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应用灰色系统理论分析了云南热区主要造林树种———山桂花、西南桦、马尖相思、高阿丁枫４种人工纯林的土壤理化性状，结果表明：有机质、全氮、有效氮、ｐＨ值、水解酸、阳离子交换量、土壤容重、总孔隙度、毛管孔隙度等因素对４种人工林生长的影响较大。此外，１９９３～１９９７年，山桂花林分的土壤肥力呈上升趋势，与季风常绿阔叶林和次生林相同，而西南桦、马尖相思、高阿丁枫３种林分的土壤肥力，１９９３～１９９５年呈下降趋势，１９９５～１９９７年有所回升，与山地雨林相同。幼林期的土壤理化性状分析结果证明，４种人工林均可在云南热区造林经营
The gray system theory was used to analyze the soil physical and chemical properties of four afforestation species, such as Osmanthus fragrans, Betula alnoides, Acacia mangium, Acapentia fortunei and Artemisia gigatica in the hot area of Yunnan. The results showed that the contents of organic matter, total nitrogen, available nitrogen, pH, hydrolytic acid, cation exchange capacity, soil bulk density, total porosity, capillary porosity and other factors have a greater impact on the growth of four plantations. In addition, from 1993 to 1997, the soil fertility of Shannon-Guihua forest was in an upward trend, which was the same as that in the monsoon evergreen broad-leaved forest and the secondary forest. However, the soil fertility of the three stands including Betula alnoides, Acacia mangium, ~ 1995 showed a downward trend, from 1995 to 1997 has picked up, and the same mountain rainforest. The analysis of soil physical and chemical properties in young forest period proved that all four kinds of plantations could be afforestation in hot area of Yunnan