Perception and adaptation strategies of forest dwellers to climate variability in the tropical rainforest in eastern Cameroon: The case of the inhabitants of the Belabo-Diang Communal Forest.

The design of appropriate adaptation strategies to the impacts of climate change requires a contextual study of local perceptions due to the non-homogeneity of climate in a given agro-ecological area. The research objective of the current study aims to examine the evolution of climate parameters from 1983 to 2019 linked to the perceptions of local populations and appropriate adaptation measures in the Belabo-Diang Communal Forest of Cameroon. The methodological approach includes collecting and analyze climate data from 1983 to 2019; and surveying existing local perceptions and adaptive strategies among 540 households using semi-structured questionnaires. A significant increase in temperature of about 1 °C over 36 years (1983-2019) and a non-significant decrease in precipitation (95.36 mm) over the same period were observed. Local perceptions related to climate change vary according to the sector of activity and are mainly associated with more heat in the dry season (90%), late onset of rains (84%), drought recurrence (82%), less rainfall during the year (80%), and increase in the duration of drought (80%). For 82-100% of households, according to the activity sector, no appropriate adaptation measures to climate change were applied depending on activities. The adaptation measures used by less than 0-20% of respondents, include mainly the abandonment or change of activity, and modification of the agricultural calendar. With the lack of appropriate and adequate adaptation measures by the riparian populations, this study appears necessary to inform policy-makers of the need to develop and implement more appropriate strategies to enable the riparian people living in forest area of Cameroon to better adapt to these effects of climate changes.

Assessing plant diversity change in logged and unlogged dense semi-deciduous production forest of eastern Cameroon.

This study was carried out in the dense semi-deciduous production forest of East Cameroon. The objective of this work of this study was to provide comparative floristic knowledge that can serve as a basis for the planning and sustainable management of ligneous plant resources in Communal Forests before and after logging. Sampling was done in unlogged and logged forest. Data collection was carried out using the linear transects subdivided into 10 plots of 25 m × 20 m (500 m2) with an equidistance of 225 m for the inventory of all trees with dbh ≥10 cm installed measured at 1.3 m above ground level. Nested quadrats 5 m × 5 m, oriented south-west and north-east were set up in each plot for the counting and identification of all individuals with a diameter less than 10 cm. The analysis of inventory data showed that the floristic composition was higher in the unlogged forest. The individuals were more evenly distributed in the logged (Pielou's equitability index = 0.83) than in the unlogged forest. The study of the functional spectra showed that the flora of the two forest types was dominated by Guinean-Congolese species (67.57% in the unlogged forest and 63.07% in the logged forest) and Phanerophytes, particularly Mesophanerophytes. The dominance of sarcochorous species reveals that the main mode of dissemination in this forest is zoochory, particularly endozoochory. The presence of pleochroic species in the logged forest reveals the importance of dissemination by water in the environment. The plants surveyed were divided into five plant assemblages (three for logged forest and two for unlogged forest) based on ecological parameters. The findings of this study suggest that forest management which combines assisted natural regeneration with the natural process of secondary succession facilitates the reconstitution of the vegetation cover and, by extension, the conservation of biodiversity in post-logging forest concessions.

Height-diameter allometry and above ground biomass in tropical montane forests: Insights from the Albertine Rift in Africa.

Tropical montane forests provide an important natural laboratory to test ecological theory. While it is well-known that some aspects of forest structure change with altitude, little is known on the effects of altitude on above ground biomass (AGB), particularly with regard to changing height-diameter allometry. To address this we investigate (1) the effects of altitude on height-diameter allometry, (2) how different height-diameter allometric models affect above ground biomass estimates; and (3) how other forest structural, taxonomic and environmental attributes affect above ground biomass using 30 permanent sample plots (1-ha; all trees ≥ 10 cm diameter measured) established between 1250 and 2600 m asl in Kahuzi Biega National Park in eastern Democratic Republic of Congo. Forest structure and species composition differed with increasing altitude, with four forest types identified. Different height-diameter allometric models performed better with the different forest types, as trees got smaller with increasing altitude. Above ground biomass ranged from 168 to 290 Mg ha-1, but there were no significant differences in AGB between forests types, as tree size decreased but stem density increased with increasing altitude. Forest structure had greater effects on above ground biomass than forest diversity. Soil attributes (K and acidity, pH) also significantly affected above ground biomass. Results show how forest structural, taxonomic and environmental attributes affect above ground biomass in African tropical montane forests. They particularly highlight that the use of regional height-diameter models introduces significant biases in above ground biomass estimates, and that different height-diameter models might be preferred for different forest types, and these should be considered in future studies.