全球气候变化对野生动物的影响

全球气候变化及其影响引起了人们的关注。随着全球气候变暖,北半球物候期提前,一些野生动物的分布区北移,动物的繁殖、种群变化都发生了不同程度的变化,有的物种甚至灭绝。青藏高原是全球变化的敏感地区之一,位于青藏高原东北部的青海湖地区正向暖干化方向发展。与历史分布比较,青海湖地区现生动物的分布和组成发生了较大的变化。设计自然保护区时,考虑全球气候变化对野生动物的影响,有利于保护物种多样性,有利于保持生态系统的功能完整性。     

昆虫对全球气候变暖的响应

过去的100年全球地表平均温度显著上升,全球气候变暖对生物的影响引起世界范围内的广泛关注。和其他生物一样,昆虫也受到了气候变暖的影响,如繁殖发育速度增快、遗传变异、种群多样性降低、分布区扩大、种群爆发、外来入侵、种群灭绝等等。全球变暖引起的昆虫响应对农林业以及人类健康存在潜在风险,因此本文主要从物候、分布区、生长发育及繁殖、形态、行为与生理、分子水平这些方面综述全球气候变暖背景下昆虫如何响应,并讨论了目前研究动态和未来的研究方向,意在为气候变化条件下昆虫科学管理策略(如种群监控、模型预测、风险评估、遗传多样性、抗性遗传等)提供指导意义。     

气候变化对鸟类影响：长期研究的意义

过去一个多世纪全球气候发生了明显变化,地球表面温度正在逐渐变暖。已有大量研究结果表明,鸟类已经在种群动态变化、生活史特性以及地理分布范围等方面对全球气候变化作出了相应的反应。根据全球范围内气候变化对鸟类影响的研究资料,尤其是北美和欧洲的一些长期研究项目的成果,综述了气候变化对鸟类分布范围、物候、繁殖和种群动态变化等方面的可能影响。这些长期研究项目为探讨气候变化在个体和种群的水平上如何长时间地影响鸟类提供了独特的机会,对未来中国鸟类学研究也会有所裨益。     

气候变化对鸟类影响：长期研究的意义

过去一个多世纪全球气候发生了明显变化，地球表面温度正在逐渐变暖。已有大量研究结果表明，鸟类已经在种群动态变化、生活史特性以及地理分布范围等方面对全球气候变化作出了相应的反应。根据全球范围内气候变化对鸟类影响的研究资料，尤其是北美和欧洲的一些长期研究项目的成果，综述了气候变化对鸟类分布范围、物候、繁殖和种群动态变化等方面的可能影响。这些长期研究项目为探讨气候变化在个体和种群的水平上如何长时间地影响鸟类提供了独特的机会，对未来中国鸟类学研究也会有所裨益。     

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。     

气候变化下极端高温对昆虫种群影响的研究进展

全球平均温度升高导致极端高温事件发生幅度、频率和持续时间增加,对生物和生态系统造成显著影响.以往气候变暖与昆虫种群关系的研究多关注平均温度的变化,常导致过高地估计了温度升高对昆虫的正面作用,而忽视了自然界存在的极端高温的不利影响.本文综述了气候变化下极端高温对昆虫种群地理分布、种群统计参数和种群增长、行为及种间关系等影响的研究进展.极端温度通过限定昆虫的适宜温度阈限和耐受温度范围决定其在不同纬度、海拔和景观地区的分布.极端高温通过即时和后续效应抑制昆虫的发育、存活、繁殖等核心生命参数,进而改变了昆虫种群统计参数和种群增长.极端高温可通过影响昆虫的体温调节、取食及扩散等行为改变其发育、繁殖等核心生命参数.昆虫对极端高温的反应具有物种特异性,不同种类昆虫对气候变化的响应不同,导致相对优势度、群落结构、食物链等种间关系发生变化,进而影响生态系统的功能.目前关于极端高温对昆虫种群影响的研究多关注发生在夏季的热浪天气和日间极端高温.气候变化导致温度的升高在季节间具有非对称性,发生在春、秋、冬季节相对的极端高温对昆虫种群未来发展的影响将是未来该领域研究的重点.     

气候变化对野生植物的影响及保护对策

以温室气体浓度持续上升、全球气候变暖为主要特征的全球气候变化对野生植物及生物多样性造成的潜在影响, 已经引起了国际学者的高度关注。本文总结了全球气候变化的现状与未来趋势, 概述了中国野生植物的保护及管理现状, 从不同侧面综述了国内外关于全球气候变暖对野生植物影响的研究进展和动态, 包括气候带北移、两极冰山退缩、高海拔山地变暖、海平面上升、早春温度提前升高、荒漠草原土壤增温、旱涝急转弯等对野生植物造成的影响以及气候变暖对种间关系和敏感植物类群的影响, 并从气候变化背景下全球生态系统敏感度、植物多样性、物种迁移与气候槽(sink areas)、物种适应与灭绝以及物候节律5个方面分析了未来全球变暖影响野生植物的总体趋势。在以后的野生植物保护与管理中, 应确定全球气候变化的植物多样性敏感区, 重点关注对气候变化敏感的植物类群以及气候要素改变植物-动物互作关系中的野生植物, 自然保护区的建设要重点考虑全球气候变化的影响, 通过在全球范围内对野生植物分布和种群变化进行长期、系统的追踪监测, 建立有效的数据库, 发展野生植物迁地保护的保育技术及信息网络, 发展有关野生植物对全球气候变化响应的量化指标及相应的模型。最后提出应将全球气候变化下野生植物保护与管理列入相关基金会的研究重点。     

全球气候变暖对“植物-害虫-天敌”互作系统的影响

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。     

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.     

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。     

Prediction of the distribution of Arctic-nesting pink-footed geese under a warmer climate scenario

Global climate change is expected to shift species ranges polewards, with a risk of range contractions and population declines of especially high-Arctic species. We built species distribution models for Svalbard-nesting pink-footed geese to relate their occurrence to environmental and climatic variables, and used the models to predict their distribution under a warmer climate scenario. The most parsimonious model included mean May temperature, the number of frost-free months and the proportion of moist and wet moss-dominated vegetation in the area. The two climate variables are indicators for whether geese can physiologically fulfil the breeding cycle or not and the moss vegetation is an indicator of suitable feeding conditions. Projections of the distribution to warmer climate scenarios propose a large north- and eastward expansion of the potential breeding range on Svalbard even at modest temperature increases (1 and 2 °C increase in summer temperature, respectively). Contrary to recent suggestions regarding future distributions of Arctic wildlife, we predict that warming may lead to a further growth in population size of, at least some, Arctic breeding geese.     

水菜花种群潜在生境选择与空间格局预测

国家二级保护野生植物水菜花(Ottelia cordata)，喜生于清洁的水环境中，对环境变化极为敏感，是检验湿地环境及气候变化的关键指示物种之一，在我国仅零星分布于海南北部的火山熔岩湿地区，生存状况不容乐观。研究水菜花种群潜在生境选择及其空间格局演变，有利于加强濒危物种保护保育及湿地生态系统修复、管理。该研究基于GIS平台和MaxEnt模型，结合气候、地形和土壤因子，探究水菜花种群环境限制因子及其在气候变化背景下潜在适宜生境的演变格局。结果表明，水菜花种群对温差与降水量变化敏感，等温性、最冷季度降水量、土壤类型和年均降水量对水菜花种群分布影响显著；全新世中期-当前-2070年气候变化背景下，水菜花适宜生境面积先减小后增大，分布重心呈西南-东北-西南转移格局；未来气候情景下，水菜花种群高度和中度适宜生境缩减，低适宜生境增加，南部地区将出现新增适宜生境，东北、西北及西南部适宜生境将发生消减。该研究从气候环境角度论证了水菜花种群的潜在生境选择及空间变化特征，可为濒危物种保护保育、湿地管理及其生物多样性维护工作提供参考和指导。     

Projected bioclimatic distributions in Nearctic Bovidae signal the potential for reduced overlap with protected areas

Assumptions about factors such as climate in shaping species'' realized and potential distributions underlie much of conservation planning and wildlife management. Climate and climatic change lead to shifts in species distributions through both direct and indirect ecological pressures. Distributional shifts may be particularly important if range overlap is altered between interacting species, or between species and protected areas. The cattle family (Bovidae) represents a culturally, economically, and ecologically important taxon that occupies many of the world''s rangelands. In contemporary North America, five wild bovid species inhabit deserts, prairies, mountains, and tundra from Mexico to Greenland. Here, we aim to understand how future climate change will modify environmental characteristics associated with North American bovid species relative to the distribution of extant protected areas. We fit species distribution models for each species to climate, topography, and land cover data using observations from a citizen science dataset. We then projected modeled distributions to the end of the 21st century for each bovid species under two scenarios of anticipated climate change. Modeling results suggest that suitable habitat will shift inconsistently across species and that such shifts will lead to species‐specific variation in overlap between potential habitat and existing protected areas. Furthermore, projected overlap with protected areas was sensitive to the warming scenario under consideration, with diminished realized protected area under greater warming. Conservation priorities and designation of new protected areas should account for ecological consequences of climate change.     

Matching habitat choice promotes species persistence under climate change

Species may survive under contemporary climate change by either shifting their range or adapting locally to the warmer conditions. Theoretical and empirical studies recently underlined that dispersal, the central mechanism behind these responses, may depend on the match between an individuals’ phenotype and local environment. Such matching habitat choice is expected to induce an adaptive gene flow, but it now remains to be studied whether this local process could promote species’ responses to climate change. Here, we investigate this by developing an individual‐based model including either random dispersal or temperature‐dependent matching habitat choice. We monitored population composition and distribution through space and time under climate change. Relative to random dispersal, matching habitat choice induced an adaptive gene flow that lessened spatial range loss during climate warming by improving populations’ viability within the range (i.e. limiting range fragmentation) and by facilitating colonization of new habitats at the cold margin. The model even predicted range contraction under random dispersal but range expansion under optimal matching habitat choice. These benefits of matching habitat choice for population persistence mostly resulted from adaptive immigration decision and were greater for populations with larger dispersal distance and higher emigration probability. We also found that environmental stochasticity resulted in suboptimal matching habitat choice, decreasing the benefits of this dispersal mode under climate change. However population persistence was still better under suboptimal matching habitat choice than under random dispersal. Our results highlight the urgent need to implement more realistic mechanisms of dispersal such as matching habitat choice into models predicting the impacts of ongoing climate change on biodiversity.     

Linking habitat use to range expansion rates in fragmented landscapes: a metapopulation approach

Temperature increases because of climate change are expected to cause expansions at the high latitude margins of species distributions, but, in practice, fragmented landscapes act as barriers to colonization for most species. Understanding how species distributions will shift in response to climate change therefore requires techniques that incorporate the combined effects of climate and landscape‐scale habitat availability on colonization rates. We use a metapopulation model (Incidence Function Model, IFM) to test effects of fine‐scale habitat use on patterns and rates of range expansion by the butterfly Hesperia comma. At its northern range margin in Britain, this species has increased its breadth of microhabitat use because of climate warming, leading to increased colonization rates. We validated the IFM by reconstructing expansions in five habitat networks between 1982 and 2000, before using it to predict metapopulation dynamics over 100 yr, for three scenarios based on observed changes to habitat use. We define the scenarios as “cold‐world” (only hot, south‐facing 150–250° hillsides are deemed warm enough), “warm‐world” in which 100–300° hillsides can be populated, and “hot‐world”, where the background climate is warm enough to enable use of all aspects (as increasingly observed). In the simulations, increased habitat availability in the hot‐world scenario led to faster range expansion rates, and to long‐term differences in distribution size and pattern. Thus, fine‐scale changes in the distribution of suitable microclimates led to landscape‐scale changes in population size and colonization rate, resulting in coarse‐scale changes to the species distribution. Despite use of a wider range of habitats associated with climate change, H. comma is still expected to occupy a small fraction of available habitat in 100 yr. The research shows that metapopulation models represent a potential framework to identify barriers to range expansion, and to predict the effects of environmental change or conservation interventions on species distributions and persistence.     

Predicting impacts of climate change on habitat connectivity of Kalopanax septemlobus in South Korea

Understanding the drivers of habitat distribution patterns and assessing habitat connectivity are crucial for conservation in the face of climate change. In this study, we examined a sparsely distributed tree species, Kalopanax septemlobus (Araliaceae), which has been heavily disturbed by human use in temperate forests of South Korea. We used maximum entropy distribution modeling (MaxEnt) to identify the climatic and topographic factors driving the distribution of the species. Then, we constructed habitat models under current and projected climate conditions for the year 2050 and evaluated changes in the extent and connectivity of the K. septemlobus habitat. Annual mean temperature and terrain slope were the two most important predictors of species distribution. Our models predicted the range shift of K. septemlobus toward higher elevations under medium-low and high emissions scenarios for 2050, with dramatic reductions in suitable habitat (51% and 85%, respectively). In addition, connectivity analysis indicated that climate change is expected to reduce future levels of habitat connectivity. Even under the Representative Construction Pathway (RCP) 4.5 medium-low warming scenario, the projected climate conditions will decrease habitat connectivity by 78%. Overall, suitable habitats for K. septemlobus populations will likely become more isolated depending on the severity of global warming. The approach presented here can be used to efficiently assess species and habitat vulnerability to climate change.     

Uncertainty in predictions of range dynamics: black grouse climbing the Swiss Alps

Empirical species distribution models (SDMs) constitute often the tool of choice for the assessment of rapid climate change effects on species’ vulnerability. Conclusions regarding extinction risks might be misleading, however, because SDMs do not explicitly incorporate dispersal or other demographic processes. Here, we supplement SDMs with a dynamic population model 1) to predict climate‐induced range dynamics for black grouse in Switzerland, 2) to compare direct and indirect measures of extinction risks, and 3) to quantify uncertainty in predictions as well as the sources of that uncertainty. To this end, we linked models of habitat suitability to a spatially explicit, individual‐based model. In an extensive sensitivity analysis, we quantified uncertainty in various model outputs introduced by different SDM algorithms, by different climate scenarios and by demographic model parameters. Potentially suitable habitats were predicted to shift uphill and eastwards. By the end of the 21st century, abrupt habitat losses were predicted in the western Prealps for some climate scenarios. In contrast, population size and occupied area were primarily controlled by currently negative population growth and gradually declined from the beginning of the century across all climate scenarios and SDM algorithms. However, predictions of population dynamic features were highly variable across simulations. Results indicate that inferring extinction probabilities simply from the quantity of suitable habitat may underestimate extinction risks because this may ignore important interactions between life history traits and available habitat. Also, in dynamic range predictions uncertainty in SDM algorithms and climate scenarios can become secondary to uncertainty in dynamic model components. Our study emphasises the need for principal evaluation tools like sensitivity analysis in order to assess uncertainty and robustness in dynamic range predictions. A more direct benefit of such robustness analysis is an improved mechanistic understanding of dynamic species’ responses to climate change.     

Habitat associations of thermophilous butterflies are reduced despite climatic warming

Climate warming threatens the survival of species at their warm, trailing‐edge range boundaries but also provides opportunities for the ecological release of populations at the cool, leading edges of their distributions. Thus, as the climate warms, leading‐edge populations are expected to utilize an increased range of habitat types, leading to larger population sizes and range expansion. Here, we test the hypothesis that the habitat associations of British butterflies have expanded over three decades of climate warming. We characterize the habitat breadth of 27 southerly distributed species from 77 monitoring transects between 1977 and 2007 by considering changes in densities of butterflies across 11 habitat types. Contrary to expectation, we find that 20 of 27 (74%) butterfly species showed long‐term contractions in their habitat associations, despite some short‐term expansions in habitat breadth in warmer‐than‐usual years. Thus, we conclude that climatic warming has ameliorated habitat contractions caused by other environmental drivers to some extent, but that habitat degradation continues to be a major driver of reductions in habitat breadth and population density of butterflies.     

Enhanced shrub growth in the Arctic increases habitat connectivity for browsing herbivores

Habitat connectivity is a key factor influencing species range dynamics. Rapid warming in the Arctic is leading to widespread heterogeneous shrub expansion, but impacts of these habitat changes on range dynamics for large herbivores are not well understood. We use the climate–shrub–moose system of northern Alaska as a case study to examine how shrub habitat will respond to predicted future warming, and how these changes may impact habitat connectivity and the distribution of moose (Alces alces). We used a 19 year moose location dataset, a 568 km transect of field shrub sampling, and forecasted warming scenarios with regional downscaling to map current and projected shrub habitat for moose on the North Slope of Alaska. The tall‐shrub habitat for moose exhibited a dendritic spatial configuration correlated with river corridor networks and mean July temperature. Warming scenarios predict that moose habitat will more than double by 2099. Forecasted warming is predicted to increase the spatial cohesion of the habitat network that diminishes effects of fragmentation, which improves overall habitat quality and likely expands the range of moose. These findings demonstrate how climate change may increase habitat connectivity and alter the distributions of shrub herbivores in the Arctic, including creation of novel communities and ecosystems.