西双版纳、白茫雪山、波罗的海南岸地衣纯培养放线菌多样性

【背景】在地衣共生系统中除了共生真菌、藻类以外,还蕴藏着丰富的放线菌资源。【目的】采集来自云南西双版纳、白茫雪山、德国波罗的海南岸3个地区的地衣,对获得的地衣纯培养放线菌进行多样性分析。【方法】采用3种放线菌选择分离培养基,通过平板稀释涂布法分离放线菌。通过比较16S rRNA基因序列相似性以及构建系统发育树,确定纯培养放线菌的分类地位。【结果】共分离菌株1 123株,鉴定417株。其中从西双版纳17份地衣样品中分离纯化到107株放线菌,分布在7个目14个科33个属,潜在新种18株,其中链霉菌为优势菌属;从白茫雪山7份地衣样品中分离纯化到103株放线菌,分布在4个目5个科9个属,潜在新种16株。其中链霉菌为优势菌属,占比39%;从波罗的海南岸5份地衣样品中分离纯化到65株放线菌,分布在4个目8个科18个属,潜在新种5株,潜在新种菌和链霉菌为优势菌属。【结论】在本研究条件下,西双版纳可培养地衣放线菌多样性较白茫雪山和波罗的海南岸丰富。白茫雪山地衣链霉菌居多,潜在新种占比15.5%。3个地区地衣放线菌的区系组成各不相同,这与3个地区地衣所处地理环境、完全不同的气候密切相关。     

Fecal endocrine monitoring of reproduction in female snow leopards (Uncia uncia)

Although the snow leopard (Uncia uncia) is a common endangered felid species in zoos, little is known about the complex endocrine interactions controlling ovarian function and conception in this species. The goal of this work was to characterize ovarian activity throughout the estrous cycle, nonpregnant luteal phase (pseudopregnancy), and gestation in female snow leopards. This goal was accomplished using an enzyme immunoassay to measure fecal concentrations of estrogen metabolites (E) and progesterone metabolites (P). Fecal samples were collected from 12 female snow leopards (ages 18 months to 18 years) during one to three breeding seasons. In each breeding season, the majority of females (78%, 88%, and 100%, respectively) began to exhibit ovarian activity in December or January. The estrous cycle, defined by the first day of estrus (E ≥ 2 × basal concentration) to the first day of the subsequent estrus, was 12.7 ± 0.6 days (n = 145 cycles). Estrus lasted 4.3 ± 0.4 days with mean concentrations of fecal E during the follicular phase (1661 ± 139 ng/g feces) increasing 3.2-fold above basal concentrations (515 ± 32 ng/g feces). No spontaneous ovulations were observed in any of the cycling females. Nonpregnant luteal phases were observed in eight females that bred but did not become pregnant. The length of the nonpregnant luteal phase ranged from 11 to 72 days (45.7 ± 5.7 days; n = 10) with mean concentrations of fecal P during the luteal phase (12.46 ± 1.7 μg/g feces) increasing 6.2-fold above basal concentrations of P (2.01 ± 0.2 μg/g feces). Three of the females in the study became pregnant and gave birth after a gestation of 93 (n = 2) and 95 (n = 1) days. Fecal P concentrations during pregnancy increased to 11.64 ± 1.3 μg/g feces, or 5.8-fold above basal concentrations. The results of this study provide a comprehensive characterization of reproductive endocrinology in snow leopards, and confirm that fecal hormone monitoring is an effective way to monitor female snow leopards throughout the breeding season.     

Goose grazing influences the fine-scale structure of a bryophyte community in arctic wetlands

Herbivores can shape plant communities, especially in the Arctic. We tested the role of geese for structuring bryophyte communities at fine spatial scales in the arctic tundra by excluding them from 4 × 4 m areas. We surveyed the presence and absence of bryophyte species in quadrats (10 × 10 cm) divided into 25 cells outside and inside these exclosures, after 5 and 11 years of treatment. Species richness per cell (4 cm²) was higher in the presence of geese, especially after 11 years of treatment, while geese had little effect on richness at larger scales (i.e. quadrat and whole exclosure). The slope of the species–area relationship within quadrats was consequently shallower outside exclosures. Our results further suggest that the community outside the exclosures was more variable in space and time than that inside the exclosures. We conclude that goose foraging activity promotes the coexistence of bryophyte species at the centimetre scale.     

Changes in abundance and spatial distribution of geese molting near Teshekpuk Lake,Alaska: interspecific competition or ecological change?

Goose populations molting in the Teshekpuk Lake Special Area of the National Petroleum Reserve—Alaska have changed in size and distribution over the past 30 years. Black brant (Branta bernicla nigricans) are relatively stable in numbers but are shifting from large, inland lakes to salt marshes. Concurrently, populations of greater white-fronted geese (Anser albifrons frontalis) have increased seven fold. Populations of Canada geese (Branta canadensis and/or B. hutchinsii) are stable with little indication of distributional shifts. The lesser snow goose (Anser caerulescens caerulescens) population is proportionally small, but increasing rapidly. Coastline erosion of the Beaufort Sea has altered tundra habitats by allowing saltwater intrusion, which has resulted in shifts in composition of forage plant species. We propose two alternative hypotheses for the observed shift in black brant distribution. Ecological change may have altered optimal foraging habitats for molting birds, or alternatively, interspecific competition between black brant and greater white-fronted geese may be excluding black brant from preferred habitats. Regardless of the causative mechanism, the observed shifts in species distributions are an important consideration for future resource planning.     

Dealing with many correlated covariates in capture–recapture models

Capture–recapture models for estimating demographic parameters allow covariates to be incorporated to better understand population dynamics. However, high-dimensionality and multicollinearity can hamper estimation and inference. Principal component analysis is incorporated within capture–recapture models and used to reduce the number of predictors into uncorrelated synthetic new variables. Principal components are selected by sequentially assessing their statistical significance. We provide an example on seabird survival to illustrate our approach. Our method requires standard statistical tools, which permits an efficient and easy implementation using standard software.     

Resources Evaluation of Seed Plants in Yulong Snow Mountain,Lijiang, Northwestern Yunnan

Yulong Snow Mountain (Jade Dragon Snow Mountain), located in northwestern Yunnan, is belonging to one of three biodiversity centers of China. In this paper, we analyzed the composition of seed plant resource species in Yulong Snow Mountain based on databases and checklists of seed plants, and specimens collected recently in this area. More than 2815 seed plant species in Yulong Snow Mountain region were recorded, among which 96 species are endangered. Furthermore, we classified and evaluated these plant resources based on their use and biological characteristics. In addition, we propose a systematic and sustainable approach to solve the conflicts between the conservation and the economical development. This study updated the checklist of seed plants of Lijiang Alpine Botanical Garden, while also documented the basic information of plant resources in Yulong Snow Mountain. These findings provided scientific basis for future research and conservation.     

岩黄连引种栽培研究

岩黄连 ( Corydalis saxicola Bunting)为石山特有的多年生草本药用植物 ,局限分布裸露石山 ,生于石缝、石穴 ,资源稀少且濒于枯竭。通过近四年的引种栽培研究 ,表明其对丘陵区酸性土壤亦有较强的适应性 ,能正常生长发育 ,种子发芽率可达 4 0 %～ 50 % ,药材产量 (干品 ) 90 0～ 12 0 0 kg/hm2 。报道了其生物学特性和主要的栽培技术。     

A model of alpine species distribution in relation to snowmelt time and altitude

Abstract. The focus of this study is the response of species to time of snowmelt and altitude in alpine areas and an examination of changes in species response to snowmelt as altitude increases and temperature decreases. Transects (n= 43) were placed evenly along an altitudinal gradient at Finse, Hardanger‐vidda, western Norway, from ridges to late snowbeds. These gradients were systematically sampled (‘Repeated Gradient Analysis, RGA’) and an adjusted F‐test was used to determine repeated trends in species distribution along the transects. Of the 41 taxa analysed 22 showed a significant change in expected occurrence in response to time of snowmelt (when a site becomes free of snow) as altitude increased. Three types of response were observed: (1) no change in response: (2) increased occurrence as altitude increases, i.e. the taxon invades snow‐free sites as altitude increases, and (3) decreased occurrence as altitude increases, i.e. the taxon retreats from snow covered areas. It is suggested that the changes in response are due to both environmental factors (temperature related) and biological interactions. Decreases in expected occurrence are probably due to increased environmental severity as altitude increases (temperature related decreases). These species are represented by taxa preferring intermediate cover of snow. The invasion of earlier snow‐free sites is probably due to reduced competition from lee‐side taxa as altitude increases. A predictive model based on the species‐environmental relationships suggests that a 1°K temperature increase changes the limits of occurrence in response to time of snowmelt from 3 to 20 days for the different taxa.     

岩黄连茎基腐病的分离鉴定及防治

对引起药用植物岩黄莲茎基部腐烂的病原进行分离 ,获得纯的活体病原 ,然后进行病原菌的致病性测定 ,确定致病病原。根据病原形态 ,初步鉴定为 :无性态属于半知菌类葡萄孢属 (Botrytissp.) ,有性态属于子囊菌门葡萄核盘菌属 (Botrytinia sp.)。并提出岩黄连人工栽培中该病的防治方法。     

笼养暗腹雪鸡的繁殖

报道了暗腹雪鸡在笼养条件下的配对、领域、求偶行为、巢和卵、卵的受精率及人工孵化等情况。