植物生活史型的多样性及动态分析

主要阐述了植物生活史型的基本定义和基本模式。根据植物的生态幅（Ｅｃｏｌｏｇｉｃａｌ　ａｍｐｌｉｔｕｄｅ）、适合度（Ｆｉｔｎｅｓｓ）和能量分配格局将植物生活史型划分出Ｖ生活史型、Ｓ生活史型和ｃ生活史型３个基本类型以及ＶＳ生活史型、ＳＶ生活史型、ｃＳ生活史型、Ｓｃ生活史型等６个具有混合特征的过渡类型。文中分析了权衡（丁ｒａｄｅ—ｏｆｆ）植物生活史各阶段的能量需求,使之合理地进行能量分配,进而使植物生活史型获得最佳的繁殖和存活效益以及最大的适合度的重要性,指出韧生代谢和次生代谢增值物生活史型及其生活史型之间相互转换的密切关系。韧生代谢物质主要用于营养生长,次生代谢物质主要用于促进繁育和拮抗环境胁迫。植物生活史型在特定时空中依生境的连续变化而发生相互转换,呈现出具动态特征的植物生活史型诺。提出了植物生活史型的形成机制,即生境中的资源状况和干扰程度构成了环境筛的径度,进而形成选择压力,以使植物按需分配能量,合成初级代谢产物或次级代谢产物来应对选择压力,形成自身的生态幅和适应对策,最终与生境相互作用过程中表现出的适合度来表征相应的生活史型。还提出了植物生活史型之间相互转化的机制,即每一种植物生活史型均有与该生活史型相对应的生境类型、选择压力、代谢物质和生活史对策,由于时空的连续变化,生境类型也发生过渡性变化,形成过渡类型（ＥＤ、ＤＥ、ＤＦ、ＦＤ）,因而导致选择压力、代谢物质、生活史对策也发生过渡性变化,形成过渡类型ＬＭ、ＭＬ、ＭＨ、ＨＭ、ＫＲ、ＲＫ、ＲＴ、ＴＲ、ＢＰ、ＰＢ、ＰＡ、ＡＰ,最终通过ＶＳ、ＳＶ、ＳＣ、ＣＳ等过渡类型的形成而实现植物生活史型之间的相互转换。文中以高山红景天（Ｒｈｏｄｉｏｌａ　ｓａｃｈａｌｉｎｅｎｓｉｓ）等５种植物生活史型谱为例,分析了各植物生活史型谱的动态特征并指出：Ｖ生活史型的植物因营养体较为发达、寿命较长,且能通过正常的有性生殖繁衍后代,通常都能产生稳定种群;以Ｓ生活史型为主的植物,因台子中含有来自双亲的两套基因,故有性生殖过程能产生较多遗传性不同的后代,使种群的适应环境变化的能力加强,因而容易形成爆发种群;以ｃ生活史型为主的植物,其遗传物质与母体完全相同,故种群适应环境变化的能力较弱,因而容易导致种群濒危。     

甘草生活史型的划分

探讨了甘草生活史型的定性和定量划分方法并对其结果进行了对比,结果如下:生活史型定性划分法基于生态幅与扰动程度对甘草生活的生境进行划分,将野生甘草、半野生甘草和栽培甘草分别划分为C、CVS和S生活史型。生活史型定量划分法是将生长于不同生境中甘草的营养生长、克隆生殖和有性生殖形态性状参数进行主成分分析,根据主成分得分比例划分生活史型。野生甘草定量划分结果为C0.4552S0.3150V0.2297型,总体上趋于C型生活史型;半野生甘草划分结果为C0.3540V0.3534S0.2926型,其营养生长、无性生殖和有性生殖发育比较均衡,属于CVS过渡生活史型;栽培甘草划分结果为V0.8931S0.0569C0.0500型,为比较典型的V生活史型。栽培甘草的定性、定量划分结果不一致的原因主要在于生长年限太少,克隆生殖和有性生殖均不发达。对植物生活史型的定量划分方法比定性划分法更为可靠、客观。     

植物生活史型定量划分及其权重配置方法——以四棱豆生活史型划分为例

植物生活史型定量划分方法研究是植物生活史型研究的重要内容。现有的生活史型定量划分方法是基于主成分分析法(PCA)建立起来的,未考虑性状指标之间的相互影响,因此需要探索适用于"网状"结构指标体系的植物生活史型划分新方法。根据植物生活史型划分指标的层次性特点,以攀援型和矮生型四棱豆(Psophocarpus tetragonolobus)为例,分别采用主成分分析法(PCA)、层次分析法(AHP)和网络层次分析法(ANP)对性状指标进行权重配置,计算性状指标的综合得分和生活史型划分参数,结果如下:与ANP相比,PCA计算的V型(营养生长型)参数值偏低(x在0.39以下),S型(有性生殖型)参数值偏高(z在0.453以上);AHP计算的V型参数值偏高(x在0.614以上),S型参数值偏低(z在0.088以下);3种方法计算的生活史型划分参数差异明显。由于PCA、AHP均要求性状指标之间相互独立,不能排除性状指标之间的关联,因此基于PCA、AHP的四棱豆生活史型划分结果均出现了偏差,表明性状指标之间的相关性影响了生活史型划分结果。ANP的指标体系为"网状"结构,其控制层、网络层各个指标之间均存在关联。构建ANP的判断矩阵时提取了性状指标的相关矩阵信息,权重配置反映了性状指标之间的相关关系。基于ANP方法对攀援型和矮生型四棱豆生活史型的划分结果分别为V0.517C0.327S0.156和V0.416C0.43S0.154。当性状指标之间的相关不显著时,可采用PCA和AHP法分配权重;当性状指标之间存在显著相关时,采用ANP法进行权重配置更为恰当。综上所述,基于ANP的植物生活史型划分方法解决了性状指标之间相互影响问题,为植物生活史型定量研究提供了新的有效方法。     

孑遗植物四合木(Tetraena mongolica)的濒危肇因与机制

对我国特有单属种孑遗植物四合木 (Tetraena mongolica Maxim) 的地理分布、生境条件、种群数量动态、空间分布格局、种间关系、种群的生命表、生殖力表、有性生殖、无性繁殖和遗传变异等种群生态学特征及其濒危肇因进行了系统分析.研究结果表明:四合木种群为高群集分布,种群曲线属Leak凸型.年龄结构不合理,其存活曲线接近于Deevey ê型,且将演化为小种群,群落内的生境异质性显著,种群处于不稳定阶段.四合木从开花期到结果期,生殖分配 (RA) 呈下降的趋势,生殖过程中胚胎发生败育、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.分布区城市化、工业化以及过度放牧等原因造成其种群孤立和生境破碎化是物种导致濒危的外因,四合木生态适应性和生境适宜性下降造成遗传多样性逐步丧失.同时提出对我国特有植物四合木进行异地保护的可能性与必然性.     

湖南德夯风景区峡谷特殊生境植物区系与生态适应性初探

对湖南德夯风景区峡谷特殊生境植物区系和生态适应性进行了初步研究,调查统计结果表明:(1)该区共有维管束植物1 162种,隶属于148科566属.其中蕨类植物90种(21科,44属,占总数的7.7%)、裸子植物1种(1科,1属)、被子植物1 071种(126科,521属,占总数92.2%),有草本704种(占60.6%)、木本458种(占39.4%).(2)峡谷特殊生境区系是德夯植物区系的主体,体现了该区植物区系的特征与性质.有峡谷生境专性种160种,分别归属71科121属,其中蕨类植物36种( 15科,23属)、被子植物124种(单子叶植物11种,双子叶植物113种),草本植物102种(占63.7%)、灌木26种(占16.3%)、乔木21种(占13.1%)、藤本11种(占6.9%).(3)群落中灌木层和草本层的优势物种大部分为峡谷生境专性种,乔木层优势植物中专性种较少.(4)德夯峡谷特殊生境专性种在生长型、器官形态、生活史、生态适应类群及适应性分区等方面形成了一系列与环境相适应的特征以及特定的适应分布结构,随着群落演替的进行,峡谷生境专性植物由少逐步增多,演替后期则逐步减少.     

樟子松（Pinus svlvestris var. mongolica）人工群落生活史型谱

以东北林业大学植物园内的樟子松人工群落为研究对象,应用主成分分析方法在对群落内不同种的生活史型进行划分的基础上,对松科樟子松和白扦、槭树科糖槭、豆科紫穗槐、木犀科暴马丁香、蔷薇科毛果绣线菊和托盘、红豆杉科东北红豆杉、菊科飞廉和线叶旋覆花、禾本科扁穗草、罂粟科白屈菜、唇形科夏至草、十字花科荠菜14种植物生活史型及谱特征进行了定量化分析,以此为依据对群落演替和健康水平进行评价的可行性进行了探讨。结果发现此群落中主林层植物(樟子松和白扦)营养生长(Vegetationgrowth,V)达到46%,有性生长(Sexualgrowth,S)在35%,无性生长(Clonegrowth,C)约为19%;演替层植物(糖槭、紫穗槐、暴马丁香、毛果绣线菊、托盘和东北红豆杉)营养生长超过50%,无性生长略高于有性生长;草本层植物(飞廉、扁穗草、线叶旋覆花、白屈菜、夏至草和荠菜)营养生长接近于47%,有性生长只比营养生长少了4%,无性生长只占到11%。这些发现说明了主林层的生活史型是以营养生长为主的VS过渡生活史型,演替层植物应为V生活史型而草本植物为VS过渡类型。群落的生活史型是V0.49S0.33C0.18,属于VS过渡生活史型,在样地调查的14种植物中,生活史型大部分以营养为主,综合评价此群落处于以营养生长为主(49%)的健康群落水平,此群落中有性生长占总生活史型得分的33%,有向有性生长发展的趋势,但在一段时间内该群落应为稳定群落。     

附生蕨类植物的克隆性研究进展

石松类及蕨类植物在高等植物中处于比较特殊的进化与系统发育地位, 同时具有孢子植物(孢子)与种子植物(维管束)的双重特征。附生蕨类植物是蕨类植物中占据独特生境的一个大类群, 其生活史策略及进化历史与其附生生长的森林生态系统紧密相关。大部分附生蕨类植物的克隆生长习性及克隆生活史性状在其生态适应中具有重要作用, 但这方面未引起广泛关注。本文主要综述了中国山地森林中附生蕨类植物的根状茎克隆生长、克隆性与生态适应性、不同克隆生长方式与进化等方面, 并展望了蕨类植物克隆性在森林生态系统过程与功能中的作用, 以及今后如何将蕨类植物生态学研究与气候变化、植被恢复、土地利用变化等全球变化的主流方向进行结合。     

孑遗植物四合木(Tetraena mongolica)的濒危肇因与机制

对我国特有单属种孑遗植物四合木 (Tetraena mongolica Maxim) 的地理分布、生境条件、种群数量动态、空间分布格局、种间关系、种群的生命表、生殖力表、有性生殖、无性繁殖和遗传变异等种群生态学特征及其濒危肇因进行了系统分析。研究结果表明：四合木种群为高群集分布,种群曲线属Leak凸型。年龄结构不合理,其存活曲线接近于Deevey ê型,且将演化为小种群,群落内的生境异质性显著,种群处于不稳定阶段。四合木从开花期到结果期,生殖分配 (RA) 呈下降的趋势,生殖过程中胚胎发生败育、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。分布区城市化、工业化以及过度放牧等原因造成其种群孤立和生境破碎化是物种导致濒危的外因,四合木生态适应性和生境适宜性下降造成遗传多样性逐步丧失。同时提出对我国特有植物四合木进行异地保护的可能性与必然性。     

不同生境白屈菜(Chelidonium majus)生活史型特征及其与不同器官单宁、黄酮、生物碱含量的关系

运用主成分分析法,对不同生境条件下白屈菜植物生活史型相关的营养生长（vegetative growth,V）、有性生长（sexual growth,S）和克隆生长（clonal growth,C）的主成分得分及比例进行定量计算,并以此为基础研究了生活史型特征参数及次生代谢产物单宁含量、黄酮含量与生物碱含量的相关关系,目的是为植物活性成分环境定向诱导培育提供实验依据。研究结果表明：（1）对于不同光照状况的全光照（空地）、70%光照（榆树林内）和40%光照下（白扦林内）的9个样地白屈菜生活史型划分发现,全光照下白屈菜种群生活史型为V0.34S0.41C0.25,为SV生活史型,空地为DE（Disturbed but still Excellent）生境;榆树林下和白扦林下的白屈菜生活史型分别可表示为V0.28S0.38C0.34和V0.27S0.40C0.33,均为SC生活史型,榆树林下和白扦林下为DF（Disturbed and Fragile）生境。（2）白屈菜植株次生代谢产物（单宁、黄酮和生物碱）含量,空地均低于榆树林下和白扦林下生境。各样地白屈菜不同器官单宁含量：叶片（种（根（茎;黄酮含量：种（叶片（根（茎;生物碱含量：叶片（根（茎,各样地白屈菜茎和根的生物碱含量无明显差异,空地白屈菜叶片中生物碱含量低于榆树林下和白扦林下白屈菜植株59%～56.7%。（3）白屈菜生活史型与次生代谢产物（单宁、黄酮和生物碱）含量相关性分析结果中,显著的线性关系显示,白屈菜次生代谢产物（单宁、黄酮和生物碱）含量与营养生长和有性生长成负相关,与克隆生长成正相关。实验结果表明,较于空地的DE生境,林（榆树和白扦）下的DF生境条件差,使白屈菜向C型转变,同时也促进了次生代谢产物（单宁、黄酮和生物碱）的积累。结果可以为野生植物的人工定向培育中生境选择和目的活性成分定向累积提供基于形态学的评价方法和理论。     

一年生盐生植物耐盐机制研究进展

盐生植物是一类能够在盐土上完成生活史的天然植物, 在与盐土协同演化过程中形成了一系列适应盐生环境的特殊生存策略。其中一年生盐生植物因其生活史短、方便培养和观察、易于基因转化和后代繁殖, 已成为耐盐机制研究的主要对象。一年生盐生植物面临多变的生境胁迫, 具有更大的生存风险, 所以具有不同于多年生盐生植物的更稳妥的适应机制, 主要体现在种子的高盐休眠、复水速萌、形态和萌发的多态性、存在持久种子库及调节资源分配等方面。种子萌发后的生长、发育和繁殖等生活史的各阶段都要经受严峻的盐生胁迫环境。通常所说的耐盐机理是指成株对盐分的调控, 按照植物种类不同而分为稀盐、泌盐和拒盐3种耐盐形式。该文在对国内外相关文献进行分析归纳的基础上, 首先介绍了一年生盐生植物的常见类型, 然后分别从种子特征、形态结构、生理生化和生态习性等方面综述了一年生盐生植物的耐盐机制。     

Different temperature perception in high‐elevation plants: new insight into phenological development and implications for climate change in the alpine tundra

In alpine habitats, predicted warmer and longer growing seasons will influence plant phenology, with important implications for species adaptation and vegetation dynamics. However, little is known on the temperature sensitivity of different phenophases and on the characteristics allowing phenological variation among and within species. By integrating interannual micro‐climatic variability with experimental warming, we explored how the phenology of three alpine species is influenced by temperature and what mechanisms underlie intra‐ and inter‐specific phenological differences. The present study demonstrated that alpine plants have different temperature responses during their reproductive cycle, do not have constant thermal thresholds and heat‐use efficiencies to achieve the seed dispersal stage and can change their temperature sensitivity to flower along snowmelt gradients. In addition, the length of the reproductive cycle, which proved to be species‐specific under experimental warming, does not seem to be the only life‐history trait under selective pressure due to the short‐length of the snow‐free period. In a warming climate scenario, the phenology of sexual reproduction will be considerably altered, and alpine plants may be subjected to changes in population dynamics driven by altered perception of environmental cues appropriate for coordinating the timing of key life‐history events.     

Timing of autumn bird migration under climate change: advances in long-distance migrants,delays in short-distance migrants

As a response to increasing spring temperature in temperate regions in recent years, populations of many plant and animal species, including migratory birds, have advanced the seasonal start of their reproduction or growth. However, the effects of climate changes on subsequent events of the annual cycle remain poorly understood. We investigated long-term changes in the timing of autumn migration in birds, a key event in the annual cycle limiting the reproductive period. Using data spanning a 42-year period, we analysed long-term changes in the passage of 65 species of migratory birds through Western Europe. The autumn passage of migrants wintering south of the Sahara has advanced in recent years, presumably as a result of selection pressure to cross the Sahel before its seasonal dry period. In contrast, migrants wintering north of the Sahara have delayed autumn passage. In addition, species with a variable rather than a fixed number of broods per year have delayed passage, possibly because they are free to attempt more broods. Recent climate changes seem to have a simple unidirectional effect on the seasonal onset of reproduction, but complex and opposing effects on the timing of subsequent events in the annual cycle, depending on the ecology and life history of a species. This complicates predictions of overall effects of global warming on avian communities.     

Life strategies in the xerothermous vegetation complex of the Lower Unstrut Valley (Saxony‐Anhalt,Germany)

The subjects of this study are the life strategies and life strategy species groups of plant communities in relation to changing habitat conditions along ecological gradients in the xerothermic vegetation complex of the Lower Unstrut Valley (Saxony‐Anhalt. Germany). The nine plant communities studied (Galio‐Carpinetum, Geranio‐Dictamnetum, Adonido‐Brachypodietum, Festuco‐Stipetum, Trinio‐Caricetum. Poo‐Allietum. Teucrio‐Seslerietum, Teucrio‐Melicetum, Onopordetum) could be characterized by significant life strategies ranging from Perennial stayers with diaspore years to Fugitives and Annual shuttle species. Life strategy species groups are of great synstrategic relevance for the respective plant community. They allow a functional and species‐related characterization of plant communities. Most of the plant communities are characterized by small numbered species groups which are thought to be the functional nucleus of the community and relevant to nature conservation and the biotope net discussion. A correlation of life strategies, dispersal and reproduction ecology is given in a special chapter and diagram. It reveals a strong correlation of life strategies – as a system of co‐evolved adaptive traits – to habit at conditions resp. ecological gradients. For example: Annual shuttle species are adapted to open habitats (gaps); Fugitives are mostly restricted to disturbed habitats; Short‐lived shuttle species dominate on ruderal sites; Colonists on naturally disturbed sites; Cryptophytes in the summer‐shaded herb layer of the xerothermic forests; and the moderate and stable habitats are built up by Perennial stayers. Additionally, in the tree layer of the Galio‐Carpinetum, Perennial stayers are set apart of diaspore years. Exclusive long‐range dispersal only reaches a maximum in the tree layer of the Galio Carpinetum, short‐range dispersal dominates on stable, undisturbed, extreme habitats without broader human impact. The dominance of clonal reproduction in the herb layer of the Galio‐Carpineturn is extraordinary. This reproduction type is also relatively high in most of the xerothermic communities.     

新疆早春短命植物适应荒漠环境的机理研究进展

短命植物是生活于极端干旱自然环境,利用冬春雨雪水在春末夏初迅速完成生活周期,并以种子形式渡过不良环境的特殊生态类型,它们具有生长发育快、光合效率高、繁殖率和结实性极强的特点.本文从短命植物种子萌发机制、形态结构适应性、高光效结构特征、结实特性、生活周期的可塑适应性等方面,对新疆早春短命植物的相关研究进行综述,以阐释短命植物适应荒漠环境的特殊机制.     

Plant life history and above–belowground interactions: missing links

The importance of above–belowground interactions for plant growth and community dynamics became clear in the last decades, whereas the numerous studies on plant life history improved our knowledge on eco‐evolutionary dynamics. However, surprisingly few studies have linked both research fields despite their potential to increase our mechanistic understanding of how above belowground interactions are governed. Here I briefly review studies on above–belowground interactions and plant life history and identify important research gaps. To advance our understanding of ecological strategies and eco‐evolutionary dynamics of plants and their associated organisms it is warranted to elucidate the interconnectivity and tradeoffs of plant life history traits of growth, defence, reproduction, nutrient cycling and the functional composition of above‐ and belowground heterotrophic communities. Using the concept of tradeoffs in growth, reproduction and defence we can postulate that plants in rich soil grow, reproduce and die fast whilst avoiding above‐ and belowground antagonists, whereas plants in poor soil grow slow, live and reproduce longer and invest in above‐ and belowground mutualists and defences. However, alternative scenarios are possible and depend on the selection pressure by above‐ and belowground mutualists and antagonists during plant ontogeny and via after‐life effects. To elucidate missing links between life history traits and above–belowground interactions, complementary modelling and empirical studies are needed that reveal the coupling between below‐ and aboveground plant traits of growth, defence and reproduction, their heritability and their cost/benefit relation. These cost/benefit analyses of defence should span from individuals to future generations, taking feedback effects via altered biotic communities and resource competition into account. The role of soil fertility in steering plant life history traits requires explicit testing of trans‐generational trait shifts in growth, defence, reproduction, cost/benefit of associations with mutualists and antagonists and soil feedbacks across plant genotypes/species with distinct life history traits, grown across soil fertility gradients.     

The significance of flight activity in the life cycle of Amara plebeja Gyll. (Coleoptera,Carabidae)

Summary Habitat change by means of flight activities has been observed in the life cycle of the univoltine, macropterous species Amara plebeja Gyll. The hibernation- and reproduction habitats are quite different, viz. deciduous trees and grass vegetation, respectively. Young as well as old females and males are present in both habitats, but at different periods of the year. The flight muscles are generally autolysed but apparently only temporarily. After complete reconstruction of the flight muscles, habitats are changed by mean of flying both in spring and in autumn, if weather conditions are favourable. In spring, when the individuals are flying from hibernation to reproduction habitat they may be drifted by air currents, whereby migration becomes dispersal, and founding or refounding of populations in suitable localities may result. During the autumn, the insects fly from reproduction to hibernation habitats orientating towards distinct silhouettes in the landscape.Communication No. 185 of the Biological Station, Wijster     

Adaptation of timing of life history traits and population dynamic responses to climate change in spatially structured populations

Changes in the seasonal timing of life history events are documented effects of climate change. We used a general model to study how dispersal and competitive interactions affect eco-evolutionary responses to changes in the temporal distribution of resources over the season. Specifically, we modeled adaptation of the timing of reproduction and population dynamic responses in two competing populations that disperse between two habitats characterized by an early and late resource peak. We investigated three scenarios of environmental change: (1) food peaks advance in both habitats, (2) in the late habitat only and (3) in the early habitat only. At low dispersal rates the evolutionarily stable timing of reproduction closely matched the local resource peak and the environmental change typically caused population decline. Larger dispersal rates rendered less intuitive eco-evolutionary population responses. First, dispersal caused mismatch between evolutionarily stable timing of reproduction and local resource peaks and as a result, reproductive output for subpopulations could increase as well as decrease when resource availability underwent temporal shifts. Second, population responses were contingent on competition between populations. This could accelerate population declines and cause extinctions or even reverse population trends from negative to positive compared to the low dispersal case. When dispersal rate was large and the early resource peak was advanced available niche space was reduced. Hence, even when a population survived the environmental change and obtained positive equilibrium population density, subsequent adaptation of competing populations could drive it to extinction due to convergent evolution and competitive exclusion. These results shed new light on the role of competition and dispersal for the evolution of timing of life history events and provide guidelines for understanding short and long-term population response to climate change.     

Asexual and sexual reproductive strategies in clonal plants

Most plants can reproduce both sexually and asexually (or vegetatively),and the balance between the two reproductive modes may vary widely between and within species.Extensive clonal growth may affect the evolution of life history traits in many ways.First,in some clonal species,sexual reproduction and sex ratio vary largely among populations.Variation in sexual reproduction may strongly affect plant's adaptation to local environments and the evolution of the geographic range.Second,clonal growth can increase floral display,and thus pollinator attraction,while it may impose serious constraints and evolutionary challenges on plants through geitonogamy that may strongly influence pollen dispersal.Geitonogamous pollination can bring a cost to plant fitness through both female and male functions.Some co-evolutionary interactions,therefore,may exist between the spatial structure and the mating behavior of clonal plants.Finally,a trade-off may exist between sexual reproduction and clonal growth.Resource allocation to the two reproductive modes may depend on environmental conditions,competitive dominance,life span,and genetic factors.If different reproductive modes represent adaptive strategies for plants in different environments,we expect that most of the resources should be allocated to sexual reproduction in habitats with fluctuating environmental conditions and strong competition,while clonal growth should be dominant in stable habitats.Yet we know little about the consequence of natural selection on the two reproductive modes and factors which control the balance of the two reproductive modes.Future studies should investigate the reproductive strategies of clonal plants simultaneously from both sexual and asexual perspectives.