章古台固沙林天然更新的研究

Research on Natural Regeneration of the Forest for Sand Fixation in Zhanggutai

章古台固沙林，通过经营疏伐与部分采伐，改善林分通风透光条件，促进了天然更新。在12块采伐迹地标准地调查中，共出现天然更新的乔灌木树种13种，487株。其中出现频度最高的是鼠李，达67％，分布最多的是榆树，为3921株／hm^2。在7块固沙林标准地调查中，共出现天然更新树木13种，385株。其中出现频度最高的是赤松，为43％，分布最多的也是榆树，为2980株／hm^2。天然更新的幼树多出现在沙地的丘间低地或沙丘的东北坡，而且有落沙层；同时还需要在5—6月降水比较多，年降水量比较高的年份发生。

By the way of thinning operation and partial cutting, it improved the ventilation and translucidus conditions and promoted natural regeneration of the forest for sand fixation in Zhanggutai. In the research on 12 standard piots of cutover land, there were 13 tree and shrub species and 487 seedlings for natural regeneration. 67% of them were Rhamn us parvifolius which appeared most frequently. Ulmus pumila was 3921s/hm^2 which was the most. In the research on 7 standard plots of forest for sand fixation, there were 13 tree and shrub species 385 seedlings. 43% of them were Pinus densiflora which appeared most frequently. Ulmus pumila was 2980s/hm^2 which was also the most. Most of young trees of natural regeneration grew in low sand lands among sand dunes or northeast slop of sand dunes, and including flowing sand. It also needed more precipitation in May and June occured in the years of higher annual precipitation.