Changes in climatic water balance drive downhill shifts in plant species' optimum elevations

Uphill shifts of species' distributions in response to historical warming are well documented, which leads to widespread expectations of continued uphill shifts under future warming. Conversely, downhill shifts are often considered anomalous and unrelated to climate change. By comparing the altitudinal distributions of 64 plant species between the 1930s and the present day within California, we show that climate changes have resulted in a significant downward shift in species' optimum elevations. This downhill shift is counter to what would be expected given 20th-century warming but is readily explained by species' niche tracking of regional changes in climatic water balance rather than temperature. Similar downhill shifts can be expected to occur where future climate change scenarios project increases in water availability that outpace evaporative demand.     

辽宁省杂交粳稻产量构成及光合生理生态特性研究

对辽宁省4个冠层形态具有一定差异但又具有较高产量水平的杂交粳稻组合与常规水稻品种辽粳294在籽粒灌浆期的光合生理生态特性进行了比较研究。结果表明:杂交粳稻各组合单株产量明显高于常规对照品种,每穴穗数比对照有所降低,每穗颖花数比对照高出很多,结实率和千粒重差别不大;各杂交组合的上功能叶叶面积和群体LAI都高于对照品种,各组合的叶绿素含量和光合速率平均值在灌浆初期与对照品种差别不明显,在水稻灌浆末期,各杂交组合的茎鞘干物质输出率差别较大。     

岩黄芪属3种固沙灌木或半灌木生物量蓄积特性研究

利用3年时间对3种岩黄芪属(Hedysarum L.)和3种锦鸡儿属(Caragana Fabr)植物的生长速率、生物量积累、家畜采食的幼嫩枝条比例、冠层结构等进行了对比研究。结果表明:岩黄芪属植物的生长速率显著高于锦鸡儿属植物,生长2年的岩黄芪属植物的生长速率为0.70 cm/d,锦鸡儿属植物为0.27 cm/d,岩黄芪属植物较锦鸡儿属植物能更早、更好地起到防风固沙作用。岩黄芪属植物生物量积累迅速,生长2年的岩黄芪属植物单株干重平均为41.17 g,产量干重为2 158.52 kg/hm2,锦鸡儿属植物单株干重为7.09 g,产量干重351.87 kg/hm2;生长3年的岩黄芪属植物单株干重平均为104.38 g,产量干重为3 132.63 kg/hm2,锦鸡儿属植物单株干重为14.23 g,产量干重703.88 kg/hm2,两属植物差异显著(P<0.05)。岩黄芪属植物随着年龄的增长,可供家畜采食的幼嫩枝条所占比例逐渐下降,生长2年的岩黄芪属植物8月份木质化枝条占总生物量干重的53.82%,生长3年的木质化枝条占总生物量的78.77%。     

A significant upward shift in plant species optimum elevation during the 20th century

Spatial fingerprints of climate change on biotic communities are usually associated with changes in the distribution of species at their latitudinal or altitudinal extremes. By comparing the altitudinal distribution of 171 forest plant species between 1905 and 1985 and 1986 and 2005 along the entire elevation range (0 to 2600 meters above sea level) in west Europe, we show that climate warming has resulted in a significant upward shift in species optimum elevation averaging 29 meters per decade. The shift is larger for species restricted to mountain habitats and for grassy species, which are characterized by faster population turnover. Our study shows that climate change affects the spatial core of the distributional range of plant species, in addition to their distributional margins, as previously reported.     

攀枝花印楝引种试验初报

通过试验表明,缅1和缅3种源在攀枝花干热河谷造林,次年保存率可达90%左右,月均树高生长量可达8.41~11.5 cm,地径生长量可达0.9~1.5 mm。印楝种子贮藏不宜超过3周,其发芽率可达80%以上。播种前经1%H2SO4溶液浸泡15 min或65℃温水浸泡30 min催芽,其发芽率可达90%以上。印楝适宜于攀枝花干热河谷海拔1500 m,尤其是海拔1300 m以下地区造林,以砾质红色石灰土最佳,山地碳酸盐红褐土次之,整地规格以种植穴长、宽、深60~80 cm为宜。     

The pace of shifting climate in marine and terrestrial ecosystems

Climate change challenges organisms to adapt or move to track changes in environments in space and time. We used two measures of thermal shifts from analyses of global temperatures over the past 50 years to describe the pace of climate change that species should track: the velocity of climate change (geographic shifts of isotherms over time) and the shift in seasonal timing of temperatures. Both measures are higher in the ocean than on land at some latitudes, despite slower ocean warming. These indices give a complex mosaic of predicted range shifts and phenology changes that deviate from simple poleward migration and earlier springs or later falls. They also emphasize potential conservation concerns, because areas of high marine biodiversity often have greater velocities of climate change and seasonal shifts.     

Rapid changes in flowering time in British plants

The average first flowering date of 385 British plant species has advanced by 4.5 days during the past decade compared with the previous four decades: 16% of species flowered significantly earlier in the 1990s than previously, with an average advancement of 15 days in a decade. Ten species (3%) flowered significantly later in the 1990s than previously. These data reveal the strongest biological signal yet of climatic change. Flowering is especially sensitive to the temperature in the previous month, and spring-flowering species are most responsive. However, large interspecific differences in this response will affect both the structure of plant communities and gene flow between species as climate warms. Annuals are more likely to flower early than congeneric perennials, and insect-pollinated species more than wind-pollinated ones.     

感染萧氏松茎象幼虫的绿僵菌菌株的初步筛选

应用10个绿僵菌菌株对萧氏松茎象幼虫进行致病力试验,结果表明,以浓度为(1.5±0.5)×106个.mL-1的孢子悬液喷菌,校正死亡率最高为91.90%,最低为15.28%,僵虫率最高为91.32%,最低为24.80%,LT50为5.39-10.12 d,单头虫体平均产孢量为106-107个.头-1.Ma1291-2、MaWP-01菌株对萧氏松茎象幼虫致病力较强,喷菌7 d后僵虫率分别为89.56%、91.32%,LT50分别为5.49、5.72 d,经不同剂量测定LC50分别为2.5707×104、1.9871×104个.mL-1,这2个菌株对萧氏松茎象生物防治有较大的开发利用价值.     

Increase of maximum life-span in Sweden, 1861-1999

A fundamental question in aging research is whether humans and other species possess an immutable life-span limit. We examined the maximum age at death in Sweden, which rose from about 101 years during the 1860s to about 108 years during the 1990s. The pace of increase was 0.44 years per decade before 1969 but accelerated to 1. 11 years per decade after that date. More than 70 percent of the rise in the maximum age at death from 1861 to 1999 is attributable to reductions in death rates above age 70. The rest are due to increased numbers of survivors to old age (both larger birth cohorts and increased survivorship from infancy to age 70). The more rapid rise in the maximum age since 1969 is due to the faster pace of old-age mortality decline during recent decades.     

Contribution of the Patagonia Icefields of South America to sea level rise

Digital elevation models of the Northern and Southern Patagonia Icefields of South America generated from the 2000 Shuttle Radar Topography Mission were compared with earlier cartography to estimate the volume change of the largest 63 glaciers. During the period 1968/1975-2000, these glaciers lost ice at a rate equivalent to a sea level rise of 0.042 +/- 0.002 millimeters per year. In the more recent years 1995-2000, average ice thinning rates have more than doubled to an equivalent sea level rise of 0.105 +/- 0.011 millimeters per year. The glaciers are thinning more quickly than can be explained by warmer air temperatures and decreased precipitation, and their contribution to sea level per unit area is larger than that of Alaska glaciers.     

乳源木莲毛竹混交林生长及土壤肥力研究

对杉木乳源木莲混交林砍伐杉木后形成的乳源木莲毛竹新林型的生长及土壤肥力状况进行研究,结果表明：乳源木莲毛竹枝叶分布层次明显,乳源木莲位于林分上层,林分结构合理,物种多样性较高;乳源木莲在2002-2012年的10年间能够保持较高生长量,有利于培育乳源木莲大径材;3种混交处理中,2002--2012年不同密度乳源木莲平均胸径、平均树高及单株立木材积生长量虽有差异,但差异较小;不同处理毛竹高径生长、产笋量和总产材量均存在差异,以RD处理、RC处理为好。乳源木莲毛竹混交林是拟自然更新的林型,能够改善林地土壤肥力,具有省工、适用、高效的经营特点,适宜在中亚热带林区高丘低山区域推广应用。     

浙江省农业气候资源时空变化特征研究

基于浙江省20个气象站点1961-2010年的逐日气象数据,分析了浙江省农业气候资源的时空分布特征和变化规律。结果表明: 气候变暖背景下,浙江省气温显著升高,≥10℃积温增加,气温稳定≥20℃终日延迟,作物气候生长期增长。热量资源要素在空间上具有一定的纬向分布特征。1961-2010年浙江省日照时数年际间呈显著下降趋势,其中以金衢盆地与台州玉环地区减少最为明显;年均降水量增加,降水天数减少,雨日平均降水强度年际间呈明显上升趋势,以舟山及嘉兴-宁波-台州沿海增速最大。沿海岛屿及金衢地区的参考作物蒸散量较高,丽水地区最少。1961-2010年全省平均湿润指数为164,整体上表现出增加趋势。本研究结果可为浙江省农业种植区划、生产布局调整及制定气候变化对策提供参考。     

莱芜市雷暴日的气候特征

深入了解莱芜市雷暴发生的气候规律以及演变趋势。利用1971~2000年莱芜市观测站资料,从雷暴的初、终日及绝对变率、雷暴日的年、月分布及变化趋势,以及雷暴初、终日的候平均气温阈值等方面进行了分析。随着年代的推移,初、终雷日的平均日期都更加趋于稳定,但终雷日的年际差异大;雷暴期相对稳定,年代际变化不大,总的趋势略有变短的倾向,年雷暴日数变化趋势是减少的,平均倾向率为每10年-2.5 d;雷暴的月分布基本呈单峰对称分布,7月份是雷暴的最为集中的1个月份;雷暴日与气侯平均气温的对应关系是,雷暴初日所对应的气侯平均气温为12℃,雷暴终日所对应的侯平均气温为14℃。从60年代到90年代,莱芜市平均初雷日、终雷日的变化不大。     

西施舌苗种的中间培育

利用平均壳长为24.0 mm、平均个体重为2.0 g的西施舌人工稚贝进行水泥池中间培育试验。结果显示:采用150％的日流水量并结合底质定期冲洗和更换等措施,经177 d培育,西施舌苗种平均壳长为40.0mm,平均个体重为9.8g,基本达到养成所需的规格标准。其壳长生长速度为0.09 mm/d,体重生长速度为0.04g/d。成活率为68％,高于潮间带围网培育和土池中间培育。     

西施舌苗种的中间培育

利用平均壳长为24.0 mm、平均个体重为2.0 g的西施舌人工稚贝进行水泥池中间培育试验。结果显示:采用150％的日流水量并结合底质定期冲洗和更换等措施,经177 d培育,西施舌苗种平均壳长为40.0mm,平均个体重为9.8g,基本达到养成所需的规格标准。其壳长生长速度为0.09 mm/d,体重生长速度为0.04g/d。成活率为68％,高于潮间带围网培育和土池中间培育。     

2种大径丛生竹林结构与生长特征

以撑绿竹和硬头黄竹为研究对象,开展了年龄、母竹留养、胸径结构和立竹密度对2种大径丛生竹生长影响的研究。结果表明:2种丛生竹结构特征对其出笋率、繁殖率和生物量增长率有重要的影响。其中,硬头黄竹退笋率随着年龄结构指标的增加而升高,繁殖率和生物量增长率随着年龄结构指标的升高而降低。撑绿竹在年龄结构0.75~1.25时,有较低的退笋率,较高的繁殖率和生物量增长率。硬头黄竹保留2~3株母竹可以取得较高的繁殖率和生物量增长率;撑绿竹保留2~5株母竹时,具有较高的繁殖率和生物量增长率。留养母竹的平均胸径并非越大越好,硬头黄竹母竹平均胸径为4.0 cm时,退笋率最低,繁殖率和生物量增长率最高;撑绿竹母竹平均胸径6.5 cm时,具有较低的退笋率,最高的繁殖率和生物量增长率。硬头黄竹在立竹密度6 000株·hm^-2、撑绿竹在立竹密度5 818株·hm^-2时,有最低的退笋率,最高的繁殖率和生物量增长率。2种大径丛生竹合理结构模式为:硬头黄竹2 000~3 000丛·hm^-2,留养母竹2~3株·丛^-1,年龄结构为0~0.49,母竹平均胸径4.0 cm;撑绿竹1 066~2 909丛·hm^-2留养母竹2~5株·丛^-1,年龄结构为0.75~1.25,母竹平均胸径6.5 cm。     

Interpretation of Climate Change and Agricultural Adaptations by Local Household Farmers: a Case Study at Bin County,Northeast China

Although climate change impacts and agricultural adaptations have been studied extensively, how smallholder farmers perceive climate change and adapt their agricultural activities is poorly understood. Survey-based data (presents farmers' personal perceptions and adaptations to climate change) associated with external biophysical-socioeconomic data (presents real-world climate change) were used to develop a farmer-centered framework to explore climate change impacts and agricultural adaptations at a local level. A case study at Bin County (1980s–2010s), Northeast China, suggested that increased annual average temperature (0.6°C per decade) and decreased annual precipitation (46 mm per decade, both from meteorological datasets) were correctly perceived by 76 and 66.9%, respectively, of farmers from the survey, and that a longer growing season was confirmed by 70% of them. These reasonably correct perceptions enabled local farmers to make appropriate adaptations to cope with climate change: Longer season alternative varieties were found for maize and rice, which led to a significant yield increase for both crops. The longer season also affected crop choice: More farmers selected maize instead of soybean, as implicated from survey results by a large increase in the maize growing area. Comparing warming-related factors, we found that precipitation and agricultural disasters were the least likely causes for farmers' agricultural decisions. As a result, crop and variety selection, rather than disaster prevention and infrastructure improvement, was the most common ways for farmers to adapt to the notable warming trend in the study region.     

基于结构优化的择伐对锐齿槲栎天然林结构与生长的影响

以甘肃小陇山林区锐齿槲栎天然林为对象,分析基于结构优化的择伐方式林分和未择伐林分的树种组成、生物多样性、径级结构、空间结构及生长之间的差异。结果表明：1)2008-2018年,择伐后的林分密度、平均胸径、平均树高、胸高断面积和树种数均呈现出先下降后增加的趋势,而Shannon-Wiener指数值和Pielou均匀度指数呈现增加的趋势;未择伐样地林分的密度、树种数、Shannon-Wiener指数值和Pielou均匀度指数呈现下降的趋势,而平均胸径、平均树高和断面积呈现增加的趋势;2)择伐样地和未择伐样地10 a间林木径级分布结构和林木的分布格局没有改变;而择伐样地的林木混交程度不断提高,未择伐样地的林木混交程度下降;3)2次调查间隔期内,择伐样地的胸径平均相对生长率分别较未择伐高18.4%和55.2%,胸高断面积相对生长率分别较未择伐高18.2%和54.4%;4)2008-2013年,择伐样地的进阶率和死亡率均高于未择伐样地,而在2013-2018年,择伐样地死亡率大幅下降。5)择伐样地和未择伐样地内各径级间的胸径平均生长率呈现随径级的增加而下降的趋势,且各径级间差异显著。择伐样地和未...     

Licking rates of albino rats

Local licking rates of eight albino rats, when the rats were given tap water at the end of a short runway after 23 hours of water deprivation, averaged a little over seven licks per second. Small variations within sessions were found, rates being slightly but consistently higher at the beginning than later on in sessions. Inter-session and individual differences were also observed, but were only of theorder of one lick per second. Within practical limits, it appears that licking rates of rats are constant.     

Recent plant diversity changes on Europe's mountain summits

In mountainous regions, climate warming is expected to shift species' ranges to higher altitudes. Evidence for such shifts is still mostly from revisitations of historical sites. We present recent (2001 to 2008) changes in vascular plant species richness observed in a standardized monitoring network across Europe's major mountain ranges. Species have moved upslope on average. However, these shifts had opposite effects on the summit floras' species richness in boreal-temperate mountain regions (+3.9 species on average) and Mediterranean mountain regions (-1.4 species), probably because recent climatic trends have decreased the availability of water in the European south. Because Mediterranean mountains are particularly rich in endemic species, a continuation of these trends might shrink the European mountain flora, despite an average increase in summit species richness across the region.