Local variation in plant community with slope aspect as a tool for forest restoration in Malagasy tropical montane forest

To address the loss in forest cover and biodiversity in tropical regions, human intervention in forest restoration is vital to help the forests get back the structure and diversity they have lost. Therefore, stakeholders involved in forest restoration activities require comprehensive information about the structure and composition of original forests in the region to make informed decisions regarding the selection of appropriate species and plant communities to reproduce. The objective of this study is to characterize the forest structure and identify the contribution of terrain topography to the distribution of plant communities in a tropical humid montane forest in the central region of Madagascar. Species composition and tree basal area across 30 plots were measured, and similarities between plots were analyzed. The analysis identified two different communities. The statistical tests demonstrated significant segregation between the two groups along the south-north axis but it was not significant along the west-east axis. The first community, referred to as the “north-slope community NC”, dominated the north-facing slopes, and the second community, hereafter “south-slope community SC” dominated the east, south and west-facing slopes. Species and functional diversity of SC were higher, but the community-weighted wood density was lower than NC. To facilitate future forest restoration efforts in the region, the study recommends replicating NC on slopes with aspects ranging from 288° to 63° (in the clockwise direction) and SC on other slopes. This study underscores the influence of terrain topography and slope aspects on ecosystem and species diversity in tropical montane forests.