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东北西部、内蒙东部营造的农田防护林带,有的已郁闭成林,起到了良好的防护效果。但是,在树种的选择上,多半采用杨、柳、榆等阔叶树种。这些树种生长周期短,材质较差,林带胁地现象亦较为严重,在春季风沙危害严重时期又处于无叶状态,林带的防护性能大为减弱。因此,因地制宜地引进一些常绿针叶树种更替阔叶林带,对于增加林带防护效益,提高农田防护林生态体系的稳定性和多样性是极为重要的。中国科学院林业土壤研究所于1962年在辽宁西部营造了油松试验林带,生长发育良好,防风效果(特别在春耕播种时期)大大超过落叶林带,现将针叶林带防风性能的观测结果整理如下。
Some farmland shelter belts in the western part of Northeast China and eastern Inner Mongolia have been closed to forests and played a good protective effect. However, the choice of species, mostly Yang, Liu, Yu and other broad-leaved species. The growth of these species is short, the material is poor, the phenomenon of threatening forest belt is also more serious, in the serious risk of spring sandstorm and in a leafless state, the protective properties of the forest belt greatly weakened. Therefore, the introduction of some evergreen conifers to replace the broad-leaved forest zone according to the local conditions is very important for increasing the benefit of forest protection and improving the stability and diversity of the farmland shelterbelt ecological system. The Institute of Forestry and Soil Science, Chinese Academy of Sciences in 1962 in western Liaoning to create a Pinus tabulaeformis experimental belt, growth and development of good, wind-resistant effect (especially during the spring sowing period) greatly exceeded the deciduous forest zone, now the coniferous forest windshield performance observations are summarized below.