人工林和天然林的比较评价

对人工林和天然林的生态学和林学特性进行了比较和分析。指出天然林对病虫害的抵抗能力强,能持久地生产木材和发挥多重效益,并与很多物种的生存有密切关系。因人工林多样性低,稳定性差,轮伐期短,集约栽培的工业人工林尽管速生,但对地力消耗大,若没有优越的土地条件和额外的施肥,生产力将不能持久。提出我国应实行人工林和天然林并重的方针,要对大量发展工业人工林可能产生的隐患给予重视,要对已保存不多的原始林实行不改变林相的经营方式,避免将它们大面积地改变为人工林的作法。

A Comparative Evaluation of the Man-made Forest and Natural Forest

An analysis is made of the forest production and research results in all contries, and a comparison is made of the ecology and silvicultural traits of the man-made and natural forests, It is concluded that natural forest is better than man-made forest in respect of disease and insect resistance, maintenance of soil fertility, sustainable timber production, species preservation, and environmental protection The advantages of man-made forest are timber evenness, short rotation, fast tree growth, and higher economic returns, but it needs good soil conditions, and must be able to compensate for its disadvantage economically, In some cases, man-made forest usually has a shorter regeneration cycle, and can help restore the ground vegetation denuded long ago. Yet low functional diversity is its serious defect. Now importance is attached to man-made forest, rather than to natural forest. Therefore, a simultaneous development policy is suggested. In virgin forests selective felling and natural regeneration should be practiced as often as possible, so as to keep landscape, biotic species and genetic diversity, Secondary forests should be diverted into progressive succession. Common man-made forests should be established in non-stocked forest land, cutover area or burns where natural regeneration cannot meet social demand, or in areas where high quality man-made forest can be well developed as expected. Relatively, some industrial plantations may be built in areas with good climate and soils and suitable for intensive forest management. In establishing man-made forests attention should be paid to the combined use of proper tree species.