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561.
Climate change is driving rapid and widespread erosion of the environmental conditions that formerly supported species persistence. Existing projections of climate change typically focus on forecasts of acute environmental anomalies and global extinction risks. The current projections also frequently consider all species within a broad taxonomic group together without differentiating species-specific patterns. Consequently, we still know little about the explicit dimensions of climate risk (i.e., species-specific vulnerability, exposure and hazard) that are vital for predicting future biodiversity responses (e.g., adaptation, migration) and developing management and conservation strategies. Here, we use reef corals as model organisms (n = 741 species) to project the extent of regional and global climate risks of marine organisms into the future. We characterise species-specific vulnerability based on the global geographic range and historical environmental conditions (1900–1994) of each coral species within their ranges, and quantify the projected exposure to climate hazard beyond the historical conditions as climate risk. We show that many coral species will experience a complete loss of pre-modern climate analogs at the regional scale and across their entire distributional ranges, and such exposure to hazardous conditions are predicted to pose substantial regional and global climate risks to reef corals. Although high-latitude regions may provide climate refugia for some tropical corals until the mid-21st century, they will not become a universal haven for all corals. Notably, high-latitude specialists and species with small geographic ranges remain particularly vulnerable as they tend to possess limited capacities to avoid climate risks (e.g., via adaptive and migratory responses). Predicted climate risks are amplified substantially under the SSP5-8.5 compared with the SSP1-2.6 scenario, highlighting the need for stringent emission controls. Our projections of both regional and global climate risks offer unique opportunities to facilitate climate action at spatial scales relevant to conservation and management.  相似文献   
562.
563.
海岸带既是区域经济发展的黄金地带,亦是陆海系统交互胁迫的敏感区域,快速城镇化与工业化导致海岸带关键生态系统服务受损、生态网络格局紊乱、珍稀物种安全保障空间萎缩等重大生态安全问题。以闽三角海岸带珍稀物种-栖息地系统为研究对象,从“多物种-多生境-多尺度”视角出发,基于陆海统筹理念系统评估了闽三角海岸带珍稀物种-栖息地系统的脆弱性,建立了基于物种水平的海岸带生态保护与修复网络,构建了海岸带陆海统筹生态安全“一张图”。研究结果表明:(1)高强度围填海驱动下,闽三角红树林与水鸟栖息地脆弱性显著增加,高脆弱区域主要集中于九龙江河口、厦门同安湾和泉州湾;(2)闽三角生态安全网络由12条水鸟迁徙廊道和11个生态节点组成,其中影响陆海统筹生态安全的生态节点4个,预警生态节点3个;(3)闽三角海岸带未来安全韧性生境(水鸟栖息地与文昌鱼、中国鲎低脆弱生境较密集的区域)分布于云霄红树林保护区、东山岛近岸、九龙江河口、厦门大嶝海域、围头湾、深沪湾。本研究能够为设计规划未来韧性海岸带“受损海水-滨海湿地-珍稀物种”一体化修复与保护的生态安全格局,保障陆海统筹生态安全提供理论支撑和一体化解决方案。  相似文献   
564.
ABSTRACT

Climatic anomalies associated with El Niño bring prolonged droughts and night-time frosts that devastate subsistence gardens in the Papua New Guinea highlands. As a customary process of adaptation to the subsequent food insecurity caused by crop-destroying frosts, people migrate to lower altitude areas where kin and friends provide sustenance and social support. However, with increasing economic development and the demise of collective kin endeavours in the region, long-distance migration networks no longer appear to offer people respite from food insecurity. In this paper, I examine the changes in social responses to El Niño-caused food shortages at varying scales – from subsistence farmers to international aid agencies – over the past several El Niño events. The paper explores the production of vulnerability when customary social-ecological systems of adaptation intersect with regional and national politics, development efforts, and humanitarian aid agencies.  相似文献   
565.
The concept of vulnerability is widely used in research ethics to signal attention to participants who require special protections in research. However, this concept is vague and under‐theorized. There is also growing concern that the dominant categorical approach to vulnerability (as exemplified by research ethics regulations and guidelines delineating vulnerable groups) is ethically problematic because of its assumptions about groups of people and is, in fact, not very guiding. An agreed‐upon strategy is to move from categorical towards analytical approaches (focused on analyzing types and sources of vulnerability) to vulnerability. Beyond this agreement, however, scholars have been advancing competing accounts of vulnerability without consensus about its appropriate operationalization in research ethics. Based on previous debates, we propose that a comprehensive account of vulnerability for research ethics must include four components: definition, normative justifications, application, and implications. Concluding that no existing accounts integrate these components in a functional (i.e., practically applicable) manner, we propose an integrative and functional account of vulnerability inspired by pragmatist theory and enriched by bioethics literature. Using an example of research on deep brain stimulation for treatment‐resistant depression, we illustrate how the integrative‐functional account can guide the analysis of vulnerability in research within a pragmatist, evidence‐based approach to research ethics. While ultimately there are concerns to be addressed in existing research ethics guidelines on vulnerability, the integrative‐functional account can serve as an analytic tool to help researchers, research ethics boards, and other relevant actors fill in the gaps in the current landscape of research ethics governance.  相似文献   
566.
植物水力性状能够反映植物对不同水分条件的适应能力,研究热带珊瑚岛特殊生境下优势植物的水力功能特征对深入理解热带珊瑚岛植物的水分适应策略,从而选择热带珊瑚岛植被构建和恢复的适生物种具有重要意义。该研究以中国热带珊瑚岛生境中2种优势适生木本植物:抗风桐(Pisonia grandis)和草海桐(Scaevola sericea)为研究对象,比较了其叶片和枝条的水力性状,并分析了其水分适应策略。结果表明, 抗风桐的叶片栓塞抗性、枝条边材比导水率和叶片膨压丧失点显著高于草海桐,而枝条栓塞抗性、叶片导水率、边材密度和叶面积边材面积比均显著低于草海桐。抗风桐的叶片具有比枝条更强的抗栓塞能力,对水分胁迫敏感,但同时选择以高效的枝干水分运输来满足叶片高蒸腾需求的充足供水。草海桐枝条与叶片则存在水力脆弱性分区,在面临水分胁迫时叶片充当“安全阀”以保证枝干木质部的水力安全。抗风桐与草海桐能够通过协调叶片与枝条水力性状采取不同的水分适应策略,从而更好地适应热带珊瑚岛的特殊生境。  相似文献   
567.
Prenatal exposure to carcinogenic polycyclic aromatic hydrocarbons (c‐PAHs) through maternal inhalation induces higher risk for a wide range of fetotoxic effects. However, the most health‐relevant dose function from chronic gestational exposure remains unclear. Whether there is a gestational window during which the human embryo/fetus is particularly vulnerable to PAHs has not been examined thoroughly. We consider a longitudinal semiparametric‐mixed effect model to characterize the individual prenatal PAH exposure trajectory, where a nonparametric cyclic smooth function plus a linear function are used to model the time effect and random effects are used to account for the within‐subject correlation. We propose a penalized least squares approach to estimate the parametric regression coefficients and the nonparametric function of time. The smoothing parameter and variance components are selected using the generalized cross‐validation (GCV) criteria. The estimated subject‐specific trajectory of prenatal exposure is linked to the birth outcomes through a set of functional linear models, where the coefficient of log PAH exposure is a fully nonparametric function of gestational age. This allows the effect of PAH exposure on each birth outcome to vary at different gestational ages, and the window associated with significant adverse effect is identified as a vulnerable prenatal window to PAHs on fetal growth. We minimize the penalized sum of squared errors using a spline‐based expansion of the nonparametric coefficient function to draw statistical inferences, and the smoothing parameter is chosen through GCV.  相似文献   
568.
许嘉慧  孙德亮  张虹  文海家  吴健平  黄艳 《生态学报》2023,43(11):4594-4603
进行生态风险多尺度综合评价,对环境管理及风险决策具有重要意义。以三峡库区滑坡重点监测县域为例,基于“危险性-脆弱性-潜在损失”三维模型,以随机森林模型评估滑坡危险性,采用景观格局指数表征生态脆弱性,利用生境质量核算潜在生态损失,进行格网、行政、子流域多尺度下的滑坡灾害生态风险评价,提出适合各尺度的风险管理措施,在此基础上选择最适宜尺度并结合研究区实际情况进行验证。结果表明,生态风险等级较高区域集中于长江两岸沿线,三峡库区建设对研究区滑坡生态风险产生较大影响;两两尺度风险分布结果具有一定相似性,而三种尺度共同作用结果又存在一定差异;子流域尺度在保证生态结构完整性的前提下评价结果好于其他两种尺度,更适合三峡库区县域的生态风险评价;研究区东部风险防范类型相对单一,而西部风险防范类型较多,需做到精细化管理。研究增加了多尺度综合评价实例,对今后开展整个三峡库区滑坡生态风险研究奠定一定理论和实践基础。  相似文献   
569.
《Cell reports》2023,42(7):112755
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570.
在全球气候变化背景下,筛选抗旱强的城市绿化花卉植物是应对未来持续干旱下水资源短缺和城市绿化建设的重要途径。该研究以常见的城市绿化花卉植物山茶(Camellia japonica)和西洋杜鹃(Rhododendron hybridum)为材料,利用光学技术构建花瓣和叶片栓塞脆弱性曲线,并观察两种植物的花瓣及叶片形态结构特征,比较两种植物花瓣和叶片组织在水分胁迫期间的抗旱性。结果表明:(1)山茶和西洋杜鹃的生长土壤水势之间在自然干旱下没有显著差异,均从第9天开始与对照相比显著降低;西洋杜鹃叶片和花瓣水势在自然干旱后第9天显著降低,而山茶叶片和花瓣水势在自然干旱持续到第12天时显著降低。(2)西洋杜鹃花瓣和叶片水势的P50值(发生50%栓塞时对应的水势值)分别为-3.24 MPa和-4.40 MPa,分别大于山茶花瓣(-3.99 MPa)和叶片(-5.92 MPa)。(3)山茶和西洋杜鹃间的花瓣厚度、上下表皮厚度没有显著差异,而山茶花瓣的脉密度和气孔密度均显著大于西洋杜鹃花瓣;山茶叶片厚度、上下表皮厚度、海绵组织厚度、叶脉密度均显著大于西洋杜鹃。研究发现,西洋杜鹃的栓塞脆弱性大于山茶,其耐旱...  相似文献   
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