气候变化对陕西苹果生长适宜性影响

摘要

利用陕西苹果生产基地县及其以北地区气象观测和物候观测资料,采用时间序列分析和专家打分方法,分析了近50年来影响陕西苹果产量和质量的主要气象因子、花期霜冻和高温日数的变化特征以及气候变化对陕西苹果生长的气候适宜性评分的影响.结果表明:年平均气温和夏季平均最低气温具有明显的上升趋势,夏季相对湿度变化不大,近30年(1979-2008年)年降水量明显少于1961-1990年平均值;1961-1990年、1971-2000年、1979- 2008年3个30年苹果基地县大部分果区气候适宜性总评分没有明显变化;温度升高、降水减少是研究区域一些县(区)苹果生长气候适宜性评分变化的主要原因.1961年以来,4月中旬霜冻频率的增加使渭北西部果区和延安果区遭遇花期冻害的可能性增加;20世纪90年代以来,高温日数的增加使果树受高温热害的影响增大.%Based on the meteorological data from 1961 and phenological observations data from 2001 of the northern part of Shaanxi Province, the main meteorological factors that influence apple production and quality,the features of frosts over the apple blooming periods and the average days of high temperature as well as the impact of climate change on apple growth during the past 50 years are analyzed, using the methods of time series analysis and agricultural climatic indices and grade criterion for apple planting demarcation of China. The results suggest that among the factors affecting apple planting, the annual mean temperature is in a rising trend. The rate of rising trend is about 0. 23-0. 37℃/10 a across Yan'an and the north area of it, and is about 0. 14-0. 24℃/10 a in Guanzhong and Weibei apple planting areas. The minimum mean temperature from June to August is in a smaller rising trend, too. The mean relative humidity in the same period doesn't change much. The mean annual precipitation is in a decreasing trend. In the recent 30 years (1979-2008) ,the mean annual precipitation becomes obviously less than the average from 1961 to 1990.Analysis on apple growth during the three periods of 1961 to 1990, 1971 to 2000 and 1979 to 2008show that the grades of climatic suitability of apple growth remains in former climatic suitability range.Due to the rising of annual mean temperature, the grade of the west Guanzhong apple planting area decreases, but the grade of the north apple planting area increases. Due to the minimum mean temperature of summer rising, the years of grades are not in suitable range in Huanghe River bank and Guanzhong areas are increasing years. Precipitation change results in the grades decreasing in part of Guanzhong and the east of other apple planting areas. That is to say, in some regions the rising of the annual average temperature and the declining of the mean annual precipitation have resulted in the grades change of climate suitability for apple growth. Increasing frost frequency, especially in the second ten days of April in recent years since 1961, increases the possibility of frost damage on apple flowering in Yan'an and the west of Weibei apple planting areas where the date of apple flower is ahead of before. Since the 1990s, the increasing high temperature days have caused growing damage on apple production and should be noticed.