细鳞斜颌鲴(Plagiognathops microlepis)三个群体线粒体Cyt b基因的遗传变异

应用线粒体Cyt b基因序列分析法,研究了细鳞斜颌鲴三个群体(粱子湖群体19尾、龙窝湖群体19尾、淮河群体18尾)的遗传变异关系.结果显示:细鳞斜颌鲴线粒体Cyt b基因大小为1149 bp.三个群体共测出10种单倍型,116个核苷酸变异位点,多态位点百分率为10.09％,碱基组成中A+T含量(57％左右)明显高于G+...     

吉林省敦化市乡村人群气候变化感知的偏差及群体分异研究

通过问卷调查,具体分析了吉林省敦化市乡村人群对气候变化趋势和极端冷暖年的感知偏差及人群分异.发现乡村人群对气候变化趋势的感知与科学事实比较符合,由于对变暖转折年代更敏感,因而对变暖的确认度在一些时段与科学事实在变化程度或幅度上存在比较大的偏差.乡村人群对极端冷暖年不如对趋势感知的准确度高.经验积累影响乡村人群对气候变化...     

2002年1月份南极普里兹湾海域南极磷虾(Euphausia superba Dana)的丰度和种群结构研究

对2002年1月份在南极普里兹湾海域三条断面(68.5°E、70.5°E和73°E)用IKMT网采集的幼体后期南极磷虾(E.superba)的水平分布和种群结构进行了研究.南极磷虾主要位于64°S以南的海域,64°S以北磷虾数量很少.南极磷虾的平均丰度和生物量分别为68.85 ind·1 000 m-3和24.16 g...     

西藏灌木林种群分布格局

以西藏地区370个灌木林标准地调查数据为基础,计算了包括负二项式K值、方差/均值比率t值、丛生指标、平均拥挤指数、聚块性指标、扩散指标、格林指数和Cassic指标,定量测度了各标准地内种群的分布格局类型及集聚强度,分析了西藏灌木种群分布格局随海拔和坡度的变化特征。研究结果表明,1.西藏优势灌木种群分布格局包括集群分布和随机分布两种,其中,随机分布占60%;2.随着海拔及坡度的增加,西藏灌木种群均呈现由集群分布向随机分布变化的趋势,且大部分地区的灌木种群呈随机分布。     

汶川地震灾后重建地区的人口容量分析

Assessment of population carrying capacity is a key task in the reconstruction planning of areas struck by disasters, in which the precision of estimation is required. This study developed a decision-making model for estimating the population capacity of the involved townships and cities in the 2008 Wenchuan Earthquake based on the assessment of the suitability for reconstruction of the areas. Through analysis, arable land resources were argued to be the critical constraint of population capacity in these areas. Then, the spatial differentiations of the post-quake development conditions across different regions were analyzed with respect to their natural environments, socio-economic development and quake damages. The expected levels of urbanization, family incomes and income structures, output levels of land, and the reliance of agricultural population on arable land were estimated by different regions. With these parameters, the population capacities of the involved townships and cities in three scenarios were estimated. The total population capacity of the entire areas is abundant compared with the actual post-quake population; however, the status of over-population substantially varies across space. It was suggested to put the emphasis of post-quake resettlement policy on those counties where earthquake had been the main causes of over-population. In the Full Recovery Scenario, three mountain counties were identified including Wenchuan, Beichuan and Maoxian, with a total over-population of about 100,000 people.     

Genetic variability of half-smooth tongue sole Cynoglossus semilaevis populations using microsatellite markers

Ten highly variable microsatellite loci were performed in order to evaluate the genetic variability of wild and hatchery samples of half-smooth tongue sole Cynoglossus semilaevis. A group of 200 genotypes belonging to four wild samples, Laizhou (LZ), Weihai (WH), Qingdao (QD), Rizhao (RZ) and one hatchery sample, Mingbo (MB), were screened. All of the ten microsatellite loci screened in this study showed marked polymorphism. A total of 70 different alleles were observed over all loci. The number of alleles per locus ranged from 4.2 to 10.6. The average of expected and observed heterozygosity ranged from 0.67 to 0.82, and from 0.77 to 0.87, respectively. A total of 10, 16, 10, 11 and 5 unique alleles each were found in LZ, WH, QD, RZ and MB populations. The effective number of alleles varied from 2.87 for HSTS_7 to 6.83 for HSTS-h. The number of average genotypes ranged from 6.0 for HSTS_a to 15.4 for HSTS_h. As compared with the wild populations, the hatchery population, MB, showed significant genetic changes such as fewer alleles per locus (P <0.05), a smaller number of low frequency alleles (P <0.05), a small number of unique alleles and a small number of genotypes (P <0.05), all indicative of a reduction in genetic diversity.     

Effect of UV-B radiation on the population dynamics of the rotifer Brachionus urceus

The effect of UV-B radiation enhancement at experimental doses of 0.00,0.24,0.48,0.72,0.96,and 1.20 kJ/m 2 on the population dynamics of the rotifer Brachionus urceus feeding on the alga Chlorella sp.was studied under controlled laboratory conditions using clonal culture and life-table techniques.The results show that UV-B radiation treatment significantly shortened the survival time of the rotifer (P <0.05): The longest survival time (336 h) occurred in the control (0.00 kJ/m 2 ) while the shortest (222 h) occurred when exposed to the highest UV-B radiation treatment (1.20 kJ/m 2 ).The fecundity of the rotifer B.urceus was enhanced by the lower UV-B radiation treatment (0.24 and 0.48 kJ/m 2 ) but inhibited by the higher treatments (0.96 and 1.20 kJ/m 2 ).Life expectancy also was obviously affected by UV-B radiation (P <0.05).The highest life expectancy occurred in the control (0.00 kJ/m 2 ),and it became shorter with increasing doses of UV-B radiation.The resutls in the present study indicate that the life expectancy of the rotifer B.urceus can be used as an indicator for UV-B radiation enhancement.     

Spatial and temporal variability of deep-water algal assemblages in the Northwestern Mediterranean: The effects of an exceptional storm

There are deep-water populations of the endemic and threatened Mediterranean brown alga Cystoseira zosteroides in the Medes Islands Marine Reserve (NW Mediterranean). Here, the distribution, population structure, individual growth, mortality and recruitment rates of this species over two years are described in relation to the effects of an exceptional storm. We found a high spatial variability in the structure and dynamics of C. zosteroides populations at small geographical scales, suggesting that environmental factors acting at the population level display a key role in population size structure, mortality and recruitment. The elevated mortality rates recorded at some locations (almost 80%) is amongst the highest recorded for perennial algae as a consequence of a single storm, emphasizing the importance of episodic catastrophic events in the maintenance of these deep-water, slow-growing populations. These findings are of particular importance not only to fully understand the ecology of C. zosteroides, but also for its conservation.     

基于土地利用分类模型和重力模型耦合的人口分布模拟——以武汉市人口数据为例

将土地分类模型和重力模型耦合形成新模型,并以武汉市人口数据为例,用耦合后的新模型模生成武汉市人口网格数据.经数据验证表明,耦合后的新模型在计算精度方面有了较大的提高.     

基于区域差异类型的流动人口快速监测方法

改革开放以来,我国流动人口增长迅猛,但目前我国还缺乏对流动人口进行快速动态监测的有效方法与方案,特别是未能考虑我国流动人口的区域差异性,这已成为各级政府在进行科学决策和及时行动时的主要制约因素之一.本文尝试提出一种基于区域差异的我国流动人口快速监测方法,旨在应用流动人口区域差异的知识来改正流动人口监测样点网络布局方案和...