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81.
牛背梁自然保护区(108°45′~109°04′E,33°47′~33°56′N)位于秦岭山脉东段,地跨秦岭南北坡。采用样线调查法和访问调查法,于2003年5月~2004年8月,对该保护区食肉动物及偶蹄动物的区系特征和生态分布进行了研究。该保护区共有18种食肉动物及偶蹄动物,其中属我国级、级重点保护动物的兽类分别有2种和7种。分析表明,保护区的有蹄类动物物种丰富,秦岭分布的有蹄类在该区域均有分布,但食肉动物种数仅占整个秦岭地区的45.5%。这些兽类中,属于东洋界的兽类有12种,占66.7%;属古北界的仅1种,占5.5%;其余5种为广布种,占27.8%。牛背梁保护区在动物地理区划上应属古北界和东洋界物种交汇的区域,且为东洋界逐渐向古北界过渡的区域。分析该区域食肉动物及偶蹄动物的生态分布发现,这些物种的垂直分布幅度有很大的差异。垂直分布幅度在海拔高差1300m以上、1000m左右、450~700m之间的物种各占1/3。结果还表明,区内这些兽类物种的丰富度随海拔的升高具有先升后降的垂直变化规律。不论是秦岭南坡还是北坡,分布在海拔1800~2200m区域的兽类物种最多,所占比例大于80%;而在海拔2600m以上区域,兽类种数降至最少,仅占50%左右。兽类丰富度的海拔梯度也体现于这些兽类在各植被类型中的分布上。中山针阔叶混交林中分布的兽类种数最多,而在中低山落叶阔叶林、亚高山针叶林及亚高山灌丛草甸中分布的兽类则较少。  相似文献   
82.
甘肃临夏盆地晚中新世大唇犀化石的年龄结构与生活环境   总被引:4,自引:4,他引:0  
甘肃临夏盆地的晚中新世红粘土堆积中含有大量的三趾马动物群化石,其中犀科化石,特别是大唇犀最为丰富。通过对临夏盆地晚中新世具有代表性的大唇犀化石的年龄结构的分析,初步了解到化石群各年龄段个体的百分比和种群动态。大唇犀化石中成年个体的数量占优势,明显多于老年个体,与正常生活群中的年龄结构吻合,由此可初步断定是突发性事件引起了犀牛种群的灾害性死亡。再进一步对化石的风化、磨蚀、聚集状态及所受的水动力特征等进行分析,发现骨骼受到了弱水流的短距离搬运,说明化石埋藏地离动物死亡地不远。以上分析结果与沉积学特征相结合,说明临夏盆地晚中新世三趾马动物群的集群死亡可能与严重的干旱化事件有关。  相似文献   
83.
Aim To study (1) the large-scale distribution patterns of freshwater fishes in the Western Ghats of India; (2) the endemism and uniqueness of the fishes in various zones; and (3) the threat status of fishes by categorizing them under low risk (LR), vulnerable (VU), endangered (EN) and critically endangered (CR). Location The Western Ghats of India. Methods The scientific literature describing the freshwater fishes of the Western Ghats was reviewed. Data describing the lists of the species were extracted and complied. The species accumulation curve was plotted using Michaelis–Menten-like equation. The Western Ghats was divided into six zones and similarity of the species was calculated using Jacquard's index. Results Literature to date records 288 species belonging to 12 orders, 41 families and 109 genera, of which 118 species are endemic and 51 are unique. However, the species accumulation curve shows that there might be 345 species in this region, indicating that 16% species have not been recorded to date. An analysis of the distribution pattern of fishes in the Western Ghats suggests that the southern region is more diverse than the northern and central regions. The southern region shows high endemism and high uniqueness while the northern region shows high endemism but less uniqueness. The similarity index between the zones indicates that as the distance between the zones increases similarity decreases. The status of 105 of 288 species was not known due to data deficiency but among the remaining 183 species, 58 species were categorized as LR, 41 as VU, 54 as EN, 24 as CR while the remaining six species were introduced. Conclusions The distribution patterns of fishes in the Western Ghats are discussed in accordance with the geography of Western Ghats, its climatic conditions and ‘Satpura Hypothesis’. The threat status of fishes found in Western Ghats suggests that at least 41% of fish fauna is threatened by either being VU, EN or CR. Implication of potent conservation measures is necessary to conserve the fish fauna of Western Ghats.  相似文献   
84.
Termites play important roles in organic matter decomposition, nutrient cycling, and soil structure in tropical rain forests. When forests are replaced by agriculture, termite species richness, abundance, and function often decline. We compared the termite assemblage of a primary forest site with that of a low plant diversity, palm-based agroforest (five plant species) and a high plant diversity, home-garden agroforest (10 plant species) using a rapid biodiversity assessment protocol. In comparing the primary forest termite species composition to previously published studies, we found soil feeders and the Apicotermitinae to be more dominant than previously reported in Amazonia. Thirty percent of the species belonged to the Apicotermitinae, and an unusually high percentage (57%) of species were soil feeders. Unexpectedly, the palm-based agroforest, despite its lower plant diversity, was closer to primary forest in termite species composition, rate of species accumulation, and proportions of species in taxonomic and functional classes than was the home-garden agroforest. This suggests that particular plant attributes may better determine the termite assemblage than plant diversity alone in these agroecosystems. Unlike other agroecosystems reported in the literature, Apicotermitinae and soil feeders were proportionally more abundant in these agroforests than in primary forest. The ability of agroforests to support populations of soil feeders has a potentially positive effect on soil fertility in these agroecosystems; insomuch as feeding guild is a proxy for function, these closed-canopy agroforests may be able to sustain the same termite-mediated functions as primary forest.  相似文献   
85.
Abstract. 1. Euedaphic collembola alter their soil distribution in response to above‐ground aphid herbivory of Poa annua L. Graminae, a host grass. 2. Two mechanisms potentially underpin this effect. Carbon‐rich aphid honeydew falling onto the soil surface may affect mycophagous collembola; alternatively aphid‐induced changes in root biomass may be necessary to produce changes in collembola abundance. 3. When compared to a plant‐only control, aphid herbivory increased the number of collembola in the top 5 cm of soil, reduced both foliar and root biomass, and increased shoot/root ratio. Honeydew addition had no effect on collembola numbers or any recorded host‐plant parameter. 4. Honeydew deposition is not responsible for the increased numbers of collembola found in the upper soil after aphid herbivory; aphid‐induced reductions in root biomass may be the most important factor explaining knock‐on effects of aphid herbivory on soil fauna.  相似文献   
86.
The migrations of Gymnocephalus baloni Balon's ruffe into the side branch of the Danube at Schönbühel were restricted to the spawning season between the end of April and mid-June. The main environmental factor correlating with the immigration is assumed to be water temperature. Water level changes influence emigration.  相似文献   
87.
中国西北地区蚂蚁区系特征   总被引:12,自引:0,他引:12  
长有德  贺达汉 《动物学报》2002,48(3):322-332
于1997-2000年对宁夏、甘肃、青海及内蒙古西北部地区进行了系统的蚁类标本采集,获得标本1000余号,并对其进行了系统的分类鉴定,获得蚂蚁3亚科16属79种。本调查区蚁类区系组成呈现以下特征:古北界分布的有15属,代表属为蚁属、红蚁属、毛蚁属、原蚁属、箭蚁属、收获蚁属等;东洋界分布的有9属,代表属为火蚁属、细胸蚁属、酸臭蚁属、光胸臭蚁属和弓背蚁属等;在种级水平上,古北界分布的有79种,东洋界分布的仅17种。蒙新区分布的成分有15属,其中以铺道蚁属、原蚁属及箭蚁属为主体,蚁属和心结蚁属次之;区分布的成分有4属,以蚁属和毛蚁属为主体;东北区分布的成分有5属,蚁属和毛蚁属为主体;华北区分布的成分有15属,其中以蚁属、红蚁属和毛蚁属为主体,仅心结蚁属无分布;华中区、华南区和西南区分布的成分均不明显。在种级水平,华北区和蒙新区分布的成分为主体,分别占51和49种,其次为华中区、青藏区和东北区的成分,分别占17、15和15种,华南区和西南区的成分最少,分别为8和5种。在区系分类的基础上,根据优势种、特有种,并结合植被、地形、地貌将调查区划分为6个蚁类区:黄土高原蚁类区、荒漠蚁类区(其下设4个蚁类亚区;荒化草原蚁类亚区、草原化茺蚁类亚区、典型荒蚁类亚区和荒漠绿洲蚁类亚区)、荒漠沼泽蚁类区、高寒灌草丛蚁类区、贺兰山蚁为区和六盘山蚁类区。利用主成分分析对不同草原类型的蚂蚁群落进行了相似性分析,结果表明:荒漠化草原群落、草原化荒漠群落、典型荒漠群落和荒漠绿洲群落明显靠近,构成荒类集团,荒漠森林草原(贺兰山)群落明显远离于荒漠类群,反而与典型草原(黄土高原区)群落靠近,这与蚁类区划结果是十分吻合的。此外,利用主成分分析对79种蚂蚁划分为10个生态种组。  相似文献   
88.
89.
记述松盲蝽属Pinalitus Kelton中国种类共7种,其中包括中国2新纪录和4新种,即红褐松盲蝽P.rubeolus Kulik, 黑头松盲蝽P.nigriceps Kerzhner, 长喙松盲蝽P.rubricatus (Fallén)(后两种为中国新纪录种);冷杉松盲蝽P.abietis sp. nov.,高山松盲蝽P.alpinus sp. nov.,华山松松盲蝽P.armandicola sp. nov.,泰山松盲蝽P.taishanensis sp. nov..文章提供了分种检索表.  相似文献   
90.
江西九连山自然保护区昆虫区系分析   总被引:11,自引:1,他引:10  
据对有较详细分布资料的1312种昆虫的分析,该区的昆虫区组成以东洋界成员为主体计817种,占总数的62.27%,说明本区昆虫属于东洋界范畴,按中国动物区划分析表明,华中,华南,西南三区的昆虫亲缘关系最为密切,阐述了182种昆虫在我国东部地区分布的南北限。  相似文献   
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