雄性短尾猴的等级顺位、睾酮水平与肠道寄生虫感染强度的关系

在等级森严的非人灵长类群体中,睾酮对雄性顺位维持有着重要作用,且影响着体内寄生虫种类和荷虫量。本研究以栖息于安徽黄山的雄性短尾猴为研究对象,通过计算成年雄性的等级顺位,测定其粪便中睾酮含量以及寄生虫的荷虫量,探讨雄性等级顺位、睾酮水平与健康间的平衡关系。结果表明：共检测出10种肠道寄生虫,包括4种蠕虫、5种原虫和1种螨虫;其中雄性短尾猴个体间睾酮水平（1.00±0.42） ng/g和肠道寄生虫荷虫量（112.44±83.62）EPG均存在显著差异（Kruskal-Wallis H,P<0.05）;等级顺位与睾酮水平呈正相关（Spearman, N=8,ρ= 0.326, P<0.05）,与肠道原虫类的荷虫量呈负相关（Spearman, N=8,ρ= - 0.345, P<0.05）,与肠道蠕虫类的荷虫量无相关性（Spearman, N=8,ρ= 0.065, P>0.05）;睾酮水平与肠道原虫类寄生虫的荷虫量呈负相关（Spearman, N=8,ρ= -0.546, P<0.05）,与肠道蠕虫类的荷虫量无相关性（Spearman, N=8,ρ= -0.013, P>0.05）。本研究表明高顺位雄性拥有更高的睾酮水平,这不仅对其顺位的维持具有重要作用,对原虫类寄生虫也具有明显的抑制作用。     

青藏高原和内蒙古高原典型草地植物叶片肾型和哑铃型气孔器气孔特征及其与环境的关系

该研究利用植物制片技术,以中国青藏高原和内蒙古高原典型草地常见种或优势种植物的叶片为研究对象,通过比较分析叶片哑铃型气孔器和肾型气孔器的特征及其与环境因子的关系,揭示植物叶片两类气孔器对环境因子的响应策略。结果表明:(1)叶片哑铃型气孔器气孔指标的变异系数小于肾型气孔器。(2)叶片哑铃型气孔器气孔指标与环境气候指标的关系弱于肾型气孔器。(3)叶片哑铃型气孔器气孔特征与环境关系在叶片上下表面之间存在显著差异,而肾型气孔器气孔特征与环境因子的关系在叶片上下表面之间无显著差异。(4)叶片哑铃型气孔器的气孔特征与降水关系密切,而肾型气孔器气孔特征与温度关系密切。(5)同一种气孔器的气孔特征在两个地区(青藏高原和内蒙古高原)间存在显著差异。研究认为,肾型气孔器和哑铃型气孔器的气孔特征及其与环境之间的关系存在差异,在分析气孔特征时有必要将肾形与哑铃形保卫细胞形成的气孔器加以区分,该研究结果有助于进一步理解中国草地植物叶气孔特征对气候变化的响应与适应策略。     

Shifts in priming partly explain impacts of long‐term nitrogen input in different chemical forms on soil organic carbon storage

Input of labile organic carbon can enhance decomposition of extant soil organic carbon (SOC) through priming. We hypothesized that long‐term nitrogen (N) input in different chemical forms alters SOC pools by altering priming effects associated with N‐mediated changes in plants and soil microbes. The hypothesis was tested by integrating field experimental data of plants, soil microbes and two incubation experiments with soils that had experienced 10 years of N enrichment with three chemical forms (ammonium, nitrate and both ammonium and nitrate) in an alpine meadow on the Tibetan Plateau. Incubations with glucose–¹³C addition at three rates were used to quantify effects of exogenous organic carbon input on the priming of SOC. Incubations with microbial inocula extracted from soils that had experienced different long‐term N treatments were conducted to detect effects of N‐mediated changes in soil microbes on priming effects. We found strong evidence and a mechanistic explanation for alteration of SOC pools following 10 years of N enrichment with different chemical forms. We detected significant negative priming effects both in soils collected from ammonium‐addition plots and in sterilized soils inoculated with soil microbes extracted from ammonium‐addition plots. In contrast, significant positive priming effects were found both in soils collected from nitrate‐addition plots and in sterilized soils inoculated with soil microbes extracted from nitrate‐addition plots. Meanwhile, the abundance and richness of graminoids were higher and the abundance of soil microbes was lower in ammonium‐addition than in nitrate‐addition plots. Our findings provide evidence that shifts toward higher graminoid abundance and changes in soil microbial abundance mediated by N chemical forms are key drivers for priming effects and SOC pool changes, thereby linking human interference with the N cycle to climate change.     

Fossil leaves of Buxus (Buxaceae) from the Upper Pliocene of Yunnan,SW China

A new species, Buxus pliosinica H.S. Huang, T. Su et Z.K. Zhou n. sp. (Buxaceae) is designated based on leaf architecture and cuticular features of five compressed fossil leaves from the Upper Pliocene Sanying Formation of Yunnan, SW China. Leaves of B. pliosinica are elliptic and small, with entire margin, retuse tip, intramarginal vein, and exmedially ramified tertiary veins. The leaves are hypostomatic with anomocytic stomatal apparatuses and giant stomata. Based on comparisons of leaf morphological and cuticular features, B. sempervirens Linnaeus is considered as the nearest living relative of B. pliosinica. Morphologically, these species share similar elliptic shape and size, cuneate base, retuse tip, similar ranges of petiole length, angles of 2° vein to midvein, and distance from the intramarginal vein to the margin. In terms of cuticular features, they are similar in type of stomatal apparatus, maximum length of giant stomata and range of stomatal length, but differ in the presence of indumentum. This discovery represents the first fossil record of Buxus from the SE margin of the Tibetan Plateau, and confirms the existence of Buxus in this region by the late Pliocene. Meanwhile, the newly described fossil species contributes to our understanding of the evolution of extant Buxus.     

The diet of Pteropus voeltzkowi, an endangered fruit bat endemic to Pemba Island, Tanzania

The diet of the Pemba flying fox Pteropus voeltzkowi , a species endemic to the island of Pemba off Tanzania, was investigated. Faecal pellets, ejecta and dropped fruits were collected from under roosts to facilitate dietary analysis. This was supplemented by data from local villagers and school students. The main component of the diet was mango ( Mangifera indica ), but bats also ate breadfruit ( Artocarpus altilis ), figs ( Ficus spp.), flowers, leaves, and other fruit. Pollen from at least five plant species was also found in faecal pellets. Pteropus voeltzkowi may be one of the only species on the island that disperses larger seeds. The germination rate of bat‐ingested seeds was higher than that for seeds from ripe fruit, and this appeared to be linked to selective ingestion of viable seeds by bats.     

川西高原不同坡向云、冷杉树轮对快速升温的响应差异

在川西高原松潘县二道海林区的东南坡、西北坡和扎日寺林区的东坡用零信号法建立4条云、冷杉树轮年表,通过年轮 气候响应分析、多因素方差分析等方法研究不同坡向树木生长对快速升温的响应差异.结果表明： 快速升温(1980年)后,东坡紫果云杉生长显著加速(0.011 a^-1),而西北坡紫果云杉生长则显著降低(-0.006 a^-1),东南坡紫果云杉和西北坡岷江冷杉生长降低,但不显著.随着快速升温,不同坡向云、冷杉径向生长与气候因子的关系均出现显著变化.快速升温后,生长季温度对东坡紫果云杉径向生长的促进作用显著增加,对东南坡和西北坡紫果云杉径向生长的抑制作用也显著增加,但生长季温度对西北坡岷江冷杉径向生长的影响在升温前后变化不明显.5月降水量对东坡紫果云杉径向生长由升温前的抑制作用变为升温后的显著促进作用,而对东南坡和西北坡紫果云杉径向生长的抑制作用显著增加,5月降水量对西北坡岷江冷杉径向生长的影响在升温前后变化不明显.树轮与帕尔默干旱指数响应分析表明,快速升温后,不同坡向的土壤湿度变化是造成树轮响应差异的重要原因.多因素方差分析表明,坡向与温度、降水的综合作用是影响紫果云杉径向生长的重要因素.因此,在模拟预测树木生长对气候变暖的响应动态时,应考虑不同坡向与温度、降水的综合作用.     

交通设施对可可西里藏羚季节性迁移的影响

本文基于对可可西里自然保护区内藏羚跨越青藏公路及青藏铁路的监测结果,初步探讨了公路及铁路对藏羚季节性迁移的影响。观测结果显示,目前对藏羚迁移的主要干扰因素为：交通设施自身的屏障作用、人为活动、公路交通流量、未清理施工现场及未恢复植被等。本文通过对野生动物通道的使用情况监测和对不同通道形式的使用评价,为未来铁路建设和野生动物通道的优化提供了科学依据。     

西藏那曲地区藏族人群15个短串联重复序列位点多态性的研究

利用基因扫描技术调查西藏自治区那曲地区藏族人群D8S1179、D21S11、D7S820、CSF1PO、D3S1358、TH01、D13S317、D16S539、D2S1338、D19S433、VWA、TPOX、D18S51、D5S818及FGA共15个短串联重复序列(STR)基因座多态性分布,获得15个基因座的群体遗传学数据。结果显示:15个STR位点在那曲地区藏族人群中具有遗传多态性,基因型分布符合Hardy-Weinberg平衡,DP在0.758 8—0.960 4之间,H在0.476 2—0.862 0之间,PIC在0.446 4—0.861 5之间,EPP在0.385 0—0.856 0之间,累积个体鉴别力为0.999 999 999,累积非父排除率为0.999 999 998。15个STR位点适合作为那曲地区藏族人群的遗传标记用于人类学、疾病连锁分析、法医学亲子鉴定和个体识别等领域的研究。     

川西北高原藏原羚夏季生境选择

利用数量化理论对川西北高原藏原羚夏季生境选择进行了研究,发现影响藏原羚夏季生境选择的主要因子有水源、植被类型、隐藏条件,次要因子为食物丰盛度、人为干扰和海拔高度;其最适生境为隐蔽条件较好、水源较近的草甸草原。