气候变暖背景下柑橘木虱在中国的适生区变化

Suitable distribution changes of Asian citrus psyllid Diaphorina citri in China under global warming

为明确气候变暖背景下柑橘木虱Diaphorina citri在中国的适生区变化趋势,通过对影响柑橘木虱分布的关键气候环境变量进行筛选,并基于其在中国的历史分布数据,利用最大熵MaxEnt模型分析过去50年间气候变暖对柑橘木虱在中国的适生区变化趋势的影响。结果表明,影响柑橘木虱适生区的6个主要气候环境变量是最冷季节降水量、最冷季节平均温度、冬季日平均气温小于等于-5℃的日数、温度季节性变化标准差、最暖月最高温度以及8月日平均气温大于30℃的日数。受气候变暖影响,20世纪60年代至21世纪初,柑橘木虱在我国的总适生区、中适生区和高适生区分布面积呈明显扩大趋势,高适生区扩大趋势较中适生区更为明显。其中高适生区在广西、贵州、湖南、江西、湖北、安徽和浙江等省区增加明显;中适生区在云南、贵州、重庆、湖北、安徽、江西和江苏等省市增加明显;低适生区的总体面积虽然在减少,却是由于中、高适生区北移造成的,且湖北省、四川省、重庆市和江苏省的北部部分地区由原来的不适生区转为低适生区。表明气候变暖导致我国气候更加适宜柑橘木虱生存,高适生区、中适生区和低适生区的北界都在北移,而其传播的柑橘黄龙病扩散风险加大,需要给予足够的重视。

To clarify the changing trend of the suitable areas of Asian citrus psyllid Diaphorina citri in China under the background of climate change, the key climate-environmental variables and climatic suitability for D. citri were calculated, and the suitable areas of D. citri in China were modeled by the maximum entropy model(MaxEnt) with the historic distribution data from the 1960 s to the beginning of the 21 st century. The results showed that the key climate-environmental variables limiting the distribution of D. citri were the precipitation and average temperature in the coldest season, the days of daily average temperature below -5℃ in winter, standard deviation of temperature seasonality, the maximum temperature of warmest month and the days of daily average temperature above 30℃ in August. Affected by climate warming, the distribution of D. citri displayed an obvious expansion trend in China from 1960 s to the beginning of the 21 st century, including the total suitable areas, highly suitable areas and moderately suitable areas. In particular, the highly suitable areas expanded more obviously than the moderately suitable areas. The highly suitable areas increased significantly in Guangxi, Guizhou, Hunan, Jiangxi, Hubei, Anhui and Zhejiang;meanwhile, the moderately suitable areas expanded in Yunnan, Guizhou, Chongqing, Hubei, Anhui, Jiangxi and Jiangsu. The slightly suitable areas decreased due to the northward movement of the highly and moderately suitable areas. At the same time, the northern parts of Hubei, Sichuan, Chongqing and Jiangsu turned from the originally unsuitable areas to slightly suitable areas. The results indicated that the global warming provided better survival conditions for D.citri in China and the northern boundary of the highly, moderately and slightly suitable areas for D. citri expanded northward. With the increasing risk of Huanglongbing(Candidatus Liberobacter asiaticus),enough attention should be paid to the psyllid.