Complementary allometric model of understory tree biomass in the semi-deciduous rainforest of Cameroon

Abstract

Forest understorey contains remarkable plant diversity, contributing to the heterogeneous environments for other biotic gatherings and soil supplement aggregations. Nonetheless, the biomass of the understorey vegetation is neglected because of the lack of appropriate allometric equations without which there are uncertainties in biomass estimation. This study was aimed at developing multispecies allometric equations that will be used to estimate the aboveground biomass of different compartments (trunk, crown, and leaves) of understorey trees in the semideciduous rainforest of Cameroon. Understorey tree diameter (1.0-10.0 cm), height, and crown diameter were measured on 1023 trees as biomass predictors. The results showed that the fit of the model improves with more predictive variables, four of which were considered in all studied compartments (trunk, crown, and leaves). Existing specific and pantropic allometries based on diameter tend to overestimate the aboveground biomass of understorey trees when compared to the allometry developed in this study. This study highlighted the importance of a specific aboveground biomass allometric equation for understorey trees. Furthermore, the multispecies allometric equation developed for understorey trees complements those recently developed for overstorey trees, thereby contributing to the total aboveground woody biomass estimation in semi-deciduous forest in the Congo Basin.

Stand Diversity and Carbon Stock of a Tropical Forest in the Deng Deng National Park, Cameroon

“…Khaine et al[67] who recorded 75 species and 31 families in a tropical forest in Myanmar and Pappoe et al[68] in the Kakum National Park in Ghana who had 73 species, 6 genera and 28 families. These results are however low when compared to those obtained from other studies in Cameroon like Ntonmen et al[34] in the Mindouru community forest in the East region of Cameroon who recorded 186 species, 93 genera and 38 families, Kabelong et al[38], who worked in the periphery of the Deng Deng National Park with 187 species distributed in 43 families, Djomo et al[69] who found 105 species in the Yokadouma District in the East Region and Sainge et al[70] in the Kimbi-Fungom National Park in Cameroon who recorded 178 species, 110 genera and 42 families. Similarly, the mean tree species richness of 25.1 species/ha is very low in comparison to other National Parks in Cameroon like 43.1 species/ha in Kimbi-Fungom National Park (KFNP)[70], the rainforests of the Rumpi Hills (lowland forest 117.5 spe-…”

“…Secondly, the sampling for this study was from 2 cm which therefore excluded most of the species found in the <2 cm diameter size class in the savannah plot thereby decreasing the number of species. Ntonmen et al, [34] studied the understorey of the Mindourou community forest, Kabelong et al [38] carried out a study in the periphery of the Deng Deng National Park and Sainge et al [70] worked on the species from ≥1 cm in the Kimbi-Fungom National Park. The periphery of the Deng Deng National Park is highly associated with anthropogenic activities and the presence of nearby primary forests which thus allows for the implantation of new species and individuals along the periphery of the National Park thus a higher species richness.…”

“…Unfortunately, no real attempts have been made to estimate the state of biomass in most African forests, as estimating change in biodiversity and Carbon stock became difficult [30] in Africa in general and Cameroon in particular [31]; creating considerable uncertainty about the above-and belowground quantity and distribution of carbon stocks in African forests [32]. This study is one of few in Cameroon and the broader Congo Basin region that has calculated diversity, above-ground biomass, and carbon in a semi-deciduous forest [32] [33] [34] [35]; as despite the importance of this forest reserve, its biodiversity, Carbon storage capacity, the relationship between tree diversity and their ability to store Carbon remains poorly known.…”