气候变化对生物多样性的影响:脆弱性和适应

气候变化对生物多样性影响及其适应直接关系着未来生物多样性的保护.气候变化对生物多样性影响、生物多样性在气候变化影响下的脆弱性、生物多样性适应气候变化方面进行了总结分析,对存在的问题进行了讨论,对今后研究提出了一些建议.过去的气候变化已使物种物候、分布和丰富度等改变,使一些物种灭绝、部分有害生物危害强度和频率增加,使一些生物入侵范围扩大、生态系统结构与功能改变等.未来的气候变化仍将使物种物候和行为、分布和丰富度等改变,使一些物种灭绝、使有害生物爆发频率和强度增加,并将可能使生态系统结构与功能发生改变等.生物多样性适应气候变化包括了自然适应和人为适应两个方面,自然适应体现在物种适应性进化、迁移、生态系统稳定性和弹性等,人为适应体现在种质基因保存、物种异地保护、自然保护区规划设计、生态系统适应性管理、生态恢复和气候灾害防御等.目前,生物多样性对气候变化影响的脆弱性、生物多样性自然适应和人为适应气候变化方面的研究都还不系统深入,需要加强生物多样性自然适应和人为适应气候变化方面的研究.     

温带落叶林的植物物候特征及其对气候变化的响应

植被物候是气候变化对生物圈产生长期或短期影响的重要指示因子。气候变化已经明显改变了许多物种的营养生长和繁殖物候,尤其是在温带地区。研究温带森林物候变化及其对全球变暖的响应,对认识森林物种共存,协同进化以及森林保护和经营等有重要意义。通过概述温带森林下物候研究的进展发现,光照和积温是影响木本植物展叶及繁殖物候的关键因素,林下层树木通过更早展叶,以尽量减少生长季林冠层遮阴对下层树木生长的影响,更早时期开花的树木具有从顶部向四周次第开花的时空格局,林冠层树种开花具有较好的同步性。而草本植物的物候通常受融雪时间和冠层动态的影响更大,并且,温带森林下不同生活史对策的草本植物的物候特征对气候变化的响应也不尽相同,存在明显的季节动态。繁殖物候、光照的季节变化、光合特征、授粉成功之间的联系决定了林下不同繁殖特性的草本植物的繁殖成功率。量化的、多指标、多对象的定位监测是精准物候研究的基础,物候变化的机理和建立可预测的物候模型将是未来研究的重点。     

极端干旱对荒漠草原群落物种多样性和地上生物量碳氮的影响

极端干旱及其对植物群落物种多样性的影响是气候变化及其影响评估的重要内容之一,而有关干旱荒漠草原区气候变化与植物群落多样性及其功能关系的研究鲜见报道。为明晰极端干旱对荒漠草原物种多样性和地上生物量的影响,利用野外极端干旱处理试验平台,研究了荒漠草原沙生针茅群落物种多样性和地上生物量及其碳、氮密度对极端干旱的响应特征。结果表明,极端干旱改变了荒漠草原沙生针茅(Stipa glareosa)群落的物种组成,进而使物种多样性发生变化。在8月份,生长季5-8月截雨66%和6-7月干旱60 d两种极端干旱处理都降低了群落的Shannon-Wiener指数和物种丰富度指数。两种极端干旱处理使地上现存生物量较对照降低了50%以上(P0.05)。生长季5-8月截雨66%干旱处理使凋落物生物量较对照降低了61%(P0.05),同时使凋落物生物量的碳氮密度显著低于对照。两种极端干旱处理使地上现存生物量的碳氮密度显著低于对照。因此,极端干旱不仅改变了荒漠草原群落的物种组成,而且改变了地上生物量,影响了植被碳氮密度,从而减弱荒漠草原植物群落地上部分的碳氮汇功能。     

基于随机森林模型预估气候变化对动物物种潜在生境的影响

以白冠长尾雉(Syrmaticus reevesii)、中华穿山甲(Manis pentadactyla)和藏酋猴(Macaca thibetana)这3种动物作为研究对象,采用当前(1950—2000年)、2050年和2080年3个时期的气候数据,利用随机森林模型预估气候变化对动物物种潜在生境的影响。其中,2050和2080年的气候数据由3种大气环流模型(MIROC32-medress、CCCMA-CGCM2和BCCR-BCM2.0)和1个温室气体排放预设情景(SRES-A2)下2050和2080年的气候数据进行平均后得到。每一时期的气候数据包含19个生物气候因子,将19个生物气候因子全部作为环境变量,通过随机森林模型分别模拟并预测这3种动物在当前气候条件下的潜在生境,以及未来2050和2080年气候条件下的潜在生境,并用潜在生境质心(centroids)的位置变化来表征物种潜在生境的偏移情况,分析潜在适宜生境面积及物种最适宜海拔高度的变化,采用受试者工作特征曲线和真实技巧统计值评价模型的预测精度。结果表明,3种动物的潜在生境逐渐向北偏移,最适宜海拔高度逐渐升高。其中,中华穿山甲潜在生境的北移速度最快,至2080年北移量达133 km;白冠长尾雉的最适宜海拔高度上升最快,至2080年上升152 m。3种动物的潜在生境面积均逐渐增加,白冠长尾雉的增幅最大。建议在动物保护行动中考虑气候变化对物种的影响,制定长期的保护策略。     

生态因子对川渝地区壳斗科植物物种丰富度的影响

西南川渝地区是我国壳斗科植物分布最为丰富的地区之一.以川渝地区壳斗科植物为研究对象,以皮尔逊相关系数(r 0.8)以及方差膨胀因子(VIF 10)为准则,选取代表现代气候、生境异质性和历史气候变化的9个生态因子,基于地理加权回归模型(GWR)探究生态因子对壳斗科植物物种丰富度的影响,并与经典的全局最小二乘回归法(OLS)进行比较.结果显示:(1)分布在川渝地区的壳斗科植物有6属共74种,主要以栎属(Quercus)和柯属(Lithocarpus)为主;(2)物种丰富度(SR)表现为南部最高,物种丰富度中心为川西南锦屏山东南部—鲁南山西侧、横断山中部的邛崃山南段—大凉山北段以及四川盆地东南缘大娄山东段,可达到29-35种;(3)GWR模型预测精度优于OLS,其预测结果表明海拔变幅、潜在蒸散量和最暖季降雨量是影响川渝壳斗科植物物种丰富度的主要因子,且影响程度表现出明显的空间差异性.整体来看,GWR模型可为探究物种-生态因子关系的空间异质特征提供一种新的方法,在生物多样性研究中具有较好的应用前景.(图3表2参51)     

东北春麦对气候变化的响应预测

农业是气候变化的主要敏感部门之一,气候要素的变化必然会对农业生产带来影响,反之通过一定的管理措施,农业也可以一定程度上适应气候变化.文章采用英国 PRECIS(Providing Regional Climate for Impacts Simulation)模型输出的未来气候变化情景,利用CERES-wheat模型研究了2070s气候变化对我国东北春麦生产的影响,并对不同地区的适应水平进行了分析.结果表明,气候变化会对东北的春小麦生产带来不利影响,东北西部地区产量下降明显,灌溉春麦的产量降低幅度小于雨养春麦.CO2的肥效作用可以缓解产量的降低幅度,同时通过品种更换以及灌溉等措施也可以降低不利影响,综合的适应措施较单一措施的补偿效果更好.     

气候变化将导致大量动植物灭绝

很多动植物不可能经受住气候变化。新的分析表明,在一个由1103种陆地植物和动物组成的样本中,有15%~37%的物种预计到2050年将因气候变化而灭绝。这些物种中,有些将没有任何地方适合它们生存;另一些将不能到达适合它们生存的地方。迅速改用不产生温室气体的技术,并与碳的吸收技术相结合,有可能使15%~20%的物种避免灭绝气候变化将导致大量动植物灭绝@肖辉林     

北京市云蒙山自然保护区北部区域鸟类多样性监测

鸟类对环境条件与气候变化的响应较为敏感,开展鸟类多样性监测对于理解气候变化背景下生物多样性动态具有现实意义。基于以往调查,2019年通过样线法和红外相机法,对北京市云蒙山自然保护区具有代表性的北部区域鸟类多样性开展调查,了解10年间鸟类物种变化。调查记录到鸟类16目43科157种,占北京市野生鸟类(493种)的31.8%;在区系组成上,古北界成分占比最大(109种);本区有5种国家一级重点保护鸟类,29种国家二级重点保护鸟类,北京市重点保护鸟类54种;与2010年第一次科学考察对比(169种),鸟类物种组成出现变化,其中未见物种52种,新增加物种40种,鸟类居留型存在变化,新增东洋界起源繁殖种类;结合密云区近10年气温升高的趋势,鸟类组成可能在一定程度上受此影响。研究结果为后续进一步开展鸟类多样性监测提供了阶段性参考信息,有助于深入理解生物多样性长期动态及其影响因素,并为提升本区鸟类物种保护成效提供科学依据。     

科研动态

由国家自然科学基金委员会组织实施的国家杰出青年科学基金1994年度评审结果日前揭晓,中国科学院生态环境研究中心研究员方精云、胡鞍钢博士榜上有名,分获60万元和30万元的基金资助.方精云博士主要从事“我国植物物种多样性分布及某些关键物种遗传多样性”的研究.从物种、分子和细胞水平上研究以木本植物为主的物种多样性的分布规律,将有助于揭示东亚地区物种高度丰富的机理;建立东亚区域植被气候系统模式,合理地解释全球植被气候格局;也为预测未来气候变化对物种     

Changes in distribution patterns of weed species richness in agricultural lands on Qinghai-Tibet Plateau under climate change北大核心CSCD

农田杂草是阻碍农业生产的主要因素之一.明确农田杂草丰富度分布格局对农业生产管理具有重要意义.以青藏高原农田杂草为研究对象,利用物种分布模型探讨基于县域尺度的农田杂草物种丰富度分布格局及其未来(2050s)的变化,利用逐步回归筛选影响物种丰富度的环境因子,基于传统最小二乘法(OLS)和地理加权回归模型(GWR)分析环境因子对农田杂草物种丰富度的影响,并对两种分析方法进行比较.结果显示:(1)分布在青藏高原的农田主要杂草有51科284种,其中59种单子叶杂草、222种双子叶杂草、135种一年生杂草和149种多年生杂草.青藏高原农田杂草物种丰富度呈由西向东递增的变化规律,物种丰富度中心(丰富度值为167-194)主要集中在一江两河、河湟谷地和川西北等地区;(2)全球气候变化背景下,未来(2050s)青藏高原农田杂草物种丰富度整体呈由东南向西北方向增加的趋势,其中SSP1-2.6情境下最多增加43种,SSP5-8.5情境下最多增加49种;(3)GWR模型优于OLS,其结果表明青藏高原农田杂草物种丰富度的主要驱动因子是最冷季平均温、太阳辐射和最干月降水量,上述变量对杂草丰富度的影响存在明显的空间差异性,其中最冷季平均温由南向北逐渐从负向影响转变为正向影响.太阳辐射整体在青藏高原东部边缘等地区对农田杂草丰富度起正向的影响,在藏东南、青藏高原北部边缘等地区起负向的影响.最干月降水量对整个研究区域起负向影响,并表现出影响力由南向北逐步递增的趋势.上述结果表明青藏高原农田杂草物种丰富度调查不足,实际观测到的丰富度值明显低于当前气候下潜在的丰富度值,存在低估现象.当前气候背景下的农田杂草物种丰富度中心分布地区在未来仍是重点监管对象,且未来青藏高原部分地区作物可能面临新的杂草入侵风险.建议未来研究应注重于青藏高原粮食主产区农田杂草群落结构和功能调查、杂草和作物种间关系、耕地尺度上丰富度驱动因子分析等方面,为区域杂草管理和防治提供充分科学依据.(图6表2参53)     

Evaluating and managing wildlife impacts of climate change under uncertainty

Wildlife managers face the daunting task of managing wildlife in light of uncertainty about the nature and extent of future climate change and variability and its potential adverse impacts on wildlife. A conceptual framework is developed for managing wildlife under such uncertainty. The framework uses fuzzy logic to test hypotheses about the extent of the wildlife impacts of past climate change and variability, and fuzzy multiple attribute evaluation to determine best compensatory management actions for adaptively managing the potential adverse impacts of future climate change and variability on wildlife. A compensatory management action is one that can offset some of the potential adverse impacts of climate change and variability on wildlife. Implementation of the proposed framework requires wildlife managers to: (1) select climate impact states, hypotheses about climate impact states, possible management actions for alleviating adverse wildlife impacts of climate change and variability, and future climate change scenarios; (2) choose biological attributes or indicators of species integrity; (3) adjust those attributes for changes in non-climatic variables; (4) define linguistic variables and associated triangular fuzzy numbers for rating both the acceptability of biological conditions under alternative management actions and the relative importance of biological attributes; (5) select minimum or maximum acceptable levels of the attributes and reliability levels for chance constraints on the biological attributes; and (6) define fuzzy sets on the extent of species integrity and biological conditions and select a fuzzy relation between species integrity and biological conditions. A constructed example is used to illustrate a hypothetical application of the framework by a wildlife management team. An overall best compensatory management action across all climate change scenarios is determined using the minimax regret criterion, which is appropriate when the management team cannot assign or is unwilling to assign probabilities to the future climate change scenarios. Application of the framework can be simplified and expedited by incorporating it in a web-based, interactive, decision support tool.     

Climate heterogeneity modulates impact of warming on tropical insects

Evolutionary history and physiology mediate species responses to climate change. Tropical species that do not naturally experience high temperature variability have a narrow thermal tolerance compared to similar taxa at temperate latitudes and could therefore be most vulnerable to warming. However, the thermal adaptation of a species may also be influenced by spatial temperature variations over its geographical range. Spatial climate gradients, especially from topography, may also broaden thermal tolerance and therefore act to buffer warming impacts. Here we show that for low-seasonality environments, high spatial heterogeneity in temperature correlates significantly with greater warming tolerance in insects globally. Based on this relationship, we find that climate change projections of direct physiological impacts on insect fitness highlight the vulnerability of tropical lowland areas to future warming. Thus, in addition to seasonality, spatial heterogeneity may play a critical role in thermal adaptation and climate change impacts particularly in the tropics.     

Current Practices and Future Opportunities for Policy on Climate Change and Invasive Species

Abstract:  Climate change and invasive species are often treated as important, but independent, issues. Nevertheless, they have strong connections: changes in climate and societal responses to climate change may exacerbate the impacts of invasive species, whereas invasive species may affect the magnitude, rate, and impact of climate change. We argue that the design and implementation of climate-change policy in the United States should specifically consider the implications for invasive species; conversely, invasive-species policy should address consequences for climate change. The development of such policies should be based on (1) characterization of interactions between invasive species and climate change, (2) identification of areas where climate-change policies could negatively affect invasive-species management, and (3) identification of areas where policies could benefit from synergies between climate change and invasive-species management.     

Future habitat loss and extinctions driven by land‐use change in biodiversity hotspots under four scenarios of climate‐change mitigation

Numerous species have been pushed into extinction as an increasing portion of Earth's land surface has been appropriated for human enterprise. In the future, global biodiversity will be affected by both climate change and land‐use change, the latter of which is currently the primary driver of species extinctions. How societies address climate change will critically affect biodiversity because climate‐change mitigation policies will reduce direct climate‐change impacts; however, these policies will influence land‐use decisions, which could have negative impacts on habitat for a substantial number of species. We assessed the potential impact future climate policy could have on the loss of habitable area in biodiversity hotspots due to associated land‐use changes. We estimated past extinctions from historical land‐use changes (1500–2005) based on the global gridded land‐use data used for the Intergovernmental Panel on Climate Change Fifth Assessment Report and habitat extent and species data for each hotspot. We then estimated potential extinctions due to future land‐use changes under alternative climate‐change scenarios (2005–2100). Future land‐use changes are projected to reduce natural vegetative cover by 26‐58% in the hotspots. As a consequence, the number of additional species extinctions, relative to those already incurred between 1500 and 2005, due to land‐use change by 2100 across all hotspots ranged from about 220 to 21000 (0.2% to 16%), depending on the climate‐change mitigation scenario and biological factors such as the slope of the species–area relationship and the contribution of wood harvest to extinctions. These estimates of potential future extinctions were driven by land‐use change only and likely would have been higher if the direct effects of climate change had been considered. Future extinctions could potentially be reduced by incorporating habitat preservation into scenario development to reduce projected future land‐use changes in hotspots or by lessening the impact of future land‐use activities on biodiversity within hotspots.     

Potential effects of climate change on ecosystem and tree species distribution in British Columbia

A new ecosystem-based climate envelope modeling approach was applied to assess potential climate change impacts on forest communities and tree species. Four orthogonal canonical discriminant functions were used to describe the realized climate space for British Columbia's ecosystems and to model portions of the realized niche space for tree species under current and predicted future climates. This conceptually simple model is capable of predicting species ranges at high spatial resolutions far beyond the study area, including outlying populations and southern range limits for many species. We analyzed how the realized climate space of current ecosystems changes in extent, elevation, and spatial distribution under climate change scenarios and evaluated the implications for potential tree species habitat. Tree species with their northern range limit in British Columbia gain potential habitat at a pace of at least 100 km per decade, common hardwoods appear to be generally unaffected by climate change, and some of the most important conifer species in British Columbia are expected to lose a large portion of their suitable habitat. The extent of spatial redistribution of realized climate space for ecosystems is considerable, with currently important sub-boreal and montane climate regions rapidly disappearing. Local predictions of changes to tree species frequencies were generated as a basis for systematic surveys of biological response to climate change.     

Scenarios of change in the realized climatic niche of mountain carnivores and ungulates

Mountains are among the natural systems most affected by climate change, and mountain mammals are considered particularly imperiled, given their high degree of specialization to narrow tolerance bands of environmental conditions. Climate change mitigation policies, such as the Paris Agreement, are essential to stem climate change impacts on natural systems. But how significant is the Paris Agreement to the survival of mountain mammals? We investigated how alternative emission scenarios may determine change in the realized climatic niche of mountain carnivores and ungulates in 2050. We based our predictions of future change in species niches based on how species have responded to past environmental changes, focusing on the probabilities of niche shrink and niche stability. We found that achieving the Paris Agreement's commitments would substantially reduce climate instability for mountain species. Specifically, limiting global warming to below 1.5°C would reduce the probability of niche shrinkage by 4% compared with a high-emission scenario. Globally, carnivores showed greater niche shrinkage than ungulates, whereas ungulates were more likely to shift their niches (i.e., face a level of climate change that allows adaptation). Twenty-three species threatened by climate change according to the IUCN Red List had greater niche contraction than other species we analyzed (3% higher on average). We therefore argue that climate mitigation policies must be coupled with rapid species-specific conservation intervention and sustainable land-use policies to avoid high risk of loss of already vulnerable species.     

Assessing the Effects of Climate Change on Aquatic Invasive Species

Abstract:  Different components of global environmental change are typically studied and managed independently, although there is a growing recognition that multiple drivers often interact in complex and nonadditive ways. We present a conceptual framework and empirical review of the interactive effects of climate change and invasive species in freshwater ecosystems. Climate change is expected to result in warmer water temperatures, shorter duration of ice cover, altered streamflow patterns, increased salinization, and increased demand for water storage and conveyance structures. These changes will alter the pathways by which non-native species enter aquatic systems by expanding fish-culture facilities and water gardens to new areas and by facilitating the spread of species during floods. Climate change will influence the likelihood of new species becoming established by eliminating cold temperatures or winter hypoxia that currently prevent survival and by increasing the construction of reservoirs that serve as hotspots for invasive species. Climate change will modify the ecological impacts of invasive species by enhancing their competitive and predatory effects on native species and by increasing the virulence of some diseases. As a result of climate change, new prevention and control strategies such as barrier construction or removal efforts may be needed to control invasive species that currently have only moderate effects or that are limited by seasonally unfavorable conditions. Although most researchers focus on how climate change will increase the number and severity of invasions, some invasive coldwater species may be unable to persist under the new climate conditions. Our findings highlight the complex interactions between climate change and invasive species that will influence how aquatic ecosystems and their biota will respond to novel environmental conditions.     

Effects of climate change and anthropogenic activity on ranges of vertebrate species endemic to the Qinghai–Tibet Plateau over 40 years

Over the past 40 years, the climate has been changing and human disturbance has increased in the vast Qinghai–Tibet Plateau (QTP). These 2 factors are expected to affect the distribution of a large number of endemic vertebrate species. However, quantitative relationships between range shifts and climate change and human disturbance of these species in the QTP have rarely been evaluated. We used occurrence records of 19 terrestrial vertebrate species (birds, mammals, amphibians, and reptiles) occurring in the QTP from 1980 to 2020 to quantify the effects of climate change and anthropogenic impacts on the distribution of these 4 taxonomic groups and estimated species range changes in each species. The trend in distribution changes differed among the taxonomic groups, although, generally, ranges shifted to central QTP. Climate change contributed more to range variation than human disturbance (the sum of the 4 climatic variables contributed more than the sum of the 4 human disturbance variables for all 4 taxonomic groups). Suitable geographic range increased for most mammals, amphibians, and reptiles (+27.6%, +18.4%, and +27.8% on average, respectively), whereas for birds range decreased on average by 0.9%. Quantitative evidence for climate change and human disturbance associations with range changes for endemic vertebrate species in the QTP can provide useful insights into biodiversity conservation under changing environments.     

Frequency, not relative abundance, of temperate tree species varies along climate gradients in eastern North America

There have been many attempts to model the impacts of climate change on the distributions of temperate tree species, but empirical analyses of the effects of climate on the distribution and abundance of tree species have lagged far behind the models. Here, we used forest inventory data to characterize variation in adult tree abundance along climate gradients for the 24 most common tree species in the northeastern United States. The two components of our measure of species abundance--local frequency vs. relative abundance--showed dramatically different patterns of variation along gradients of mean annual temperature and precipitation. Local frequency (i.e., the percentage of plots in a given climate in which a species occurred) varied strongly for all 24 species, particularly as a function of temperature. Relative abundance when present in a plot, on the other hand, was effectively constant for most species right up to their estimated climatic range limits. Although the range limits for both temperature and precipitation were quite broad for all of the species, the range of climates within which a species was common (i.e., high frequency) was much narrower. Because frequency in sites within a given climate shows a strong sensitivity to temperature, at least, this suggests that the processes determining canopy tree recruitment on new sites also vary strongly with climate.