干热河谷印楝生长与立地条件关系

对元谋干热河谷印楝人工林生长与土壤物理性质、化学性质和地形因子的关系进行了分析研究。单因子分析结果表明,印楝树高生长量指标与坡位、土壤含水量、土壤毛管孔隙度、有效土层厚度、土壤速效P含量之间呈显著或极显著正相关;逐步回归分析结果表明,坡位、土壤毛管孔隙度、土壤有机质含量及其组合是影响印楝生长的主导因子。缺磷少氮和水分含量低是印楝人工林土壤的共同特点,在选择造林地或制定营林措施时应当引起重视。

Relationship between Growth Increment of Azadirachta in dica and Site Condition in Hot and Arid Valley

Azadirachta indica is an excellent multiple purpose tree adaptive to the climate of hot and arid valley.It has played an important role in ecological environment construction and in regional economy development since introduced into China.This paper aimed at giving some evidences of the relationship between growth increment of Azadirachta indica plantation and site conditions basis on the investigating materials of the neem plantation in Yuanmou County.The results of simple regression showed that the height increment of the top tree and mean tree of the plantation increased corresponding to the slope location (from mountaintop to the valley), soil moisture, soil capillary porosity, available soil depth, and rapid available P₂O₅ with linear function.The results of stepwise variable selection showed that the main factors effecting tree growth were slope location,soil capillary porosity and organic matter contents.The multiple equations were worked out based on data analysis.