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根据2003年全国林业有害生物发生与防治情况,结合有害生物发生规律及今年气象预测综合分析,预测今年全国林业有害生物仍属偏重发生年份,呈上升趋势,总发生面积比去年的1.3亿亩略有上升,预计在1.35亿亩左右。业务主管部门预计,今年全国林业有害生物总体发生趋势为:松毛虫总体发生平稳,在江南地区、东北东部局部严重发生现象可能增加;杨树病虫在东北、华北和江淮地区发生面积将有小幅上升;森林害鼠(兔)在西北地区和西南局部危害程度将有所加重;松树钻蛀性害虫在西南地区发生范围进一步扩大;危险性病虫仍呈扩散态势。此外,天然次生林、灌木林和荒漠植被病虫害发生趋于加重,外来有害植物在华南、西南部分地区将继续蔓延。在1.35亿亩林业有害生物发生面积中,松林线虫病预计发生120万亩,发病面积维持上年
According to the occurrence and control of forestry pests in 2003, combined with the pest occurrence law and the comprehensive analysis of the meteorological forecast this year, the forestry pests in this year are still predicted to be year-over-year in China, with a rising trend of total occurrence area of 130 million mu There is an increase of about 135 million mu. Business authorities estimate that the overall trend of forestry pests in the country this year will be as follows: the overall occurrence of pine caterpillars will be steady, and the occurrence of some serious diseases may increase in the southern part of Jiangnan and the eastern part of northeast China; the occurrence of poplar pests and diseases in the northeast, north China and the Jianghuai area will be slightly smaller Increased; forest harmful rats (rabbits) in Northwest China and Southwest China will increase the degree of local damage; pine borers pest insects in the southwestern region to further expand the scope of the risk of pests and diseases were still spreading. In addition, occurrence of pests and diseases in natural secondary forests, shrubberies and desert vegetation tends to increase, and exotic harmful plants will continue to spread in southern China and parts of southwest China. In the area of 135 million mu of forest pests occurring, 1.2 million mu of pine nematode disease is expected to occur, and the area of disease maintained for the previous year