Local Scale Edaphic Surveys in and out of a Pericopsis elata (Harms) Meeuwen Natural Forest Stand in East Cameroon

摘要

One of the problems limiting high survival rates of Pericopsis elata (afrormosia, assamela), a high value timber species, is lack of data on its pedological requirements. A study was conducted in the East Region of Cameroon to identify possible soil properties favoring its spatial distribution. Two test areas, in and out of a Pericopsis elata natural forest stand were identified and in each sampling units of 50 × 50 m delineated. Thirty eight and sixteen quadrats in and out of the stands were respectively sampled for soil physico-chemical properties, number of stems and diameter at breast height. Soil samples in each quadrat were analyzed following standard laboratory procedures. Soil properties were tested for normality and compared for the two sites using Student’s t-test. Principal component analysis and correlation analysis were performed on tree and soil data to identify soil factors responsible for spatial distribution. From our findings, key soil indicators favouring Pericopsis elata distribution appear to be acidity (soil pH and exchangeable acidity), base status (base saturation and exchangeable bases) and texture (clay content). More specifically, optimal soil conditions for growth and survival of Pericopsis elata are: pH (4.1 - 5.0), exchangeable acidity (<4.67 cmolc style="font-family:Verdana, Helvetica, Arial;white-space:normal;background-color:#FFFFFF;">·kg-1), base saturation (6.2% - 17.8%), and clay content (24.0% - 49.0%), which should be considered in site selection for reforestation with Pericopsis elata.