贵州青岩油杉种群年龄结构和动态的研究

研究了青岩油杉种群年龄结构的类型,动态规律及其与群落演替和环境之间的相互关系。结果表明,青岩油杉种群年龄结构有增长型,稳定型,始衰型和中衰型4类,存活曲线呈现凹型,凸型,间断型和散点型,随着群落的发育和演替,青岩油杉种群年龄结构的变化趋势为增长型→稳定型→衰退型→残留型。青岩油杉本身的生物生态学特性,群落内阔叶树的发展,地理隔离,人为干扰等是影响青岩油杉种群年龄结构及其动态变化的重要因素。     

南盘江流域铁坚油杉种群空间结构特征分析

铁坚油杉[Keteleeria davidiana(Bertr.)Beissn]为第三纪残遗裸子植物,被列为中国濒危树种,也是南盘江流域天然植被的重要组分。该研究于南盘江流域的广西雅长兰科植物国家级自然保护区内,采用典型样地法建立了1块面积为100m×80m的永久性标准固定样地,并运用林分空间结构参数二元分布(BDFSSSP)法分析铁坚油杉种群整体、大树(DBH≥15.79cm)和小树(5cm≤DHB15.79cm)的空间结构特征,以揭示南盘江流域内天然次生群落中铁坚油杉种群的结构多样性。结果表明:(1)铁坚油杉种群整体处于随机偏向均匀分布(W=0.468)状态,混交度适中(M=0.480),个体径阶分化明显(U=0.472)。(2)多数大树同时处于优势地位(U=0.204)和中度混交(M=0.436)状态,格局为随机分布(W=0.483)。(3)小树的分布格局和混交状态与种群整体相似,但大部分小树都是劣势木(U=0.75~1.00)。研究认为,南盘江流域铁坚油杉种群与其相邻种群之间的空间结构具有多样性,铁坚油杉种群内部的空间结构也具有多样性,暗示整个种群可能处于稳定状态。     

青岩油杉的核型分析

本文报道了青岩油杉（Ｋｅｔｅｌｅｒｉａｄａｖｉｄｉａｎａｖａｒ．ｃｈｉｅｎ－ｐｅｉ（Ｆｌｏｕｓ）ＣｈｅｎｇｅｔＬ．Ｋ．Ｆｕ）的染色体数目及核型,并与铁坚杉（Ｋ．ｄａｖｉｄｉａｎａ）和台湾油杉（Ｋ．ｄａｖｉｄｉａｎａｖａｒ．ｆｏｒｍｏｓａｎａ．）的核型进行了比较,讨论了三种油杉核型进化趋势,提出了铁坚杉种群的变异及进化趋势为南面的类型比北面的类型进化。     

中国油杉属植物的生态地理分布与系统演化

油杉属是东亚特有属,全世界油杉属共有12种2变种,中国有10种2变种,中国是油杉属的特有中心和分布中心。在地史时期,油杉属植物曾广泛分布于北半球的欧洲、北美和东亚。油杉属的现代分布有残余的特征,种类大多产于中国西南部和中部,种类数量由西向东逐渐递减。根据生态习性与分布区气候特征,中国主要油杉属植物的生态地理分布可分为:内陆型(东部温凉型、东部温暖型、西南季风型)、沿海型和岛屿型。湘黔桂地区是油杉属的现代分布中心和分化、发展中心。从染色体资料来看,其演化趋势为:江南油杉→矩鳞油杉→黄枝油杉→台湾油杉。结合地理分布,油杉属植物可能起源于中国西南,而后向东发展。从分布区南北向看,核型不对称性为:台湾油杉>青岩油杉>铁坚油杉,南部类型比北部类型要进化。     

珍稀植物蓑衣油杉濒危机制的初步研究

对云南特有珍稀植物蓑衣油杉（Keteleeria evelyniana var. pendula）的地理分布、自然生境概况及种群大小和年龄结构等种群特性进行研究,并掌握其形态特征、生长发育规律及种子散布和萌发等生物学特性。结果表明：蓑衣油杉在云南省华宁县主要分布于平地和吗哒等山区村寨周边地区;现有蓑衣油杉自然居群均为小种群,高群集分布,年龄结构不合理,种群处于相对不稳定阶段;虽然种子的种翅特征利于远距离传播,但可育种子产率极低,种子向幼苗难以转化使其有性生殖受阻,生活史趋于断裂,是最终导致其濒危的重要内因之一;自然生境的严重破坏、成年植株的过度采挖对蓑衣油杉种群的生存构成严重威胁,也是造成部分野生种群个体数量急剧减少的主要外因。本文还针对蓑衣油杉的濒危机制提出进行保护和利用的有效措施。     

北京东灵山海拔梯度上辽东栎种群结构和空间分布

种群年龄结构和空间分布格局是种群生态学的核心研究内容.为了阐明辽东栎种群海拔梯度分布特点,在北京东灵山地区辽东栎海拔分布范围(1000～1800m)内调查10条样带,研究种群大小级结构和空间分布的变异.种群的平均胸径在海拔梯度上表现出两段式的分布特征,海拔1480m为两段分布的分界点,在每一段内随海拔增加平均胸径也增加, 这反映了海拔梯度上种群的不同发育历史.种群密度、种群的聚集程度、种群的结构在海拔梯度上的分布特征都与平均胸径分布相似,种群密度和聚集程度与平均胸径为负相关系,其分布趋势与平均胸径相反.总体上,东灵山海拔梯度上辽东栎种群还是比较稳定的.辽东栎种群结构和空间分布在海拔梯度上的分布特征是种群发育历史、物种特性、环境、干扰等因素在海拔梯度上综合作用的结果.     

安徽黄山甜槠种群的结构与分布格局

通过对安徽黄山甜槠〔Ｃａｓｔａｎｏｐｓｉｓｅｙｒｅｉ（Ｃｈａｍｐ．ｅｘＢｅｎｔｈ．）Ｔｕｒｔｃｈ．〕种群大小级、存活曲线和分布格局的研究,探讨了该地区甜槠种群的结构和分布格局特征。结果表明甜槠种群具有增长型和平稳增长型的动态特征;同时,甜槠种群呈集聚分布格局,这可能与甜槠的生物学特性有关;但在不同发育阶段,种群分布格局不同,随着种群年龄的增加和径级的增大,分布格局由集聚分布变为随机分布,这可能主要由于种内和种间竞争引起的种群数量动态变化所致。或许这也是甜槠种群的生存策略之一。     

大盘山自然保护区香果树种群结构与分布格局

在大盘山自然保护区设置了4个有代表性的样地,应用相邻格子法进行调查获得野外资料。对香果树种群进行统计,绘制径级结构图和高度结构图、编制种群的特定时间生命表;应用理论分布模型和聚集强度指数进行种群分布格局分析。结果表明：香果树种群结构呈纺锤型,幼苗严重不足,种群有衰退的趋势;其更新是以无性繁殖为主;种群格局整体上呈集群分布,但在不同发育阶段,分布格局有所差异：幼树阶段一般为集群分布,中树和大树向随机分布发展,这种分布格局变化与其生物学和生态学特性密切相关;其格局规模在介于8S和32S之间。分析认为,香果树的种群结构和分布格局受到了多种因素的影响,如群落区域小生境、香果树生物学特征以及人为干扰外等,在以上各因素的综合作用下,使得该种群形成典型的小种群。     

祁连山北坡高寒草地狼毒种群格局

在祁连山北坡高寒退化草地,采用空间序列代替时间序列与点格局相结合的分析方法,研究了小尺度上狼毒种群的组成特征和分布格局.结果表明:伴随狼毒分盖度的增加,狼毒植株数总体上呈现先增大后减小的分布规律;幼株分布格局由随机分布向聚集分布过渡,聚集强度表现出先增强后减弱的规律,成株分布格局基本表现为随机分布;狼毒分盖度较低时,不同大小级狼毒种群在0～100 cm尺度上均表现为随机分布,狼毒分盖度较高时,随着种群的发育,分布格局由聚集分布向随机分布过渡.种群的分布格局与种群的扩散阶段存在密切的关系,狼毒种群通过斑块合并、斑块吞并以及竞争作用和协同作用的相互转化实现种群的扩散.     

滇中次生常绿阔叶林优势树种的空间格局

采用Ripley的点格局分析方法对滇中次生常绿阔叶林中优势种滇青冈(Cyclobalanopsis glaucoides)和滇油杉(Keteleeria evelyniana)的分布格局以及不同径级分株之间的相互关系进行了分析.结果表明:(1)总体来看,两个优势物种各径级株数分布较均匀,二者的增长处于稳定期.(2)两个优势物种在总体上及不同径级阶段主要呈聚集分布.随径级的增加,滇青冈种群的聚集程度逐渐降低,而滇油杉种群的聚集程度呈现降低-增加-降低的趋势.两个优势物种的幼树、中树和大树主要呈空间正相关或无空间关联性.(3)两优势种群不同径级之间在不同尺度下基本上无关联性,这可能是二者的生存策略存在较大差异而造成的.研究表明,在滇中森林恢复过程中,应结合植物种群的密度控制及种间相互作用来构建群落的结构.     

Population proteomics: an emerging discipline to study metapopulation ecology

Proteomics research has developed until recently in a relative isolation from other fast-moving disciplines such as ecology and evolution. This is unfortunate since applying proteomics to these disciplines has apparently the potential to open new perspectives. The huge majority of species indeed exhibit over their entire geographic range a metapopulation structure, occupying habitats that are fragmented and heterogeneous in space and/or through time. Traditionally, population genetics is the main tool used to studying metatopulations, as it describes the spatial structure of populations and the level of gene flow between them. In this Viewpoint, we present the reasons why we think that proteomics, because of the level of integration it promotes, has the potential to resolve interesting issues specific to metapopulation biology and adaptive processes.     

A general measure of human population growth regulation

A general measure relating the relative effects of mortality and fertility in damping population growth has been derived from stable population theory. This measure, called the Index of Growth Regulation, can be calculated from a life table and a fertility schedule. It is a single number which integrates the fertility and mortality aspects of a population. It has intuitive meaning, and can be related to social aspects of the population. It can be used to compare any two populations, and for this purpose it has advantages over traditional comparative statistics such as life expectancy, which consider only mortality. By selecting life tables representing general stages of human cultural evolution, it has been shown that hunting-gathering populations were regulated more by mortality than by fertility factors. That is, more growth which could have occurred did not occur due to the incidence of mortality than to the incidence of infecundity. The two forces were of about equal weight before the industrial revolution, and fertility has had a predominant role in population regulation since the beginning of industrialization.     

黄腹角雉的种群数量及其结构研究

1983—1986年在浙江省乌岩岭自然保护区,应用标图法和线路统计法,对野生黄腹角雉种群、数量进行了统计分析。结果表明冬季种群约50只。种群数量有明显的季节变动:繁殖后期数量增加,秋末冬初开始明显下降。黄腹角雉繁殖力低,卵的损失率高,使种群数量上升十分缓慢。成体性比接近1:1,在各样区之间略有差异。在性比偏离1:1较大的样区,亚成体比例较高。     

Evidence of population structuring following population genetic analyses of Fasciola hepatica from Argentina

Fasciola hepatica, the liver fluke, is a trematode parasite that causes disease of economic importance in livestock. As a zoonosis this parasite also poses a risk to human health in areas where it is endemic. Population genetic studies can reveal the mechanisms responsible for genetic structuring (non-panmixia) within parasite populations and provide valuable insights into population dynamics, which in turn enables theoretical predictions of evolutionary dynamics such as the evolution of drug resistance. Here we genotyped 320 F. hepatica collected from 14 definitive hosts from four provinces in Argentina. STRUCTURE analysis indicated three population clusters, and principal coordinate analysis confirmed this, showing population clustering across provinces. Similarly, pairwise F_ST values amongst all four provinces were significant, with standardised pairwise F_ST (F′_ST) ranging from 0.0754 to 0.6327. Therefore, population genetic structure was evident across these four provinces in Argentina. However, there was no evidence of deviation from Hardy–Weinberg equilibrium, so it appears that within these sub-populations there is largely random mating. We identified 263 unique genotypes, which gave a clonal diversity of 82%. Parasites with identical genotypes, clones, accounted for 26.6% of the parasites studied and were found in 12 of the 14 hosts studied, suggesting some clonemate transmission.     

Synchronous dynamics and rates of extinction in spatially structured populations

We explore extinction rates using a spatially arranged set of subpopulations obeying Ricker dynamics. The population system is subjected to dispersal of individuals among the subpopulations as well as to local and global disturbances. We observe a tight positive correlation between global extinction rate and the level of synchrony in dynamics among thesubpopulations. Global disturbances and to a lesser extent, migration, are capable of synchronizing the temporal dynamics of the subpopulations over a rather wide span of the population growth rate r. Local noise decreases synchrony, as does increasing distance among the subpopulations. Synchrony also levels off with increasing r: in the chaotic region, subpopulations almost invariably behave asynchronously. We conclude that it is asynchrony that reduces the probability of global extinctions, not chaos as such: chaos is a special case only. The relationship between global extinction rate, synchronous dynamics and population growth rate is robust to changes in dispersal rates and ranges.     

武夷山木荷种群结构和动态的研究

 本文采用“空间序列代替时间变化”的方法,对武夷山区常绿阔叶林演替过程中木荷种群动态规律进行了研究,结果表明,在木荷种群侵入黄山松幼林向木荷林以及成熟木荷、甜槠、青冈林的发展过程中,种群结构由增长型→稳定型→成熟型→衰退型,空间分布格局由随机型趋于集群分布,种群密度呈现负增长;在成熟木荷、甜槠、青冈林中,由于种间和种内竞争的影响以及林窗效应,木荷种群结构和密度有一个波动性的变化过程,在这一变化过程中,木荷种群仍趋于集群分布。此外,对成熟木荷、甜槠、青冈林中木荷种群不同大小级的分布格局动态进行了研究,表明其幼苗、幼树和中树等级的个体均呈集群分布,而大树等级的个体呈随机分布。根据上述研究结果,对木荷种群动态机制作了探讨。     

中国兽类种群生态学研究进展与展望

兽类种群生态学是现代生态学的核心研究内容。Charles Sutherland Elton在20世纪20年代发现小哺乳动物种群波动现象,标志着现代种群生态学研究的开始。什么因素调节种群波动的问题一直是现代种群生态学领域的研究热点。我国兽类种群生态学研究始于20世纪50年代,迄今,已走过了70年的发展历程,并取得了重要成果。本综述基于20世纪50年代以来我国学者在主流中文期刊及科学引文索引（Science Citation Index,简称SCI）刊物发表的历史文献,分别从种群波动格局、种群统计参数变化、种群内部和外部调节等不同层面评述了我国在鼠类和大型兽类种群生态学的研究历程及现状,同时探讨了未来的研究方向。     

Comparing the genetic diversity and structure of indigenous Korean and Chinese populations of Laodelphax striatellus Fallén using mitochondrial haplotypes

The small brown planthopper, Laodelphax striatellus Fallén, is a major migratory pest from China to Korea and transmits viral diseases of rice plants. In this study, we compared the genetic structures of overwintered indigenous Korean and Chinese populations. The eight Korean populations consisted of 33 haplotypes, and 16 of these were newly identified. The genetic diversity of the Korean population revealed high haplotype diversity (Hd) and low nucleotide diversity (π) of 0.86 ± 0.017 and 0.0024 ± 0.0001 on average, respectively. These values for the Chinese population were Hd = 0.92 ± 0.016 and π = 0.0026 ± 0.0002. Overall, genetic distances by pairwise F_ST were generally low, ranging from ? 0.022 to 0.089. Moreover, the Korean population revealed its ongoing population expansion by showing negative values in the neutrality test (Tajima's D = ? 1.4, Fu's Fs = ? 15.8) and a unimodal pattern in the mismatch distribution analysis. The genetic structures and population relationships were determined using 8 indigenous Korean and 30 Chinese populations by Bayesian approaches and population tree construction, respectively. The genetic structure was inferred as five (K = 5), and all indigenous Korean populations as well as 10 Chinese populations from the Shanghai city, Anhui, Henan, Jiangsu, Liaoning, Shandong, and Zhejiang provinces were grouped into ‘G3’. These results provide partial support for unidirectional gene flow by migratory Chinese populations into Korea. Further analysis conducted using specimens from China and Korea collected in similar periods is necessary to clarify the migration population's origin and its effect on the genetic structure of the indigenous populations.