不同人工林土壤培肥效果的主分量分析

PCA on the Effect of Different Artificial Forests on Soil Fertility Improvement

对元谋县小横山、岭庄、磨诃3个试验点不同人工林29项土壤因子进行了测定,运用主分量分析筛选出评价元谋地区几种主要人工林土壤肥力的5个综合因子,并用主分量分析结果进一步对所选的林分进行综合评分、排序。13年生赤桉纯林的得分低于其对照地的得分,表明赤桉纯林土壤肥力下降的事实;其余林分的得分均高于相应对照地的得分,这表明这几种人工林培肥效果显著,尤以13年生苏门答腊金合欢最好(其得分最高);就小横山而言,混交林的得分高于纯林(13年生苏门答腊金合欢纯林除外),表明混交林对土壤的培肥效果优于纯林。

29 soil factors of different plantations in different experimental sites （Xiaohengshan,Lmgznuang and Mohe） in Yuanmou County, Yunnan Province, were determined. By the method of PCA, five synthesized factors were selected as targets for evaluating soil fertility. The results were quantified, scored and sequenced to the collected data relevant to the soil fertility in the selected plots by using PCA. The result showed that the score of 13 years - old Eucalyptus camalduensis pure plantation was lower than that of the corresponding comparison. It revealed the fact that soil degradation exists in Eucalyptus camalduensis pure plantation. While the score of others artificial plantations were higher than that of the corresponding comparison. It showed that the effect of those artificial plantations on soil fertility improvement was obvious, and the effect of 13 year- old Acacia glauca pure plantation on soil fertility improvement was the best. Except 13 yearold Acacia glauca pure plantation,the scores of mixed plantations were much higher than those of the pure plantations in Xiaohengshan site. It revealed that the effect of those mixed plantations on soil fertility Improvement were better than that of the pure plantation.