用线性回归、相对变率、非整数波及小波周期分析等方法,分析了自有气象记录以来,吉林省不同区域日平均气温稳定≥7℃初日、终日,≥10℃积温及5～9月平均气温之和等几项与农业生产有密切关系的界线温度条件的长期变化特征,揭示了它们的时间变化趋势和周期变化规律,探讨了未来10a内这些条件的可能变化趋势及农业生产问题。

The change featur and cycles of the agricultural boundary temperature in every region of Jilin province were analyzed by using the linear regression, no integral wave and Wavelet analysis methods. And the change tendency of main agroclimate factors in the future 10 years were analyzed. The main factors include: the first date and final date of air temperature >7℃, stably; the ≥10℃ accumulated temperature, and the air mean temperature from May to Sept. The result shows that the first dates have a shift to an earlier date in the recent half century, and the thermal resources in the agricultural season have a increasing tendency. but the temperature condition has become unsteady in recent years. The first and end date of the limit temperature keep cycles variation with 20, 15 and 9 years, the accumulated temperature and mean temperature keep several cycles variation with 60, 15-16, 9 and 3-4 years. By the year 2010, the warmer period will end in the longer (60 years) climate cycle, and increasing tendency of the thermal resouse and the advance tendency of the seeding time will be subsiding. The future several years in the short cycle, the accumulated temperature should reduce, low temperature calamity and frost should happen frequently, the agricultural actions, such as seeds arranging and seeding period in every region should be adjusted.