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1 造林绿化植物材料的选择1.1 选择要求 森林是人类赖以生存的绿色屏障、土地是林木生长的基础 ,土壤墒情 (水分 )是树种成活的关键。西北黄土高原地区造林立地条件是陡坡农田和荒山荒滩 ,其降水特点是春冬雨雪少 ,夏秋雨水多 ,年降水量时空分布不均。造林绿化植物在选择时
1 Afforestation Selection of Plant Materials 1.1 Selection of Requirements The forest is a green barrier on which human beings depend. Land is the basis of forest growth. Soil moisture (moisture) is the key to the survival of the tree species. The conditions of afforestation site in Northwest Loess Plateau are steep slope farmland and barren hill wasteland. The precipitation is characterized by less rainfall in spring and winter, more precipitation in summer and autumn, and uneven distribution of annual precipitation in space and time. Afforestation plants at choice