Effect of Thinning on Pericopsis elata (Harms) Meeuwen (Fabaceae) Found in Forest Plantations in the East and South Regions of Cameroon

摘要

This paper assesses the response of Pericopsis elata trees to silvicultural operations conducted in abandoned plantations settled between 1972 and 1975 in the East and South regions of Cameroon. Trees quality and DBH were evaluated before and 6 years after 2009 thinning. The silvicultural treatment of thinning improved the quality (physiognomy), the annual diameter increment and the stand basal area of trees. The average percentage of winding trees dropped from 82.8% in 2009 before thinning to 44.1%, six years later after thinning (2015). The most important average diameters were observed in thinned plots (27.3 ±10.4 cm - 30.5 ±10.0 cm) compared to non-thinned plots (22.9±13.2 cm-23.3±10.8 cm). Thinned plots gained at least 6 cm in diameter in 6 years, which is trice compared to the 2 cm observed in the non-thinned plots. The average annual diameter increment was 0.45 cm/year in thinned plots against 0.34 cm/year in non-thinned plots in the same period. Thinned plots have gain at least 6 m2/ha in the stand basal area against 1 m2/ha for non-thinned plots.