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1.
Few studies exist on phenotypic composition of the sable populations in the Russian Far East, China and Japan. We present new data on the morphological diversification of sable for 20 mainland and island populations in an effort to document existing variability and produce baseline data that would be useful in constructing phylogenies for this species. Сlinal variability of skull size, cranial phene, foramen in fossa condyloidei inferior (FFCI), and fur coloration is revealed. One district, Central Sikhote-Alin, is characterized by sables with the minimum cranial size and the maximum phene expression. The area between the Uda River and Goryun and Amgun rivers is inhabited by sables of the darkest fur coloration. Moving out from those areas in all directions we were detected a trend of increasing skull size, reduction of cranial phene, and decreasing color intensity of fur. The skull size of sable is consistent with Bergmann’s rule. Special attention paid to the particular morphological properties of insular populations in specific climatic conditions and under isolation from the continent. They are characterized by minimal expression phene FFCI (Bolshoi Shantar, Iturup, and Hokkaido islands) and larger skull size, especially in sable of Kamchatka Peninsula. It is hypothesized that the area of the lower Amur Basin was a source of sable postglacial dispersal on the Eurasian Continent.  相似文献   

2.
Larval amphibians are particularly likely to encounter variation in rearing temperature and resource availability due to variation in aquatic breeding habitats. In this study, plasticity in growth rates, larval mass, larval period, and size at metamorphosis were examined in Rana kukunoris Nikolskii, 1918 under different combinations of temperature and food level. Larval period and larval body mass was sensitive to food level, and varied with temperature. Tadpoles metamorphosed at an older age at low temperature than those reared at warm temperature. Food level was a significant affect on larval period at low temperature, but not at warm temperature. Mass was heavier for tadpoles reared at low temperatures than those reared at warm temperatures. The effect of food level depended on temperature, because larvae reared at low temperature that were offered a high food level achieved a larger size than larvae offered a low food level, but this did not occur at warm temperature. Therefore, we suggest that high food availability at low temperature prolonged developmental periods, thus larvae are larger as metamorphs than those reared at warm temperatures.  相似文献   

3.
Future climate conditions for the Mediterranean region based on an ensemble of 16 Global Climate Models are expressed and mapped using three approaches, giving special attention to the intermodel uncertainty. (1) The scenarios of mean seasonal temperature and precipitation agree with the projections published previously by other authors. The results show an increase in temperature in all seasons and for all parts of the Mediterranean with good intermodel agreement. Precipitation is projected to decrease in all parts and all seasons (most significantly in summer) except for the northernmost parts in winter. The intermodel agreement for the precipitation changes is lower than for temperature. (2) Changes in drought conditions are represented using the Palmer Drought Severity Index and its intermediate Z-index product. The results indicate a significant decrease in soil moisture in all seasons, with the most significant decrease occurring in summer. The displayed changes exhibit high intermodel agreement. (3) The climate change scenarios are defined in terms of the changes in parameters of the stochastic daily weather generator calibrated with the modeled daily data; the emphasis is put on the parameters, which affect the diurnal and interdiurnal variability in weather series. These scenarios indicate a trend toward more extreme weather in the Mediterranean. Temperature maxima will increase not only because of an overall rise in temperature means, but partly (in some areas) because of increases in temperature variability and daily temperature range. Increased mean daily precipitation sums on wet days occurring in some seasons, and some parts of the Mediterranean may imply higher daily precipitation extremes, and decreased probability of wet day occurrence will imply longer drought spells all across the Mediterranean.  相似文献   

4.
To assess the stability of individual development of the pygmy wood mouse (Apodemus uralensis) in mountain areas with different ecogeographic conditions, the levels of fluctuating asymmetry in a series of skull phenes have been evaluated in ten samples from the Western and Central Caucasus. Attention has been focused on the influence of change in environmental conditions along the elevational gradient and the impact of some anthropogenic factors. An increase in the index of fluctuation asymmetry FAnm has been revealed in samples from populations exposed to pollutants and, in the absence of pollution, from areas where the average annual temperature drops below 5°С (mid-mountain regions). Instability of skull development observed in A. uralensis from the foothills of the Western Caucasus may be a consequence of competitive relationships with the Black Sea field mouse A. ponticus, a sympatric species that inhabits the same biotopes as does A. uralensis but numerically prevails over it.  相似文献   

5.
Based on 30-year collection of red fox skulls from the Middle Urals, the north of Kurgan oblast, and the south of Tyumen oblast, an increase in average values of craniometrics characters has been revealed in both young and adult animals of both sexes. This increase shows a weak but statistically significant correlation with annual average temperature. The rates of increase in different characters are not equal.  相似文献   

6.
基于BNU-ESM模式的地球工程(G4实验)和非地球工程(RCP4.5)情景下的2010~2099年中国日值平均气温数据,采用多种数理统计方法,诊断地球工程实施对中国不同区域气温变化的影响。结果表明:(1)2010~2099年两种情景下中国不同区域的年平均气温均呈增加趋势。地球工程实施的2020~2069年,地球工程有效降低了中国不同区域年平均气温的增加趋势。(2)地球工程实施的2020~2069年,中国多数地区的年平均气温降温幅度超过了1.0℃,对《巴黎协定》制定的1.5℃温控目标的实现具有积极推动作用。且地球工程实施结束后的2070~2099年中国不同区域的气温并未出现报复性反弹。(3)2010~2099年两种情景下的中国不同区域年平均气温均发生了突变。地球工程的实施使得中国绝大多数地区的气温突变推迟了11~19 a。(4)基于交叉小波变换的中国不同区域年平均气温序列的高能量波谱区振荡表明,两种情景下的高频年均气温在1~4 a尺度上存在反位相关系,表明地球工程短期内改变了气温变化方向。基于小波相干的中国不同区域年平均气温序列的低能量波谱区振荡表明,地球工程并未从根本改变气温长期变化趋势。  相似文献   

7.
The effect of environmental factors affecting the population dynamic of phytoplankton population was studied seasonally in a closed freshwater pond with the natural water of Lake Kasumigaura, Japan. The predominant phytoplankton species in the pond were classified as Oscillatoria tenuis, Synedra ulna, Chlamydomonas cingulata and Cyclotella kutzingiana, with dominant species of Melosira italica, Synechococcus sp. and Cryptomonas ovata. The most important limiting factor for filament length and cell size of most of the phytoplankton community was temperature. Availability of most nutrients had profound effects on the phytoplankton growth as nonlimiting factors. Based on our results, it is suggested that cell cycle progression was also temporally regulated by a multiplicity of external factors such as temperature, nutrients, dissolved oxygen (DO) and pH. At high pH and high temperature, consistent increase of cell division of some phytoplanketers such as Synedra, Cyclotella, Chlamydomonas and Melosira occurs, and there also may be species-specific responses for other species of phytoplankters. In addition, the cell divisions of phytoplankters are differentially regulated in different phytoplankton species.  相似文献   

8.
Leaf size, shape, and parameters of venation in Betula pendula and B. pubescens have been studied along a 1600-km latitudinal zonal transect in the Urals and Western Siberia. The results show that leaf size and venation density depend on the geographic location of population, with these parameters in the two species changing in opposite directions along the transect. In its northern part (forest tundra-southern taiga), B. pubescens shows a positive correlation of leaf area with long-term-average air temperature, while this correlation in B. pendula is negative. In the southern part, correlations of leaf size with long-term average precipitation in the two species are also opposite in sign. Parameters of leaf shape in both species depend mainly on weather conditions in the current year rather than on long-term average climatic parameters. The conclusion is drawn that B. pendula and B. pubescens have different mechanisms of structural adaptation of leaves to climate and weather conditions that are based on changes in leaf size and shape.  相似文献   

9.
There is an increasing number of “mass events” in mainland China. My study extends the current studies to the context of China and tries to examine the potential impacts of climate changes on human conflicts in China. The results suggest a strong linkage between the deviation of monthly mean temperature from the historical mean and the number of mass events in a province. If the current trend of warming persists, in the next 6–8 decades, the number of mass events in China will increase by over 8.8%.  相似文献   

10.
This study deals with the question of how winegrowing in Spain may be altered by anthropogenic climate change. The present state and expected future development of three bioclimatic indices relevant for winegrowing were assessed by observation, and four regional climate models from the EU-ENSEMBLES project were investigated. When comparing the 2061–2090 scenario period to the 1961–1990 reference period, the models unanimously indicate a significant increase in the mean of the two considered thermal indices over the entire study region. However, for the index based on temperature and precipitation, the models are heavily biased when verified against observations and generally disagree on the size of the projected future change. For this index, unanimous model agreement was only found for northwestern Spain where all models indicated a significant decrease in the mean. From these results, regional climate change is expected to negatively affect the quality of wine in the growing regions of central and southern Spain, and the Ebro valley, whereas positive effects should be expected in the northwest. No significant changes in the risk of mildew infestation are to be expected except for the northwest, where this risk is projected to decrease.  相似文献   

11.
In Yakutia, the brown bear inhabits the forest and forest-tundra zones. Compared to bears from other regions of Russia, Yakutian bears have slightly smaller body and skull sizes and are mainly herbivorous, with their wood spectrum being relatively narrow. Their fecundity averages 1.68 cubs per parous female. The bears make their dens at a depth reaching 2.5–3 m. The denning period begins early and is 195–210 days long. An electroencephalographic analysis of the effect of a 1–10 kDa peptide fraction from the bear brain on Wistar rats has shown that wintering bears are in the state of sleep, or “superficial hibernation.”  相似文献   

12.
Phenotypic variation in the widespread Siberian and Mongolian butterfly species Coenonympha amaryllis (Stoll, 1782), an indicator of undisturbed steppe communities, is analyzed. It is shown that its size variation is influenced by a complex of climatic factors, the most important of them being the average starting date of the frost-free period and average annual temperature in the region. Longitude-dependent variation in size is described by a “sawtooth curve” characteristic of species with changing voltinism.  相似文献   

13.
Competition between several cladoceran species has been studied with the use of simulation. The results have demonstrated that, in most cases, one or two species survive. Under conditions of the minimum food supply, the most competitive species have the selective advantage. With an increase in food supply, the survival of low-competitive species was observed more often. The mean body size of surviving species increases with an increase in food reproduction.  相似文献   

14.
利用1960~2010年重庆34个气象台站的气象资料,运用统计学方法、IDW插值法分析了重庆市全年及温度生长期的平均气温、≥10℃积温、降水量和日照时数等农业气象资源的时空变化特征。结果表明:研究期内,重庆市年平均气温总体呈缓慢上升趋势,增幅为037℃/10 a,温度生长期内≥10℃积温亦呈上升趋势,平均增速为1162℃/10 a,以东北部偏东地区增加趋势尤为明显;全市年降水量和温度生长期内降水量均呈东南向西北逐渐减少态势,平均下降速率分别为1972 mm/10 a和1185 mm/10 a;约90%的站点年均日照时数和温度生长期内日照时数均呈减少趋势,且西部减少的趋势较东部更加显著  相似文献   

15.
It is possible to estimate radon exposure to man retrospectively by the in vivo measurement of the decay product (210)Pb, which accumulates in the bones. For in vivo methods, knowledge of the distribution of (210)Pb in the skeleton is needed to determine the optimal site for measurement, the skull or the knee. In this study the activity of (210)Pb in a variety of bone samples from 3 individuals have been measured in vitro using underground gamma-ray spectrometry. The individuals were unlikely to have had elevated intakes of Rn. These measurements give baseline data on the bone massic activity of (210)Pb. They show that the massic activity is similar for each of these people and there are similar massic activities of (210)Pb in the skull and the knee of the 2 individuals for which the skull was measured. Additionally for 2 of the individuals trabecular and cortical bone were separated and massic activities were found to be strongly correlated indicating that the (210)Pb is associated with the hydroxyapatite.  相似文献   

16.
为进一步了解安徽省双季稻安全生产界限温度日期变化特征,以安徽省22个双季稻生产市(县)气象观测站1961~2017年日平均气温为基础,采用线性趋势法和Mann-Kendall非参数检验法,分析了安徽省沿江双季稻区早稻安全播种期、移栽期和晚稻安全齐穗期、成熟期及双季稻安全生长期日数、积温变化特征。结果表明:近50年安徽省沿江地区早稻安全播种期呈显著提前趋势(P<0.05),其中薄膜育秧平均提前1.8 d/10 a,露天育秧提前1.5 d/10 a;早稻安全移栽期呈极显著提前趋势(P<0.01),平均提前2.5 d/10 a;晚稻安全齐穗期、成熟期推迟趋势不显著(P>0.05);安全生产期日数和积温增加显著(P<0.01),平均增幅分别为2.6和62.7℃·d/10 a。安全生产期日数和积温增加对双季稻种植和品种选择具有积极作用,但晚稻采用直播、机插等栽种方式有遭遇低温冷害的风险。  相似文献   

17.
The gyrfalcon in the Yamal Peninsula nests mostly on trees. The average brood size in this species decreased from 3.1 nestlings per active nest (n = 28) between 1973 and 1989 to 2.2 (n = 22) between 1998 and 2008. This decrease is probably explained by switching to the habit of using mostly smaller nests (built by the rough-legged buzzard, raven, or hooded crow) instead of large nests built by the white-tailed eagle. The survival rate of gyrfalcon nestlings in smaller nests is considerably lower: the average brood size is only 1.6 (n = 12), compared to 2.5 (n = 20) in medium-sized and 3.0 (n = 34) in large nests. The possible role of increase in snow cover density caused by climate warming in making large nests less accessible to the gyrfalcon is discussed.  相似文献   

18.
Permafrost wetlands are one of the most sensitive plant communities in response to global warming. Global warming could induce natural plant communities to shift into cooler climate zones, or extirpate. To understand how plant communities in permafrost wetlands are affected by global warming, we examined the patterns of plant species diversity in the 24 permafrost wetlands in the Great Hing’an Mountains along a latitudinal gradient. This gradient was characterized by a northward decline in mean annual temperature (Δ = 3.5°C) and mean annual precipitation (Δ = 38.7 mm). Our results indicated that latitudinal patterns in species diversity existed in the permafrost wetlands. The numbers of family, genus and species, the Gleason index and Shannon-Wiener index for shrubs decreased linearly with decreasing latitude, but increased for herbaceous plants. The latitudinal patterns in species diversity had influenced strongly by temperature. Simple linear regression yielded about 2 decreases in shrub number and 9 increases in herbaceous species number with an increase of mean annual temperature by 1°C, with 0.33 decreases in shrub diversity and 0.29 increases in herbaceous species diversity. If temperature warms 3.7°C by 2100, herbaceous plants might increase in the permafrost wetlands, with species number increasing 48% or 6 times and species diversity increasing 40% or 2 times; and some shrub species might decrease and even disappear in part of the areas with lower latitude, with species number decreasing 50–100% and species diversity decreasing 69–100%. The permafrost wetlands in the Great Hing’an Mountains might continue degenerating and shift northward with global warming over the next century.  相似文献   

19.
Populations from different environmental habitats indicate variation in life history traits and these differences are mostly related to longevity, age and size at maturity. In this study, age structure, longevity, survivorship and sexual size dimorphism of Near Eastern fire salamander (Salamandra infraimmaculata) were assessed by means of skeletochronological analysis. Maximum lifespan was recorded to be twelve years in females and eleven years in males and age at maturity was estimated as three and four years for both sexes. Females had significantly larger SVL than that of males, while age structure and mean age did not differ between sexes. Age and body size were positively correlated with each other for both females and males. Since the populations of the Near Eastern fire salamander in Turkey are in decline, the present study which provides preliminary data on life history traits of this species could be helpful for future biological studies.  相似文献   

20.
基于国家气候中心提供的2000站逐日地面气温资料,运用高温日数、平均高温度数以及日最高气温这3个指标刻画1961~2015年长江三角洲(简称长三角)地区的夏季高温时空演变,并在对上述指标进行突变检测的基础上,比较其转折前后的夏季高温空间分布特征。结果表明:(1)长三角夏季高温指标在2000年左右存在气候突变,2000年以后夏季高温日数和强度出现显著上升;(2)较之2000年前,2000年后的高温度日数的分布型更为集中,前三个EOF模态解释方差均有所上升,EOF1分布较为相似,EOF2不再呈现带状分布,EOF3局地性特征减弱;(3)2000年后的长三角夏季高温日数增长明显,年平均高温日数达到20 d以上的区域向北扩展至32°N附近,向东扩展至往浙江东部沿海;年平均高温日数达到30 d以上的区域更扩展至31°N以南、121°E以西所有地区,高温日数最多可达近50 d;(4)2000年后高温度日数呈明显增加,从2000年前的10~20℃·d增加到20~50℃·d,以30~31°N一带增长最为显著。浙江中部和南部地区在2000年后高温日数增长明显,但高温强度增长较弱;安徽东部、浙江北部和上海地区高温日数和强度均增长明显。  相似文献   

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