Abstract:

【Objective】 The period from 1950s to 2007 was divided into two stages,i.e., 1950s-1980 and 1981-2007, then the geographical shift of northern limit for tropical crops and the possible risk of cold damage in the cold-sensitive areas after the shift were analyzed and compared. 【Method】 Using the standard of China farming system regional planning and some agro-meteorological indicators, the geographical shift of safe northern limit were compared and analyzed and the change map were draw by ArcGIS. Using the synthesized index of cold damage, the risks of cold damage in sensitive area of planting tropical crops were evaluated. 【Result】 Compared with the results during the period from 1950s to 1980, in the 80% climate guarantee rate, the safe northern limit moved northward by 0.86 latitude during the period from 1981 to 2007. Its interdecadal change was obvious, and the respective annual rating of moving northward was 0.03 and 0.06 latitude during the 1990s and the period 2000-2007. In the 80% climate guarantee rate, the risk of cold damage in sensitive area of planting tropical crops reached 3.0 times higher than the non-sensitive area, especially the risk caused by severe or very severe cold damage reached 3.5 times. 【Conclusion】 The safe Northern limit has shown an obvious northward moving under climate warming and the rate of northward moving shows an accelerated trend. The risk of cold damage is increased in the moving sensitive region of the safe northern limit.

Key words: climate warming')">climate warming, tropical crops, northern limits, risk of cold damage