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新民地区杨树(美×青、健杨、小×黑、新民二号等)1—3年生人工幼林地上部越冬后大量死亡现象,近年日趋严重,已引起关注。一九七九、一九八○两年全县有一万多亩杨树人工幼林地上部死亡。国营新民县机械林场仅一九八一年春季,就有8,487亩幼林受害,死亡面积4,537亩,地上部死亡幼树达45万多株。芦屯工区一九七八年秋季营造的1,943亩幼林,地上部甚至连续三年枯死,严重影响了防护及经济效益。
Poplar trees in Xinmin area (the United States × Green, Jian Yang, small × black, Xinmin II, etc.) 1 - 3 year-old artificial upper forest overwinter after a large number of deaths in recent years, increasingly serious, has attracted attention. In 1979, in 1980, more than 10,000 mu of poplar young plantations died in the upper part of the county. In the spring of 1981, a total of 8,487 mu of young forest were damaged in the state-run Xinmin County Machinery Forest Farm, with a total area of 4,537 mu dead and over 450,000 saplings dead above ground. 1,994 mu of young trees were planted in the Lutun Area in the autumn of 1978. The shoots even died three consecutive years and seriously affected the protection and economic benefits.