly contribute to the genetic structure and the expansion of genetic diversity.  相似文献   

2.
Evolutionary biologists have a long‐standing interest in how acoustic signals in animals vary geographically, because divergent ecology and sensory perception play an important role in speciation. Geographic comparisons are valuable in determining the factors that influence divergence of acoustic signals. Bats are social mammals and they depend mainly on echolocation pulses to locate prey, to navigate and to communicate. Mounting evidence shows that geographic variation of bat echolocation pulses is common, with a mean 5–10 kHz differences in peak frequency, and a high level of individual variation may be nested in this geographical variation. However, understanding the geographic variation of echolocation pulses in bats is very difficult, because of differences in sample and statistical analysis techniques as well as the variety of factors shaping the vocal geographic evolution. Geographic differences in echolocation pulses of bats generally lack latitudinal, longitudinal and elevational patterns, and little is known about vocal dialects. Evidence is accumulating to support the fact that geographic variation in echolocation pulses of bats may be caused by genetic drift, cultural drift, ecological selection, sexual selection and social selection. Future studies could relate geographic differences in echolocation pulses to social adaptation, vocal learning strategies and patterns of dispersal. In addition, new statistical techniques and acoustic playback experiments may help to illustrate the causes and consequences of the geographic evolution of echolocation pulse in bats.  相似文献   

3.
Habitat structure has been considered as an important factor affecting the acoustic evolution of birds, and bird songs are increasingly affected by artificial environmental variation. Invasive plants sometimes can dramatically alter native habitats, but the song variation of native songbirds migrating into invaded habitats has received little attention. The invasion of smooth cordgrass Spartina alterniflora in the coastal wetlands of eastern China has drastically altered the vegetation structure and some small passerines have begun to use invaded habitats to breed. In this study, we compared the song type prevalence and the song characteristics of male plain prinia Prinia inornata to identify differences in vocal behavior between native and invaded habitats. We also tested for differences in vocal behavior in relation to singing perch and wind speed variation between different habitats. The results indicated that males of plain prinia in invaded habitats sang shorter songs than those in native habitats and had a lower song diversity. The homogeneous vegetation structure and higher wind speed in invaded habitats likely leads to males changing the traditional perched singing style. The song variation may be related to the founder effect, the alteration of vegetation structure and microclimate in invaded habitats. This finding highlights the need for better understanding the behavioral evolution of native species in the process of adapting to the invaded habitat. In the future, experimental manipulation is needed to ascertain how the invasive plant drove these vocal behavior changes of native songbirds.  相似文献   

4.
Leopoldamys edwardsi is a species with wide distribution ranges in southern China but is not discussed in studies on geographic variation and species differentiation. We used 2 mitochondrial (Cytb, CO1) and 3 nuclear (GHR, IRBP and RAG1) genes to clarify species phylogeography and geographical differentiation. Maximum likelihood (ML) and Bayesian phylogenetic inference (BI) trees consistently indicated that L. edwardsi is a species complex containing 3 main lineages with high Kimura‐2‐parameter (K2P) divergences (i.e. lineages LN, LS and LHN) found in the northern and southern China and Hainan Island, respectively. The 3 species delimitation methods, automated barcoding gap discovery, Bayesian poisson tree process analysis and Bayesian phylogenetics and phylogeography, consistently supported the existence of cryptic species. Divergence times among the main lineages were inferred to be during the Pleistocene, with LHN/LS split at 1.33 Ma and LN/(LHN+LS) at 2.61 Ma; the diversifications of L. edwardsi complex might be caused by the rapid uplifts of Tibetan Plateau, paleoclimate change and complex topography. The divergence between LHN and LS was probably related to the separation of Hainan Island from the mainland via the formation of the Qiongzhou Strait. Lineages LN and (LS+LHN) likely diverged due to the Wuyi‐Nanling mountain range forming a dispersal barrier. Our results suggested that L. edwardsi complex contains at least 3 distinct species: LHN represents L. hainanensis, endemic to Hainan Island and previously considered as a subspecies L. e. hainanensis; LS represents a cryptic species distributed throughout the southern Chinese continent; and LN represents the nominotypical species L. edwardsi.  相似文献   

5.
We used mitochondrial cytochrome b and ND4 genes and 9 microsatellite loci to determine genetic diversity, population structure, evolutionary history, and migration patterns within the Reeves’ butterfly lizard Leiolepis reevesii (Agamidae). Considering molecular-based phylogeographical lineages, we then performed niche equivalency and similarity tests between divergent lineages. Phylogenetic analyses based on mitochondrial DNA (mtDNA) data revealed 2 lineages (A and B) diverging ≈0.84 million years ago and, respectively, restricted to the northern and southern portions of the Wuzhishan and Yinggeling mountain ranges. Lineage B contains individuals from southern Hainan; Lineage A includes individuals from all other localities and can be further divided into 3 clusters according to microsatellite data. The null hypothesis that the 2 lineages shared identical niches was rejected in all niche equivalency tests, indicating niche shifts during genetic divergence. Similarity tests provided evidence of niche conservatism, suggesting that the 2 lineages share more characteristics of their niche spaces than randomly expected. The niche similarity and equivalency tests indicated a complex niche pattern in which both lineages share a main portion of their ecological spaces. The climatic niche of Lineage B represented a marginal and specialized fraction of the entire ecological space of the climatic niche of Lineage A, with warmer conditions. Isolation caused by orogenesis and subsequent niche divergence, together with local adaptation, may have led to genetic differentiation and further lineage sorting in L. reevesii.  相似文献   

6.
The light‐vented bulbul Pycnonotus sinensis is a small resident passerine that is found widely in central and south China, North Vietnam, and some East Asian islands, including Hainan, Taiwan and the Ryukyu Islands. Its subspecies status has been under considerable debate. A total of 10 subspecies have been proposed, but only 4 are widely recognized, including 1 continental taxon, P. s. sinensis, and 3 insular subspecies: P. s. hainanus, P. s. formosae and P. s. orii. Two mitochondrial DNA genes and 9 microsatellite loci were used to investigate the genetic divergence of this species, to identify the evolutionary status of 2 insular subspecies (P. s. hainanus and P. s. formosae) and to uncover probable historical causes that shaped them. The results reveal that P. s. formosae has diverged significantly from the other 2 subspecies because of a substantial time of isolation for populations on Taiwan Island. There was no significant genetic differentiation between P. s. sinensis and P. s. hainanus. The notable morphological difference in P. s. hainanus might be attributed to a rapid, recent adaptation to the tropical environment of Hainan Island. The low genetic divergence between P. s. sinensis and P. s. hainanus might result from a recent divergence or gene flow between them. Two insular subspecies of light‐vented bulbul populations might have diverged recently from their continental relatives through a complex evolution history owing to island isolation, ecological isolation, and possibly even hybridization. Both P. s. hainanus and P. s. formosae should be considered important conservation units because of their morphological and genetic distinctiveness.  相似文献   

7.
祁连山北坡及河西走廊蝶类垂直分布及群落多样性研究   总被引:1,自引:1,他引:1  
1998-2004年,对祁连山北坡及河西走廊蝶类的垂直分布进行了调查,依据植被、海拔、气候、土壤等不同因子将该地区蝶类分布的生境划分为5种类型,对不同生境(垂直带)蝶类区系组成及群落多样性进行了研究。结果表明,祁连山北坡及河西走廊蝶类共有128种,分属8科74属,不同生境蝶类群落的组成中,科、属、种3级组成顺序大致为:高山亚冰雪稀疏植被带<走廊绿洲、山地荒漠带<亚高山灌丛草甸带<山地草原带<山地森林草原带。不同等级的多样性指数结果排序基本一致:山地森林草原带>山地草原带>亚高山灌丛草甸带>走廊绿洲、山地荒漠带>高山亚冰雪稀疏植被带,多样性指数与物种丰富度相关(r=0.987 8,P<0.01),而与均匀度不相关(r=0.377 4,P>0.05)。 G-F指数可以简便而有效地反映昆虫区系中物种多样性信息,同时使用Shannon-Wiener 指数和 G-F指数,将科、属多样性与物种多样性综合考虑,较为全面地评价了蝶类群落多样性。各垂直带之间相似性系数较低,蝶类垂直分布差异非常明显。  相似文献   

8.
1. The development of prenatal acoustic communication was investigated in Muscovy ducks, comparing the vocalisation activities and call types in isolated eggs and pairs of embryos (two eggs in shell contact).

2. Incubator experiments showed that the number of vocalisations in embryos which had mutual acoustic contact was nearly twice that of isolated ones.

3. An acoustic interaction, that is, an exchange of signals, was only recognised after the first chick had hatched, that is, between embryos and chicks.

4. Specific call types used for communication were the double call and the trill call.  相似文献   


9.
Human activities have dramatically altered the distribution and density of large herbivores worldwide, particularly on islands. For example, thousands of goats were abandoned to the mountains on Majorca Island, Spain, during the tourism boom in the 1960s. Though this mammal is common throughout the Majorcan mountain range, the impact of goats on the main mountain plant communities has not yet been evaluated. To fill this gap, we recorded goat fecal pellet accumulation and assessed the degree of browsing of 9 363 shrubs and trees located within 231 25-m2 strips systematically distributed in two mountain regions of Majorca. We also recorded the degree of regeneration of woody plants inside the same strips. The environmental factors that significantly influenced pellet accumulation were altitude, rock cover, distance to roads and paths, distance to water, and slope. The correlations between the pellet index and degree of browsing depended on species palatability and abundance. Finally, the natural regeneration of plants was heterogeneously distributed and negatively correlated with pellet accumulation. This study indicates that high levels of browsing of unpalatable species in less preferred areas are a clear indicator of strong herbivore pressure, whereas the presence of nonbrowsed palatable species could indicate low herbivore presence. Moreover, this work demonstrates that the relative abundance of fecal pellets is a good indicator of the pressure exerted by feral goats on vegetation at a fine scale. The simple pellet index used in this work correlates strongly with vegetation damage; thus, it could represent a valuable innovative tool to inform sustainable management of feral goat populations in not only Majorca but probably also other Mediterranean islands.  相似文献   

10.
青藏高原植被物候监测及其对气候变化的响应   总被引:5,自引:0,他引:5  
研究青藏高原植被物候变化对揭示高寒生态系统对全球气候变化的响应机制具有重要的科学意义。本文选取1982-2005年的GIMMS NDVI遥感数据,采用动态阈值法提取了青藏高原高寒草地的物候信息,包括植被返青期、枯黄期及生长季长度,分析了青藏高原高寒草地植被物候的时空变化及其对气候变化的响应规律。研究结果表明,1)青藏高原植被物候多年均值的空间分布与水热条件密切相关。青藏高原从东南向西北,植被返青期逐渐推迟、枯黄期逐渐提前,生长季长度因受到植被返青和枯黄的影响,呈现逐渐缩短的趋势;2)植被返青期和枯黄期的年际变化整体上呈提前的趋势,生长季长度呈增长趋势;3)高原地区的植被物候易受到海拔的影响,但存在3400 m的分界线,在3400 m以下,物候随海拔变化的波动较大,而在3400 m以上,物候与海拔的关系密切;4)气象因子是不同草地类型植被物候变化的主要影响因素,与降水相比,植被物候期与温度相关程度更高。  相似文献   

11.
In this study, we determined six “hotspots” for avian biodiversity conservation in China. We analyzed the distribution patterns of 183 threatened bird species in China in conjunction with geographical data to produce a distribution map that shows the concentrations of threatened species. The six biodiversity hotspots are: the western Tianshan Mountains; the Qilian and Hengduan mountains; southern Anhui, southern Jiangsu, and the Zhejiang Hills; the Songliao Plain and the northern region of the North China Plain; the island of Taiwan; and the island of Hainan. Based on our analysis of a species–habitat matrix, species were determined to be distributed mainly in broadleaved forest, grassland and meadows, urban and agricultural areas, wetlands, and bush. Most species were commonly found to have a range of three to five different habitat types. Apart from the six biodiversity hotspots, six ecological clusters were determined. Protection strategies indicating different levels of habitat priority among the biodiversity hotspots were also recommended.  相似文献   

12.
为探究科尔沁不同沙地类型植被动态特征及其与凋落物的关系,本试验以科尔沁沙地不同类型样地(流动沙丘、固定沙丘和封育草地)为研究对象,测定了2005-2016年生长季高峰期(8月中旬)植被特征和整个生长季(4-9月)凋落物量的动态,分析了二者的年际动态及关系。结果表明:不同类型样地植被特征差异极显著,植被密度、盖度和生物量均有明显的年际动态,且年际动态和样地类型间存在显著交互效应;凋落物量受样地类型、年、月3因素及其交互效应的影响;回归分析表明,植被特征与凋落物量呈极显著线性关系,但小区域范围内,植被特征与凋落物量关系不显著。综上,植被生长显著影响凋落物产生,但植被特征与凋落物量关系不显著,凋落物量可能还受其他因素的影响。  相似文献   

13.
张颖  黎丽倩  刘强 《草地学报》2019,27(1):274-278
对海南岛及粤西地区8个样区,3种生境(旷野、林缘和林中)假臭草(Praxelis clematidea)的染色体核型进行分析。结果表明,染色体均为二倍体,染色体数目2n=28。染色体核型表现为2A,2B,3B和3A。核型属较不对称类型,不同居群假臭草的居群亲缘关系与地理分布不完全一致,说明假臭草在入侵和传播过程中受到环境因子和人为干扰的影响较大。  相似文献   

14.
生境丧失或片段化是物种多样性丧失及物种灭绝原因之一。本文选择密点麻蜥的三种生境类型,优势植物分别是油蒿(Artemisia ordosica Krasch)、羊柴(Hedysarum mongdicum Turcz Var)和麻黄(Ephedra sinica)。对不同生境的密点麻蜥种群密度及优势植物高度、植被盖度、植被丰富度、食物(昆虫)资源量、昆虫丰富度、裸地比例6个生态因子进行调查。计算密点麻蜥密度,采用U检验及因子分析。结果表明密点麻蜥偏爱中等植被高度、盖度及具有一定裸地比例的生境;A样地中食物(昆虫)资源量、昆虫丰富度对被提取的公因子的解释能力非常强,其次是植物丰富度;而其余三个变量的解释能力不是太强。  相似文献   

15.
潜在植被NPP空间分布格局是植被长期适应自然的结果,是NPP与外界环境关系的反映,通过这种关系有助于理解地表碳循环发生的环境背景。本研究利用综合顺序分类法(CSCS)对黑河上游潜在植被进行模拟,通过植被反演计算潜在植被NPP总量以及累积量,探讨了潜在植被NPP与水热因子之间的相关性。结果表明,黑河上游潜在植被类型共有8个类,且具有明显的垂直地带性分布特征。潜在植被NPP积累量分布特征为河流流经的地区高于其他地区,在山区中,随着海拔的上升,NPP积累量呈先上升后下降的趋势,潜在植被的NPP积累量由黑河上游水热分布条件决定的。NPP积累量与≥0℃年积温在寒冷和寒温级内呈正相关,在微温级内呈负相关;与湿润度在干旱、微干、微润和湿润4个等级内呈正相关,在潮湿级内呈负相关。这种分布格局反映了潜在植被对生境和气候变化的多元适应性结构。  相似文献   

16.
17.
吕婷  刘玉萍  亢俊铧  刘涛  梁瑞芳  苏旭 《草地学报》2021,29(z1):146-155
为探讨柴达木盆地的群落物种的多样性和空间分布格局,本文以德令哈-哈拉湖沿线区域为研究对象,测定了5种不同生境下群落的物种组成和多样性指数,并分析了不同生境下群落物种多样性与海拔的关系。结果表明:该区域共记录了79种植物,菊科、禾本科、豆科、十字花科为当地的优势科种。不同生境类型的物种多样性具有相似性,但也存在差异性。从物种组成的群落相似性结果来看,高寒垫状植被与高寒金露梅(Potentilla fruticosa)灌丛草甸的物种组成相似性最高,而与高寒嵩草(Kobresia myosuroides)、杂类草草甸的物种组成相似性最低。随着海拔升高,群落物种丰富度和多样性呈先降低后增加的趋势,但均匀度保持稳定;中海拔区域的群落物种多样性最高,低海拔区域的群落物种多样性略高于高海拔区域,而造成不同生境群落物种组成和多样性差异的主要原因是水热条件和物种竞争力。  相似文献   

18.
贺兰山不同海拔土壤颗粒有机碳、氮特征   总被引:2,自引:0,他引:2  
采用颗粒大小的物理分组方法,测定了贺兰山(西坡)不同海拔具有代表性的8个样地的草地土壤颗粒有机碳和颗粒有机氮含量,并且分析了土壤颗粒碳、氮分配比例与植被特征及环境因子的关系。结果表明,土壤颗粒碳、氮含量随海拔的降低而显著降低,随土层深度的增加而降低;在4个植被类型中,二者在高山草甸最高,在草原化荒漠最低。土壤颗粒碳、氮分配比例随海拔的降低表现出先降低后升高的趋势,在高山草甸最高,山地荒漠草原最低。土壤颗粒碳、氮分配比例与植被盖度、地上生物量、年均降水量呈极显著的正相关关系,与年均温呈极显著的负相关关系。  相似文献   

19.
张俊忠  张成霞  刘丽  张东华 《草业科学》2013,30(7):1002-1006
采集高黎贡山国家自然保护区不同海拔及植被类型下0~20和20~40 cm土层的土壤样品,采用微生物常规分析法测定土壤中氨化细菌、芽孢杆菌、硝化细菌、反硝化细菌、好气性固氮菌、嫌气性固氮菌、好气性纤维素降解菌、嫌气性纤维素降解菌和溶磷菌的数量,分析了不同海拔及植被类型下土壤微生物类群数量的分布特征。结果表明,随海拔的升高,土壤微生物类群的总数量呈单峰变化趋势;各土壤微生物类群数量总体表现为氨化细菌>芽孢杆菌>反硝化细菌>好气性固氮菌>硝化细菌>嫌气性固氮菌>溶磷菌>好气性纤维素降解菌>嫌气纤维素降解菌的分布特点;不同植被类型土壤中,微生物类群总数不同,表现为阔叶林>针阔混交林>稀疏灌丛>咖啡地>雪地。  相似文献   

20.
The mountains of northern Mozambique have remained poorly studied biologically until recent years with surveys covering a variety of taxonomic groups highlighting their biological and conservation value. Even so, the medium and large mammal fauna remains poorly known and to date no systematic mammal surveys have been published from any of Mozambique’s mountains. We present results of a medium and large mammal survey of Serra Jeci’s Mt Chitagal, Mt Sanga and the Njesi Plateau in Niassa, northern Mozambique; the first mammal diversity data collected from these isolated mountains. We recorded 27 mammal species, of which six represent range expansions; Sykes’s monkey (Cercophitecus mitis), Mozambique dwarf galago (Paragalago granti), Smith’s red rock hare (Pronolagus rupestris), lesser cane rat (Thryonomys gregorianus), rock hyrax (Procavia capensis) and African buffalo (Syncerus caffer). We also reviewed and collated records of medium and large mammals from previously published fieldwork on northern Mozambique’s mountains, amounting to a total of 34 large mammal species from seven montane areas, highlighting the lack of mammalian knowledge in Mozambique’s Afromontane habitats.  相似文献   

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