Plant reproductive phenology following selective logging in a semideciduous tropical forest in the East Region of Cameroon

Abstract

Objective: Changing forest composition and structure caused by selective logging may affect forest phenology either alone or in combination with other environmental factors. The present study aims to analyze the phenological pattern of some exploitable timber tree species in two forest types.

Methodology and Results: Eleven economically important tree species were selected for monitoring at three DBH size classes using the crown density method originally devised by Koelmeyer (1959). Quantitative monthly data were collected from September 2011 to December 2014 for the timing, duration and frequency of flowering, and fruiting. A total of 58 individuals were observed in both forest types. There was a significant difference between forest types and species for flowering (p ≤ 0.001) and fruiting (p ≤ 0.001). However, there was no significant difference in flowering and fruiting between individuals of the same species in both forest types. Flowering occurred during the light wet season and fruiting during the heavy wet season to ensure the availability of seeds to germinate into seedlings.

Conclusions and application of findings: Phenology was mainly constrained by the biotic determinants of phenology. However while the determinants of phenology are intact in the unlogged forest types, they are destabilized by selective logging causing an alteration in plant species. Thus, activities that are specifically designed to enrich selectively logged sites are necessary in order to promote the natural regeneration of timber species after selective logging.

Keywords: Forest type, Flowering, Fruiting, Plant size, Proximate factors, Ultimate factors