基于潜在植被的中国陆地生态系统对气候变化的脆弱性定量评价

 陆地生态系统对气候变化的响应及其脆弱性评价研究是当前全球变化领域的重要内容之一。该研究在生态系统过程模型的基础上,耦合了潜在 植被对气候变化的动态响应,模拟气候变化对潜在植被分布格局和生态系统主要功能的影响,以潜在植被的变化次数和变化方 向定义植被分布 对气候变化的敏感性和适应性,以生态系统功能特征量的年际变率及其变化趋势定义生态系统功能对气候变化的敏感性和适应性,进而对生态 系统的脆弱性进行定量评价,分析不同气候条件下我国陆地生态系统的脆弱性分布格局及其区域特点。结果表明,我国自然生态系统气候脆弱 性的总体特点为南低北高、东低西高,气候变化将会增加系统的脆弱性。采用政府间气候变化委员会排放情景特别报告国内和区域资源情景, 即IPCC-SRES-A2气候情景进行的预测模拟表明,到21世纪末我国不脆弱的生态系统比例将减少22%左右,高度脆弱和极度脆弱的生态系统所占的 比例较当前气候条件下分别减少1.3%和0.4%。气候变化对我国陆地生态系统的脆弱性分布格局影响不大。不同气候条件下,高度脆弱和极度脆 弱的自然生态系统主要分布在我国内蒙古、东北和西北等地区的生态过渡带上及荒漠-草地生态系统中。总体而言,华南及西南大部分地区的生 态系统脆弱性将随气候变化而有所增加,而华北及东北地区则有所减小。     

基于景观格局的矿区生态脆弱性评价——以吉林省辽源市为例

矿区自然生态系统脆弱性研究不仅对生态资源及生态环境有重要作用,还对资源合理利用及实现区域可持续发展有指导意义.在分析生态脆弱性概念与评价方法的基础上,依循“压力,状态-响应”评估框架,基于景观格局指数,从自然生态系统压力度、敏感性、恢复力3方面出发构建矿区自然生态系统脆弱性评价指标体系.以辽源市为例,对其进行系统分析与评价.结果表明:各类自然生态系统类型中,辽源市草地的脆弱性最高、林地最低;33个乡镇中,杨木林镇生态脆弱性最高、东丰县县城最低;从4个区县来看,脆弱性大小为龙山区＞西安区＞东丰县＞东辽县;用地分布格局,自然生态环境,采矿、居民点等人为干扰,是影响生态脆弱性空间分异的主要原因.     

气候变化影响下海岸带脆弱性评估研究进展

近百年来,全球气候系统正经历着以全球变暖为主要特征的显著变化。研究海岸带系统对气候变化的响应机制,评估气候变化对海岸带社会、经济和生态的潜在影响,提出切实可行的应对策略,是保障海岸带系统安全的重要前提。回顾了IPCC的四次评估报告,分析了全球气候变化对海岸带的影响。总结了海岸带脆弱性评估框架以及脆弱性评价指标体系,综述了国内外气候变化影响下海岸带脆弱性评估研究的进展。在综述国内外该领域研究进展的基础上,展望了气候变化影响下海岸带脆弱性评估研究。全球气候变化及其对海岸带的影响还有大量的科学技术问题需要进一步探讨,同时也需要对各种适应气候变化措施的可行性和有效性进行研究和验证。     

基于生态系统演变机理的生态系统脆弱性、适应性与突变理论

随着气候变化影响广度与深度的增加,生态系统脆弱性、适应性与突变理论逐渐被广泛应用到生态学研究领域中,探讨和评估各类生态系统对气候变化的敏感性、脆弱性和适应性,可谋求更好的方式来应对气候变化对区域生态系统带来的深远影响,服务于国家生态系统可持续管理及生态安全建设.虽然相关研究已获取许多进展,区分了气候敏感区和某些生态系统...     

高寒生态脆弱区气候变化对农户生计的脆弱性影响评价——以甘南高原为例

气候变化是21世纪人类面临的最严峻挑战之一,加剧了许多国家和地区的脆弱性,对以自然资源为生计基础的农业人口的影响尤为显著。明确气候变化对农户生计脆弱性的影响,对于制定有效的气候变化适应政策,增强农户的气候变化适应能力,减轻农村贫困人口的生计脆弱性具有重要意义。本文以甘南高原为例,建立了气候变化对农户生计脆弱性影响评价指标体系,基于539份农户调查问卷,分析了气候变化对农户生计的影响,并利用多元线性回归模型分析了影响农户生计脆弱性的关键因素。结果表明:(1)气候变化对甘南高原不同类型农户生计的影响不同,其中,青年户主型农户生计的脆弱性最强,中年户主型农户生计的脆弱性最小;从低收入农户到高收入农户、从低教育水平农户到高教育水平农户、从纯农户到二兼户,其生计脆弱性趋于降低,但从低抚养比农户到高抚养比农户,其生计脆弱性趋于增大;(2)气候变化对甘南高原不同区域农户生计的影响存在差异,其中,纯牧区农户生计的脆弱性最强,农区农户生计脆弱性最小;(3)农户生计的脆弱性与农户的年龄和受教育水平、家庭人均收入水平、非农化水平及生计多样化水平呈负相关,与家庭抚养比呈正相关。最后,提出了减轻农户生计脆弱性的建议。     

海平面上升影响下长江口滨海湿地脆弱性评价

研究滨海湿地对气候变化的响应,评估气候变化对其影响,并提出切实可行的应对策略,是保障海岸带生态系统安全的重要前提.本研究以长江口滨海湿地为对象,采用“源-途径-受体-影响”模型和IPCC脆弱性定义分析了气候变化引起的海平面上升对滨海湿地生态系统的主要影响.构建了基于海平面上升速率、地面沉降速率、生境高程、生境淹水阈值和沉积速率为指标的脆弱性评价指标体系.在GIS平台上量化各脆弱性指标,计算脆弱性指数并分级,建立了海平面上升影响下滨海湿地生态系统脆弱性的定量空间评估方法,实现了在不同海平面上升情景（近30年长江口沿海平均海平面上升速率和IPCC排放情景特别报告中的A₁F₁情景）和时间尺度（2030和2050年）下,长江口滨海湿地生态系统脆弱性的定量空间评价.结果表明： 在近30年长江口平均海平面上升速率（0.26 cm·a^-1）情景下,至2030年,研究区轻度脆弱和中度脆弱的滨海湿地分别占6.6%和0.1%;至2050年,轻度脆弱和中度脆弱的滨海湿地分别占9.8%和0.2%.在A₁F₁ （0.59 cm·a^-1）情景下,至2030年,轻度脆弱和中度脆弱的滨海湿地面积比例分别为9.0%和0.1%;至2050年,轻度脆弱、中度脆弱和高度脆弱的面积比例分别为9.5%、1.0%和0.3%.
     

木本植物木质部栓塞脆弱性研究新进展

木质部空穴化和栓塞是木本植物在干旱等条件下遭受水分胁迫时产生的木质部输水功能障碍, 在全球气候变化的大背景下, 栓塞脆弱性对干旱响应的研究已成为热点和重要内容。近年来有关木质部栓塞脆弱性与植物输水结构和耐旱性的关系已有大量研究并取得一定成果, 但是, 不同学者在不同地区对不同材料的研究结果存在很大不同。该文就近年来这一研究领域取得的成果及争议问题进行了概括和总结, 主要涉及木质部栓塞脆弱性(P₅₀)及脆弱曲线的建立方法、木质部栓塞脆弱性与木质部结构(导管直径、导管长度、纹孔膜、木质部密度、纤维及纤维管胞)间的关系和木质部栓塞脆弱性与耐旱性的关系, 并对未来工作进行展望, 提出在未来的工作中应对同一树种使用Cochard Cavitron离心机法、Sperry离心机技术与传统方法建立的脆弱曲线进行比较验证、计算P₅₀值、分析植物个体器官水平差异(根、茎、叶)、测定树种生理生态指标, 探索植物栓塞脆弱性与输水结构和耐旱性的关系, 从而评估不同类型植物在未来气候变化下的耐旱能力。     

海平面上升影响下广西钦州湾红树林脆弱性评价

全球气候变化所导致的海平面上升等现象对海岸带产生显著影响。红树林是生长在热带、亚热带沿海潮间带的生态系统,对海平面上升极为敏感。以广西钦州湾红树林生态系统为对象,采用SPRC(Source-Pathway-Receptor-Consequence)评估模式分析了气候变化所导致的海平面上升对红树林生态系统的主要影响。构建了以海平面上升速率、地面沉降/抬升速率、生境高程、日均淹水时间、潮滩坡度和沉积速率为指标的脆弱性评价体系。在GIS平台上量化各脆弱性指标,计算脆弱性指数并分级,建立了定量评价红树林生态系统脆弱性方法,实现了在不同海平面上升情景(近40年来广西海平面平均上升速率、IPCC预测的B1和A1FI情景)和时间尺度下(2030年、2050和2100年),广西钦州湾红树林生态系统脆弱性的定量空间评价。研究结果表明,在近40年广西海平面平均上升速率与B1情景下,钦州湾红树林在各评估时段表现为不脆弱。而在A1FI情景下,至2050年研究区域41.3%红树林为低脆弱,至2100年增加至69.8%。研究采用的SPRC评估模型、脆弱性评价指标体系和定量空间评估方法能够客观定量评价气候变化所导致的海平面上升影响下红树林生态系统脆弱性,可为制定切实可行的应对措施和保障海岸带生态系统安全提供科学依据。     

南水北调中线汉中市水源地生态脆弱性评价与特征分析

南水北调中线工程是为了缓解我国华北地区水资源严重短缺的一项大型调水工程,其水源地的生态环境质量,直接关系到中线工程的水质安全及其长效运行,对区域社会经济发展具有重要影响。以位于南水北调中线工程水源地的汉中市为研究对象,基于遥感和GIS技术,采用"压力—状态—响应"评价模型框架,利用空间主成分分析方法对汉中市生态脆弱性进行定量评价。结果表明:1)汉中市生态脆弱性整体处于中等偏高水平,其形成是人类活动与自然环境相互作用的结果,年均气温、年均降水量、人均GDP、土壤侵蚀强度和海拔为主要的驱动因子;2)不同海拔梯度上,中山区和高中山区生态脆弱性程度高,其次为高山区,低山区和丘陵区生态脆弱性程度相对较弱;3)不同行政区划上,西部和东部的略阳县、宁强县、佛坪县、西乡县和镇巴县5个县区脆弱性程度最高,中部的汉台区生态脆弱性程度最弱,其他各县区生态脆弱性程度居中;4)汉中市生态脆弱性指数具有强烈的空间自相关性特征,其空间异质性具有明显的各向异性特点,45°和135°方向上的空间变异最大。研究可为水源地生态建设与恢复、区域可持续发展规划提供理论基础和科学依据。     

农户对气候变化的感知与适应研究综述

气候变化是21世纪人类面临的最严峻挑战之一,加剧了许多国家和地区的脆弱性,人类如何适应气候变化已成为当前全社会普遍关注的话题.气候变化对以自然资源为生计基础的农业人口的影响尤为显著,更好地理解农户对气候变化的适应机制和适应过程对于制定有效的适应政策非常重要.公众感知作为理解人文响应行动的基础,已为探明农户对气候变化的适应机制和适应过程提供了一个新视角.本文基于国内外农户对气候变化的感知和适应的理论研究和实践进展,在分析气候变化对农户生计的影响、系统总结农户面临的主要适应障碍的基础上,梳理了农户的气候变化感知与适应的关系,阐释了农户适应气候变化过程中的关键认知要素,介绍了农户对气候变化的感知与适应关系分析框架,提出了农户对气候变化的感知与适应关系研究中应关注的关键问题.     

Long-term ecological vulnerability assessment of Indian Sundarban region under present and future climatic conditions under CMIP6 model

Vulnerability assessment of ecosystem bestows an idea about the ecosystem health and its ability to resist environmental stress. Indian Sundarban region situated at the southwest part of Ganga-Brahmaputra-Meghna delta has been under constant threat of frequent climate hazards and long-term climate change. Various attempts have been made for vulnerability assessment of this mangrove ecosystem focusing only on static non-temporal variables. The present work hypothesises that mangrove ecosystems are highly adaptive and respond to the changing environment by various natural resilience strategies at the ecosystem level. So, a better understanding of the dynamics of mangrove ecosystem will provide an idea about the state of vulnerability for this ecosystem. The present study uses 16 parameters to create exposure, sensitivity and adaptive capacity risk indices and constructs the vulnerability status for the Indian Sundarban. The results showed that the sea-level rise will happen between 0.7 m to 0.9 m under baseline climate conditions. The CMIP6 multi-model ensemble showed that the future minimum temperature for the region will go up to 29.48 °C, thereby reducing the max and min temperature difference for the region. The fuzzy AHP-based vulnerability assessment revealed that the western Sundarban is more prone to climate vulnerability. The island-like Surendranagar, Lothian, and West-Ajmalmari are extremely vulnerable. The proximity to human habitat will play an important role in climate change sensitivity to the Sundarban region. The time series analysis of mangrove forests showed the Mann-Kendall ‘τ’ value varies between 0.82 to −0.83. The central Sundarban forests area shows a varying degree of forest health deterioration. The assessments from the present study and the maps will help the environmental and risk-managers to identify the regions needing more climate change adaptation strategy.     

The exposure,sensitivity and vulnerability of natural vegetation in China to climate thermal variability (1901–2013): An indicator-based approach

Vulnerability assessments can be helpful in assessing the impact of climate change on natural ecosystems and are expected to support adaptation and/or mitigation strategies in the 21st century. A challenge when conducting such assessments is the integration of the multi-level properties and processes of ecosystems into an assessment framework. Focusing on the primary stresses of climate thermal variability (at both upper and lower extremes), this study proposes a quantitative indicator system—following the IPCC framework of vulnerability assessment—that assesses the impact of historical climate change, during 1901–2013, on the natural terrestrial vegetation types in China. The final output of the vulnerability assessment was expressed as a composite index, composed of ecosystem exposure, sensitivity and resilience to climate thermal change, and including biological, ecological and spatial traits of vegetation types in the assessment. The exposure to temperature variability was generally higher in January than in July, and higher in non-arborous vegetation types than forests. In contrast, sensitivity was higher for forests, wetlands and alpine tundra regions, especially for small areas and areas with scattered patterns. Original forests—especially those distributed in the north—had lower resilience than other vegetation types. The vulnerability of natural vegetation types in China to the temperature variability of the past century was very low to moderate, with a few exceptions, including tropical mangroves and the semi-arid to arid vegetation types in northwestern China, which had high vulnerability. Vulnerability was stronger in winter than in summer. Our results are generally in accord with the scenario-based projections on the geographical pattern of vegetation vulnerability to climate change, and revealed the difference caused by not considering moisture. The risks for these fragmented and narrow-range ecosystems are highlighted, and the importance of natural resilience is stressed for the assessment of vegetation vulnerability to climate change. Given the inadequate coverage of the natural reserve network in China (after the large investment in recent decades) found in the high-vulnerability vegetation types (with a few exceptions), the assessment of natural resilience of ecosystems could be critical for the optimal design of socio-economic strategies in response to the impacts of future climate change.     

基于植被生产力的西南地区生态系统脆弱性特征

中国西南地区是全球生物多样性保护的重要地区之一.在全球气候变化背景下,该地区生态系统呈现出脆弱性增加的趋势.本研究基于生态系统总初级生产力(GPP),根据IPCC有关脆弱性的概念,计算西南地区生态系统的脆弱性,并分析了该区脆弱等级的空间分布格局,以及生态系统脆弱性与降水、温度、海拔、坡度和植被类型等因子间的相关性.结果表明: 西南地区生态系统脆弱性呈现由东南向西北逐渐增强的趋势,区域内多数地区为轻度、中度脆弱区(二者共占69%).脆弱等级随着区域内年平均降水量、多年平均温度的增加而减少,随着区域内海拔、坡度的增加而增加.西南喀斯特山区和西北山地农牧交错区呈现较高的脆弱性,更容易受气候变化或其他外界扰动的影响.针叶林、灌丛和草地的脆弱性相对较高,未来可能更容易受到气候变化的影响.     

生物多样性适应气候变化的国家政策和措施: 国际经验及启示

气候变化已成为威胁生物多样性及生态系统服务功能的主要因素之一, 许多国家已经意识到必须提高本国生物多样性适应气候变化的能力。一些国家出台了国家战略, 采取增加连通性、改进现有保护区域的管理和恢复措施等基于生态系统的适应措施, 采用跨学科与跨部门协作手段加强生物多样性适应气候变化的监测和评估, 并且从制度和资金等方面加强政策措施的落实。作者对部分发达国家和发展中的生物多样性大国的生物多样性适应气候变化的相关政策和措施进行了梳理, 并结合我国现状提出以下建议: (1)把生物多样性适应气候变化作为国家整体适应战略中的优先措施之一; (2)将提高生物多样性和生态系统的恢复力作为适应气候变化的基础性原则; (3)整合并完善国家生物多样性监测网络, 参考国际通行标准制定信息和数据收集标准, 并且尽快对气候变化下我国生物多样性脆弱性开展全面且持续的评估。     

Trait‐based climate vulnerability assessments in data‐rich systems: An application to eastern Bering Sea fish and invertebrate stocks

Trait‐based climate vulnerability assessments based on expert evaluation have emerged as a rapid tool to assess biological vulnerability when detailed correlative or mechanistic studies are not feasible. Trait‐based assessments typically view vulnerability as a combination of sensitivity and exposure to climate change. However, in some locations, a substantial amount of information may exist on system productivity and environmental conditions (both current and projected), with potential disparities in the information available for data‐rich and data‐poor stocks. Incorporating this level of detailed information poses challenges when conducting, and communicating uncertainty from, rapid vulnerability assessments. We applied a trait‐based vulnerability assessment to 36 fish and invertebrate stocks in the eastern Bering Sea (EBS), a data‐rich ecosystem. In recent years, the living marine resources of the EBS and Aleutian Islands have supported fisheries worth more than US $1 billion of annual ex‐vessel value. Our vulnerability assessment uses projections (to 2039) from three downscaled climate models, and graphically characterizes the variation in climate projections between climate models and between seasons. Bootstrapping was used to characterize uncertainty in specific biological traits and environmental variables, and in the scores for sensitivity, exposure, and vulnerability. The sensitivity of EBS stocks to climate change ranged from “low” to “high,” but vulnerability ranged between “low” and “moderate” due to limited exposure to climate change. Comparison with more detailed studies reveals that water temperature is an important variable for projecting climate impacts on stocks such as walleye pollock (Gadus chalcogrammus), and sensitivity analyses revealed that modifying the rule for determining vulnerability increased the vulnerability scores. This study demonstrates the importance of considering several uncertainties (e.g., climate projections, biological, and model structure) when conducting climate vulnerability assessments, and can be extended in future research to consider the vulnerability of user groups dependent on these stocks.     

Extinction vulnerability of coral reef fishes

With rapidly increasing rates of contemporary extinction, predicting extinction vulnerability and identifying how multiple stressors drive non-random species loss have become key challenges in ecology. These assessments are crucial for avoiding the loss of key functional groups that sustain ecosystem processes and services. We developed a novel predictive framework of species extinction vulnerability and applied it to coral reef fishes. Although relatively few coral reef fishes are at risk of global extinction from climate disturbances, a negative convex relationship between fish species locally vulnerable to climate change vs. fisheries exploitation indicates that the entire community is vulnerable on the many reefs where both stressors co-occur. Fishes involved in maintaining key ecosystem functions are more at risk from fishing than climate disturbances. This finding is encouraging as local and regional commitment to fisheries management action can maintain reef ecosystem functions pending progress towards the more complex global problem of stabilizing the climate.     

Mapping the Drivers of Climate Change Vulnerability for Australia’s Threatened Species

Effective conservation management for climate adaptation rests on understanding the factors driving species’ vulnerability in a spatially explicit manner so as to direct on-ground action. However, there have been only few attempts to map the spatial distribution of the factors driving vulnerability to climate change. Here we conduct a species-level assessment of climate change vulnerability for a sample of Australia’s threatened species and map the distribution of species affected by each factor driving climate change vulnerability across the continent. Almost half of the threatened species assessed were considered vulnerable to the impacts of climate change: amphibians being the most vulnerable group, followed by plants, reptiles, mammals and birds. Species with more restricted distributions were more likely to show high climate change vulnerability than widespread species. The main factors driving climate change vulnerability were low genetic variation, dependence on a particular disturbance regime and reliance on a particular moisture regime or habitat. The geographic distribution of the species impacted by each driver varies markedly across the continent, for example species impacted by low genetic variation are prevalent across the human-dominated south-east of the country, while reliance on particular moisture regimes is prevalent across northern Australia. Our results show that actions to address climate adaptation will need to be spatially appropriate, and that in some regions a complex suite of factors driving climate change vulnerability will need to be addressed. Taxonomic and geographic variation in the factors driving climate change vulnerability highlights an urgent need for a spatial prioritisation of climate adaptation actions for threatened species.     

气候变化对“山水林田湖草”重大生态工程的影响

“山水林田湖草”重大生态保护与修复工程是中国对复杂生态环境治理的重要探索。鉴于目前大多数重大生态工程未系统地考虑气候变化对重大生态工程的影响问题,针对气候变化对高寒草地、北方林区以及风沙源区生态的影响,以实施了多年的三江源生态保护工程、三北防护林工程和京津风沙源治理工程为重点,分析了重大生态工程对全球气候变化的响应,解构了重大生态工程与气候的反馈关系和影响程度,指出了中国“山水林田湖草”重大生态工程实施过程中可能存在的问题,并给出了应对建议。结果表明：（1）气候变化对重大生态工程影响研究不足,尤其是涉及区域生态系统结构、功能、生物多样性与脆弱性等方面以及气候变化在工程实施效果贡献率的研究。（2）缺乏有效区分气候变化和工程实施效果的评估方法。目前能够定量识别气候变化对生态系统恢复的试验和方法比较少见,且缺乏对气候变化未来风险预估,导致制订的措施不能有效适应气候变化从而达到生态效益的最大化。所以在今后设计和实施“山水林田湖草”重大生态保护与修复工程时,要充分考虑自然规律、地理地带性差异和气候因素对生态系统的影响,并且加强建设生态综合监测和工程评价体系,根据未来不同的气候变化情景制订不同的措施,并依据气候动态预估来适当调整措施,使得生态工程能发挥出最大效益,以保证修复工程的系统性、区域性和整体性。