摘要
褐飞虱是影响我国水稻生产的重要迁飞性害虫之一,它的爆发严重影响水稻的生长,并诱发水稻病害,导致水稻减产。研究复杂地形条件下褐飞虱的迁出虫源地、空中迁飞轨迹、降落区,探明复杂地形对褐飞虱迁飞的影响机制,对害虫测报与防治、农业防灾减灾和保障我国粮食安全具有重要的理论意义和实践价值。为了分析覆盖复杂地形的大气动力场、温度场、湿度场对褐飞虱迁入及降落分布的影响,采用WRF-Flexpart耦合轨迹计算模式和GIS空间分析等方法,对2008年9月30日—10月3日发生在广东曲江、肇庆、梅县三站和湖北宜昌、安徽东至、江西吉安三站的褐飞虱迁入和降落过程进行了数值模拟,以揭示复杂地形条件下褐飞虱种群降落和密度分布的时空变化结构。(1)广东曲江、肇庆、梅县三站的后向轨迹模拟结果显示,迁入三站的虫源均来自该站点的西北方向。地形较高且复杂多变时,褐飞虱难以穿越且迁飞距离较短、方向多变。(2)湖北宜昌、安徽东至、江西吉安三站的前向轨迹模拟结果显示,当站点附近的山脉较低且有山谷通道,褐飞虱沿山脉顺风方向迁飞,且迁飞距离较远。当山脉地势较高且没有明显的山谷,则褐飞虱遇到山脉阻挡而转向造成种群滞留。(3)褐飞虱迁飞种群的密度沿山脉走向呈带状分布,山坡较为陡峭、断崖显著时,向远离山体的方向迁飞。若山脉由多个山岭构成,则褐飞虱可从其峡谷穿越,密度分布较为分散。(4)强水平气流有利于褐飞虱的远距离迁飞,下沉气流对褐飞虱降落起着重要的作用,当有强下沉气流且气温较高时,有利于褐飞虱种群的降落,并聚集形成高密度迁入区。(5)垂直方向上,在一定的温度范围内,褐飞虱趋向于在暖层中迁飞。褐飞虱密度沿河谷地带呈带状分布且密度高值区多分布在较温暖的地区。秋季,褐飞虱降落区多分布在相对湿度50%左右的区域。模拟的褐飞虱迁飞轨迹、迁飞方位角和迁飞距离等与实际发生的褐飞虱迁飞路径和降虫区之间偏差较小,该模拟方法较大程度地提高了我国迁飞性害虫的业务预报水平。未来拟提高测报褐飞虱虫情数据的时空分辨率,以为得到较高准度和精度的模拟结果。
The brown planthopper,Nilaparvata lugens（ Stl）,is one of the most damaging pests affecting rice production in China. An outbreak of N. lugens can increase the incidence of disease and insect pest damage,both of which seriously affect the growth and the yield of rice. In order to analyze the influence of atmospheric dynamics,temperature,humidity,and other meteorological factors on the migration and density distribution of N. lugens over complex terrain,numerical simulations were performed. These simulations coupled the Flexpart model with the Weather Research and Forecast Model and the spatial analysis functions of GIS. These models and programs were used to simulate the N. lugens immigration and landing event that occurred at 6 plant protection stations,including Qujiang,Zhaoqing,Meixian in the Guangdong Province and Yichang in the Hubei Province,Ji＇an in the Jiangxi Province,and Dongzhi in the Anhui Province,from September 30 th to October 3rdin 2008（ BST）. The simulation was in turn used to investigate the spatio-temporal distribution of the N. lugens＇ landing and density patterns as they passed through the complex terrain of China.（ 1） The simulation of the reverse trajectory of the insects showed that the N. lugens at all three stations all originated from sites in the northwest. As the site of origin was in an area of complex terrain,the migration distances of the N. lugens were much shorter,and the direction was changeable and unpredictable.（ 2） According to the results of simulations of forward trajectories,if the mountains were low and were with a valley as channel for N. lugens＇ migration,N. lugens could migrate along two mountainsides,lengthening their travel distance. If the mountains were high and there were no obvious valleys,migrating N. lugens could would directions and stay in their location of origin,because their route was blocked by the mountains.（ 3） When the slope of the mountains was steep,the density of the N. lugens was distributed along the mountains,because N. lugens could migrate along the mountain range. If the mountains consisted of multiple hills and peaks,N. lugens could pass through the areas of lower elevation,leading the density of N. lugens to be sporadically distributed.（ 4） The northeast wind allowed N. lugens to migrate further. Downdrafts coupled with high temperatures in this area,were conducive to N.lugens making landfall in higher densities.（ 5） To a certain extent,the result of the analysis of temperature distribution showed that N. lugens migrated towards warm areas. Ultimately,this led to the result that a higher density of N. lugens made landfall in warmer areas and along river valleys. In autumn,N. lugens landed in regions where the relative humidity was over 50%. There are some deviations from N. lugens＇ immigration trajectories,azimuth angles,and differences between simulated results and actual observations. These results indicate that this simulation can considerably enhance the ability of various operations to forecast of the movements of migratory pests in China. In future,we plan to improve the spatial and temporal resolution of the observational data of N. lugens,which will allow us to achieve more robust simulated results.
出处
《生态学报》
CAS
CSCD
北大核心
2016年第16期5263-5275,共13页
Acta Ecologica Sinica
基金
国家自然科学基金资助项目(41475106
41075086)
江苏省农业科技自主创新基金项目(CX(12)3056)
江苏省高校自然科学研究项目(14KJA170003)
江苏省普通高校研究生科研创新计划项目(CXLX13_496)
江苏高校优势学科建设工程资助项目(IRT1147)
关键词
褐飞虱
地形
Flexpart
WRF
轨迹
Nilaparvata lugens（Stl）
terrain
Flexpart Model
WRF Model
trajectory
