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(1)根据计算,在海拔2000米以下的阳坡每公顷需要保留母树269株,在阴坡也需要保留122株才能保证在4年内完成更新,而在海拔2000米以上阳坡或阴坡则只需分别保留母树23或15株,在同样的时间内就能完成更新。由上述数字看:在2000米以下的地方,由于成苗率过低,每公顷需要保留的母树很多,实际上已接近或超过林分中Ⅰ、Ⅱ级木的总数,给森工采伐造成困难,同时
(1) According to the calculation, 269 mulberry trees need to be preserved per hectare on the sunny slopes below 2000 meters above sea level, 122 mulberry trees need to be preserved on the shady slopes to ensure that they can be renewed within 4 years, while at sunny elevation of 2000m or shady slopes Only need to keep 23 or 15 parent trees, respectively, in the same time will be able to complete the update. According to the figures above, in the area below 2000 meters, there are many mother trees per hectare to be kept due to the low seedling rate, which is actually close to or exceeding the total number of wood grades I and II in the stand, which makes it difficult for the forest handicrafts ,Simultaneously