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101.
102.
Tiejun Wang Xinping Ye Andrew K. Skidmore Albertus G. Toxopeus 《Journal of Biogeography》2010,37(5):865-878
Aim To examine the effects of forest fragmentation on the distribution of the entire wild giant panda (Ailuropoda melanoleuca) population, and to propose a modelling approach for monitoring the spatial distribution and habitat of pandas at the landscape scale using Moderate Resolution Imaging Spectro‐radiometer (MODIS) enhanced vegetation index (EVI) time‐series data. Location Five mountain ranges in south‐western China (Qinling, Minshan, Qionglai, Xiangling and Liangshan). Methods Giant panda pseudo‐absence data were generated from data on panda occurrences obtained from the third national giant panda survey. To quantify the fragmentation of forests, 26 fragmentation metrics were derived from 16‐day composite MODIS 250‐m EVI multi‐temporal data and eight of these metrics were selected following factor analysis. The differences between panda presence and panda absence were examined by applying significance testing. A forward stepwise logistic regression was then applied to explore the relationship between panda distribution and forest fragmentation. Results Forest patch size, edge density and patch aggregation were found to have significant roles in determining the distribution of pandas. Patches of dense forest occupied by giant pandas were significantly larger, closer together and more contiguous than patches where giant pandas were not recorded. Forest fragmentation is least in the Qinling Mountains, while the Xiangling and Liangshan regions have most fragmentation. Using the selected landscape metrics, the logistic regression model predicted the distribution of giant pandas with an overall accuracy of 72.5% (κ = 0.45). However, when a knowledge‐based control for elevation and slope was applied to the regression, the overall accuracy of the model improved to 77.6% (κ = 0.55). Main conclusions Giant pandas appear sensitive to patch size and isolation effects associated with fragmentation of dense forest, implying that the design of effective conservation areas for wild giant pandas must include large and dense forest patches that are adjacent to other similar patches. The approach developed here is applicable for analysing the spatial distribution of the giant panda from multi‐temporal MODIS 250‐m EVI data and landscape metrics at the landscape scale. 相似文献
103.
Miaoda Shen Zhuoyang Li Duo Lv Ge Yang Ronghuan Wu Jun Pan Shuo Wang Yifan Li Sanzhong Xu 《Journal of cellular and molecular medicine》2020,24(13):7370-7377
This study aimed to describe the 25‐hydroxyvitamin D (25(OH)D) and parathyroid hormone (PTH) status of Southeast Chinese individuals influenced by season. The secondary aim was to determine the cutoff for sufficient 25(OH)D in a four‐season region. From January 2011 to June 2014, a total of 17 646 individuals were evaluated in our study. The serum levels of PTH were detected simultaneously in 5579 cases. A total of 25(OH)D and intact PTH were measured by the electrochemiluminescent immunoassay. The distribution of the concentration, prevalence and seasonal variability of 25(OH)D and PTH were studied. The mean 25(OH)D concentration in our study was 43.00(30.40) nmol/L. The prevalence of insufficiency (25(OH)D < 50 nmol/L) was 62.87% and that of deficiency (<30 nmol/L) was 28.54%. Mean serum 25(OH)D levels revealed a limited sinusoidal profile throughout the year and were significantly higher in Autumn. On the other hand, PTH levels showed an opposite response to seasonal effects relative to 25(OH)D. Age, BMI and daylight were not significantly correlated with 25(OH)D and serum PTH reached a plateau at higher values of serum 25(OH)D of 42.86 nmol/L. This study demonstrated that Vitamin D insufficiency is highly prevalent in Southeast China. The concentration of 25(OH)D in the male group was generally higher than that in the female group. Seasonal variation was an important aspect of 25(OH)D and PTH concentration. This study revealed that the optimal serum threshold of 25(OH)D for bone health should be between 40 and 50 nmol/L for Southeast Chinese individuals. 相似文献
104.
Yaoqi Li Peter B. Reich Bernhard Schmid Nawal Shrestha Xiao Feng Tong Lyu Brian S. Maitner Xiaoting Xu Yichao Li Dongting Zou Zheng‐Hong Tan Xiangyan Su Zhiyao Tang Qinghua Guo Xiaojuan Feng Brian J. Enquist Zhiheng Wang 《Ecology letters》2020,23(6):1003-1013
A key challenge in ecology is to understand the relationships between organismal traits and ecosystem processes. Here, with a novel dataset of leaf length and width for 10 480 woody dicots in China and 2374 in North America, we show that the variation in community mean leaf size is highly correlated with the variation in climate and ecosystem primary productivity, independent of plant life form. These relationships likely reflect how natural selection modifies leaf size across varying climates in conjunction with how climate influences canopy total leaf area. We find that the leaf size?primary productivity functions based on the Chinese dataset can predict productivity in North America and vice‐versa. In addition to advancing understanding of the relationship between a climate‐driven trait and ecosystem functioning, our findings suggest that leaf size can also be a promising tool in palaeoecology for scaling from fossil leaves to palaeo‐primary productivity of woody ecosystems. 相似文献
105.
《Journal of Asia》2020,23(4):915-922
The genus Dilar Rambur, 1838 (Neuroptera, Dilaridae) is the most species-rich genus of the family Dilaridae and is diverse in China, previously with 32 described species. Here we report two new species of Dilar from the southern part of the Hengduan Mountains, Sichuan, southwestern China, namely Dilar muliensis sp. nov. and Dilar punctulosus sp. nov. A revised key to species of Dilar from China is provided.www.zoobank.org/urn:lsid:zoobank.org:pub:27EC214B-6587-4E38-BDAC-295F7389ABF3. 相似文献
106.
《Journal of Asia》2020,23(3):845-851
The geographical distribution patterns of Asian Metaeuchromius are analysed with MaxEnt and ArcGIS based on known localities and nineteen environmental variables. The results suggest that the most highly suitable area of the genus located in southeastern China. Precipitation of the warmest quarter (Bio18) and temperature seasonality (Bio4) are the most significant variables affecting geographical distribution Metaeuchromius. Furthermore, a new species from Jiangxi Province, southeast China is added to the genus, Metaeuchromius grandispinata Li, sp. nov. Its habitus, tympanic organs and genitalia are illustrated, and two maps showing geographical distribution patterns of Metaeuchromius in Asia are provided. 相似文献
107.
《Palaeoworld》2020,29(3):512-533
Abundant and diverse small shelly fossils have been reported from Cambrian Series 2 in North China, but the co-occurring brachiopods are still poorly known. Herein, we describe seven genera, five species and two undetermined species of organophosphatic brachiopods including one new genus and new species from the lower Cambrian Xinji Formation at Shuiyu section, located on the southern margin of North China Platform. The brachiopod assemblage comprises one mickwitziid (stem group brachiopoda), Paramickwitzia boreussinaensis n. gen. n. sp., a paterinide, Askepasma toddense Laurie, 1986, an acrotretoid, Eohadrotreta cf. zhenbaensis Li and Holmer, 2004, a botsfordiid, Schizopholis yorkensis (Holmer and Ushatinskaya in Gravestock et al., 2001) and three linguloids, Spinobolus sp., Eodicellomus cf. elkaniiformis Holmer and Ushatinskaya in Gravestock et al., 2001 and Eoobolus sp. This brachiopod assemblage suggests a late Age 3 to early Age 4 for the Xinji Formation and reveals a remarkably strong connection with coeval faunas from East Gondwana, particularly the Hawker Group in South Australia. The high degree of similarity (even at species level) further supports a close palaeogeographic position between the North China Platform and Australian East Gondwana during the early Cambrian as indicated by small shelly fossil data. 相似文献
108.
《Palaeoworld》2020,29(1):126-136
Permian–Triassic boundary microbialites (PTBMs) are organosedimentary carbonates formed immediately after the end-Permian mass extinction. All those reported PTBMs constrained by convincing conodont biozones are present stratigraphycally not higher than the Hindeodus parvus zone and most of them are dominated by thrombolites. This paper provides the first record of a brief, but spectacular development of stromatolite-dominated PTBMs within the basal Isarcicella isarcica conodont zone of the earliest Triassic from the Xikou section of South Qinling Block that was at the margin of the North China Block during the Permian–Triassic transition and was geographically separated from the major occurrence of post-extinction microbialites in the South China Block. This stromatolite cap overlies a 3.7-m-thick oolitic limestone and is composed of a lower 0.2-m-thick bed and an upper 0.5-m-thick bed, separated by a 0.2-m-thick greyish green siliciclastic mudstone. These two stromatolite beds mainly consist of columnar stromatolites with subordinate domal stromatolites. The intercolumn and interstitial spaces within the stromatolites are filled with oolitic grainstones. At the microscopic scale, laminoid structures in stromatolites comprise wavy, millimetric-domical and tangled laminae. The increased grain and fossil contents and/or bioturbation in the domical and tangled laminae indicate that the formation of these laminae is likely related to an increase in the populations and the disruptions by benthic metazoans, as well as an influx of sediment grains. The δ13Ccarb values fluctuate between 2‰ and 3‰ in the uppermost Permian strata; a distinct negative shift of 1.9‰ occurs at the topmost oolitic grainstone, just below the lower stromatolite bed, and the lowest value of −0.1‰ is located at the base of the upper stromatolite bed. The stratigraphic succession from stromatolites to thrombolites of the PTBMs may represent a transgressive succession and/or a transient ecosystem recovery immediately after the end-Permian mass extinction. The thrombolites-dominated PTBMs mainly developed in near-equator shallow marine geographic locations, and stromatolite-dominated PTBMs mainly developed at higher latitude settings, which probably indicates that a relatively lower diversity and abundance of marine benthic metazoans existed at higher latitudes after the end-Permian mass extinction. 相似文献
109.
广西百色盆地旧石器工业因含有众多的手斧且年代早到803 kaBP而闻名于世。盆地内发育有7级河流阶地,其中第IV级阶地发现有手斧和玻璃陨石。自从1973年第一个石器地点被发现,越来越多的遗址或地点被调查发现和发掘。以前研究认为,百色盆地旧石器只出自网纹红土层,年代均为803 kaBP。2013年以前,通常只在土状堆积的上部发掘,从来没有人对第IV级阶地的沉积物从地表到底部砾石层进行系统发掘,因此关于第IV级阶地的整体地层堆积情况及含石器层位很模糊。2013-2014年,广西文物保护与考古研究所会同田东县博物馆对百色盆地最重要的旧石器遗址之一——田东高岭坡遗址进行了系统的考古发掘。此次发掘从遗址的地表往下一直发掘到砾石层,揭露出厚度超过7m的完整地层序列,发现1处小型石器制造场和1处用火遗迹。在不同地层中发现石制品800多件,包括砍砸器、手镐、刮削器等。涵盖旧石器和新石器两个时代。根据地层对比和石制品的特征及测年结果,我们把旧石器时代文化遗存可分为3期:第一期的年代早于或等于803 kaBP,第二期为15 kaBP,第三期约为10 kaBP。 相似文献
110.
古DNA捕获技术目前已获得极大的发展,能够从骨骼和环境沉积物等多种材料中获取到目的DNA片段,而且对于保存环境较差的低纬度地区,同样能够获取有效的内源DNA片段,极大地丰富了古DNA研究的材料来源。本文围绕这一新技术开展总结和讨论,主要分为两个方面:1)总结并介绍该技术应用前景;2)应用这一技术打开了中国南方早期人群研究的新局面,梳理该新技术的应用对史前中国南方人群古基因组研究所获得的新认识,并对中国南方早期人群古基因组深入分析;另外,利用古DNA捕获技术成功获取云南3446~3180 BP的大阴洞遗址4例高质量线粒体基因组信息,并开展了人群遗传历史的研究。 相似文献