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一、采种母树林 马尾松、杉木、云南松等树种的采种母树林,应在国营林场、采育场或有条件的社队林场的现有人工林和天然林中选取建立。选作为母树林的林子应具备下列条件: 1、生长特别良好、树干通直、树冠完满、疏伐后的林木,枝下高相当树高1/2占全林75％以上的为一级母树林,50—75％的为二级母树林,30—50％的为三级母树林。通过疏伐后杉树每亩均匀保留30—40株,松树20—30株。
I. Seed Production Seed trees such as Pinus massoniana, Cunninghamia lanceolata and Pinus yunnanensis should be selected and established in the existing plantations and natural forests in state-owned forest farms, quarry farms, or conditional community teams. Selected as the parent woods of the forest should have the following conditions: 1, the growth is particularly good, straight trunk, crown full, thinning of the trees, the branches of the high equivalent of 1/2 tall trees accounted for more than 75% of the whole forest for the mother Woods, 50-75% for the second-level parent woods, 30-50% for the third-level parent woods. After the thinning of fir trees per acre retained 30-40 evenly, 20-30 pine trees.