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黑水机械化林场现有林21万亩。在1963年前,曾先后选用杨、柳、榆、械、黄、花、柞等20多个树种造林,其效果均不理想,有些逐年死亡,以致报废。剩下的几种也表现为生长衰弱,干形弯曲,呈“小老树”状态,且易感染病虫害。其中仅杨树面积就达10万亩,占造林总面积的50％。为选择适宜树种解决树种单一的问题,我场于1964年春开始进行樟子松(Pinus sylyestris Lvar. mongclica Litvin.)引种造林
Blackwater mechanized forest 21 million mu of existing forest. Before 1963, there were successively selected more than 20 tree species such as Yang, Liu, Yu, Armed, Huang, Hua and Oak for afforestation. Their effects were unsatisfactory and some died each year, causing them to be scrapped. The remaining species also showed weak growth, dry bending, was “small old tree” state, and susceptible to pests and diseases. Only poplar area reached 10 million mu, accounting for 50% of the total afforestation area. In order to choose a suitable tree species to solve the problem of single tree species, my field began in the spring of 1964 Pinus sylvestris (Pinus sylyestris Lvar. Mongclica Litvin.) Introduction afforestation