粮食生产系统对气候变化的响应:敏感性与脆弱性

Analysis on Agricultural Sensitivity and Vulnerability to Climate Change and Countermeasures

气候变暖延长了作物适宜生长季,缩短了实际生育期,改变了作物的种植界线;在一些区域促进了产量增高,给作物品质带来负面影响,并改变了气象灾害与病虫害的规律,导致损失增加。未来粮食生产系统对气候变化表现出较强的敏感性,如温度增高1℃,冬小麦生育期日数平均缩短17d左右,水稻和玉米平均缩短7-8 d,但地区之间存在差异。气候变化将威胁作物产量的稳定性,并影响作物品质。脆弱性主要是面对极端事件的影响,特别是在减小暴露度和提高适应能力两个方面,因为雨养农业的暴露度明显高于灌溉农业。为此,本文提出了相应的对策建议,以降低粮食生产系统对气候变化的脆弱性。一是加强对敏感性的评估能力建设,包括完善和改进各类评估指标体系和模型,创新和发展评估方法和工具;结合实地观测和案例研究,科学评估气候变化的影响与敏感性,识别和降低研究中的不确定性;提高人类对气候系统及其变化的认识,提高气候变化影响及相应领域敏感性的认识。二是加强粮食生产系统适应能力建设,包括对已有的农田基础设施进行改造,增强对气象灾害的防御能力;通过调整农业生产结构,有计划地选用抗旱涝、抗高低温和抗病虫害等抗逆品种和新品种;发展节水农业,加强推广旱作农业技术;综合多学科的理论方法,进一步开展粮食生产系统与气候变化有关的影响和适应研究。三是加强自然和社会系统体系和功能建设,包括加强高新技术和适用技术的推广,加快科技创新和技术引进步伐;通过立法、行政、财政税收等方式,积极推进农业保险,探索农业政策保险与商业保险相结合的风险分担机制;通过调整经济结构、提高能源效率,增加粮食生产系统固碳减排能力,维护良好的生态环境。

Climate warming prolonged adaptable growth season of crops, shortened actual growth period, changed crops planting boundaries. It also boosted crops yield growth in certain regions and destroyed crops quality, and affected the occurrence of meteorological disasters and diseases and pest damage, which resulted in more grain yields loss. Crop production system will become more sensitive to climate change in futrue. For example, with 1℃ increasing, the avarage growth period will be shorten 17 days for winter wheat, and 7 - 8 days for maize and rice. Of course differences will differ in regions. Climate change will threaten crop yield stability and affected crop quality. Vulnerability is mainly in the aspect of being affected by extreme climate events, which include reducing exposure and improving adaptive capability, because the exposure of rainfed agriculture is higher than that of irrigated agriculture. Therefore, we put forward three suggestions to reduce the vulnerability of crop production system to climate change. Firstly, strenthen evaluation capability to senstivity, which include improving all kinds of evaluation index systems and models, developing new evaluation metheds and tools, conducting practise study and case study to reduce the uncertainty, and raising awareness of climate system and climate change, climate change impact and their senstivity. Secondly, strenthen adaptive capacity construction for crop production system, which include rebuilding existing farmland infrastructure to improve meteoroligical disaster defence, adjusting agricultural structure and adopting new varieties with wide resistance, popularizing water saving technology and dry farming technology, and carrying out research with interdisciplinary therioes and methods. Thirdly, strenthen function construction for natural and social systems, which include popularizing high-tech and new technology, carrying out agricultural insurance, improving enengy efficency and increasing carbon sequestration and emission reduction ability to maintain favorable ecological environment.