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我们在淳化县进行造林典型设计中,曾对该县及同类地区分布的一些混交林作了调查研究,并搜集了一些外地混交林调查资料,通过分析、研究、归纳和整理,提出了适于黄土高原地区营造混交林的造林树种和混交类型,并根据多年生产实践,总结出革灌覆盖造林方式,现介绍如下,供参考。一、混交类型1.油松、侧柏混交:侧柏是中性树种,幼年树冠狭窄,这一生物学特性决定了它特别适于营造混交林,这已为国内大量事实所证实。如山东省林业厅调查设计队在泰山林场的调查和中国林科院徐化成在河北西陵的调查,都证明混交林中的侧柏平均树高比纯林中的大40%以上,同时也比与之混交的及同样条件下纯植的油松生长得好。又如北京
In the typical design of afforestation in Chunhua County, we conducted a survey on some mixed forests distributed in this county and similar areas, and collected some survey data of mixed forest in foreign countries. Through analysis, research, induction and arrangement, we put forward suitable In the Loess Plateau to create mixed forest afforestation species and mixed types, and based on many years of production practice, summed up the method of afforestation covered with leather, are presented below for reference. First, the type of mixed 1. Pinus tabulaeformis, Platycladus hybrid: Platycladus is a neutral tree species, juvenile canopy narrow, the biological characteristics of the decision it is particularly suitable for creating mixed forest, which has been confirmed by a large number of domestic facts. For example, a survey by the forestry department of Shandong Province on the Taishan Forest Farm and a survey by Xuhua Cheng of China Academy of Forestry in Xiling, Hebei Province all proved that the average height of Oriental Arborvitae in mixed forest is over 40% larger than that in pure forest, Pinus tabulaeformis grows well mixed with purebred plants under the same conditions. Another example is Beijing