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1.
We present a general framework for modelling adaptive trait dynamics in which we integrate various concepts and techniques from modern ESS-theory. The concept of evolutionarily singular strategies is introduced as a generalization of the ESS-concept. We give a full classification of the singular strategies in terms of ESS-stability, convergence stability, the ability of the singular strategy to invade other populations if initially rare itself, and the possibility of protected dimorphisms occurring within the singular strategy's neighbourhood. Of particular interest is a type of singular strategy that is an evolutionary attractor from a great distance, but once in its neighbourhood a population becomes dimorphic and undergoes disruptive selection leading to evolutionary branching. Modelling the adaptive growth and branching of the evolutionary tree can thus be considered as a major application of the framework. A haploid version of Levene's soft selection model is developed as a specific example to demonstrate evolutionary dynamics and branching in monomorphic and polymorphic populations. 相似文献
2.
Combined use of leaf size and economics traits allows direct comparison of hydrophyte and terrestrial herbaceous adaptive strategies 总被引:1,自引:0,他引:1
Background and Aims
Hydrophytes generally exhibit highly acquisitive leaf economics. However, a range of growth forms is evident, from small, free-floating and rapidly growing Lemniden to large, broad-leaved Nymphaeiden, denoting variability in adaptive strategies. Traits used to classify adaptive strategies in terrestrial species, such as canopy height, are not applicable to hydrophytes. We hypothesize that hydrophyte leaf size traits and economics exhibit sufficient overlap with terrestrial species to allow a common classification of plant functional types, sensu Grime''s CSR theory.Methods
Leaf morpho-functional traits were measured for 61 species from 47 water bodies in lowland continental, sub-alpine and alpine bioclimatic zones in southern Europe and compared against the full leaf economics spectrum and leaf size range of terrestrial herbs, and between hydrophyte growth forms.Key Results
Hydrophytes differed in the ranges and mean values of traits compared with herbs, but principal components analysis (PCA) demonstrated that both groups shared axes of trait variability: PCA1 encompassed size variation (area and mass), and PCA2 ranged from relatively dense, carbon-rich leaves to nitrogen-rich leaves of high specific leaf area (SLA). Most growth forms exhibited trait syndromes directly equivalent to herbs classified as R adapted, although Nymphaeiden ranged between C and SR adaptation.Conclusions
Our findings support the hypothesis that hydrophyte adaptive strategy variation reflects fundamental trade-offs in economics and size that govern all plants, and that hydrophyte adaptive strategies can be directly compared with terrestrial species by combining leaf economics and size traits. 相似文献3.
The present work is the outcome of both biological anthropology and prehistoric research. The theses of cultural ecology became
the basis for research on biological and cultural changes of human groups. More than 80 human bones series from the Neolithic
cultures of Central Europe have been used here. The role of economic processes (ie: the additional role of cultural system)
within the general picture of a given system has been stressed here. As far as anthropological analysis is concerned, the
estimation of biological population state and dynamics and the morphological characteristics including the skull morphology,
have been used in the present work.
In order to observe the mutual interrelations 2 developmental systems for 2 cultural units, the Linear Pottery Culture and
the Corded Ware Culture have been constructed. As we think there 2 systems present 2 different adaptational strategies in
the Neolithic in Central Europe. The adaptational strategy is understood as socially generated concept of the creation of
man-and-environment relation. 相似文献
4.
Summary The relationship between ichthyotoxicity and predation-related defensive functional morphology was examined in alcyonacean soft corals of the central and northern regions of the Great Barrier Reef (GBR), Australia. Approximately 170 specimens were assessed encompassing a number of genera within three families: 1) the Alcyoniidae (Lobophytum, Sarcophytum, Sinularia, Cladiella, Parerythropodium, and Alcyonium); 2) Neptheidae (Lemnalia, Paralemnalia, Capnella, Lithophyton, Nephthea, Dendronephthya, Scleronephthya, and Stereonephthya), and 3) Xeniidae (Anthelia, Efflatounaria, Cespitularia, Heteroxenia, and Xenia). Ichthyotoxicity data were derived from earlier studies which used Gambusia affinis Baird and Girard (Vertebrata, Pisces) as a test organism. These data were compared to morphological data collected from specimens in the field and laboratory. Three sets of statistical analyses were performed, each considering a progressively narrower group of taxa. The first included 68 specimens and considered 16 morphological characters in each, falling into the general categories of gross colony form, colony texture, presence of mucus, colony color, polyp retractility, and sclerite morphology and distribution. These were tested for independence against ichthyotoxicity data. The second set of analyses involved a more restricted morphological data set derived from 28 species of Sinularia in combination with 28 species within the Nephtheidae, comparing them to their respective toxicity ranks. The third analysis considered the previous two taxonomic groups separately in relation to their toxicity levels.The attempt to consider many morphological characters in a taxonomically diverse collection did not reveal any general association in the Alcyonacea between defensive morphology and toxicity, and those associations which did emerge were clearly erroneous. The second analysis, considering only Sinularia spp. and nephtheids, demonstrated a negative association between ichthyotoxicity and the morphological characters of a) polypary armament, b) microarmament of the individual polyp, and c) strong mineralization of the coenenchyme. The third analysis revealed that the negative association found between toxicity and the first two characters was derived entirely from the nephtheids while the association detected between toxicity and the third character was restricted to Sinularia. It is concluded that a relationship between toxicity and morphology can be demonstrated, but it is heavily dependent upon which specific morphological characters are being considered and at what level of taxonomic resolution the analysis is being performed. An approach utilizing many characters over many taxa is unlikely to yield significant, reliable, or meaningful results.Australian Institute of Marine Science Contribution Number 383 相似文献
5.
In two-stage adaptive treatment strategies, patients receivean induction treatment followed by a maintenance therapy, giventhat the patient responded to the induction treatment they received.To test for a difference in the effects of different inductionand maintenance treatment combinations, a modified supremumweighted log-rank test is proposed. The test is applied to adataset from a two-stage randomized trial and the results arecompared to those obtained using a standard weighted log-ranktest. A sample-size formula is proposed based on the limitingdistribution of the supremum weighted log-rank statistic. Thesample-size formula reduces to Eng and Kosorok's sample-sizeformula for a two-sample supremum log-rank test when there isno second randomization. Monte Carlo studies show that the proposedtest provides sample sizes that are close to those obtainedby standard weighted log-rank test under a proportional hazardsalternative. However, the proposed test is more powerful thanthe standard weighted log-rank test under non-proportional hazardsalternatives. 相似文献
6.
Julie Reveillaud Andre Freiwald David Van Rooij Erwan Le Guilloux Alvaro Altuna Anneleen Foubert Ann Vanreusel Karine Olu-Le Roy Jean-Pierre Henriet 《Facies》2008,54(3):317-331
Studies on the distribution of scleractinian corals in the Bay of Biscay were relatively numerous during the nineteenth and the first half of the twentieth century. Yet, recent reports are scattered, sometimes unpublished, and therefore knowledge about the current coral occurrence in the area is limited. This study aims at compiling the available historical and more recently collected information on the occurrence of scleractinian corals in the Bay of Biscay. Data from two recent cruises are included and compared with previous explored coral sites from as early as 1830 up to 1995. A database of 347 records including 34 described species of scleractinians highlights that the slope of the Bay of Biscay is an important habitat for scleractinians. This could be expected due to the high topographic relief providing the necessary hard substrate and accelerated bottom current flow that corals require. Further exploration of the occurrence and ecology of corals in the area is recommended to support the conservation of cold-water coral reefs along the European margin. Electronic supplementary material The online version of this article (doi:) contains supplementary material, which is available to authorized users. 相似文献
7.
于2010年5月对大亚湾溶解无机碳(DIC)进行采样调查,分析了大亚湾溶解无机碳空间分布特征,并讨论了大亚湾溶解无机碳与各环境要素(pH、水温、溶解氧和叶绿素a等)的相关性。大亚湾表层水域的DIC含量在24.26~26.13mg.L-1之间;底层水域的DIC含量在24.06~26.89mg.L-1之间。大亚湾表层水体中DIC含量的高值区集中在大辣甲-桑洲连线以北水域,然后呈现出向四周逐渐递减的分布趋势;底层水体中DIC含量高值区集中于西南部水域(大辣甲南部),总体呈现出由南部向北部逐渐递减的分布趋势。大亚湾DIC与水温和叶绿素a呈现负相关系,与pH、DO和盐度呈现正相关关系,但从相关的显著性来看,DIC与以上各环境因子的相关系数均不高。 相似文献
8.
木本植物的构型及其在植物生态学研究的进展 总被引:23,自引:0,他引:23
一般认为 ,木本植物的植株结构由枝系和根系两个亚系统构成[5,3 8] 。其地上部分的枝或茎的顶端分生组织和侧生分生组织通过不断重复的、持续的活动产生新的分枝 ,构成了复杂的枝系结构和多样的形态特征。传统的植物学研究中曾以树木的形态特征作为植物形态学、分类学和植被类型划分的依据。由于植物种群生态学中构件理论的提出[6,4 1] ,人们已经意识到植物体的各构件单元之间的关系和等级结构 ,认为木本植物地上部分存在着两种尺度的整合 ,即各构件单元在枝条水平上的整合以及各枝条构成的冠幅复合体[1,2 1] 。植物体不同的枝系特征以及枝… 相似文献
9.
徐明;于晶;郭水良;曹同 《植物研究》2013,33(4):441-447
以“Index Muscorum”中的20个藓类植物地理分布单位为分析区域,基于标本信息和相关文献,统计了世界砂藓属84种植物在20个地理单位的分布数据,应用除趋势对应分析法和三维空间图直观地展示了世界砂藓属植物的地理分布格局。发现世界砂藓属植物分布明显地分为南半球区和北半球区,并与岗瓦纳古陆和劳亚古陆有较好的对应性。南半球区包括Am.2,Am.3,Am.4,Am.5,Am.6,Afr.2,Afr.3,Afr.4,Austr.1,Austr.2,As.4和Ant.等12个地理单位;北半球区包括Am.1,Eur.,As.1,As.2,As.3,As.5,Afr.1和Oc.等8个地理单位。砂藓属中的无瘤类群在南、北半球分布广泛,而叶片细胞壁具瘤的Niphotrichum和Codriophorus亚属的种类主要分布在北半球。推测砂藓属植物的起源应早于联合古陆分裂以前,其祖先类群的叶片细胞表面光滑无瘤。 相似文献
10.
11.
Comparison of the results of ichthyoplankton surveys conducted at 97 stations in the eastern part of the Peter the Great Bay of the Sea of Japan, in June–July 2007 with the similar research data of the 1950s shows that at present, as was the case 50 years ago, flatfish eggs belonging mainly to the yellowfin sole Limanda aspera and brown sole Pleuronectes herzensteini prevail in the local ichthyoplankton (up to 86%). The highest concentrations of these species’ eggs were recorded in the Vostok Bay and Strelok Bay. The spawning activity of flatfish in 2007 is found to be lower than in the mid 1900s, but the significance of the eastern part of the Peter the Great Bay for flatfish reproduction remains large. The importance of long-term monitoring in this area, which is being subjected to steadily growing anthropogenic impacts, is also proven. 相似文献
12.
R. S. Wotton 《Hydrobiologia》1982,96(3):243-251
The life histories of Simulium noelleri Fried. and S. truncatum Ldstr. were studied at a lake-outlet site in Finland. A detailed study was made of the second summer generation of both species
and this consisted of a single, synchronized cohort in S. noelleri, and overlapped cohorts in S. truncatum. Larvae of the two species also show differences in their habitat preference: those of S. noelleri predominate on the sluice which marks the beginning of the river, and S. truncatum larvae just downstream from the sluice. In winter, the latter site was dominated by immature individuals of two other species,
S. erythrocephalum de Geer and S. equinum L., and these were found downstream from the two ‘lake-outlet’ species during the summer.
Adult females of S. noelleri are able to mature a first batch of eggs without taking a blood meal but those of S. truncatum need to feed on blood before eggs can be fully developed. The consequences of these different reproductive strategies on
the ecology of individuals of the two species is discussed. 相似文献
13.
Derong Xiao Kun Tian Hua Yuan Yuming Yang Ningyun Li Shouguo Xu 《Frontiers of Biology in China》2008,3(3):338-343
Using GPS technology and community research methods for plant communities, we investigated the distribution patterns of aquatic
plant communities in the high plateaus of the Napahai Wetlands, Yunnan, China, as well as the species changes of plant communities
compared with that of 24 years ago since 2005. We found that the types and numbers of aquatic plant communities have changed.
Some pollution-tolerant, nutrient-loving plant communities such as Scirpus tabernaemontani, Zizania caduciflora, Myriophyllum spicatum, and Azolla imbricata flourished, while the primary aquatic plant communities were reduced or even disappeared. The number of aquatic plant communities
were increased from nine to 12 with the addition of two new emergent plant communities and one new floating-leaved plant community.
The increase in emergent plant communities was significant. From east to west and from south to north, various types of plant
communities were continuously distributed, including floating-leaved plant communities, emergent plant communities and submerged
plant communities. The composition of the communities became more complicated and the number of accompanying species increased,
while the percentage ratio of dominant plant species declined. In 2005, the coverage of emergent plant communities was the
largest (528.42 hm2) followed by submerged plant communities (362.50 hm2) and the floating-leaf plant communities was the smallest (70.23 hm2). The variations in the distribution of aquatic plant communities in the Napahai Wetlands reflect the natural responses to
the change of the wetland ecological environment. This study indicates that human disturbances have led to an inward movement
of the wetland shoreline, a decrease in water quality and a reduction in wetland habitat.
__________
Translated from Acta Ecologica Sinica, 2006, 26(11): 3624–3630 [译自: 生态学报] 相似文献
14.
气孔是植物控制气体交换和调节水分散失的门户.大部分高等植物气孔的分布格局是相邻气孔之间被一至多个表皮细胞所间隔.而在有限分布的几个科属的植物种中发现气孔成簇分布的现象,即由2至多个紧密相邻的气孔器组成相对独立的单元,称为气孔簇(stoma tal cluster).以中国原产的盾叶秋海棠(Begonia peltatifolia Li)为研究对象,探讨了叶表皮气孔簇的发育机制及其分布格局.结果表明:气孔发育初期,气孔拟分生组织的成簇(相邻紧密)排列可能是气孔簇形成的主要机制;气孔副卫细胞恢复分裂形成的卫星拟分生组织也对气孔簇的形成起一定的作用.把气孔簇和单个气孔视为一个气孔单元发现,盾叶秋海棠气孔单元密度(单位面积中气孔单元数)和气孔单元大小(气孔单元所包含气孔数)在叶片上呈有规律的分布:前者由叶片中部向叶尖、叶缘逐圈增多,而后者逐圈减少.对这种分布格局的成因进行了讨论. 相似文献
15.
盾叶秋海棠叶表皮气孔簇的发育及分布格局 总被引:4,自引:0,他引:4
气孔是植物控制气体交换和调节水分散失的门户。大部分高等植物气孔的分布格局是相邻气孔之间被一至多个表皮细胞所间隔。而在有限分布的几个科属的植物种中发现气孔成簇分布的现象 ,即由 2至多个紧密相邻的气孔器组成相对独立的单元 ,称为气孔簇 (stomatalcluster)。以中国原产的盾叶秋海棠 (BegoniapeltatifoliaLi)为研究对象 ,探讨了叶表皮气孔簇的发育机制及其分布格局。结果表明 :气孔发育初期 ,气孔拟分生组织的成簇 (相邻紧密 )排列可能是气孔簇形成的主要机制 ;气孔副卫细胞恢复分裂形成的卫星拟分生组织也对气孔簇的形成起一定的作用。把气孔簇和单个气孔视为一个气孔单元发现 ,盾叶秋海棠气孔单元密度 (单位面积中气孔单元数 )和气孔单元大小 (气孔单元所包含气孔数 )在叶片上呈有规律的分布 :前者由叶片中部向叶尖、叶缘逐圈增多 ,而后者逐圈减少。对这种分布格局的成因进行了讨论 相似文献
16.
17.
重金属在土壤—水稻系统中的行为特性 总被引:33,自引:3,他引:33
重金属在土壤_水稻系统中的行为特性王新吴燕玉(中国科学院沈阳应用生态研究所,110015)BehaviourPropertyofHeavyMetalsinSoil_RiceSystem.WangXin,WuYanyu(InstituteofAppl... 相似文献
18.
长白山地表藓类分布格局与环境因子的关系 总被引:6,自引:0,他引:6
对长白山自然保护区41个样地中的42种主要地表藓类分布与6种重要环境因子间的关系进行了定量研究。应用双向指标种分析法(TWINSPAN)发现调查的41个样地可分成4个样地组,42种地面藓 类可分成4种藓类群,应用除趋势典范对应分析(DCCA)的研究结果表明,海拨高度、土壤含砂量、土壤酸度、林冠层郁闭度、土壤含水量是5个影响42种地表藓类分布格局的主要环境因子,在DCCA排序图上,显示出藓类群与样地类型良好的对应性,藓类群1-4分别在落叶松(Larix olgensis)沼泽地、高山苔原、暗针叶林、亚高山岳松(Betula ernanni)林和岳松-落叶松林中占优势。 相似文献
19.
In 1980 a long-term study of the fishery resources of the San Francisco Bay estuary was initiated in an effort to delineate the importance of freshwater inflow to fish and invertebrate abundance and distribution in the bay. An analysis of the trawl data collected between January 1980 and December 1982 illustrates the influence of the timing and magnitude of freshwater inflows on fish fistribution and abundance in this estuary from the perspective of monthly, seasonal and annual time scales. Normally found in the delta, Suisun Bay and San Pablo Bay during periods of increased salinity, pelagic species moved downstream after the two peak flows studied, while demersal species usually found in Central San Francisco Bay moved upstream. Such upstream movements may be due in part to transport by strong density-driven currents.Timing and magnitude of monthly catches of some species varied on a seasonal cycle coincident with variations of freshwater inflow. Most species, especially the marine species, showed no consistent cycle of monthly catches. In the wet years of 1980 and 1982 the distributions of freshwater, estuarine and anadromous species were extended downstream into San Pablo, Central and South San Francisco Bays and some marine species, including the flatfish, were more abundant in the upstream areas. In the dry year of 1981 when bay salinities were higher, few marine species extended their distributions upstream into San Pablo and Suisun Bays. Jacksmelt was the only fish of the 15 most abundant species with its peak abundance in 1981. Most marine species were more abundant in the San Francisco Bay estuary in the wet years. 相似文献
20.
为了解同域分布的两种无尾两栖类动物武夷湍蛙(Amolops wuyiensis)和凹耳蛙(Odorrana tormotus)在高噪音环境下的求偶鸣声特征及其适应策略,该研究利用超声录音设备录制并分析了繁殖季节武夷湍蛙和凹耳蛙雄性个体在同一噪音环境下的求偶鸣声。结果显示,繁殖期武夷湍蛙在不同时段均能发出3~6个音节数不等的单一鸣声,每个音节由2~10个声脉冲组成,鸣声平均持续时间为2198.20ms,主频为2231.90Hz,信噪声强差为33.00dB,且鸣声不含超声组分,不具备超声通讯的基础。凹耳蛙在每天的18:00—21:00有集中鸣叫行为,鸣声平均持续时间为331.80ms,主频为6665.50Hz,信噪声强差为37.00dB,且鸣声谐波包含超声组分,与前人描述一致。经进一步分析发现,武夷湍蛙和凹耳蛙的鸣声主频和声强均高于背景噪音,噪音不会对其鸣声产生掩蔽作用。通过比较分析得知,武夷湍蛙鸣声主频率<凹耳蛙,推测其声信号传播距离相对后者更远,该蛙在噪音环境下有可能通过调整自身的发声策略(即采用多音节鸣叫声、增加鸣叫时长和鸣叫频次等)来完成种内通讯,并通过改变鸣声时长来体现雄性自身的品质,以便提高对雌性的吸引力。而相同噪音环境下的凹耳蛙则可能采用较为节约能量的方式提高声信号频率的通讯策略,完成种内竞争和交流。 相似文献