[CO2]升高对粮食作物影响的研究进展

自工业革命以来,由人类活动引起的大气CO_2浓度([CO_2])不断攀升,正驱动着全球气候变化,对全球农业产生重大影响。本文归纳总结了目前作物对高[CO_2]响应的主要研究技术手段,以及作物对高[CO_2]响应的机理研究,并进一步梳理了当前全球关于[CO_2]升高对作物产量和营养品质影响的研究。结果表明:相比封闭式或半封闭式环境控制试验系统,开放式试验系统(如开放式CO_2控制系统FACE)由于其能更加真实地模拟自然条件下作物对未来高[CO_2]的响应和适应情况,被公认为是目前研究作物对高[CO_2]响应的最理想手段。[CO_2]增高会增加C3作物光合速率、生物量和产量,在一定程度上缓解气候变化对农作物产生的负面影响,但是作物对大气[CO_2]的升高存在光合适应现象,当作物长期暴露在高[CO_2]条件下时,高[CO_2]对作物的促进作用会逐渐减缓。近10年的FACE试验发现,对高[CO_2]出现高应答的水稻品种,其光合速率和产量在高[CO_2]下的增加幅度比早期的主要粮食作物FACE试验结果平均高出两倍。此外,高[CO_2]会明显降低大部分非豆科C3作物中蛋白质和矿物质(如锌、铁)以及部分维生素的含量,加剧目前全球约2亿人由于维生素和矿物质元素等营养缺乏导致的健康问题。如何充分利用未来高[CO_2]实现高增产的同时,减缓粮食养分下降的负面影响,是迫切需要解决的科学问题。     

气候变暖对我国水稻生产的综合影响及其应对策略

气候变暖已是不争的事实,预计到21世纪末全球地表平均气温仍将上升1.5℃以上。水稻是我国最重要的口粮作物,全国80%以上的人口以稻米为主食,探明气候变暖对我国“口粮绝对安全”的潜在影响意义重大。作者依据多年的田间增温试验及长期观察,并结合国内外现有研究,阐明了我国粮食主产区气候变暖的基本态势,总结发现温度升高1.5℃对我国水稻生产的潜在影响正负参半,并取决于具体的稻作季节和地区。但是,随着水稻种植制度调整,尤其是南方双季稻种植面积下降,温度升高对我国水稻生产的负面影响将逐步递增。最后,作者提出了应对气候变暖的气候智慧型稻作技术创新建议,并展望了该研究领域的重点内容和方向。     

Positionality and protocol in field research: Undertaking community‐based investigations in Samoa

This article considers the experiences of a Samoan female geographer undertaking community‐based field research in her home country, and identifies some lessons for researchers working in similar circumstances. The paper suggests that ethical behaviour in research is ‘place‐specific’, and there is therefore a need to employ culturally sensitive and ‘location‐specific’ methodologies when undertaking community‐based research fieldwork. For the lead researcher, growing up in Samoa played a significant role in gaining an understanding of a set of robust and effective procedures to evaluate citizens' resilience to climatic and other environmental challenges. Fluency in everyday and more formal local languages, and awareness of local differences, each with multi‐layered connections to local communities, understanding cultural nuances and practising respect for va tapuia [sacred space or relationships] protocols, together facilitated the process of knowledge acquisition and helped to confirm the validity of the conclusions derived from the study.     

罗布泊盐湖沉积物磁性特征及其环境意义

以罗布泊盐湖沉积物为研究对象,以环境磁学为主要研究方法,探讨罗布泊盐湖沉积物磁性特征的影响因素和环境意义.根据磁性特征可将罗布泊LOP1剖面沉积物分为两类:磁铁矿主导和铁硫化物(胶黄铁矿和黄铁矿)主导.磁铁矿主要来源于物源区塔里木盆地.胶黄铁矿和黄铁矿是早期还原成岩作用的产物,对磁性特征产生显著影响,胶黄铁矿主导层具有...     

BUILDING CLIMATE-RESILIENT FOOD SYSTEMS IN EAST AND SOUTHEAST ASIA: VULNERABILITIES,RESPONSES AND FINANCING

Food system resilience to climate change is uniquely imperative for bringing Sustainable Development Goals within reach and leaving no one behind. Food systems in East and Southeast Asia are interacting with planetary boundaries and are adversely affected by extreme weather-related events. A practical question for East and Southeast Asian stakeholders is how to foster climateresilient food systems in the face of lingering food system vulnerabilities and policy gaps. This paper reviews food syste...     

土壤有机碳库及其控制因子的研究进展

土壤碳库的动态平衡影响作物产量和土壤肥力的高低,是土壤肥力保持和提高的重要研究内容。本文简要评述了气候、植被、土壤理化特性和农业生产对土壤有机碳分解的影响,介绍了土壤有机碳库及其控制因子的研究进展。     

Tomato brown rugose fruit disease: current distribution,knowledge and future prospects

Tomato is the most economically important fruit/vegetable crop grown worldwide. However, viral diseases remain an important factor limiting its productivity, with estimated quantitative and qualitative yield losses in tomato crops often reaching up to 100%. Many viruses infecting tomato have been reported, while new viral diseases have also emerged. The climatic changes the world is experiencing can be a contributing factor to the successful spread of newly emerging viruses, as well as the establishment of disease in areas that were previously either unfavourable or where the disease was absent. Because antiviral products are not available, strategies to mitigate viral diseases rely on genetic resistance/tolerance to infection, control of vectors, improvement in crop hygiene, roguing of infected plants and seed certification. Tomato brown rugose fruit virus (ToBRFV) is an emerging viral threat to tomato productivity and is currently spreading into new areas, which is of great concern to the growing global production in the absence of mitigation measures. This review presents the current knowledge about ToBRFV and future prospects for an improved understanding of the virus, which will be needed to support effective control and mitigation of the impact it is likely to cause.     

青藏高原草地降水利用效率时空动态及对气候变化的响应

本研究利用CASA(Carnegie-Ames-Stanford Approach)模型模拟了2000—2013年青藏高原草地净植被生产力(Net Primary Production,NPP),结合实测数据、气象数据和土地覆被数据计算了草地降水利用效率（PUE）,探究其时空分布特征,以及不同草地类型PUE及其对气候变化的响应。结果表明：青藏高原草地PUE在研究年限内呈现波动增加趋势,增加速率为每年0.0035 g·m^-2·mm^-1,14 a的平均值为0.38 g·m^-2·mm^-1。PUE的空间分布具有明显的异质性,呈现东部高、中西部低的基本格局。PUE分布在0.2～0.4 g·m^-2·mm^-1之间的比例最大,占青藏高原总面积的55.63%,呈减少趋势的区域主要分布在青藏高原的北部和西部,以及东部的边界地区,呈增加趋势的地区集中在研究区的中部和南部。研究年限内PUE的变异系数分布在0.07～0.85之间,变化稳定的区域所占面积最大,为总面积的43.43%,主要分布在唐古拉山脉和横断山脉附近。不同草地类型间PUE均值存在差异,具体表现为：草甸（1.06 g·m^-2·mm^-1）>坡面草地（0.80 g·m^-2·mm^-1）>平原草地（0.30 g·m^-2·mm^-1）>高山与亚高山草甸（0.29 g·m^-2·mm^-1）>荒漠草地（0.23 g·m^-2·mm^-1）>高山与亚高山草地（0.094 g·m^-2·mm^-1）。总体上,青藏高原草地PUE与降水成负相关关系,而与气温呈正相关,PUE的变化对降水响应更加敏感。     

1957—2015年叶尔羌河流域气候变化特征及其径流响应

根据流域内气象、水文站点的长期观测数据,利用线性趋势、相关系数、累积距平、Mann-kendall(M-K)突变检验等方法分析不同区域的干、湿季气候变化特征,并假定不同的气候情景组合,分析径流对气候变化的响应程度。结果表明:(1)1957-2015年4个单元气温和降水量呈增加趋势;除上游外,相对湿度、平均风速和大风日数呈减小趋势,流域径流量呈增加趋势。(2)气温在1996年发生突变;降水量未出现明显突变点;相对湿度在2005年左右发生突变;除下游外,平均风速在1983年发生突变;径流量于1993年发生突变,突变后径流量增加了9.08×10^8m^3。(3)相关性分析显示,流域径流量与湿季平均气温、平均最低(最高)气温呈极显著正相关,与湿季平均风速、大风日数和相对湿度呈负相关,除上游径流与干季降水量呈正相关外,其他区域与降水量呈负相关。(4)敏感性分析表明,当降水量不变,气温升高1℃,径流量增加9.06%;当气温不变,降水量增加10%,径流量减小1.67%,这主要与径流组成有关。流域77.4%的径流量来自雪冰融水补给,当降水量增加时,气温降低,减少了冰川积雪的融化,因而流域径流与气温呈正相关,与降水量呈负相关,且对气温变化更敏感。