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苗木凋萎系数因树种、土壤质地而异,过去对它研究较少,通常沿用农业上得出的经验公式计算[如:永久凋萎系数=土壤最大吸湿水×1.5(1.3～2.5),或用小麦、棉花等农作物的测定结果,但这些数据并不适用于林业上的造林苗木。近年来有些研究人员对一些树种进行了测定,也得到了初步结论,但测定方法尚欠精确,特别是常绿针叶树种,凋萎迹象
The seedling wilting coefficient varies according to tree species and soil texture. In the past, it was rarely studied, and was usually calculated according to the empirical formula obtained from agriculture [eg, permanent wilting coefficient = maximum soil moisture absorption × 1.5 (1.3 ~ 2.5) Measured results for crops such as wheat and cotton, but these data do not apply to forestry seedlings. In recent years, some researchers measured some tree species and obtained preliminary conclusions. However, the methods of determination are still not accurate, especially the evergreen conifer species, signs of withering