干旱区生态环境知识资源中心

The Araripe Plateau in the tropic semi-arid region is characterized by great environmental diversity. The Araripe National Forest and several forest management units (FMU) are located in this area with mostly red-yellow Oxisols. The goal of this study was to identify a basic indicator that could represent a set of physical, chemical and biological properties of soils of the Plateau. Multivariate analysis was used to indicate changes in soil properties of a FMU. Soil samples were analyzed in triplicate (0-20 cm layer), from 15 points of the FMU and four points of the National Forest. Nine soil properties were selected to characterize differences between preserved and exploited sites, including those in recovery phases. The results show that two principal components account for approximately 76 % of the variance of the data: the first indicator of biological, chemical and physical soil quality and the second indicator of soil compaction. Multivariate cluster analysis of the first principal component group showed the formation of three sub-groups: the National Forest sub-group and two sub-groups of the FMU in different recovery stages. The Tukey test (5 % significance) applied to the grouping of organic matter content of soils agreed with results from multivariate cluster analysis. This indicates that this organic matter can be used as main indicator of changes in soil properties for the study area.