163 resultados para Central Scandinavian Mountains
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空中花粉是植被类型、气候状况与大气环境质量的指示物之一。空中花粉雨的取样实验对化石花粉谱的解释和古植被的恢复具有指导意义,因此空中花粉分析成为第四纪孢粉学和古生态学研究的有效辅助手段。本研究在新疆天山中段北坡进行了短期的空中花粉监测(2001年7月~2006年7月),目的是获得局域性和区域性植被所散发的花粉类型及其数量信息,并探讨花粉数量的植被与气候指示意义、花粉传播以及受环境条件影响的程度,同时分析和检测花粉浓度受气候条件的影响情况。空中花粉的收集使用Cour-type捕捉器,分别在3个不同海拔梯度进行5年连续的空中花粉收集(夏秋季节每周一个样品,冬春季节每两周一个样品)。取样地点分别是新疆天山中段北部的天池气象观测站(43°53'58.38"N, 88°07'15.75"E , 海拔1942.5m)、中科院阜康荒漠生态系统定位站(44°17'27.41"N, 87°55'52.65"E, 海拔477m)和准噶尔盆地古尔班通古特沙漠南缘的北沙窝试验站(44°22'40.74"N, 87°55'9.74"E, 海拔443m),取样点的植被带跨度天山北坡的森林草原到低海拔的典型荒漠。 光学显微镜鉴定的空中花粉主要有43种类型(24科30属),而蕨类、苔藓与真菌孢子数量较少。孢粉类型多样性指数为2.45(Shannon Index)。显然,从样品中所鉴定的空中花粉种类与所观察的植物种类有很大的差距。花粉类型与数量在三个不同海拔梯度的取样点上也有明显差异。天池取样点的花粉类型较丰富,与天山北坡垂直带植被分布以及丰富的植被成分相对应,花粉的优势种类为雪岭云杉(Picea schrenkiana)、蒿属(Artemisia)、藜科(Chenopodiaceae)、柽柳科(Tamaricaceae)和麻黄属(Ephedra),高代表性的外源荒漠花粉类型“削弱了”本地花粉类型的代表性;阜康与北沙窝取样点的花粉类型主要来自荒漠成分的藜科、蒿属、麻黄属、蒺藜科(Zygophyllaceae, 白刺属Nitraria为主)、柽柳科(柽柳属为主)、蓼科(Polygonaceae, 沙拐枣属Calligonum为主)等耐旱植物。花粉数量与植被数量并非简单的线性关系。空中和表土花粉的数量分析表明,藜科、蒿属、麻黄属花粉具有超代表性;雪岭云杉花粉的代表性适中;禾本科(Gramineae)、榆属(Ulmus)、白刺属、柽柳科、沙拐枣属花粉代表性较差。 5年平均花粉浓度大小依次是阜康(81.668 grains/100m3)>天池(51.726 grains/100m3)>北沙窝(45.7685 grains/100m3)。蒿属花粉的峰值出现在秋季,并且出现双峰现象(可能与不同蒿类花期分布不均有关),而其它木本和草本类植物花粉浓度的峰值为单峰,具有明显的季节性,春夏之交开花的桦木属、榆属等类型较为明显。藜科花粉的峰值出现在夏季,麻黄和柽柳的峰值出现在盛夏,桦木属、柳属Salix、雪岭云杉等花粉浓度峰值出现在初夏,与其花期物候相对应。木本植物花粉以雪岭云杉为主,其次为桦木属(Betula)、榆属、柳属、胡颓子科(Elaeagnaceae)花粉,柳属花粉百分比在三个取样点分配比较均匀,桦木属花粉在空间分布上差异明显,与植物分布数量相关。胡颓子科的花粉出现时间短,数量也较少。榆属花粉出现的季节性明显,代表性也较差。因此解释地层中出现类似的低代表性和高代表性的花粉类型时,需要注意其百分比数量的适当校正。木本植物花粉百分比随海拔高度变化成正比关系,对植被的指示性较好。雪岭云杉的年平均花粉浓度在天池取样点明显高于其它两个取样点,5年的平均花粉浓度和百分比与海拔高度呈正比。天池取样点的百分比最高为28.85%,平均为21.15%,而北沙窝与阜康两地5年平均百分比含量分别为0.69%和1.57%,这种时空变化规律与植被数量的关系密切。藜科花粉百分比在阜康和北沙窝取样点占绝对优势,5年的平均花粉浓度与海拔高度呈反比。蒿属花粉年平均浓度与海拔高度关系微弱(R2=0.04,p =0.46),而花粉百分比与海拔高度有显著的线性正比关系(R2=0.72,p<0.0001)。但在低海拔的两个取样点之间差异不明显。 年平均花粉百分比和花粉浓度随海拔梯度而变化,主要花粉类型的变化规律存在差异。暗针叶林雪岭云杉花粉的年平均百分比在低海拔的阜康和北沙窝地区低于3%,在盛花期的6月初,低海拔的取样点也未见超过5%,雪岭云杉花粉的传播在研究区范围内数量分布变化较大,再次表明该类型的花粉在原地沉积效率很高。空中花粉数量能够较好地指示主要的植被带,盛花期内50%以上的雪岭云杉花粉含量则指示了雪岭云杉森林植被带,而高含量的蒿属植物花粉指示了天山山前冲积平原上的蒿类荒漠,相反,高含量的藜科花粉代表了低海拔地区的荒漠。雪岭云杉花粉百分比与浓度均与海拔高度呈显著的线性正比关系,表明雪岭云杉花粉传播的局限性。主要的非木本植物藜科花粉的浓度与海拔高度成反比,蒿属则相反,表明藜科与蒿属花粉在研究区具有很好的植被与气候指示意义。 花粉绝对数量、百分比、浓度具有明显的年际变化,其原因与气候状况的变化有关,年平均花粉浓度、主要类型的花粉浓度与气候参数(降水量、平均温度、最高和最低温度、相对湿度等)的相关分析表明,降水量和湿度与花粉浓度呈负相关程度较高,与其它气候参数则呈显著的正相关。干旱指数、花粉比值、花粉百分比(AP,NAP)与七月份平均气温,年平均降水量的相关系数(Pearson correlation),Ar/Ch与七月平均温度在0.01水平上呈显著的正相关(R2=0.894), 与年平均降水量在0.01水平上呈显著的负相关(R2=0.874)。AP花粉百分比与七月份平均温度呈显著的负相关(R2=0.71, p<0.0001),与年降水量呈正相关(R2=0.43, p=0.01),而NAP花粉正相反。利用短期监测的空中花粉雨数据计算得到的花粉比值以及干旱指数在研究区具有明确的指示意义,尤其是干旱指数、Ar/Ch、Ar/Ep,这些都可为表土花粉、植被与气候关系模型的建立提供重要的参考信息。 气候参数在很大程度上影响大气花粉的浓度,而风速和风向对空中花粉的传播、散布影响较大,花粉的来源与传播受风向和风速的控制。不同取样点的空中花粉数量差异受地形条件影响很明显,这种差异也可利用地形空气动力学特征的差异来解释,天池监测站因“逆坡”(upslope)的气流促进了低海拔的花粉流向高海拔传播。 研究区的空中花粉数量信息是研究表土花粉、植被和气候关系以及第四纪古生态学的重要基础。本研究提高了对研究区空中孢粉的类型及其传播规律的认识和理解,增加了解空中花粉受环境影响的主要因素及其影响程度,对地层孢粉类型鉴定和花粉数据的解释提出指导性建议,对本地区的古植被与古环境研究增加现代孢粉学的参考依据和信息,并可为建立区域性的现代孢粉-植被-气候关系模型提供可靠依据。 同时,本报告也讨论了存在问题和不足,并提出了今后工作的可能完善方案。
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2005年9月至2006年4月,对无量山一群黑长臂猿进行观察,研究黑长臂猿在植物种子传播中的作用.观察记录黑长臂猿一天的排便次数并收集粪便.通过直接观察和收集长臂猿粪便确定长臂猿取食的果实种类.以森林中采集的果实种子为对照标本,对粪便中的种子进行鉴定,并记录各种种子的数量,测量其长度、宽度和重量.结果表明观察期间黑长臂猿共取食31种果实,其中有1种在被取食时尚未成熟,另有2种果实的种子在取食后遭到破坏,还有1种植物的种子不能被长臂猿吞食而得不到传播,黑长臂猿可为27种植物传播种子.黑长臂猿个体平均每天排便2次,粪便的平均湿重为22.7 g,每份粪便平均含有1种植物的种子;在不包含小种子(直径<3 mm)的情况下,平均每份粪便中含有12粒种子.总的来说,黑长臂猿是有效的种子传播者.
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We tested the intergroup spacing hypothesis with a 13-month field study of the interaction of singing behaviour between 3 neighbouring groups of black-crested gibbons (Nomascus concolor jingdongensis) at Mt. Wuliang, Central Yunnan, China. Neighbouring gr
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1. The stripe-backed weasel Mustela strigidorsa is one of the rarest and least-known mustelids in the world. Its phylogenetic relationships with other Mustela species remain controversial, though several unique morphological features distinguish it from congeners. 2. It probably lives mainly in evergreen forests in hills and mountains, but has also been recorded from plains forest, dense scrub, secondary forest, grassland and farmland. Known sites range in altitude from 90 m to 2500 m. Data are insufficient to distinguish between habitat and altitudes which support populations, and those where only dispersing animals may occur. 3. It has been confirmed from many localities in north-east India, north and central Myanmar, south China, north Thailand, north and central Laos, and north and central Vietnam. Given the limited survey effort, the number of recent records shows that the species is not as rare as hitherto believed. Neither specific nor urgent conservation needs are apparent.
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We studied seasonal variation in the activity budget of a habituated group of Nomascus concolor jingdongensis at Mt. Wuliang, Central Yunnan, China from March 2005 to April 2006 via scan sampling at 5-min intervals. The study site is near the northern extreme of the distribution of hylobatids, at high altitude with extreme seasonality of temperature and rainfall. During the day, feeding manifested a bimodal pattern of high activity levels in mid-morning and mid-afternoon, whereas resting reached a peak at midday, with proportionally less time used for traveling. Annually, the group spent an average of 40.0% of the time resting, 35.1% feeding, 19.9% traveling, 2.6% singing, 1.2% playing, and 1.3% in other activities. The proportion of time allocated to activities showed significant monthly variations and was influenced by the diet and temperature. Gibbons increased traveling and playing time and decreased feeding time when they ate more fruit, and they decreased traveling, singing, and playing time and increased feeding time when they ate more leaves. Moreover, when the temperature was low, the gibbons decreased time traveling and increased time resting. In summary, black-crested gibbons employed high-effort activities when they ate more fruit and energy-conservation patterns when they ate more leaves and in low temperature. Behavioral data from the site are particularly useful in understanding gibbon behavioral adaptations to different sets of ecological conditions.
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Data on sleep-related behaviors were collected for a group of central Yunnan black crested gibbons (Nomascus concolor jingdongensis) at Mt. Wuliang, Yunnan, China from March 2005 to April 2006. Members of the group usually formed four sleeping units (adult male and juvenile, adult female with one semi-dependent black infant, adult female with one dependent yellow infant, and subadult male) spread over different sleeping trees. Individuals or units preferred specific areas to sleep; all sleeping sites were situated in primary forest, mostly (77%) between 2,200 and 2,400 m in elevation. They tended to sleep in the tallest and thickest trees with large crowns on steep slopes and near important food patches. Factors influencing sleeping site selection were (1) tree characteristics, (2) accessibility, and (3) easy escape. Few sleeping trees were used repeatedly by the same or other members of the group. The gibbons entered the sleeping trees on average 128 min before sunset and left the sleeping trees on average 33 min after sunrise. The lag between the first and last individual entering the trees was on average 17.8 min. We suggest that sleep-related behaviors are primarily adaptations to minimize the risk of being detected by predators. Sleeping trees may be chosen to make approach and attack difficult for the predator, and to provide an easy escape route in the dark. In response to cold temperatures in a higher habitat, gibbons usually sit and huddle together during the night, and in the cold season they tend to sleep on ferns and/or orchids.
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We used data on loud duetted and solo songs collected from one habituated polygynous group of black-crested gibbons (Nomascus concolor jingdongensis) on Mt. Wuliang, Yunnan, to test several hypotheses about the functions of these songs. The major function
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The authors thank Peng Shi, Scott Groom, and two anonymous reviewers for helpful comments. This work was supported by grants from the National Basic Research Program of China (973 Program, 2007CB411600), National Natural Science Foundation of China, and Bureau of Science and Technology of Yunnan Province (to Y.-P.Z.).
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Central serotonin (5-HT) dysregulation contributes to the susceptibility for mental disorders, including depression, anxiety, and posttraumatic stress disorder, and learning and memory deficits. We report that the formation of hippocampus-dependent spatia
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All Sinocrossocheilus species, except S. microstomatus, are reviewed. Four new species, S. labiata, S. papillolabra, S. nigrovittata, and S. longibulla, are described. The genus Sinocrossocheilus differs from other genera of Cyprinidae by the last simple dorsal fin ray being unserrated and unossified, the last unbranched anal fin ray being unserrated and unossified, the 5-branched anal fin rays, the mouth gap being inferior, the rostral cap covering the lower jaw and connecting directly with the lower lip, a row of fleshy lobes on the lower jaw, and a cloudy black spot above the pectoral fin. Sinocrossocheilus labiata is small and has 22 predorsal scales; S. longibulla has a very large air bladder; S. papillolabra possesses a well-developed ventral fin and a wide band covered by fleshy papillae on the lower lip; and S. nigrovittata possesses black longitudinal stripes along the lateral line. Crossocheilus bamaensis and Crossocheilus liuchengensis are transferred to the genus Sinocrossocheilus. Sinocrossocheilus species are endemic to the central and eastern Yunnan-Guizhou Plateau of China, where river systems are anfractuous, including seasonal rivers, cave rivers, underground rivers, and streamlets between mountains. These separated rivers probably provide conditions for the allopatric speciation of the Sinocrossocheilus.
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We have cloned a mouse homologue (designated Myak) of the yeast protein kinase YAK1. The 1210 aa open reading frame contains a putative protein kinase domain, nuclear localization sequences and PEST sequences. Myak appears to be a member of a growing family of YAK1-related genes that include Drosophila and human Minibrain as well as a recently identified rat gene ANPK that encode a steroid hormone receptor interacting protein. RNA blot analysis revealed that Myak is expressed at low levels ubiquitously but at high levels in reproductive tissues, including testis, epididymis, ovary, uterus, and mammary gland, as well as in brain and kidney. In situ hybridization analysis on selected tissues revealed that Myak is particularly abundant in the hormonally modulated epithelia of the epididymis, mammary gland, and uterus, in round spermatids in the testis, and in the corpora lutea in the ovary, Myak is also highly expressed in the aqueduct of the adult brain and in the brain and spinal cord of day 12.5 embryos, Mol. Reprod. Dev. 55:372-378, 2000. (C) 2000 Wiley-Liss, Inc.