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1.
Geographical information system (GIS)‐based cluster analyses and comparative ecological approaches were applied to unravel the hitherto controversially discussed role of the Mekong River as a biogeographical barrier to the amphibian fauna in Indochina. Referring to the unique and independent history of the Lower Mekong, south of the Lao–Cambodian border, this approach focused on the amphibians of southern Indochina and adjacent parts of eastern Thailand. To date, 131 amphibian species have been recorded from this region. In concordance with previous studies, our GIS‐based analyses revealed that the amphibian fauna of the Cardamom Mountains, west of the Mekong, possessed no closer affinity to the herpetofauna of the Southern Annamites. In addition, a statistical comparison of ecological characters showed an occurrence of ecological differentiation among amphibians across the Lower Mekong. Our results suggest that the Lower Mekong serves as, or at least coincides with, a biogeographical barrier in southern Indochina. Here, we discuss this hypothesis, together with selected species spatial distribution patterns, their species‐specific ecological traits and the palaeogeographical background of the region. © 2015 The Linnean Society of London, Biological Journal of the Linnean Society, 2015, 114 , 905–914.  相似文献   

2.
Wasgomuwa National Park is situated south of Polonnaruwa and north of Mahiyangana in Sri Lanka and is bordered by two rivers Mahaweli Ganga and Amban Ganga. Bioclimatically most of the park lies in the dry zone of the country but the south west embraces the intermediate zone. The vegetation is broadly a dry monsoonal forest but forms an interesting mosaic of vegetation types from Semi evergreen forest to abandoned paddy fields, on a finer scale.The vegetation of the park was studied in detail on ground and also using aerial photographs. It was possible to classify the vegetation into many distinct types or phytosociological units, based on their cover, site characteristics, physiognomy and species composition.  相似文献   

3.
The principles and methods of the vegetation mapping undertaken at the French Institute, Pondicherry, are dealt with herein. Particularly, the characterisation of the different types of vegetation and especially the originality of the method: the dynamic interpretation of the vegetation and the depiction of the bioclimatic conditions. The programme of the forest map of South India at scale 1:250 000, undertaken in collaboration with the forest departments of the concerned states, is then described with special attention given to the source and the collection of data. This map has been conceived to serve as a basic document for the sustainable management of the forests. Three examples of its application are given. They concern the detection of anomalies between the existing forest cover and the prevalent climatic environment; the detection of areas for which protection is urgently needed; the selection of regions showing a particular interest in the field of nature conservation or as gene pool reserve. Finally, an example of a thematic map of sensibility of the forests is given, using the vegetation map as a basis.  相似文献   

4.
We developed Blue Intensity (BI) measurements from the crossdated ring sequences of Fokienia hodginsii (of the family Cupressaceae) from central Vietnam. BI has been utilized primarily as an indirect proxy measurement of latewood (LW) density of conifers (i.e., LWBI) from high latitude, temperature-limited boreal forests. As such, BI closely approximates maximum latewood density (MXD) measurements made from soft x-ray. The less commonly used earlywood (EW) BI (EWBI) represents the minimum density of EW and is influenced by the lighter pixels from the vacuoles or lumens of cells. The correlation of our BI measurements with climate, strongest for EWBI, rivals that for total ring width (RW), and we demonstrate that it can be successfully employed as an independent predictor for reconstruction models. EWBI exhibits robust spatial correlations with winter and spring land temperature, sea surface temperature (SST) over the regional domain of ENSO, and the Standardized Precipitation Evapotranspiration Index (SPEI) over Indochina. However, in order to mitigate the effects of color changes at the heartwood – sapwood boundary we calculated ΔBI (EWBI-LWBI), and it too exhibits a significant (p < 0.05), temporally stable response to prior autumn (Oct-Nov) rainfall and winter (December to April) dry season temperature. We interpret this response as reflecting a potential cavitation defense by reducing lumen diameter as a means to safeguard hydraulic conductivity in the stem, and to prevent the xylem from imploding due to negative pressure. This study has wide implications for the further use of BI from the global tropics, though it is unclear how many tropical tree species will be appropriate for use. It seems very likely that other wood anatomical measurements can be combined with BI and RW for climate reconstruction.  相似文献   

5.
通过野外调查和标本研究,报道越南、老挝两地凤尾蕨属Pteris 7个新记载的物种,它们分别是P.argyraea、四川凤尾蕨P.sichuanensis、两广凤尾蕨P.maclurei、 单叶凤尾蕨P.pseudopellucida、 有刺凤尾蕨P.setuloso-costulata、 琼南凤尾蕨P.morii、 栗轴凤尾蕨P.wangiana.  相似文献   

6.
    
Genus Pteris from Vietnam and Laos is revised in this paper. Seven species newly reported from Vietnam and Laos are P.argyraea, P.sichuanensis, P.maclurei, P.pseudopellucida, P.setuloso costulata, P.morii, and P.wangiana.  相似文献   

7.
    
The Anopheles dirus Peyton & Harrison complex of mosquitoes (Diptera: Culicidae) comprises seven known species, including important malaria vectors in Southeast Asia. Specific identification of each species of the complex, which cannot be distinguished using morphological characters, is crucial for understanding vector ecology and implementing effective control measures. Derived from individual random amplified polymorphic DNA (RAPD) markers, sequence characterized amplified regions (SCAR) were analysed for the design of specific paired-primers. Combination of six SCAR primers resulted in the development of a simple, robust, single multiplex PCR able to identify three important malaria vectors among the four most common species (A, B, C, D) of the complex: species A from several Southeast Asian countries, species B from Perlis, Malaysia, and species C and D from Thailand.  相似文献   

8.
    
In the present paper the species belonging to the Neoserica (sensu lato) septemlamellata group, that included so far only four known species, are revised. Here we describe eleven new species originating mainly from Indochina and Southern China: N. daweishanicasp. n., N. gaoligongshanicasp. n., N. guangpingensissp. n., N. igorisp. n., N. jiulongensissp. n., N. plurilamellatasp. n., N. weishanicasp. n., N. yanzigouensissp. n. (China) N. sapaensissp. n. (China, Vietnam), N. bansongchanasp. n., N. takakuwaisp. n. (Laos). The lectotypes of Neoserica septemlamellata Brenske, 1898 and N. septemfoliata Moser, 1915 are designated. Keys to the species and species groups are given, the genitalia of all species and their habitus are illustrated and distribution maps are included.  相似文献   

9.
10.
描述了产于老挝北部和越南北部的豚蝎属2新种:老挝豚蝎Chaerilus laoticus sp.nov.和越南豚蝎Chaerilus vietnamicus sp.nov.。为比较,根据保存在法国自然历史博物馆的系列标本,重新描述和图示了产于越南南部的佩氏豚蝎Chaerilus petrzelkai Kovaík,2000。老挝豚蝎,新种Chaerilus laoticus sp.nov.(图20 ~38,54 ~57,62,63 , 66 , 67)正模♂,副模:4 ♂♂, 4♀♀,老挝库安县(Xiang Kuang, 1 500m) ,1939年1月,C.Dawydoff采。模式标本保存在法国自然历史博物馆, 1 ♂和1♀保存在河北大学博物馆。体长19 ~21mm。身体基色为浅黄至浅红黄色。背甲前缘平直,雄蝎几乎无脊和具弱的颗粒,雌蝎具稀疏而强的颗粒;雄蝎背沟浅,雌蝎背沟适度深。后体脊较显著;节Ⅰ腹脊退化,节Ⅱ腹脊较显著。触肢螯的可动指和固定指齿缘具7 ~8排斜齿。雄蝎栉板具5个栉齿,雌蝎栉板具4 ~5个栉齿。生殖板亚卵圆形。听毛模式B型。词源:新种的种名以模式标本的采集地而拟定。越南豚蝎,新种Chaerilus vietnamicus sp.nov.(图39 ~49 ,58 , 59 , 68)正模♀,越南老街红河(接近中国河口边界) , 1960年,采集者不详。保存在河北大学博物馆。体长26.5mm。身体基色为浅黄至浅红黄色。背甲前缘稍凹入,几乎无脊和具弱的颗粒;背沟深。后体脊适度到较显著,腹脊退化或缺。触肢螯的可动指和固定指齿缘具14 ~15排斜齿。栉板具4 ~5个栉齿。生殖板亚三角形。听毛模式B型。词源:新种的种名以模式标本的采集地而拟定。  相似文献   

11.
The community structure of testate amoebae inhabiting different microhabitats (soil and tree-moss) within a tropical forest biome in Nameri National Park, northeastern India, was investigated. A total of 33 testate amoebae species belonging to 13 genera were identified. Species belonging to the class Lobosea constituted 73% of total testate amoebae density in the soil habitat, whereas the class Filosea constituted the most dominant forms (58%) in the moist tree-moss habitat. The relative abundance of species was higher in the tree-moss habitat compared to the soil habitats of the forest. Although multivariate analysis suggested a significant difference in assemblage patterns between the habitats, the turnover in species (i.e., beta diversity) was insignificant. Species accumulation curves (SAC) constructed using both parametric and non-parametric species richness estimators revealed that the asymptote of species richness was achieved by a low number of sample replicates in both habitats. The temperature and pH of the substratum on testate amoebae distribution patterns suggest the importance of additional background factors on testate amoebae community structure. Further studies involving more biotopes, seasons, and trophic interactions are recommended to document a complete record of testate amoebae diversity and their interactions with environmental gradients in the tropical forest biomes of northeastern India.  相似文献   

12.
    
Aristolochia bhamoensis from Myanmar is here described and illustrated. This new species is morphologically similar to A. faviogonzalezii (confined to northern Vietnam) and A. cathcartii (growing in the Himalayan region) but is distinguished from the latter two species by having a cream‐white upper part of the perianth tube, with visible purple ridges, a trumpet‐shaped limb, 5.0–5.5 cm diameter, inner surface of limb lobes densely covered with dark‐purple bristles, a nearly circular mouth, 3.2–3.5 cm wide, upper half of throat being dark‐purple to blackish, without striations or dots, and lower half purple, with conspicuous white striation. Morphological characters such as a 3‐lobed gynostemium and a 3‐lobed limb support a placement of the new species in the subgenus Siphisia. A diagnostic key is provided to the seven Siphisia species known from Myanmar.  相似文献   

13.
1. The lack of a globally accepted list of English‐language names for mammal species leads to various problems stemming from the reduced ability to communicate unambiguously. This impacts directly on their conservation. We use the larger mammals of Indochina to exemplify the use of an explicit set of principles designed to provide each species with a unique and non‐misleading (or at least minimally so) English name. 2. For most species, a suitable name is already in use, sometimes generally so. For species for which multiple names are in use, standardization would consist of adopting the most suitable name. Only for a very few species are all extant names so unsuitable that a neologism should be coined. One species, Panthera pardus, presents potentially insoluble problems. 3. Name standardization among the world's birds has generated some controversy, but this has not led to abandonment of the process. Much can be learned by those developing a similar process for mammals, through studying the bird‐naming process. Progress can be advanced by detractors indicating whether they oppose standardization per se, the principles used or the names resulting from application of the principles. Also, proponents of standardization should always emphasize that the purpose of the process is to produce a list available for those who want to use it, not to produce a binding selection that must be used in all circumstances.  相似文献   

14.
Plant wealth and diversity of four sacred groves – twoanthropogenic stands and two natural forest patches – along the southeastcoast of India adjoining Pondicherry was studied. A total of 111species, belonging to 103 genera in 53 families, were recorded from thefour sites, which together measure 15.6 ha. The number of woody species (girth at breast height(gbh) 20 cm) was 20 each in Keezbuvanagiri (KBG) andKilialamman (KLM) grove, followed by 13 in Periyakattupalayam (PKP) and 15in Periyamudaliar chavadi (PMC). Based on the important value index (IVI), PMCgrove is an association of Aglaia elaeagnoidea,Borassus flabellifer and Pterospermumsuberifolium. A two-layered forest structure resembling tropical dryevergreen forest (TDEF) was found there. Stratification was obscured in the KBGgrove, as the scrub species were abundant, indicating a scrub woodland formation.PKP and KLM were characterised by the abundance of a few species. The presenceof a stout liana of Secamone emetica (gbh 35cm), the robustness of Cretaeva magna (gbh 220cm), Syzigium cumini (gbh 207.45cm), P. suberifolium (gbh 128.7cm) and Tamarindus indica (gbh 250cm), and survival of evergreen species like A.elaeagnoidea and Pamburus missionis isbotanically significant; Polyalthia suberosa is a raretaxon found only within the groves. The persistence of the groves until thepresent time is a testimony to the sacred grove status enjoyed by them.  相似文献   

15.
 在森林植被生物量遥感动态监测方面最基础性的研究是探讨生物量与遥感数据及其派生数据、地形数据和气象数据之间的相关性。为此,以我国云南省西双版纳的热带森林植被为例,分别对幼龄林、中龄林、近熟林和成过熟林的生物量与其对应的LANDSAT TM数据及其派生数据、气象数据和地形数据之间的相关性进行了分析。首先,利用森林资源连续清查的林业固定样地数据,通过各树种组的各器官生物量估算模型计算出各样地森林植被的生物量,并根据样地的坐标来建立样地GIS数据库。然后,利用地形图对遥感图像进行几何校正,并对遥感图像进行主成分变换、缨帽变换以及植被指数的计算来产生其派生数据。其次,将栅格样地数据、遥感数据(如LANDSAT TM数据)及其派生数据(如各种植被指数数据、主成分数据、缨帽变换的亮度、绿度和湿度数据)、栅格地形数据(如DEM和坡向)和栅格气象数据(包括年平均温度、大于0 ℃的积温、年平均降雨量和湿润度)统一到同一坐标系和投影下,并将所有的数据内插为30 m分辨率的格网数据,利用样地数据与遥感数据及其派生数据、地形数据和气象数据进行栅格空间叠加分析,从而得到各样地的样地数据、遥感数据及其派生数据、地形数据和气象数据。再次,根据各样地优势树种所属的龄组将所有的数据层化为幼龄林、中龄林、近熟林和成过熟林等几个不同龄组的样本数据。最后,分别对幼龄林、中龄林、近熟林和成过熟林的样地生物量与其对应的遥感数据和派生数据、气象数据和地形数据进行相关性分析。研究表明,在所有的因子中,幼龄林的生物量与LANDSAT 的TM1和TM6波段的亮度值在0.05的水平上呈显著相关,其相关系数均为-0.33;中龄林的生物量与降雨量在0.05的水平上呈显著相关,其相关系数为0.33;近熟林的生物量与LANDSAT TM的派生数据VI3、LANDSAT的TM4和缨帽变换的亮度值在0.05的水平上呈显著相关,其相关系数分别为0.50、-0.45和-0.45;成过熟林的生物量与主成分变换的第二主成分(PC2)在0.05的水平上呈显著相关,其相关系数为-0.46。在0.05的水平上,近熟林的生物量与LANDSAT TM的派生数据VI3的相关系数最高,达到0.50,其次是成过熟林的生物量与主成分变换的第二主成分的相关系数,为-0.46。  相似文献   

16.
Tan.  BC Ninh  Tr 《云南植物研究》1998,20(3):271-275
报道了越南藓类的2个新记录,即:海南花锦藓Chionostomum hainanensis Tan &Jia和毛齿匍灯藓Plagiomnium tezukae T.Kop.;泰国藓类的3个新纪录,即:糙叶梨果藓Mastopoma scab#颍椋妫铮欤椋酰? Tan & T.Ninh,毛尖狗尾藓Rhapidostichum piliferum Broth。,细枝羽藓Thuidium delicatu  相似文献   

17.
We estimated the number of species in a tropical forest landscape in Quintana Roo, Mexico, based on the relationship between reflectance values of satellite imagery and field measurements of plant species density (mean number of species per plot). Total species density as well as that of tree, shrub and vine species were identified from 141 sampling quadrats (16543 individuals sampled). Spatial prediction of plant diversity was performed using universal kriging. This approach considered the linear relationship between plant species density and reflectance values of Thematic Mapper™, as well as the spatial dependence of the observations. We explored the linear relationships between spectral properties of TM bands and the species density of trees, shrubs and vines, using regression analysis. We employed Akaike Information Criterion (AIC) to select a set of candidate models. Based on Akaike weights, we calculated model-averaged parameters. Linear regression between number of species and reflectance values of TM bands yielded regression residuals. We used variogram analysis to analyze the spatial structure of these residuals. Results show that accounting for spatial autocorrelation in the residual variation improved model R2 from 0.57 to 0.66 for number of all species, from 0.58 to 0.65 for number of tree species, from 0.26 to 0.41 for number of shrub species and from 0.13 to 0.17 for species density of vines. The empirical models we developed can be used to predict landscape-level species density in the Yucatan Peninsula, helping to guide and evaluate management and conservation strategies.  相似文献   

18.
19.
论季雨林的水平地带性   总被引:6,自引:0,他引:6       下载免费PDF全文
季雨林是受制于湿度因子的经度地带性植被类型,它是随着湿度条件的下降由热带雨林向热带疏林过渡的居间类型,而不是受制于温度因子的纬度地带性植被类型,不是随着温度条件的下降由热带雨林向亚热带常绿阔叶林过渡的居间类型。我国南亚热带的榕树群系、黄桐群系,以及热带北缘的青皮群系均不应是季雨林,前二者是典型的南亚热带低地常绿阔叶林或南亚热带雨林,后者则是热带雨林的一分类群。  相似文献   

20.
广东季雨林的几个问题   总被引:5,自引:2,他引:5       下载免费PDF全文
 季雨林是分布在具有明显干湿季节变化热带地区,在干季或多或少,甚至全部落叶的森林植被;是介于热带雨林向热带稀疏林过渡的居间类型,而不是由热带雨林向亚热带常绿阔叶林过渡的植被类型。应归属于经向地带性植被,而非纬度地带性植被。并且,在广东南部沿海地区的气候条件下,也不会有季雨林发育。广东南部沿海地区的榕树+香蒲桃+野苹婆(Ficus microcarpa+Syzygium odoratum+Sterculia lanceolata)群落等类型不是季雨林,而是热带季节雨林,属广义的热带雨林范畴。  相似文献   

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