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多年来风景林场造林有大的发展,许多人工林蔚然成林,茁壮成长,但也有一部分林生长不良,这部分人工林生长缓慢,经济价值,生态效益低下,从生理上和形态上表现出“小而老”的特点,便形象地把它称为“小老树”或“小老头”林。 低产林在风景林场涉及的树种有:杨树,榆树、刺槐、山杏、小叶杨等,其中,杨树“小老头”占46％,刺槐占到32％,其它树种占28％,低产林的面积占风景林场人工林面积的30％,由此可见,低产林改造是风景林场造林工作需要重视的一个课题加以研究解决。
Many afforestation in scenic forest farms have developed greatly. Many artificial forests grow naturally and grow stably. However, some of them have poor growth. The growth of artificial forest is slow, with low economic value and low ecological benefit. Physiologically and morphologically, Small and old “, it is vividly called” little old tree “or” little old man “forest. Among the tree species involved in the low-yield forest in the scenic forest farm, there are poplar, elm, black locust, apricot and poplar, among which, poplar ”young man" accounts for 46%, acacia occupies 32%, other species account for 28% Accounting for 30% of the total area of the plantations in the scenic forest farm. Therefore, the transformation of low-yield forests is a problem that needs attention in afforestation of scenic forests.