High-elevation mountain hemlock growth as a surrogate for cool-season precipitation in Crater Lake National Park,USA

Snow dominates the hydrology and climate of the United States’ central Pacific Coast, but because local measurements of snowpack and winter precipitation often extend back only a few decades, observations by themselves are not adequate to describe potential amplitude of wintertime conditions. Here we present a set of updated and extended mountain hemlock (Tsuga mertensiana [Bong.] Carr.) tree-ring width records from Crater Lake National Park, Oregon, and use these data to make inferences about snowpack prior to the start of instrumental monitoring. In July and August 2013, we collected cores from 228 trees at seven high-elevation hemlock stands that surround the crater’s rim. The oldest tree had an inner ring date of CE 1474, and the longest ring-width chronology maintained a satisfactory common signal back to the middle of the 16th century. The growth of high-elevation mountain hemlock is strongly and inversely related to cool-season precipitation, making these records some of the most southerly examples of a robust inverse cool-season moisture signal in North American tree rings. The growth of these snow-limited forests does not appear to have been affected by the substantial decline in spring snowpack observed in the past two decades across the broader Cascade Range, and we did not find any indication of changing relationships between tree growth and either monthly or seasonal winter precipitation since the early 1990s. The exceptional three-year sequence in Crater Lake tree rings between CE 1809 and 1811, which includes the narrowest ring since CE 1540 and anatomical abnormalities produced by cold weather, leads us to conclude that 1809–1810 was the most snowy and severe winter to affect south-central Oregon during the past four and a half centuries.     

Winter in the Ouchitas—A severe winter storm signature in Pinus echinata in the Ouachita Mountains of Oklahoma and Arkansas,USA

Each year severe winter storms (≈ice storms) damage trees throughout the southern USA. Arkansas and Oklahoma have a history of severe winter storms. To extend that history back beyond the reach of written records, a distinctive tree ring pattern or signature is needed. Storm-caused breakage, branch loss and bending stress provide that signature. We found a severe storm signature in shortleaf pine (Pinus echinata). We used three published site chronologies, a set of five new site chronologies from a growth-and-yield study conducted by Oklahoma State University and the unpublished Shortleaf Canyon chronology from a master’s thesis at the University of Arkansas. Our method is based on two ring width values for the first and second growing seasons after the storm standardized to the ring widths of the seven growing seasons after the storm. Concordance between storm years predicted by tree ring patterns and actual storm years was tested using Cohen’s Kappa. Concern about confounding of ice storm signals by droughts led us to test concordance between severe storms and drought in July, August and September; results were inconclusive but stand as a warning that these two phenomena cannot be distinguished with certainty in the tree ring record. Damaging severe storms occurred in about 2.8% of all years. Two out of three storms identified as “severe” produced glaze icing.     

A genetic adaptive pattern＊low hemoglobin concentration in the himalayan highlanders

Mean hemoglobin （Hb） concentration of about 3 500 subjects derived from 17 studies of Himalayan highlanders （Tibetans, Sherpas, and Ladakhis） was compared with lowlanders （Chinese Han, Indian Tamils） lived in the Himalayas, and European climbers during Everest expeditions as well as Andean natives. The results found that Hb concentration in Himalayan highlanders was systemically lower than those reported for Andean natives and lowland immigrants. These comparative data demonstrated that a healthy native population may successfully reside at high altitude without a significant elevation in Hb, and the lower Hb levels of Himalayan highlanders than those of migrated lowlanders and Andean natives are an example of favourable adaptation over the generations. In addition, excessive polycythemia has frequently been used as a marker of chronic mountain sickness （CMS）. Altitude populations who have a higher Hb concentration also have a higher incidence of CMS. The low Hb in Himalayans suggested as showing adaptation over many generations in Tibetan stock. Recent work in Tibet, suggested that Tibetans there may have adapted to high altitude as a result of evolutionary pressure selecting for genes which give an advantage at altitude. All of the population genomic and statistical analysis indicated that EPAS1 and EGLN1 are mostly likely responsible for high altitude adaptation and closely related to low Hb concentration in Tibetans. These data supported the hypothesis that Himalayan highlanders have evolved a genetically different erythropoietic response to chronic hypoxia by virtue of their much longer exposure to high altitude.     

A New Species of the Genus Protobothrops(Squamata: Viperidae) from Southern Tibet,China and Sikkim,India

A new species of the genus Protobothrops Hoge Romano-Hoge, 1983, was described from Jilong County, southern Tibet, China, and Chungthang, northern Sikkim, India. It differs from congeners by the following characters: 1) relatively large body size(total length up to 1510 mm); 2) dorsal scale rows 25–25–19; 3) except for the smooth outermost row, dorsal scales are weakly keeled; 4) relatively high number of ventral(198–216) and subcaudal(65–76 pairs) scales; 5) 7–8 supralabials; 6) 11 to 13 infralabials; 7) dorsal head uniform dark brown, laterally a reddish-brown obscure postocular streak; 8) dorsum of trunk and tail olive, with distinct black edged red brown transverse bands across the body and tail; and 9) eye from bright brown and reddish brown to mildly brown. The new species was also observed from the Haa Valley in western Bhutan.     

Emission of nitrous oxide through a snowpack in ten types of temperate ecosystems in Japan

The release of N₂O from the snow surface in winter and the soil in summer was measured in ten types of temperate ecosystems (bare ground, grassland, forest, marsh, and crop field) in Japan. The snow-covered crop field emitted by far the largest amount of N₂O during the winter. Among the snow-covered natural ecosystems studied, marshy ecosystems showed the largest effluxes of N₂O. Based on results showing that the magnitude of the winter N₂O fluxes was not negligible compared with that of the summer N₂O fluxes and because the snow period in the areas studied area is sufficiently long, we suggest that the winter N₂O fluxes contribute significantly to the annual emission of N₂O in the study areas.     

辽宁鸟类分布新记录5种:小鸦鹃、雪鹀、 红翅凤头鹃、宝兴歌鸫和黄眉姬鹟北大核心CSCD

近年来,随着观鸟活动和鸟类科研工作在辽宁的持续开展(Baietal.2015,汤姆·滨客2016),辽宁各地不断发现鸟种分布新记录种(白清泉等2019)。2012至2020年间,在丹东、大连、抚顺等市先后发现小鸦鹃(Centropus bengalensis)、雪鹀(Plectrophenax nivalis)、红翅凤头鹃(Clamator coromandus)、宝兴歌鸫(Turdus mupinensis)和黄眉姬鹟(Ficedula narcissina)5种,经查阅相关资料(邱英杰等2006,郑光美2017),确定为辽宁省鸟类分布新记录种。     

祁连山国家公园青海片区雪豹栖息地适宜性评价

雪豹是全球生物多样性保护的旗舰物种,精准评估雪豹栖息地质量可为其种群保护提供科学参考。本文选取地形、气候、植被类型和人为干扰等环境因子,采用景观连接度和MaxEnt模型两种方法,对祁连山国家公园青海片区雪豹栖息地质量进行评价。结果表明：高适宜栖息地主要分布在研究区的西部和中部,适宜面积占青海片区总面积的71.8% ~ 77.5%,两种方法预测的适宜栖息地重叠区为8 979.1 km²,占青海片区总面积的56.7%;39.8% ~ 43.3%的适宜栖息地分布在一般控制区,56.7% ~ 60.2%的适宜栖息地分布在核心保护区;疏勒河源区适宜栖息地面积最多,石羊河源区适宜栖息地面积最少,黑河源区适宜栖息地面积占比最高,约为77.1% ~ 91.8%。适宜栖息地面积整体呈现自东向西递增的趋势。一般控制区分布有较大面积的雪豹栖息地,人类活动将是一般控制区雪豹栖息地的潜在威胁。本研究对优化雪豹就地保护措施提供科学借鉴与参考。     

雪豹保护遗传学和基因组学研究进展

雪豹 (Panthera uncia) 隶属于食肉目猫科豹属,是生活在青藏高原及其周边地区的旗舰物种。随着分子生物学和高通量测序技术的发展,雪豹保护遗传学和保护基因组学研究得到快速的发展,其中非损伤性遗传取样法显著推动了雪豹保护遗传学研究。本文综述了非损伤性遗传取样法在雪豹物种鉴定、个体识别和性别鉴定等研究中的应用,雪豹的系统发生地位、系统地理格局和种群遗传结构及其亚种争议、演化历史、适应性演化和基因组特征等保护遗传学和基因组学方面的研究现状和进展,并对雪豹保护遗传学和基因组学未来发展趋势进行了展望,以期促进雪豹保护生物学研究和保护对策的科学制定。     

Integrative assessment of Western Himalayas streams using multimeric index

Multimeric index based on fish composition was used to assess integrity of shallow and wadeable streams of lower Himalayas in temperate and subtropical ecoregions. Streams were surveyed for biotic and abiotic sampling during base flow periods in pre and post monsoon seasons in 2007 and 2008. Twenty three metrics were computed based on taxonomic richness, trophic composition, habitat preferences, abundance, stress tolerance and species origin attributes of 19 fish species. Candidate metrics were analyzed for efficiency to discriminate degraded sites from non-degraded and redundancy analysis, which sorted 71% of omnivore individuals (excluding intolerant species), 40% of intolerant individuals, 44% of herbivore individuals (excluding benthic species), abundance and 44.5% of non-native individuals as potential metrics. IBI values at forest, agriculture and urban zones were ranged between (max–min) 9.9–3.22, 6.18–2.49 and 4.43–0.69 respectively. Results suggested that poor ecological conditions in streams were generally related to drainage of urban sewage and habitat fragmentation while agriculture land use seems to have moderate impact on ecological integrity of the streams. Less urbanized upstream with grasslands and forests as land use, showed excellent to good ecological integrity of the streams. Proposed index was able to distinguish varying degrees of human impact on ecological integrity of streams and thus index could be used as valuable tool for bioassessment of regional flowing water resources.