应对气候和生态环境危机促进全球可持续发展——UNEP与自然和谐共处报告简述

2021年2月18日,联合国环境署发布《与自然和谐共处：应对气候、生物多样性和污染危机的科学蓝图》。报告指出：气候变化、生物多样性下降和环境污染已经成为全球三大环境紧急情况;人与自然关系面临着社会经济发展压力加剧环境风险、遏制环境恶化的全球承诺尚未兑现、环境风险威胁可持续发展目标等多重挑战;全球亟需开展以联合国可持续发展目标为框架的系统变革,加快应对全球环境危机的重点行动,改革资源环境和经济系统,提高粮食、能源和水系统的环境友好性与可持续性,加强对人体健康与生态环境健康的协同保护,进而推动人与自然的和谐共处以及可持续发展。该报告结合全球环境评估的最新进展,强调了社会-经济-环境可持续发展仍是未来的重要研究课题,对我国社会-生态系统与可持续发展等领域的科学研究有如下启示：（1）创新社会-生态系统的综合集成研究,探寻不同发展路径和气候变化情景下社会-生态系统时空演变特征与趋势;（2）注重科学研究对决策的支撑以及与国际重大议程的衔接,探索和创新可持续发展的中国方案。     

Early-life exposure to climate change impairs tropical shark survival

Sharks are one of the most threatened groups of marine animals worldwide, mostly owing to overfishing and habitat degradation/loss. Although these cartilaginous fish have evolved to fill many ecological niches across a wide range of habitats, they have limited capability to rapidly adapt to human-induced changes in their environments. Contrary to global warming, ocean acidification was not considered as a direct climate-related threat to sharks. Here we show, for the first time, that an early ontogenetic acclimation process of a tropical shark (Chiloscyllium punctatum) to the projected scenarios of ocean acidification (ΔpH = 0.5) and warming (+4°C; 30°C) for 2100 elicited significant impairments on juvenile shark condition and survival. The mortality of shark embryos at the present-day thermal scenarios was 0% both at normocapnic and hypercapnic conditions. Yet routine metabolic rates (RMRs) were significantly affected by temperature, pH and embryonic stage. Immediately after hatching, the Fulton condition of juvenile bamboo sharks was significantly different in individuals that experienced future warming and hypercapnia; 30 days after hatching, survival rapidly declined in individuals experiencing both ocean warming and acidification (up to 44%). The RMR of juvenile sharks was also significantly affected by temperature and pH. The impact of low pH on ventilation rates was significant only under the higher thermal scenario. This study highlights the need of experimental-based risk assessments of sharks to climate change. In other words, it is critical to directly assess risk and vulnerability of sharks to ocean acidification and warming, and such effort can ultimately help managers and policy-makers to take proactive measures targeting most endangered species.     

全球环境变化对典型生态系统的影响研究:现状、挑战与发展趋势

随着全球环境变化和人类活动对生态系统影响的日益加深,生态系统结构和功能发生强烈变化,生态系统提供各类资源和服务的能力在显著下降。在这种背景下,全面认识生态系统的结构功能与全球环境变化的关系已成为当前生态学研究的热点之一。本文综述了全球环境变化对典型生态系统(包括森林生态系统、河口湿地生态系统、城市生态系统)影响以及全球环境变化适应的研究现状,分析研究面临的困难及挑战。在此基础上,提出对未来研究发展趋势的展望。在森林生态系统与全球环境变化研究上,未来应重视能更好模拟现实情景的、多因子、长期的全球环境变化控制试验,并注重不同生物地球化学循环之间的耦合作用。在湿地生态系统与全球环境变化研究上,未来应加强氮沉降、硫沉降及盐水入侵对湿地生态系统碳氮循环的影响,明晰滨海湿地的蓝碳功能,加强极端气候和人类干扰影响下湿地生态系统结构和功能变化及恢复力的研究。在城市生态系统与全球环境变化研究上,未来应深化城市生物地球化学循环机制研究,实现城市生态系统的人本需求侧重与转向,并开展典型地区长期、多要素综合响应研究。在全球环境变化适应研究上,未来应构架定量化、跨尺度的适应性评价体系,加强典型区域/部门的适应性研究以及适应策略实施的可行性研究,注重适应与减缓对策的关联研究及实施的风险评估。期望本综述为我国生态系统与全球环境变化研究提供一些参考。     

Mosquito-borne disease and climate change in Australia: time for a reality check

Will warming climate increase the risk or prevalence of mosquito-borne disease in Australia, as has been projected in a number of scientific publications and governmental reports? Unfortunately, most of these 'predictions' do not adequately consider the current and historical distribution of the vectors and diseases, their local ecology and epidemiology and the impact of societal features and the capacity for public health interventions in Australia. Overall, a strong case can be made that we are unlikely to see significant changes in the distribution of transmission of the exotic pathogens causing malaria and dengue, and while activity of endemic arboviruses such as Murray Valley encephalitis and Ross River viruses may possibly increase in some areas, it is likely to decrease in others. The ecologies of mosquito-borne diseases can be complex and difficult to predict, and any evaluation of potential effects of changes in climate will need a detailed examination of site-specific vector, host and other factors likely to influence the outcomes on human health. Of itself, climate change as currently projected, is not likely to provide great cause for public health concern with mosquito-borne disease in Australia.     

Environmental change as a driver of diversification in temporary aquatic habitats: does the genetic structure of extant fairy shrimp populations reflect historic aridification?

1. Over the past 65 my, the Australian continent experienced a pronounced shift from predominantly wet, tropical, conditions to a much drier climate. Little is known, however, about the effect of this important continent‐wide event on freshwater organisms and ecosystems. Fairy shrimps (Crustacea; Anostraca) are ancient and specialist inhabitants of temporary and saline aquatic habitats that typically prevail under semiarid conditions. Therefore, they present suitable evolutionary models to study scenarios of historic environmental change and the impact of a drying climate on aquatic ecosystems in particular.
2. Focussing on both macro‐ and micro‐evolution in the fairy shrimp genus Branchinella and using mitochondrial DNA data (16S and COI), we evaluated whether patterns of contemporary genetic variation reflect historic climate change.
3. There is a close match between episodes of Cenozoic climate change and macro‐evolutionary diversification in Australian fairy shrimps, presumably mediated by a progressive increase in the abundance and diversity of temporary aquatic habitats on the continent. Micro‐evolutionary patterns reflect both range expansion and recent contraction, linked to extreme drying events during the Pleistocene glacial periods.
4. This study effectively illustrates the potential long‐term effects of environmental change on the diversity and the evolutionary trajectories of the fauna of temporary waters. Moreover, it demonstrates the importance of adaptation to new environments and non‐adaptive processes, such as divergence in isolation, for explaining extant diversity patterns in this particular environment.