我国东南部地区青枣种植的热量条件分析

根据前人研究成果，选取≥10 ℃活动积温、年平均气温、冬季日平均气温≤8 ℃的天数、≤-2 ℃的积寒指数作为青枣种植的热量条件指标。利用广东、广西、福建的241个气象台站30 a（1981—2010年）的逐日气象观测资料，对青枣种植的热量条件进行年际、年代际分析，并应用ArcGIS的空间插值方法推算各指标的年代际空间分布。分析结果表明，21世纪以来，≥10 ℃活动积温≥6 500 ℃·d的面积较1980年代、1990年代分别增加8.77%、4.05%；年平均气温≥18 ℃的面积较1980年代、1990年代分别增加8.89%、4.69%，种植北界有所北移；适宜青枣生长的热量明显增加。冬季寒害严重影响的趋势较1990年代有所减轻，但≤-2 ℃有害积寒0~5 ℃·d的面积较1980年代、1990年代分别增加1.42%、2.78%，且影响区域约占研究区面积的85%；冬季日平均气温≤8 ℃的天数呈减少趋势，但≤-2 ℃的有害积寒、总天数年际波动性变化较大，冬季日平均气温≤8 ℃的天数、≤-2 ℃的积寒指数极大值均出现在福建宁德地区。因此，广东、广西大部地区热条件均适宜青枣种植，但在两广北部、福建仍有遭受严重寒害的可能，应该在具备防寒措施的区域种植。 

HEAT CONDITION ANALYSIS FORZIZYPHUS MAURITIANA LAM PLANTING IN THE SOUTHEAST OF CHINA

This paper presents analysis results of temperature index for growing Zizyphus Mauritiana Lam in Southern China. Based on the results of existing researches, we selected the following indexes: accumulate temperature(≥10 ℃), annual average temperature, days with average temperature below 8 ℃ and, accumulated cold temperature(≤-2 ℃). Daily meteorological data from 241 meteorological stations of Guangdong, Guangxi and Fujian were used to analyze inter-annual and inter-decadal changes of heat conditions for growing Zizyphus Mauritiana. Spatial distribution of the inter-decadal index was also included, using spatial interpolation approaches of ArcGIS software. The result shows that the area of accumulated active temperature(≥10 ℃) above 6 500 ℃·d has increased 8.77% and 4.05% in this century as compared to the 1980s and 1990s, respectively; the area of annual average temperature above 18 ℃ has also increased 8.89% and 4.69%, respectively. The northern boundary of planting Zizyphu Mauritiana Lam is shifting northward. Heat resource suitable for Zizyphus Mauritiana Lam's growth has also increased considerably. Although the effects of cold hazards in winter is less severe compared to the 1990s, the area of accumulated cold temperature (≤-2 ℃) between 0 and 5 ℃·d, which is about 85% of the study area, has increased 1.42% and 2.78% respectively compared to the 1980s and 1990s. The number of days with temperature below 8 ℃ in winter showed a decreasing trend, while the accumulated cold temperature (≤-2 ℃) and the total number fluctuated greatly between years. The maximum values of days with temperature below 8 ℃ and accumulated cold temperature (≤-2 ℃) are both present in the Ningde area of Fujian. In conclusion, most areas of Guangdong and Guangxi possess the heat condition that suits for the growth of Zizyphus Mauritiana Lam, while the northern part of Guangdong, Guangxi and Fujian may still suffer from severe cold hazards and should take protection measures in planting.