中南半岛旱季稻对我国稻飞虱早期迁入动态影响的卫星遥感监测研究

The rice planthoppers (RPH, Nilaparvata lugens & Sogatella furcifera) have been the most serious pests in the Chinese rice production. RPH is a monotrophic insect pest which only feeds the rice plant individuals. There are close relationships between the wing dimorphism, population succession, and the growth stage, cropping pattern of rice. The main insect resource region of RPH in South China is the Indochina Peninsula (i.e. Burma, Cambodia, Laos, Thailand and Vietnam). The RPH administration division for a long time has no precise forecasting accuracy of immigration RPH from oversea regions due to without obtaining basic biophysical information on oversea distribution, population succession, immigration period and insect quantity. At first of all, the rice planting planning zones of each country in Indochina Peninsula will be conducted based on the natural environmental condition, social and economical development level. Secondly, the terrain mask consisting of height and slope factors will be generated to remove the unsuitable land for cultivating rice crop. At the third step, one prerequisite criterion and exclusionary criterion based on the in situ survey GPS sampling points will be conducted to mask the perennial vegetation, open water and artificial building from the long time-series spectral profiles of MODIS indices (i.e. NDVI, EVI, etc.). Fourthly, the tempo-spatial distribution, planting area and key growth stages (viz. transplanting, heading and harvest) of irrigated rice crop which ranged from 2000 to now on will be extracted from the long time series MODIS indices and MOD15A3 product (leaf area index). Finally, the precise initial source region, immigration period and migration route will be obtained through the combination of irrigated rice crop information derived from satellite remote sensing and three-dimension particle trajectory analysis from the point of view of metapopulation and landscape ecology. The development process, fundamentals and limiting factors of initial resource of RPH in early spring will be demonstrated in South China. The outbreak infestation of RPH will be forecasted accurately in the future in China.

稻飞虱(褐飞虱和白背飞虱)是以水稻为食料的专食性害虫，其翅型分化、种群演替、迁飞行为与水稻生育期和稻作制度关系密切，是我国水稻生产上的头号生物灾害，其主要虫源来自中南半岛(缅甸、泰国、越南、老挝、柬埔寨)。长期以来，由于无法获取境外虫源分布、种群数量演化、迁入期和迁入量等基础数据，严重制约我国害虫测报业务部门对春季境外迁入稻飞虱的预测预警水平。本项目基于实地调查GPS、水稻和虫情数据，划定水稻种植分区，进行地形和多年生植被、水体、人工建筑掩膜，剔除不适宜种植水稻和非水稻种植区域，利用长时间序列MODIS光谱指数和MOD15A3影像，提取2000年至今水稻种植面积、空间分布和关键生育期(移栽、抽穗、收获)。从异质种群和景观生态的不同视角，卫星遥感和三维质点轨迹分析技术相结合，获取确切的虫源地、迁入期和迁飞路径信息，揭示我国稻飞虱早期虫源的形成过程、机制和影响因素，提高我国稻飞虱灾变预警精度。

《中南半岛旱季稻对我国稻飞虱早期迁入动态影响的卫星遥感监测研究》以我国南方稻区水稻生产过程中影响最大的迁飞性害虫稻飞虱为研究对象，系统研究了水稻生育期和稻作制度对稻飞虱迁飞时间和种群基数的影响。结合稻飞虱专食性和趋绿的生物学特性，将寄主水稻作为媒介，利用中等分辨率辐射成像仪MODIS重访周期短的优势，提取了中南半岛地区的旱季稻的空间分布和关键生育期信息，确定了我国南方稻区境外虫源地、迁入期和迁飞路径。此外，研究过程中发现：其他农作物迁飞性害虫如草地贪夜蛾与稻飞虱存在相近的生物学习性，例如冬季只能在北回归线以南和一月份10摄氏度等温线以南地区越冬，以及寄主存在交叉重叠的特征。本研究认为预期未来可以通过构建生态隔离带和改变终年繁殖区域农田景观格局来减少迁飞性害虫对我姑粮食主产区的危害，确保我国粮食安全。遗憾的是，研究周期偏短，部分研究成果暂时无法整理发表公开。