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一、前言最近几年国外资料报道,美国及芬兰等国家正在试验利用集约经营的方法培育林木,即所谓短轮伐期的密植栽培。供造纸用的木材原料也在向着速生、短轮伐期的方向发展。 1979年北京市农业科学院林业研究所和北京市造纸工业研究所共同协作,开展了杨树苗干材造纸试验(由林研所提供72—170号杨<沙兰杨×北京杨_(0018)>一年生扦插苗干材),目的是研究一年生苗干材是否适宜造纸,经济效益是否合适等。一年生杨树苗的优点是可以密植,生长速度快,当年育苗当年收益,苗干材伐取后不再育苗,仅做些抚育工作就可连续生产苗干材达5年之久,占地面积小,资金周转快,并为
I. Introduction In recent years, foreign sources have reported that countries such as the United States and Finland are experimenting with the intensive management method to cultivate trees, that is, close planting with the so-called short rotation period. The raw materials for paper-making are also moving toward quick-growth and short-rotation. In 1979, the research institute of forestry of Beijing Academy of Agricultural Sciences and Beijing Institute of Paper Industry collaborated to carry out the papermaking experiment of poplar seedling dry material (provided by Lin Institute No. 72-170 Yang Annual Cuttings dry material), the purpose is to study the annual dry stock is suitable for paper, the economic benefits are appropriate. The advantages of annual seedlings of poplar seedlings can be close planting, fast growth, the year when the benefits of nursery stock, nursery stock no longer cutting after cutting seedlings, nursery stock can only do some of the nursery stock for 5 years of continuous production, covers an area Small, fast cash flow, and for