高黎贡山东坡不同海拔梯度土壤有机质和全氮的垂直分布规律

Vertical Distribution Patterns of Soil Organic Matter and Total Nitrogen Contents in Different Altitudes of Eastern Slope of Gaoligong Mountain

通过测定高黎贡山东坡不同海拔高度0—20、20～40、40—60cm土层土壤有机质含量、全氮含量，利用相关分析方法计算了有机质与海拔高度、全氮之间的相关系数。结果表明：海拔、土壤深度、植被类型、气温、降水量对土壤有机质有着显著影响。土壤有机质与全氮含量随海拔高度呈相似的变化趋势，两者在海拔高度2500m左右达到最大值，而后略有降低再增加；在同一海拔高度，土壤有机质含量以及全氮含量随土层深度的增加而减少。0～20cm土样的有机质含量明显高于其他两层，0～20cm土壤有机质含量与20～40、40～60cm土层土壤呈显著性差异，而20～40am和40—60cm土层土壤差异不显著；海拔、土层深度、全氮含量、气温、降水量和土壤有机质含量具有显著相关性；植被类型中，河谷稀树灌木草丛的土壤有机质含量最低，寒温性灌丛草句最高。中山湿性常绿阔叶林由于植被生长良好，群落结构复杂，枯枝落叶多，土壤有机质含量也较高；土壤有机质随气温的增加而减少；随降水量的增加呈增加趋势。

The author measured the contents of organic matter and total nitrogen in different altitudes of eastern slope soil of the Gaoligong mountain, and calculated the correlation coefficients between organic matter content and altitude, total nitrogen content by using correlation analysis method. The results showed that altitude, soil depth, vegetation type, air temperature, and rainfall had significant influences on soil organic matter content. Soil organic matter content and total nitrogen content revealeda similar change trend along with the change in altitude, both reached a maximum value at the altitude of 2500 m or so, and then slightly decreased and increased again. At the same altitude, soil organic matter content and total nitrogen content decreased with the increase in soil depth. The organic matter content in 0 ~ 20 - cm - deep soil was significantly higher than that in 20 ~ 40 - cm - deep and 40 ~ 60 - cm - deep soil （P 〈 0.05 ）, but there was no significant difference in organic matter content between 20 ~ 40 - cm - deep soil and 40 -60- cm- deep soil. The soil organic matter content was significantly correlated with altitude, soil depth, total nitrogen con- tent, air temperature, and rainfall. Among various vegetation types, the soil organic matter content in river - valley scarce shrub grass was the lowest, and was the highest in low - temperature hushwood meadow. Zhongshan humid evergreen broad - leaved forest was also richer in soil organic matter due to the good growth of vegetation, complexity of community structure, and many dry bran- ches and fallen leaves. Soil organic matter content decreased with the increase in air temperature, and increased with the increase in rainfall.