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.

MASTREE+: Time‐series of plant reproductive effort from six continents

“…In systems where seed production limits recruitment, MASTREE+ can be utilised to understand the drivers of plant reproduction and regeneration (Abraham et al, 2018; Manríquez et al, 2016; Oliva et al, 2013). Intraspecific differences in fecundity and masting influence regeneration success, determining species composition and vegetation structure, including during the colonisation of new habitats (Joubert et al, 2013), and after natural and anthropogenic disturbance (Martin‐DeMoor et al, 2010; Mokake et al, 2018; Peters et al, 2005). Masting characteristics of hundreds of species can be investigated using MASTREE+, and integration with plant trait and demographic databases will enable deeper integration of masting and reproductive strategies within life history theory (Salguero‐Gomez et al, 2016).…”

Silvicultural assessment of enrichment planting with commercial tree species after selective logging

“…Forest recovery in these sites may be substantially retarded due to substrate compaction by heavy machinery use and lack Mokake et al 29 of onsite plant propagules after topsoil disturbance creating a more heterogeneous structure with patches of felling gaps, skid trails, and log yards (Fimbel et al, 2001;Putz et al, 2001). Large openings are subject to invasion by understory shrubs, lianas and herbs that can be an obstacle to tree regeneration by competing with the seedlings of slow growing economically important tree species (Mokake et al, 2018). The logged forest might therefore gradually be replaced by relatively species-poor forests dominated by pioneer species and over time by more diverse mixtures of later successional species, and ultimately the climax forest will re-establish (Chazdon, 2014); thereby affecting its biodiversity.…”

“…One approach to recover the original forest is simply to protect these forests and allow nature to take its course; but results from the natural regeneration assessments indicate competition of the seedlings of timber species with the dense undergrowth of lianas, strubs and herbs for nutrients, moisture and light (Vieira and Scariot, 2008;Mokake et al, 2018). Silvicultural interventions including planting of high-value species are therefore necessary to overcome the relative depletion of commercial tree species, to compensate for the slow growth rate, and to ensure a future commercial timber value of the forest (ITTO, 2002) thereby reestablishing or conserving the timber biodiversity of forest stands.…”