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1分布及危害本病在我国主要分布于东北及华北地区,在长白山西坡地区,主要危害抚松、靖宇、江源三县近年来的退耕还林、参后还林及其他造林项目,危害较普遍,以人工林受害最重,是落叶松的重要病害,在7～20年生的人工落叶松林内发病最重。当树林超过20年以后得病轻。针阔混交林或透光透气好的林分发病轻。落叶松叶部生病后,可提早40天左右落叶,所以叫落叶松早期落叶病。被害林分较正常林分每年树高生长平均降低21.3%,胸径生长降低74.4%,材积生长量平均
1 Distribution and Harm This disease is mainly distributed in the northeast and north China in our country. In the western slope of Changbai Mountain, the disease is mainly endangering the returning farmland to forest, returning the forest to forests and other afforestation projects in Fusong, Jingyu and Jiangyuan counties in recent years. More common, the hardest hit in plantations, is an important disease of larch, artificial larch forests in 7 to 20 years the incidence of the most serious. When the woods get sick more than 20 years later. Coniferous and broad-leaved forest or light and breathable good forest disease light. Larch leaves sick, can be about 40 days earlier deciduous, so called early deciduous larch disease. Compared with the normal stands, the average stand height of the damaged stands was reduced by 21.3% on average, the DBH growth was reduced by 74.4%, the average volume growth was average