[Characteristics of agricultural climate resources in three provinces of northeast China under global climate change].

Based on the 1961-2007 weather data from 72 meteorological stations in three provinces of Northeast China, the change characteristics of agricultural climatic factors including yearly and temperature-defined growing season's mean air temperature, > or =10 degrees C accumulated temperature, precipitation, reference evapotranspiration, and sunshine hours were analyzed. In 1961-2007, the yearly mean air temperature in the three provinces had an increasing trend, with a rate of 0.38 degrees C x 10 a(-1). The > or =10 degrees C accumulated temperature in temperature-defined growing season also had an increasing trend, and the border of > or =10 degrees C accumulated temperature belt moved northward and eastward. The area of > or =3200 degrees C x d accumulated temperature increased by 2.2 x 10(4) km2. The belt of 2800-3200 degrees C x d moved northward about 0.85 degrees and eastward about 0.67 degrees, while that of 2400-2800 degrees C x d moved northward about 1.1 degrees. The sunshine hours decreased significantly, especially in the east part of Songnen Plain, central and west plains of Jilin Province, and west part of Liaohe River Plain. The area with sunshine hours > 2800 h decreased from 13.6 x 10(4) km2 to 4. 1 x 10(4) km2, and the zone with sunshine hours 2600-2800 h moved westward about 1.5 degrees. The average sunshine hour in temperature-defined growing season was 1174 h. Comparing with that in 1961-1980, the region with more sunshine hours in temperature-defined growing season in 1981-2007 narrowed significantly, and the zone with sunshine hours 1200-1400 h moved westward about 0.9 degrees. In 1961-2007, both the yearly and the temperature-defined growing season's precipitation decreased, and the yearly reference evapotranspiration increased in Heilongjiang Province and in the eastern mountain areas of Jilin Province but decreased in the central and west plains of Jilin Province and in Liaoning Province. Comparing with that in 1961-1980, the zone of reference evapotranspiration with the value of > or =900 mm in 1981-2007 moved westward about 1 degree, and the reference evapotranspiration in temperature-defined growing season increased in most regions of Heilongjiang and Jilin Province but decreased in a rate of 0-14 mm x 10 a(-1) in most regions of Liaoning Province.