Abstract

Natural forest regeneration is the renewal of a forest crop by self-sown seed or by sprouting of stumps. However, there have been few studies on sprouting in the Cameroon tropical rainforest. The main objectives of this study were to examine the influence of stump sprouting of timber species in natural forest regeneration in the Akak forest area in Cameroon. In this study, stumps were located in forest compartments that had been selectively logged in 2013, 2015 and 2017. Stumps attributes: (1) species, (2) the diameter at the top of the mother stump, (3) the height of the mother stump, (4) the number of sprouts, both living and dead, (5) the height of the tallest sprout, (6) the basal diameter of the tallest sprout, and (7) the extent of the decay of the stump were recorded at every sprouted stump using a Global Positioning System (GPS) device. Thirteen of the 20 tree species had some stumps which had sprouted. Stumps of Nauclea diderrichii, Pterocarpus soyauxii species, Terminalia ivorensis, and Piptadeniastrum africanum sprouted most frequently, with N. diderrichii having the greatest number of stumps with sprouts. Principal component factor analysis for all the species together showed that the first factor contributed 34.1% and the second factor contributed 19.1% of the observed variation, with a communality of 66.6% while for N. diderrichii alone showed that the first two axes of the PCA explained 62.8% of the variance suggesting that sprouting dynamics could only be partially explained by the attributes that were recorded. Multiple linear regression shows that the diameter of the tallest sprout can be used to predict the height of the tallest sprout for all the species combined (p=0.000). These predicting models could help in predicting the future growth rate and stand of a tropical rainforest.

Key words: Natural forest recovery, timber species, tropical rainforest.