关键词: 气候变化, 粮食产量, 气候影响程度指数, ≥10℃积温, 生长季降雨量, 黑龙江省

Abstract: Climate warming was significant in recent 20 years in Heilongjiang province. Many researchers found that increase of heat was beneficial to agricultural production except for drought and meteorological disasters in this province. The existing researches neither fully considered the spatial difference nor the impact of economic factors. In order to disintegrate physical and economic factors in grain yields more reasonably and analyze their different impacts on changes of yields in Heilongjiang Province, we collected the data of agricultural production (labors input, power input, irrigation input, fertilizer input, agriculture output, grain yields, and sown area of crops)from 1986 to 2000 in 79 counties of Heilongjiang Province, based on which grain yield (Y) was divided into climatic yield (Yc) and economic yield (Yt) by the method of Cobb-Douglas Production Function. Daily temperature and precipitation of 30 weather stations were used to calculate accumulated temperature ≥10℃ and precipitation during growing season. EOF method was applied to analyze the spatial and temporal characteristics of grain yield, climatic impact index (Yc/Yt), accumulated temperature ≥10℃ and growing season precipitation whose relationships were also considered. The results showed that grain yields of the whole province steadily increased during the past 15 years. Fertilizer was the leading driving force of economy that influenced the economic yields. Labors and R&D Fund Input in agriculture were not as important as fertilizer input. At the same time, power and irrigation input played the relative less roles in so many economic factors. Climate warming was significant from 1986 to 2000 in Heilongjiang Province. Accumulated temperature ≥10℃ increased 21-27℃ per year, benefiting agricultural production in most parts of the province. However, no obvious precipitation trend of growing season was found, and the change of precipitation didn’t essentially affect crop yields. The climate impact index increased during 15 years with different temporal and spatial variations. From 1986 to 1993, accumulated temperature ≥10℃ increased more obviously in the northern and southwestern parts of the province than the northeastern and southeastern parts, which had greater impacts on crop yields. While the converse situation existed from 1993 to 2000. Accumulated temperature ≥10℃ increased much more obvious in the northeastern and southeastern parts than the northern and southwestern parts, so did crop yields.

Key words: climate change, crop yields, climatic impact index, accumulated temperature ≥10℃, precipitation during growing season, Heilongjiang Province