植物间正相互作用对种群动态和群落结构的影响:基于个体模型的研究进展

植物间的相互作用对种群动态和群落结构有着重要的影响。大量的野外实验已经揭示了正相互作用(互利)在群落中的普遍存在及其重要性。为了弥补野外实验方法的不足, 模型方法被越来越多地应用于正相互作用及其生态学效应的研究中。该文基于个体模型研究, 探讨了植物间正相互作用对种群动态和群落结构的影响。介绍了植物间正相互作用的定义和发生机制、植物间相互作用与环境梯度的关系。正相互作用是指发生在相邻的植物个体之间, 至少对其中一个个体有益的相互作用。植物通过直接(生境改善或资源富集)或间接(协同防御等)作用使局部环境有利于邻体而发生正相互作用。胁迫梯度假说认为互利的强度或重要性随着环境胁迫度的增加而增加, 但是越来越多的经验研究认为胁迫梯度假说需要改进。以网格模型和影响域模型为例, 介绍了基于个体的植物间相互作用模型方法。基于个体模型, 对近年来国内外正相互作用对种群时间动态(如生物量-密度关系)、空间分布格局和群落结构(如群落生物量-物种丰富度关系)影响的研究进行了总结。指出未来的研究应集中在对正相互作用概念和机制的理解, 新的模型, 新的种群、群落, 甚至生态系统问题, 以及在全球变化背景下进行相关的研究。     

鱼类“个性”行为及其研究进展

种内个体差异是动物界普遍存在的现象。鱼类"个性"(personality)行为指不同时空条件下个体间行为的稳定差异,一般与"性格(temperament)"及"行为表达谱(behavioral syndromes)"同义。"个性"行为反映了动物的生活史策略,并与其种群动态、遗传变异以及物种形成等紧密关联。本文阐明了"个性"行为的定义及其内涵、综述了鱼类勇敢性、开拓性、活动性、攻击性、社会性等"个性"行为的研究进展及其潜在的神经生物学、生理学、遗传学和生态学机制,并对未来鱼类"个性"行为的理论研究及其应用进行了展望。     

植物-植食性动物相互关系研究进展

植物光合作用固定下来的能量沿食物链首先流向相邻营养级的植食性动物。植物-植食性动物相互关系是自然界中最普遍、最重要的一种种间关系, 是食物网理论的基础与核心。该文从植食性动物对植物个体、种群和群落特征的影响, 以及植物在个体、种群和群落3个水平上对植食性动物的防御机制与策略两方面, 综述了当前植物-植食性动物相互关系的研究进展。植食性动物的采食, 可以显著改变植物个体或种群的生长、繁殖和存活率, 植物种群的变化则进一步反馈于植物群落组成和多样性特征。相应地, 植物在个体、种群和群落水平形成了一系列的防御机制, 其中在个体和种群水平以化学与物理防御为主, 而群落水平则是通过影响动物的行为或天敌而实现的。该文对相关领域的重要假说和理论进行了介绍、比较。最后, 该文提出了植物-植食性动物相互关系研究的未来发展趋势。随着全球变化和人类活动对自然系统干扰的加剧, 在不同的时空尺度上探索这些干扰如何影响动植物关系, 以及这些影响如何反馈于生态系统的结构、功能和稳定性, 不但有重要的理论意义, 也将为未来制定合理的生态系统管理政策提供实际支撑。     

科尔沁沙地草地植被恢复演替进程中群落优势种群空间分布格局研究

通过对处于流动沙地、半固定沙地和固定沙地等不同恢复演替阶段的群落的取样调查 ,研究了科尔沁沙地草地植被恢复进程中群落优势种群的空间分布格局及其动态变化。运用扩散系数、聚集指数、平均拥挤度、聚块性指数、Green指数、聚集强度、Poisson分布和负二项分布的 χ2 拟合检验等 7项指标 ,对群落优势种群的分布格局的研究结果基本一致 ,大多数物种的空间分布呈显著的聚集分布。在演替进程中种群格局强度的变化和群落总体聚集程度的变化与种群动态和群落结构的空间异质性相对应 ,较高的聚集程度是种群分布斑块化和群落结构的空间异质性的反映 ,随着演替进展 ,优势种的种群数量扩展 ,但种群分布的聚集强度下降 ,群落结构的空间异质性降低。在 7种测定分布格局的指标中 ,聚块性指数、Green指数和聚集强度是无量纲的指标 ,其大小不受种群大小的影响 ,其变化可以较好地指示格局强度本身的变化 ,并与种群动态和群落结构变化相联系     

黄河三角洲潮间带柽柳灌丛的格局及结构动态研究

采用聚集度指标与种群结构动态量化法, 分析了黄河三角洲潮间带柽柳灌丛的分布格局与结构动态变化。结果表明: (1)在潮间带, 柽柳种群从幼苗、小灌木至中灌木都服从集群分布, 大灌木为随机分布; 柽柳个体幼苗多生长在母体周围, 以母体为中心进行繁衍, 随着径级的增加, 种群个体间的竞争增加, 聚集度减小, 逐渐呈现随机分布。(2)柽柳种群结构呈纺锤型; 高度级失稳率指数显示幼苗和小灌木有很高的衰退速率, 随着群落的演替发展, 龄级较大的柽柳优势地位将被削弱。(3)种群动态预测表明, 种群明显处于衰退的早期阶段, 中小灌木的个体数量减少, 大灌木个体数增加,达到数量高峰; 虽然群落在短时期内会保持稳定, 但大灌木(或老龄个体)的数量大幅减少后, 柽柳种群将面临重度衰退。     

不同经营管理方式下锥栗林节肢动物群落的时序动态

【目的】研究不同经营管理方式对锥栗林(Castanea henryi)节肢动物群落及主要害虫种群数量时序动态的影响,为锥栗林害虫防治提供科学依据。【方法】通过对不同经营管理方式下的锥栗林节肢动物群落的系统调查,分析和比较了生产上典型的5种经营管理方式下锥栗林节肢动物群落的物种丰富度、个体数量、物种多样性指数、天敌与害虫个体数量比例及主要害虫种群数量的时序动态。【结果】不同经营管理方式下锥栗林林冠层节肢动物群落的物种丰富度、个体数量、物种多样性指数变化趋势大体一致,物种丰富度、个体数量最高值在6月,物种多样性指数最高值在5月,但不同经营管理方式下物种丰富度、个体数量、物种多样性指数高低不同,管理精细未用药型锥栗林物种多样性指数最高,管理撂荒型的物种丰富度、个体数量最高;相对锥栗林管理撂荒型,其它各种经营管理方式都明显地降低了下木层的物种丰富度、个体数量、物种多样性指数,不同经营管理方式下下木层物种丰富度、个体数量、物种多样性指数的动态变化相差较大;管理精细未用药型林冠层天敌与害虫个体数量比例相对最高,波动变化较大,自然控害能力最强;管理精细的锥栗林主要害虫栗瘿蜂Dryocosmus kuriphilus(Yasumatus)、栗实象Curculio davidi Fairmaire、栗链蚧Asterolecanium castaneae(Russell)种群数量显著低于管理撂荒和管理粗放的锥栗林。【结论】不同经营管理方式对锥栗林节肢动物群落及主要害虫种群数量的时序动态有较大影响,对锥栗林科学的精细管理有助于对主要害虫的有效控制。     

羊草草原种群分布格局的最适取样面积

只有提供足够的环境空间才能保证展现出特定群落类型的种类组成和结构特征的真实面貌,然而,反映群落种类组成的种-面积曲线所给出的最小面积远不能反映种群结构和群落结构的特征。本文将以统计学的方法对研究种群个体分布格局的最适取样面积作深入探讨。 应用Greig-Smith格局分析的原理,计算在一个由小到大的样方面积系列中测得种多度值均方的变化,得到了随样方面积逐级增大的多度值均方的变化曲线,变化曲线表明:8个植物种群的变化曲线韵峰值基本上都出现在区组16到32范围内,表示这些种群个体斑块的聚块群的平均面积在288—576平方米,所以,对多数种群来说,500平方米(12米×40米)的样方可以作为研究种群个体分布格局的最适取样面积。     

茂兰喀斯特山地广东松种群结构和动态初步研究

 广东松(Pinus kwangtungensis)是国家三类重点保护植物,为贵州茂兰国家自然保护区喀斯特山顶森林群落演替先锋树种和建群种之一。基于大小结构分析法、矩阵模型和分布格局距离方法,对茂兰喀斯特山地广东松种群结构和动态进行了初步研究。结果表明：(1)广东松种群大小结构近倒金字塔形,为中衰至衰退型种群;(2)广东松年龄(E)和胸径(D)的回归方程为E=59.968／(4.041-lnD);(3)广东松种群分布格局为斑块内种群个体集聚分布,斑块个体均匀分布;(4)广东松各径级度的种群密度(DS)随径级度(DG)呈S形变化,DS=1／(0.0584+0.018e-DG);(5)广东松种群为先锋种群,也能在山顶特殊生境中一定时期内与其它种群一起形成稳定群落;(6)分布格局距离方法能有效地用于亚热带森林树种的种群分布格局研究,矩阵模型能在—定程度上反映森林树种种群的数量和结构动态。     

坝王岭热带山地雨林群落种群垂直分布

应用中心点,四分法取样技术于海南岛坝王岭的热带山地雨林,并根据群落以及部分优势种的特性,人为划分群落和各个种的层次高度范围,研究了一部分种群在群落中的垂直空间分布。结果表明,整个群落的个体垂直空间分布均匀度较高,群落下层的物种多样性指数稍高于上层,而均匀度则稍低。各个种群的垂直空间分布多度不等,有利于揭示种群在群落结构、演替过程的作用.种群的垂直空间分布格局呈随机型或集群型。     

兰科植物种群动态研究进展

兰科植物种群动态研究中,种群统计学分析能够很好地揭示植物个体在时空上的变化,是研究种群动态的核心.在自然生境中,许多附生兰科植物更倾向于离散或斑块状分布,可以通过集合种群研究分析斑块之间个体的基因流动,判断物种种群保护的规模.长期的种群动态研究能够获得兰科植物生活史和种群动态方面的可靠信息,以及一定环境条件下其时空波动及与种群功能之间的关系;短期的研究能够更好地理解具有结构性的独立植株与其所处的群落间的关系.本文根据种群生态学原理以及兰科植物的生态特点,从种群的密度及分布、种群统计学、种群的调节、集合种群和种群生存力分析（PVA）模型等方面阐述了国内外兰科植物种群动态研究进展.     

Differences in prey personality mediate trophic cascades

Functional trait approaches in ecology chiefly assume the mean trait value of a population adequately predicts the outcome of species interactions. Yet this assumption ignores substantial trait variation among individuals within a population, which can have a profound effect on community structure and function. We explored individual trait variation through the lens of animal personality to test whether among‐individual variation in prey behavior mediates trophic interactions. We quantified the structure of personalities within a population of generalist grasshoppers and examined, through a number of field and laboratory‐based experiments, how personality types could impact tri‐trophic interactions in a food chain. Unlike other studies of this nature, we used spatial habitat domains to evaluate how personality types mechanistically map to behaviors relevant in predator–prey dynamics and found shy and bold individuals differed in both their habitat use and foraging strategy under predation risk by a sit‐and‐wait spider predator. In the field‐based mesocosm portion of our study, we found experimental populations of personality types differed in their trophic impact, demonstrating that prey personality can mediate trophic cascades. We found no differences in respiration rates or body size between personality types used in the mesocosm experiment, indicating relative differences in trophic impact were not due to variation in prey physiology but rather variation in behavioral strategies. Our work demonstrates how embracing the complexity of individual trait variation can offer mechanistically richer understanding of the processes underlying trophic interactions.     

What's your move? Movement as a link between personality and spatial dynamics in animal populations

Recent studies have established the ecological and evolutionary importance of animal personalities. Individual differences in movement and space‐use, fundamental to many personality traits (e.g. activity, boldness and exploratory behaviour) have been documented across many species and contexts, for instance personality‐dependent dispersal syndromes. Yet, insights from the concurrently developing movement ecology paradigm are rarely considered and recent evidence for other personality‐dependent movements and space‐use lack a general unifying framework. We propose a conceptual framework for personality‐dependent spatial ecology. We link expectations derived from the movement ecology paradigm with behavioural reaction‐norms to offer specific predictions on the interactions between environmental factors, such as resource distribution or landscape structure, and intrinsic behavioural variation. We consider how environmental heterogeneity and individual consistency in movements that carry‐over across spatial scales can lead to personality‐dependent: (1) foraging search performance; (2) habitat preference; (3) home range utilization patterns; (4) social network structure and (5) emergence of assortative population structure with spatial clusters of personalities. We support our conceptual model with spatially explicit simulations of behavioural variation in space‐use, demonstrating the emergence of complex population‐level patterns from differences in simple individual‐level behaviours. Consideration of consistent individual variation in space‐use will facilitate mechanistic understanding of processes that drive social, spatial, ecological and evolutionary dynamics in heterogeneous environments.     

Differences in boldness are repeatable and heritable in a long‐lived marine predator

Animal personalities, composed of axes of consistent individual behaviors, are widely reported and can have important fitness consequences. However, despite theoretical predictions that life‐history trade‐offs may cause and maintain personality differences, our understanding of the evolutionary ecology of personality remains poor, especially in long‐lived species where trade‐offs and senescence have been shown to be stronger. Furthermore, although much theoretical and empirical work assumes selection shapes variation in personalities, studies exploring the genetic underpinnings of personality traits are rare. Here we study one standard axis of personality, the shy–bold continuum, in a long‐lived marine species, the wandering albatross from Possession Island, Crozet, by measuring the behavioral response to a human approach. Using generalized linear mixed models in a Bayesian framework, we show that boldness is highly repeatable and heritable. We also find strong differences in boldness between breeding colonies, which vary in size and density, suggesting birds are shyer in more dense colonies. These results demonstrate that in this seabird population, boldness is both heritable and repeatable and highlights the potential for ecological and evolutionary processes to shape personality traits in species with varying life‐history strategies.     

A multi-trait,field-based examination of personality in a semi-aquatic turtle

Studies documenting and quantifying personality traits are common in animal behavior. Such studies often consider the nature of individual variation and personality as correlated with a variety of natural history, physiological, or ecological traits, and therefore consider the importance of personality for strategies in wild systems. Though such studies have contributed markedly to our understanding of the important aspects of personality that may covary with a variety of factors that might affect fitness, much of the research on animal personalities is taxonomically limited. To supplement and compliment the laboratory study of reptile personality, we examined the patterns of multiple personality traits in wild Eastern painted turtles (Chrysemys picta) in the field. We examined patterns of aggression, sociability, and boldness across these traits in different contexts in 103 adult, wild-caught turtles. We found strong correlations both within and among the focal behavioral axes, representing robust evidence for personality in this species. Specifically, we found strong relationships among many measures of aggression, as well as relationships between aggression and our measures of boldness. Finally, we note a tendency for sociability in our turtles, with animals scoring high on sociability showing lower tendency toward aggression. Overall, our study provides robust evidence for correlated suites of behavioral traits, or personality, in a semi-aquatic turtle surveyed in the wild. Future work should continue to expand the range of traits examined to more fully consider the ecological consequences of variation in personality in this and similar species.     

活跃性和社会性对中华倒刺鲃集群行为的影响

为考察群体中不同的个性组成对鱼类集群行为的影响及其内在机制,选取中华倒刺鲃(Spinibarbus sinensis)幼鱼为实验对象,依次测定其活跃性和社会性,随后分别根据活跃性和社会性的高低分为高、低和混合活跃性(或社会性)鱼群,考察鱼群中不同个性组成对集群时的整体运动特征以及每尾鱼的个体运动特征的影响。研究发现：(1)中华倒刺鲃的个性特征稳定且个体间变异较大;(2)高活跃性鱼群的运动时间比和速度同步性均大于低活跃性鱼群,而混合鱼群位于二者之间且与两个同质性鱼群均无显著差异;高社会性鱼群速度同步性显著小于低社会性和混合社会性鱼群,而后两者之间没有显著差异。(3)活跃性特征与集群运动时每尾鱼的运动特征(速度及其同步性等)相关,社会性特征不仅与上述运动特征关联,还与凝聚力大小(距鱼群质心距离)相关。研究表明：(1)鱼群的活跃性和社会性组成均对集群行为产生重要影响,但其内在机制截然不同。主要表现为：就活跃性而言,群体的运动状态是由群体中所有成员共同决定(平均决定机制);就社会性而言,少数低社会性成员对鱼群的运动水平表现有着主导作用(少数决定机制);(2)实验鱼的活跃性在集群行为中得到了较大...     

Behavioral types of predator and prey jointly determine prey survival: potential implications for the maintenance of within-species behavioral variation

Recent studies in animal behavior have emphasized the ecological importance of individual variation in behavioral types (e.g., boldness, activity). Such studies have emphasized how variation in one species affects its interaction with other species. But few (if any) studies simultaneously examine variation in multiple interacting species, despite the potential for coevolutionary responses to work to either maintain or eliminate variation in interacting populations. Here, we investigate how individual differences in behavioral types of both predators (ocher sea stars, Pisaster ochraceus) and prey (black turban snails, Chlorostoma funebralis) interact to mediate predation rates. We assessed activity level, degree of predator avoidance behavior, and maximum shell diameter of individual C. funebralis and activity levels of individual P. ochraceus. We then placed 46 individually marked C. funebralis into outdoor mesocosms with a single P. ochraceus and allowed them to interact for 14 days. Overall, predator avoidance behavior and maximum shell diameter were positively associated with survival for C. funebralis. However, the effects of these traits depended on the predator's behavioral type: greater predator avoidance behavior was favored with active P. ochraceus, and low predator avoidance behavior was favored with inactive P. ochraceus. We argue that, even in two-species interactions, trait variation in heterospecifics could be an important factor maintaining trait variation within populations.     

No personality without experience? A test on Rana dalmatina tadpoles

While the number of studies reporting the presence of individual behavioral consistency (animal personality, behavioral syndrome) has boomed in the recent years, there is still much controversy about the proximate and ultimate mechanisms resulting in the phenomenon. For instance, direct environmental effects during ontogeny (phenotypic plasticity) as the proximate mechanism behind the emergence of consistent individual differences in behavior are usually overlooked compared to environmental effects operating across generations (genetic adaptation). Here, we tested the effects of sociality and perceived predation risk during ontogeny on the strength of behavioral consistency in agile frog (Rana dalmatina) tadpoles in a factorial common garden experiment. Tadpoles reared alone and without predatory cues showed zero repeatability within (i.e., lack of personality) and zero correlation between (i.e., lack of syndrome) activity and risk‐taking. On the other hand, cues from predators alone induced both activity and risk‐taking personalities, while cues from predators and conspecifics together resulted in an activity – risk‐taking behavioral syndrome. Our results show that individual experience has an unequivocal role in the emergence of behavioral consistency. In this particular case, the development of behavioral consistency was most likely the result of genotype × environment interactions, or with other words, individual variation in behavioral plasticity.     

Urbanization and biological invasion shape animal personalities

Novel selective pressures derived from human activities challenge the persistence of animal populations worldwide. Behavior is expected to be a major factor driving animals’ responses to global change because it largely determines how animals interact with the environment. However, the role of individual variation in behavior to facilitate the persistence of animals in changing environments remains poorly understood. Here, we adopted an animal personality approach to investigate whether different behavioral traits allow animals to deal with two major components of global change: urbanization and biological invasions. By studying six populations of Anolis sagrei lizards, we found for the first time that anoles vary consistently in their behavior across different times and contexts. Importantly, these animal personalities were consistent in the wild and in captivity. We investigated whether behavioral traits are pulled in different directions by different components of global change. On the one hand, we found that lizards from urban areas differ from nearby forest lizards in that they were more tolerant of humans, less aggressive, bolder after a simulated predator attack, and they spent more time exploring new environments. Several of these risk‐taking behaviors constituted a behavioral syndrome that significantly differed between urban and forest populations. On the other hand, the behavior of urban A. sagrei coexisting with the invasive predatory lizard Leiocephalus carinatus was associated with dramatic changes in their foraging niche. Overall, we provide evidence that differences in animal personalities facilitate the persistence of animals under novel selective regimes by producing adaptive behaviors relevant to their ecology such as predator avoidance. Our results suggest that natural selection can favor certain behaviors over others when animals are confronted with different ecological challenges posed by global change. Therefore, we underscore the need to incorporate behavioral ecology into the study of how animals adaptively respond to human‐induced environmental changes.     

How does variation in the environment and individual cognition explain the existence of consistent behavioral differences?

According to recent studies on animal personalities, the level of behavioral plasticity, which can be viewed as the slope of the behavioral reaction norm, varies among individuals, populations, and species. Still, it is conceptually unclear how the interaction between environmental variation and variation in animal cognition affect the evolution of behavioral plasticity and expression of animal personalities. Here, we (1) use literature to review how environmental variation and individual variation in cognition explain population and individual level expression of behavioral plasticity and (2) draw together empirically yet nontested, conceptual framework to clarify how these factors affect the evolution and expression of individually consistent behavior in nature. The framework is based on simple principles: first, information acquisition requires cognition that is inherently costly to build and maintain. Second, individual differences in animal cognition affect the differences in behavioral flexibility, i.e. the variance around the mean of the behavioral reaction norm, which defines plasticity. Third, along the lines of the evolution of cognition, we predict that environments with moderate variation favor behavioral flexibility. This occurs since in those environments costs of cognition are covered by being able to recognize and use information effectively. Similarly, nonflexible, stereotypic behaviors may be favored in environments that are either invariable or highly variable, since in those environments cognition does not give any benefits to cover the costs or cognition is not able to keep up with environmental change, respectively. If behavioral plasticity develops in response to increasing environmental variability, plasticity should dominate in environments that are moderately variable, and expression of animal personalities and behavioral syndromes may differ between environments. We give suggestions how to test our hypothesis and propose improvements to current behavioral testing protocols in the field of animal personality.     

Animal personality as a cause and consequence of contest behaviour

We review the evidence for a link between consistent among-individual variation in behaviour (animal personality) and the ability to win contests over limited resources. Explorative and bold behaviours often covary with contest behaviour and outcome, although there is evidence that the structure of these ‘behavioural syndromes'' can change across situations. Aggression itself is typically repeatable, but also subject to high within-individual variation as a consequence of plastic responses to previous fight outcomes and opponent traits. Common proximate mechanisms (gene expression, endocrine control and metabolic rates) may underpin variation in both contest behaviour and general personality traits. Given the theoretical links between the evolution of fighting and of personality, we suggest that longitudinal studies of contest behaviour, combining behavioural and physiological data, would be a useful context for the study of animal personalities.