中国粮食主产区生产潜力对气候波动响应研究

Response of Production Potential to Climate Fluctuation in Major Grain Regions of China

粮食生产对粮食安全的影响是目前全球关注的热点之一,且粮食主产区的粮食生产潜力格局及其对气候变化的响应是保障中国粮食安全的关键问题。本文对逐级递减的机制法模型进行了改进,主要是修正计算太阳辐射的系数a和b,并划分不同土壤有效系数指标区来构建各自的评价指标体系,计算了1995年和2005年的光合、光温、气候和土地等4个逐级递减层次的生产潜力,并分析1995-2005气候变化对光合、光温、气候和土地四个层次生产潜力的影响。结果表明,研究区内绝大部分区域的作物有效生育期增加,并且有效生育期初日时间逐渐提前,而终日时间相应推迟;同时生育期时段内的日照时数增加;而作物有效生育期内有效降水量总体减少,且大部分地区降水多集中在有效生育期内。降水减少是整个研究区粮食生产发展的主要制约因素,各气象因子的变化整体上有利于生产潜力的增长。气候波动使得光合、光温、土地3个层次的生产潜力增长,使得气候生产潜力降低。对光合、光温、气候和土地4个层次的影响程度逐渐减小。从对水田和旱地的影响看,气候波动导致水田光合生产潜力比旱地的增加更多;而气候波动使旱地的光温生产潜力比水田的增加更多;气候波动导致旱地的气候生产潜力比水田的减少更多;气候波动导致旱地的土地生产潜力增加,但水田的土地生产潜力减少。

Grain production has an important effect on food security. The pattern of grain productive potentiality in China's major grain production areas will be needed to control food security during climate change. This study aimed to improve two aspects of the mechanism model.First,we revised the coefficients a and b for calculating solar radiation. Second,we divided the study area into different zones according to soil effective coefficients and then constructed evaluation index systems. We used these revised models to calculate the grain productive potentiality at the four levels of photosynthesis,light- temperature,climate and soil. We analyzed climate fluctuation impacts on grain productive potentiality and found that effective growth periods increased in most areas and beginning- days gradually advanced and ending- days were delayed.Sunshine duration time increased and precipitation declined in the crop effective growth period,most of which was focused in the effective growth period. The decrease in precipitation controlled grain production in the study areas and production potential benefited from changes in meteorological factors on the whole. Climate fluctuation had a positive influence on photosynthesis,light-temperature and soil production potential. In contrast,climate fluctuation had a negative influence on climate production potential. The influence of climate fluctuation on photosynthetic,light- temperature,climate and soil of production potential gradually reduced. The increase in photosynthetic production potential of paddy fields caused by climate fluctuation was more than that of dry land and the increase in the light-temperature production potential of dry land was more than that of paddy fields. The decrease in the climate production potential of dry land was lower than that of paddy fields. Climate fluctuation increased the soil production potential of dry land,and decreased the soil production potential of paddy fields.