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1.
The diversity and abundance of amphibians were investigated in Meru National Park, Kenya, using transect sampling, drift‐fence and pitfall trapping and opportunistic collecting. A total of 430 individuals under seven genera (Amietophrynus, Hemisus, Hyperolius, Phrynobatrachus, Phrynomantis, Ptychadena, Xenopus) comprising eleven species were sampled in three different habitats (apart from this, two additional species are known from Meru National Park): Acacia‐wooded grassland; Combretum‐wooded grassland; AcaciaCommiphora bushland. The sex ratio for almost all species was balanced (chi‐square, χ2; P > 0.5) and was not affected by habitat type (ANOVA: F = 8.3026, P = 0.6914). Shannon–Weaver Index (2.227) and Simpson's Index (8.244) were relatively high, and most of the eleven species sampled appeared to have a relatively even distribution (Shannon's Evenness Index, E = 0.927). However, Hemisus marmoratus and Phrynomantis bifasciatus were exclusively recorded in Acacia‐wooded grassland and in low abundances. There was a positive linear relationship of body weight against snout–vent length for two randomly selected anurans (Hyperolius glandicolor, Phrynobatrachus natalensis) among all three vegetation communities.  相似文献   

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The bat fauna of 35 islands in a large lake in central Sweden were examined using ultrasound detectors. We tested the hypothesis that there is no difference in species number between the mainland and the island fauna. Eight species were found. Species numbers were analysed against island area, area of some habitats (coniferous forest, deciduous forest, semi-open habitats and open habitats), degree of isolation (distance from mainland and from stepping stones) and time spent searching for bats. Species number increased with area of deciduous forest. Presence of houses tended to increase species number. There seems to be a negative relationship between species number and degree of isolation (nearly significant). The results suggest that at least three species, Myotis brandti (Eversmann, 1845), M. mystacinus (Kuhl, 1819) and Plecotus auritus (Linnaeus, 1758), are negatively affected by forest patchiness. These species occurred mainly on large islands. Thus, the results do not support the hypothesis. The reasons why some species avoid open habitats are discussed.  相似文献   

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Human population growth drives intrusion and progressive conversion of natural habitats for agriculture. We evaluated human impacts on bat species diversity and distribution among four vegetation types in and around Lake Bogoria National Reserve between November 2012 and July 2013. Plants were surveyed using the Braun–Blanquet cover/abundance method, whereas bats were sampled using standard mist nets erected on poles at ground level. Floristic similarity analysis revealed three broad vegetation assemblages, namely riverine vegetation, farmland and Acacia woodland/Acacia–Commiphora woodland. Two hundred and 33 bats representing eleven species in eleven genera and seven families were recorded. These were Epomophorus minimus, Rhinolophus landeri, Hipposideros caffer, Cardioderma cor, Lavia frons, Nycteris hispida, Chaerephon pumilus, Mops condylurus, Neoromicia capensis, Scotoecus hirundo and Scotophilus dinganii. Species richness estimators indicated that sampling for bats at ground level was exhaustive. Bat species richness and diversity were highest in the more structurally complex Acacia woodland compared to more homogenous farmlands where we recorded only common and generalist species that often occur in open habitats. The higher bat species richness and diversity in the Acacia woodland as compared to farmland underscore the importance of remnant natural savannah woodlands in the conservation of bats and other elements of biodiversity .  相似文献   

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Afromontane forests, like those in the Aberdare National Park (ANP) in Kenya, sustain unique avifaunal assemblages. There is a growing need for biodiversity inventories for Afromontane forests, especially through the utilisation of unskilled observers. Acoustic surveys are a potential aid to this, but more comparisons of this technique with that of traditional point counts are needed. We conducted a systematic survey of the ANP avifauna, assessing whether acoustic and traditional surveys resulted in different species richness scores, and whether this varied with habitat and species characteristics. We also investigated the role of habitat and elevation in driving variation in species richness. The ANP provides habitat types including scrub, moorland, montane, hagenia and bamboo forests. Overall, the surveys yielded 101 identified species. The acoustic method resulted in higher species richness scores compared to the traditional method across all habitats, and the relative performance of the two methods did not vary with habitat type or visibility. The methods detected different species, suggesting that they should be used together to maximise the range of species recorded. We found that habitat type was the primary driver of variation in species richness, with scrub and montane forest having higher species richness scores than other habitats.  相似文献   

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陆地植物群落物种多样性研究进展   总被引:14,自引:2,他引:14  
王永健  陶建平  彭月   《广西植物》2006,26(4):406-411
生物多样性是当前生态学研究的热点之一,物种多样性层次是最直接、最易观察和最适合研究生物多样性的层次。总结了与群落动态、生境因子、取样尺度及生态系统相关的陆地植物物种多样性研究。同时,根据目前的趋势提出了多样性动态研究的发展动向。  相似文献   

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Species diversity and abundance of small mammals were studied in Nechisar National Park, Ethiopia, during August 2008 – March 2009. Twenty species of rodents and four species of insectivores were recorded from the study area. Mastomys natalensis (17.37%), Arvicanthis dembeensis (17.09%), Mastomys erythroleucus (8.90%), Stenocephalemys albipes (8.76%), Arvicanthis niloticus (8.19%), Acomys cahirinus (7.34%), Lemniscomys striatus (6.92%), Gerbilliscus nigricauda (6.21%), Grammomys dolichurus (3.67%), Gerbilliscus robusta (2.12%), Mus proconodon (1.98%), Mus mahomet (1.41), Dendromus melanotis (1.27%), Arvicanthis abyssinicus (1.13%), Mus musculus (0.99%), Praomys fumatus (0.85%), Xerus erythropus (0.85%), Lemniscomys barbarus (0.71%), Mus tenellus (0.71%) and Otomys typus (0.28%) were the rodents and their respective relative abundance in the study area. Crocidura olivieri (1.55%), Crocidura fumosa (0.85%), Crocidura bicolor (0.57%) and Elephantulus rufescens (0.28%) were the insectivores recorded with their respective relative abundance. Mastomys natalensis was the most abundant and O. typus and E. rufescens were the least (two each). Diversity of small mammals ranged from 2.299 to 2.625 with an average of 2.412. The highest small mammal diversity was in grasslands and the lowest was in Lake Chamo shore. Small mammal density varied from 5 to 43 ha?1 and biomass varied from 244 to 2559 g ha?1 with significant changes in relation to seasons and habitats.  相似文献   

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The meiobenthos of five mangrove vegetation types in Gazi Bay,Kenya   总被引:1,自引:0,他引:1  
The vertical distribution of meiofauna in the sediments ofAvicennia marina,Bruguiera gymnorrhiza,Ceriops tagal,Rhizophora mucronata andSonneratia alba at Gazi Bay (Kenya), is described. Seventeen taxa were observed, with highest densities in the sediments ofBruguiera (6707 ind. 10 cm–2), followed byRhizophora (3998 ind. 10 cm–2),Avicennia (3442 ind. 10 cm–2),Sonneratia (2889 ind. 10 cm–2) andCeriops (1976 ind. 10 cm–2). Nematodes accounted for up to 95% of total densities; other common taxa were copepods, turbellarians, oligochaetes, polychaetes, ostracods and rotifers. High densities occurred to about 20 cm depth in the sediment. EspeciallyCeriops sediments show still high densities of nematodes (342 ind. 10 cm–2) and copepods (11 ind. 10 cm–2) in the deepest layer (15–22 cm). Particle size and oxygen conditions were major factors influencing meiobenthic distribution;Uca burrows had a major impact on distribution and abundance of meiofauna.  相似文献   

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神农架保护区大步甲和蜗步甲属生境选择与物种多样性研究   总被引:10,自引:2,他引:10  
针对神农架保护区12个代表地点的6种生境,利用巴氏罐诱法研究大步甲属(Carabus)和蜗步甲属(Cychrus)的物种和数量分布,研究发现:(1)本地区有大步甲7种,蜗步甲2种,其中Cy.bispinosus shennongding,C.ahshimaianus,C.blumenthaliellus和C.yokoae是本地的常见种,分布区域广,占个体总数的88.2%,(2)物种分布与度密切相关,常见种的垂直分布范围比较宽,海拔区间大于1000m,其他种分布相对较窄,垂直区间小于500m,从物种分布特点看,在海拔1500-2000m的范围内种类最多,在海拔2000-2500m的范围内个体数量最多,在海拔500-1000m范围内种类和数量均相对较少,(3)人为或自然干扰程序影响物种的种类组成和个体数量分布,剧烈干扰减少物种种类和数量,在中等干扰的情况下,物种种类国多,在轻度干扰的情况下,物种个体数量较多,在几乎没有干扰的情况下,物种的种类和数量也呈下降趋势,(4)生境类型影响物种的数量分布,C.blumenthaliellus的个体数量在草甸内远高于其他生境,C.yokoae在阔叶林内数量显著高于草甸,C.ohshimaianus在针叶林的数量明显高于混交林和草甸,Cy.bispinosus shennongding也倾向分布在混交林和草甸内,如果以属为单元进行比较,大步甲和蜗步甲属在不同生境内的数量变化没有达到显著性差异,但大步甲在混交林内数量低于其他生境,蜗步甲属在混交林和草甸内有数量优势,(5)比较物种多样性指数值,溪边灌丛最高,针叶林最低,均匀度指数值阔叶林最高,针叶林最低,从物种丰富度看,混交林和溪边灌丛最高,其次为针叶林,本研究结果表明,海拔和干扰程度了大步甲和蜗步甲物种种类分布,生境影响数量分布,为了保护这两属的物种多样性,要保护不同类型的特殊生境,尽量保护生境的样化,尽力控制人为干扰,减缓自然干扰,只有这样才会丰富该地区的物种多样性。  相似文献   

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Sustainable resource management requires understanding the factors that increase or decrease species richness. Regional species richness patterns may be predicted by analysing patterns of variation in the environment. A number of studies have shown that bird species richness at a regional scale is influenced by climatic variables. We examined environmental correlates of bird species richness at a quarter degree square scale (55 × 55 km). Mean annual potential evapotranspiration accounts for 46% of the observed variation in species richness, while mean annual temperature and range annual potential evapotranspiration are significantly correlated with species richness and together account for a further 5% of the observed variation. The results are consistent with the hypothesis that environmentally available energy limits regional species richness.  相似文献   

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This report documents primate communities at two sites within Noel Kempff Mercado National Park in northeastern Santa Cruz Department, Bolivia. Diurnal line transects and incidental observations were employed to survey two field sites, Lago Caiman and Las Gamas, providing information on primate diversity, habitat preferences, relative abundance, and population density. Primate diversity at both sites was not particularly high, with six observed species: Callithrix argentata melanura, Aotus azarae, Cebus apella, Alouatta caraya, A. Seniculus, and Ateles paniscus chamek. Cebus showed no significant habitat preferences at Lago Caiman and was also more generalist in use of forest strata, whereas Ateles clearly preferred the upper levels of structurally tall forest. Callithrix argentata melanura was rarely encountered during surveys at Lago Caiman, where it preferred low vine forest. Both species of Alouatta showed restricted habitat use and were sympatric in Igapo forest in the Lago Caiman area. The most abundant primate at both field sites was Ateles, with density estimates reaching 32.1 individuals/km2 in the lowland forest at Lago Caiman, compared to 14.1 individuals/km2 for Cebus. Both Ateles and Cebus were absent from smaller patches of gallery forest at Las Gamas. These densities are compared with estimates from other Neotropical sites. The diversity of habitats and their different floristic composition may account for the numerical dominance of Ateles within the primate communities at both sites. Am. J. Primatol. 46:197–211, 1998. © 1998 Wiley-Liss, Inc.  相似文献   

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青海互助北山国家森林公园不同生境的蝶类多样性研究   总被引:1,自引:0,他引:1  
为了进一步探讨高海拔地区蝴蝶种类和数量与生境结构之间的关系,1993–1997年每年的7月对互助北山国家森林公园不同生境类型(谷间平原、温性草原、针阔叶混交林、高寒灌丛草甸)中蝶类群落的结构、数量和多样性进行了调查。共获得蝴蝶标本4,745头,86种,隶属于8科57属。种类较丰富的类群主要有:粉蝶科豆粉蝶属(Colias)6种、菜粉蝶属(Pieris)5种、绢粉蝶属(Aporia)4种、云粉蝶属(Pontia)3种,蛱蝶科网蛱蝶属(Melitaea)3种;个体数量以粉蝶科和灰蝶科为最多。不同的生境蝶类在种类组成和个体数量上有明显差异,其中以针阔叶混交林物种数(44种)最多,谷间平原个体数量(1,969只)最多。物种多样性指数以针阔叶混交林中最高,高寒灌丛草甸最低;均匀度以针阔叶混交林最高,谷间平原最低;优势度以高寒灌丛草甸最高。从不同生境蝶类成分的特有性上分析,特有属和特有种含量高低依次为针阔叶混交林(20属24种)>高寒灌丛草甸(8属8种)>谷间平原(6属7种)>温性草原(5属6种)。不同生境类型间蝶类种类的相似性系数在0–0.4259之间。蝶类种类组成的聚类分析结果显示:谷间平原与温性草原最先聚为一类,然后与针阔叶混交林聚为一类,最后与高寒灌丛草甸聚为一类。为保护该地区的蝶类物种多样性,应加大宣传力度,建立自然保护区,继续加强本底资源调查。  相似文献   

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We carried out a postrelease evaluation to determine predictors of habitat use and carrying capacity for the black rhinoceros (Diceros bicornis michaeli), which are critical for monitoring how the Ruma National Park sub-population may contribute to Kenya's meta-population strategy. We determined whether level of elevation, rockiness, shade, distance to fence, roads, and human settlements predict habitat use, differences in habitat and diet preference between female and male black rhinoceros, and the ecological carrying capacity (CC) of black rhinoceros in the park. We used standard ecological methods to collect data on predictors of habitat use, habitat preference and to estimate CC. Results show, first, that none of the environmental and anthropogenic factors evaluated predicted habitat use by black rhinoceros in the park. Second, although there was no significant difference in habitat preference between the sexes (U = 16.50, p = 0.306), there was a 60% difference in Jaccard's dissimilarity in diet selection between the sexes. Third, the park can support 65 black rhinoceros. Altogether, the findings suggest that the park has potential to support other sub-populations in Kenya. We recommend that future similar studies should incorporate population viability analysis and a community-based approach to forecast the species health and extinction risk.  相似文献   

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北京南海子麋鹿苑鸟类多样性研究   总被引:1,自引:0,他引:1  
城市公园及城市其他自然保护地是城市生态系统的重要组成部分,是城市鸟类最主要的栖息场所。城市化进程对城市的自然景观和生态系统造成很大影响,鸟类生存空间不断缩小,其群落结构受到影响。南海子麋鹿苑周边正在经历快速城市化,为了摸清该地区鸟类群落组成及多样性,自2014年10月起对研究区野生鸟类种类、数量和分布特点进行连续调查,共记录鸟类18目、49科、156种;其中,国家II级重点保护鸟类16种。鸟类优势种随年份变化和季节变化不一,总体来看,绿头鸭、灰喜鹊、喜鹊、[树]麻雀等留鸟为研究区优势种。研究区鸟类Shannon多样性指数和Pielou均匀性指数呈现2018年>2017年>2016年>2015年的变化规律;鸟类Shannon多样性指数和Pielou均匀性指数呈现秋季>夏季>春季>冬季的变化规律。同时,探讨了影响鸟类多样性的因素,提出连通城市绿地,打通动物迁徙通道;坚持山水林田湖草理念,创造多样的景观;对野生动物重点保护区域限制人类活动,保护野生鸟类生境等建议。  相似文献   

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