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林木弯弓是落叶松人工林的主要自然灾害之一,一般发生在15年生以上的松林。近几年来,吉林各地屡见不鲜。仅永吉县旺起林场73年遭受弯弓倒伏的落叶松人工林就达1,212公顷,伐后出材量达19,855立方米。其中有66公顷受灾率达95％以上。75年,又有47公顷松林第11次受灾,使十多年造林之功毁于一旦。落叶松人工林这样“壮年夭折”,应当引起我们的重视,值得提出探讨。一、林木弯弓的原因:落叶松人工林的弯弓倒伏,主要是雪压引起的。73年10月22日傍晚,一次先雨后雪的天气(翌日积雪13厘米),竟使1,212公顷松林不同程度上遭受弯弓
Bow bending is one of the major natural disasters of larch plantations, usually occurs in pine forests over 15 years old. In recent years, all over Jilin are not uncommon. In Yongji County, only 1,212 hectares of larch plantation undergoing bending bow were found in 73 plots of Wangqi Forest Farm in Yongji County, leaving a total volume of 19,855 cubic meters. Among them, 66 hectares have a disaster rate of more than 95%. In 1975, an additional 47 hectares of pine forests hit the eleventh and destroyed more than 10 years of afforestation. Larch plantation such a “prime of life”, should arouse our attention, it is worth to discuss. First, the reason bowling bow: Larix plantation bow bow, mainly caused by snow pressure. On the evening of October 22, 1973, a rainy and snowy weather (13 centimeters the next day) actually caused the 1,212-hectare pines to suffer varying degrees of bowing