Impacts of global warming on the interaction between host plants,insect pests and their natural enemies

全球气候变化是近来人类关注的焦点问题,其最显著的特征是气候变暖.因为昆虫具有生活周期短、繁殖率高等特点,所以,气候变暖对昆虫的发育、繁殖和存活会产生强烈的直接影响.气候变暖促使一些昆虫提前春天的物候现象,向高纬度或高海拔地区迁移.然而,昆虫在自然界并非孤立地存在,它们与寄主植物和自然天敌相互联系、相互作用,并在长期的进化过程中逐渐适应特定区域的气候条件.因此,全球气候变暖对“植物-害虫-天敌”的种间关系必然产生直接或间接的影响,导致不同昆虫之间以及昆虫与其相关营养层的物种之间的相互关系在气候变化下呈现出时间上的异步性和空间上的错位,从而影响植物的适应性和抗虫性、害虫的发生规律和危害程度以及天敌的种群消长和控害效能.昆虫除了可以通过休眠或滞育的方式在时间上避开高温的影响外,还可以通过迁飞或移动的方式在空间上避开高温的影响,在这种迁移和扩散不同步的情况下可能使害虫食性和取食植物的害虫及其天敌的种类发生变化,从而改变生物群落的组成与结构,影响生态系统的服务和功能.     

温度升高对昆虫发生发展的影响

全世界地表平均温度在上个世纪增加了0.74℃,并且在未来还会持续增加。在过去的20年,气候变暖对生物系统的影响吸引了大量的研究。本文综述了由温度升高为主要驱动因子的气候变化对昆虫适合度的影响,主要从昆虫越冬存活率、化性(世代数)、扩散迁移、发生分布、物候关系5个方面阐述气候变暖对昆虫发生发展的作用,认为未来应长期进行昆虫种群动态监测预警,更关注气候变暖下植物-害虫-天敌互作关系的研究。     

气候变暖对昆虫影响研究进展

"全球气候变化"已成为国内外最受关注的环境问题。气候变化中以温度升高为特征的气候变暖对变温动物昆虫自身及其所在的生物群落产生直接或间接影响。从研究内容与研究方法2个方面综述了气候变暖对昆虫影响研究的国内外进展。气候变暖导致昆虫发生期提前,地理分布向更高纬度和海拔地区扩散,低温适生种种群密度下降,高温适生种种群密度增加。气候变暖改变寄主植物—害虫—天敌的物候同步性和昆虫原有种间互作关系,影响植食性昆虫的寄主植物范围和取食为害程度。长期的气候变暖带来的强烈的选择性压力引起某些昆虫种群的基因组发生变异。以日均温升高、日最高气温升高和昼夜温差变化等为主要特征气候变暖对昆虫发育、繁殖及存活等生态学指标产生重要影响。研究方法上主要是利用野外直接观察法、回归预测模型、有效积温模型、CLIMEX和GIS等生态风险评估软件、生物化石比较技术、人工气候下生态试验、检测标记基因频率变化等方法来研究气候变暖对昆虫的影响。最后简要评述了已有研究的不足并指出未来的研究方向:(1)气候变暖情景下开展昆虫种间互作研究并拓展研究对象;(2)高温下昆虫适应性研究;(3)建立完善人工模拟气候下的实验方法;(4)构建昆虫有效生态机理模型。     

植物干旱胁迫对植食性昆虫及其天敌的影响

全球正经历以变暖为主要特征的气候变化,由此带来的干旱将对农业生态系统造成重要影响。本文综述了干旱胁迫下寄主植物对植食性昆虫及其天敌影响的国内外最新研究进展。在干旱胁迫下,寄主植物物理性状、营养状况和次生代谢物质等均发生变化,这些变化导致植食性昆虫的生存环境和营养物质的获取等方面发生改变,从而影响了害虫生长发育和种群动态。干旱胁迫还导致寄主物候变化与昆虫发生不同步,使害虫缺乏食物。另外干旱也会引起植食性害虫天敌的种群发生变化,从而对植食性昆虫种群数量产生间接的影响。     

蜜粉源植物对天敌昆虫的作用及其在生物防治中的应用

寄生性和捕食性天敌昆虫成虫普遍存在通过取食蜜粉源植物补充营养的行为,这可不同程度地促进天敌昆虫性成熟、延长其寿命、提高其生殖力或寄生率,以及搜寻寄主效率和子代雌性比率,从而显著提高天敌昆虫在生物防治中的控害能力和效果。蜜粉源植物花的结构及植物对天敌昆虫产生的嗅觉、视觉信号和花蜜花粉对天敌昆虫产生的味觉信号又显著影响天敌昆虫选择蜜粉源植物的行为和结果。但是,蜜粉源植物也可成为害虫的补充营养植物,从而提高害虫的为害能力。因此,需深入研究不同蜜粉源植物对天敌昆虫及害虫的作用,趋利避害,才可能应用蜜粉源植物成功调控天敌与害虫的益害比,实现害虫的可持续控制。     

气候变暖对植物、传粉者及其相互作用的影响

植物和传粉者之间的相互作用,构成了错综复杂的传粉网络。近20年来,以全球变暖为主要特征的气候变化对开花植物、传粉昆虫和植物-传粉者相互作用的影响已成为研究热点。这些研究有助于更好地预测气候变暖对传粉网络乃至整个生态系统功能的影响。本文综述了气候变暖对开花植物个体的繁殖过程(物候、花吸引、报酬特征)和传粉昆虫活动及其相互作用产生的影响,以及在群落水平上对植物-传粉者网络产生的影响。气候变暖影响开花植物的花报酬(花蜜量、花粉的数量与质量)以及繁殖成功;温度升高对传粉昆虫的影响主要包括决定花粉流的传粉行为和传粉成功率。因此,气候变暖背景下植物、传粉者及其相互作用的改变会导致传粉网络结构发生变化,而传粉网络通过缓冲机制减少植物-传粉者间的错配而产生的负面效应,以维持自身稳定性。总体上,目前对气候变暖背景下植物-传粉者网络的研究较为薄弱,今后的研究应进一步关注以下问题:(1)气候变暖影响植物与传粉者物候匹配程度的原因、机制以及影响因素;(2)进一步探究不同生态系统中植物-传粉者的相互作用;(3)从群落水平或生态系统水平对植物-传粉者相互作用网络开展长期性研究。     

水分胁迫对植物与植食性昆虫互作的影响

水分作为一种重要的环境因子,对陆地生物生长发育有着至关重要的作用。随着全球气候变暖,异常天气频发,水分胁迫也成为了影响农作物及其害虫生长发育的重要逆境胁迫。本文从水分胁迫对植食性昆虫的直接和间接影响进行阐述:从湿度、降雨量和土壤含水量角度讨论了水分胁迫对昆虫的直接影响;从水分影响植物和天敌角度,讨论了水分胁迫对植物-植食者性昆虫-天敌三营养阶层互作的间接影响,以期为理解农业害虫发生机制及其可持续治理决策提供研究信息和理论参考。     

气候变暖对陆地植被-土壤生态系统的影响研究

由于自然因素及人类活动的长期影响,全球气候变化已经成为不容置疑的事实,并对陆地生态系统的植被及土壤产生了深远影响。陆地植被一土壤生态系统在全球气候变化中的反应与适应等过程已成为众多科学家所关注的问题。为更好地了解陆地植被一土壤生态系统对全球气候变化的响应机制,综述了气候变暖对植物的物候与生长、光合特征、生物量生产与分配,以及土壤呼吸等方面的影响,并对分析得到的结论进行了总结。分析指出,随着全球气候变暖,植物个体和群落特征以及土壤特性都会发生相应改变,高海拔地区的植被高度有增加趋势,而低海拔地区的植被可能出现矮化。然而,在以下方面还存有不确定性：（1）气候变暖导致的植被特征变化是否会减弱全球气候变化;（2）在较长时间尺度上气候变暖如何影响植物的物候和生长,特别是植物的体型;（3）高寒生态系统冬季土壤呼吸对气候变暖如何响应。     

气候变化对植物-传粉昆虫的分布区和物候及其互作关系的影响

全球气候变化对生态系统的影响是人类社会面临的紧迫而又严峻的挑战。气候变化带来的极端气候事件的增多, 直接影响到生态系统生产力和服务功能。本文总结了气候变化对植物-传粉昆虫互作的研究进展, 强调植物-传粉昆虫互作网络结构和其时空演变的解析, 以及互作关系和功能性状重组研究的重要性。近年来在气温持续上升背景下对植物-传粉昆虫互作关系影响的研究也受到了更多关注, 这些研究主要集中在两方面: 一是植物和传粉昆虫分布区的变化, 包括部分种群可能灭绝; 二是物候的变化, 即植物花期和传粉昆虫活动期的改变。植物与传粉昆虫任何一方在空间或时间上的改变, 都会导致传粉关系的错配或丢失。此外, 也可能导致植物-传粉昆虫双方的功能性状及其耦合的改变, 从而影响其互作关系的稳定。建议在今后的研究中关注: (1)覆盖生物多样性的多个尺度的研究; (2)对植物-传粉者互作网络的长期监测; (3)重要指示物种繁殖适合度评价; (4)植物-传粉昆虫互作双方功能性状在时间和空间尺度上的变化, 及其互作关系的重组; (5)关键植物和传粉昆虫类群的评估和保护。     

全球气候变暖影响植物-传粉者网络的研究进展

植物与传粉者间相互作用,构成了复杂的传粉网络。目前,以气候变化为主要特征的全球变暖对植物-传粉者网络的影响备受关注,概述了近年来这方面研究的几个主要热点问题及其进展,和相关研究方法。并在此基础上,提出了气温持续上升背景下,植物-传粉者网络未来的研究趋势。当前研究的主要热点问题有:(1)气候变暖使植物、传粉者的物候发生变化,并通过影响植物的开花时间和传粉者活动时间,导致两者在物候时间上的不同步。(2)气候变暖导致植物、传粉者的群落结构变化,促使其地理分布向更高纬度和更高海拔扩散,这可能潜在的导致两者空间分布的不匹配。(3)植物和传粉者通过增加或减少其丰富度来响应气候变暖,可能导致传粉网络结构特征发生变化。(4)面对气候变暖导致植物和传粉者间物候和地理分布错配所引发的互作改变、甚至解体,传粉网络可通过自身网络结构及快速进化来缓冲和适应。在今后研究中,以下几个问题值得探讨:1)气候变暖对植物-传粉者网络影响的大时空尺度变异模式。2)多因素协同作用对植物-传粉者网络的影响特征。3)全球气候变暖对植物、传粉者物候匹配性影响的机理。     

The Moran effect revisited: spatial population synchrony under global warming

The world is spatially autocorrelated. Both abiotic and biotic properties are more similar among neighboring than distant locations, and their temporal co-fluctuations also decrease with distance. P. A. P. Moran realized the ecological importance of such ‘spatial synchrony’ when he predicted that isolated populations subject to identical log-linear density-dependent processes should have the same correlation in fluctuations of abundance as the correlation in environmental noise. The contribution from correlated weather to synchrony of populations has later been coined the ‘Moran effect’. Here, we investigate the potential role of the Moran effect in large-scale ecological outcomes of global warming. Although difficult to disentangle from dispersal and species interaction effects, there is compelling evidence from across taxa and ecosystems that spatial environmental synchrony causes population synchrony. Given this, and the accelerating number of studies reporting climate change effects on local population dynamics, surprisingly little attention has been paid to the implications of global warming for spatial population synchrony. However, a handful of studies of insects, birds, plants, mammals and marine plankton indicate decadal-scale changes in population synchrony due to trends in environmental synchrony. We combine a literature review with modeling to outline potential pathways for how global warming, through changes in the mean, variability and spatial autocorrelation of weather, can impact population synchrony over time. This is particularly likely under a ‘generalized Moran effect’, i.e. when relaxing Moran's strict assumption of identical log-linear density-dependence, which is highly unrealistic in the wild. Furthermore, climate change can influence spatial population synchrony indirectly, through its effects on dispersal and species interactions. Because changes in population synchrony may cascade through food-webs, we argue that the (generalized) Moran effect is key to understanding and predicting impacts of global warming on large-scale ecological dynamics, with implications for extinctions, conservation and management.     

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Special issue on: The Response of Insects to Global Change Guest edited by: Prof. Feng Ge, Institute of Zoology, Chinese Academy of Sciences Understanding the effects of climate change is key to conserving human valued resources. Insects are the largest class of animals on earth and will respond to effects of global change directly and via effects on their hosts. Acting together, these direct and indirect effects will affect the development, survival, reproduction and movement of insects. Moreover, climate change may affect the temporal and spatial dynamics of outbreak species and invasive species, changing the frequency of outbreaks and their spatial patterns, size and geographical range.     

Phenological asynchrony between herbivorous insects and their hosts: signal of climate change or pre-existing adaptive strategy?

Climate change alters phenological relations between interacting species. We might expect the historical baseline, or starting-point, for such effects to be precise synchrony between the season at which a consumer most requires food and the time when its resources are most available. We synthesize evidence that synchrony was not the historical condition in two insect–plant interactions involving Edith''s checkerspot butterfly (Euphydryas editha), the winter moth (Operophtera brumata) and their host plants. Initial observations of phenological mismatch in both systems were made prior to the onset of anthropogenically driven climate change. Neither species can detect the phenology of its host plants with precision. In both species, evolution of life history has involved compromise between maximizing fecundity and minimizing mortality, with the outcome being superficially maladaptive strategies in which many, or even most, individuals die of starvation through poor synchrony with their host plants. Where phenological asynchrony or mismatch with resources forms the starting point for effects of anthropogenic global warming, consumers are particularly vulnerable to impacts that exacerbate the mismatch. This vulnerability likely contributed to extinction of a well-studied metapopulation of Edith''s checkerspot, and to the skewed geographical pattern of population extinctions underlying a northward and upward range shift in this species.     

Responses of insects to the current climate changes: from physiology and behavior to range shifts

Climate change (first of all the rise in temperature) is currently considered one of the most serious global challenges facing mankind. Here we review the diversity of insect responses to the current climate warming, with particular focus on true bugs (Heteroptera). Insects as ectotherms are bound to respond to the temperature change, and different species respond differently depending on their specific physiological and ecological traits, seasonal cycle, trophic relations, etc. Insect responses to climate warming can be divided into six categories: changes in (1) ranges, (2) abundance, (3) phenology, (4) voltinism, (5) morphology, physiology, and behavior, and (6) relationships with other species and in the structure of communities. Changes in ranges and phenology are easier to notice and record than other responses. Range shifts have been reported more often in Lepidoptera and Odonata than in other insect orders. We briefly outline the history and eco-physiological background of the recent range limit changes in the Southern green stink bug Nezara viridula (Heteroptera, Pentatomidae) in central Japan. Range expansion in individual species can lead to enrichment of local faunas, especially at high latitudes. Phenological changes include not only advances in development in spring but also shifts in phenology later in the season. The phenophases related to the end of activity usually shift to later dates, thus prolonging the period of active development. This may have both positive and negative consequences for the species and populations. As with any other response, the tendencies in phenological changes may vary among species and climatic zones. The proven cases of change in voltinism are rare, but such examples do exist. Application of models based on thermal parameters of development suggests that a rise in temperature by 2°C will result in an increased number of annual generations in many species from different arthropod taxa (up to three or four additional generations in Thysanoptera, Aphidoidea, and Acarina). The warming-mediated changes in physiology, morphology, or behavior are difficult to detect and prove, first of all because of the absence of reliable comparative data. Nevertheless, there are examples of changes in photoperiodic responses of diapause induction and behavioral responses related to search of shelters for summer diapause (aestivation). Since (1) individual species do not exist in isolation and (2) the direction and magnitude of responses even to the same environmental changes vary between species, it may be expected that in many cases the current stable relationships between species will be affected. Thus, unequal range shifts in insects and their host plants may disrupt their trophic interactions near the species?? range boundaries. Studies of responses to climate warming in more than one interrelated species or in entire communities are extremely rare. The loss of synchronism in seasonal development of community members may indicate inability of the higher trophic levels to adapt fully to climate warming or an attempt of the lower trophic level to escape from the pressure of the higher trophic levels. It is generally supposed that many insect species in the Temperate Climate Zone will benefit in some way from the current climate warming. However, there is some experimental evidence of an opposite or at least much more complex response; the influence of warming might be deleterious for some species or populations. It is suggested that species or populations from the cold or temperate climate have sufficient phenotypic plasticity to survive under the conditions of climate warming, whereas species and populations which already suffer from stress under extreme seasonal temperatures in warmer regions may have a limited ??maneuver space?? since the current temperatures are close to their upper thermal limits. Without genetic changes, even moderate warming will put these species or populations under serious physiological stress. The accumulated data suggest that responses of insects and the entire biota to climate warming will be complex and will vary depending on the rate of warming and ecological peculiarities of species and regions. Physiological responses will vary in their nature, direction, and magnitude even within one species or population, and especially between seasons. The responses will also differ in different seasons. For example, warming may negatively affect nymphal development during the hot season but at the same time accelerate growth and development during the cold season and/or ensure milder and more favorable overwintering conditions for adults. All these factors will affect population dynamics of particular species and relationships among the members of ecosystems. We should keep in mind that (1) not only selected insect species but almost all the species will be affected, (2) temperature is not the only component of the climatic system that is changing, and (3) responses will be different in different seasons. Host plants, phytophagous insects, their competitors, symbionts, predators, parasites, and pathogens will not only respond separately to climate changes; individual responses will further affect the responses of other species, thus making reliable prediction extremely complicated. Responses are expected to (1) be species- or population-specific, (2) concern basically all the aspects of organism/ species biology and ecology (individual physiology, population structure, abundance, local adaptations, phenology, voltinism, and distribution), and (3) occur at scales ranging from an undetectable cellular level to major distribution range shifts or regional extinctions. The scale of insect responses will depend on the extent and rate of climate warming. Slight to moderate warming may cause responses only in a limited number of species with more flexible life cycles, whereas a substantial increase in temperature may affect a greater number of different species and ecological groups.     

Leaf synchrony and insect herbivory among tropical tree habitat specialists

Growth defense tradeoff theory predicts that plants in low-resource habitats invest more energy in defense mechanisms against natural enemies than growth, whereas plants in high-resource habitats can afford higher leaf loss rates. A less-studied defense against herbivores involves the synchrony of leaf production, which can be an effective defense strategy if leaf biomass production exceeds the capacity of consumption by insects. The aim of this study was to determine whether leaf synchrony varied across habitats with different available resources and whether insects were able to track young leaf production among tree habitat specialists in a tropical forest of French Guiana. We predicted that high-resource habitats would exhibit more synchrony in leaf production due to the low cost and investment to replace leaf tissue. We also expected closer patterns of leaf synchrony and herbivory within related species, assuming that they shared herbivores. We simultaneously monitored leaf production and herbivory rates of five pairs of tree species, each composed of a specialist of terra firme or white-sand forests within the same lineage. Our prediction was not supported by the strong interaction of habitat and lineage for leaf synchrony within individuals of the same species; although habitat specialists differed in leaf synchrony within four of five lineages, the direction of the effect was variable. All species showed short time lags for the correlation between leaf production and herbivory, suggesting that insects are tightly tracking leaf production, especially for the most synchronous species. Leaf synchrony may provide an important escape defense against herbivores, and its expression appears to be constrained by both evolutionary history and environmental factors.     

The ecology of predispersal insect herbivory on tree reproductive structures in natural forest ecosystems

Plant-insect interactions are key model systems to assess how some species affect the distribution, the abundance, and the evolution of others. Tree reproductive structures represent a critical resource for many insect species, which can be likely drivers of demography, spatial distribution, and trait diversification of plants. In this review, we present the ecological implications of predispersal herbivory on tree reproductive structures by insects (PIHR) in forest ecosystems. Both insect's and tree's perspectives are addressed with an emphasis on how spatiotemporal variation and unpredictability in seed availability can shape such particular plant-animal interactions. Reproductive structure insects show strong trophic specialization and guild diversification. Insects evolved host selection and spatiotemporal dispersal strategies in response to variable and unpredictable abundance of reproductive structures in both space and time. If PIHR patterns have been well documented in numerous systems, evidences of the subsequent demographic and evolutionary impacts on tree populations are still constrained by time-scale challenges of experimenting on such long-lived organisms, and modeling approaches of tree dynamics rarely consider PIHR when including biotic interactions in their processes. We suggest that spatially explicit and mechanistic approaches of the interactions between individual tree fecundity and in sect dynamics will clarify predictions of the demogenetic implications of PIHR in tree populations. In a global change context, further experimental and theoretical contributions to the likelihood of life-cycle disruptions between plants and their specialized herbivores, and to how these changes may gen erate novel dynamic patterns in each partner of the interaction are increasingly critical.     

Global change and carnivore body size: data are stasis

Aim  Global warming and other anthropogenic changes to the environment affect many aspects of biology and have often been invoked as causing body size changes in vertebrates. Here we examine a diverse set of carnivore populations in search of patterns in body size change that could reflect global warming (in accord with Bergmann's rule).
Location  Global.
Methods  We used > 4400 specimens representing 22 carnivore species in 52 populations collected over the last few decades to examine whether size changed with collection date when geography and sex are accounted for. We then examined several factors related to global warming, body mass, diet, and the attributes of the different datasets, to see whether they affect the standardized slope (β) of the size versus time regression.
Results  Six of 52 populations we examined show a significant effect of year of collection on body size at the 0.05 probability level. The response of size to global warming does not reflect spatial patterns of size variation, nor do diet or body mass affect tendency of populations to change in body size. Size changes are no more pronounced in populations that have been sampled more recently. However, change, where it occurs, is rapid.
Main conclusions  There may be a tendency in the literature to report only cases where recent changes are prevalent. Although in our data only a minority of populations show body size changes, we may see changes accelerating in the future in response to more drastic climatic changes and other anthropogenic changes.     

应对全球气候变化的昆虫学研究

大气二氧化碳浓度升高、温度上升、降雨分布不均、灾害性天气出现频次增加等全球气候变化,深刻改变着农林生态系统昆虫群落的组成结构、功能和演替,使昆虫分布区域扩大、发生世代增多、生态适应性变异,从而影响了原有的植物-害虫-天敌间内在联系和各营养层间的固有平衡格局,最终导致一些害虫暴发成灾,一些昆虫种群数量下降,甚至一些昆虫物...