Altitudinal zonation of tree communities along climate and soil gradients in east African biodiversity hotspot

Abstract

Using climate and soil parameters, zonation of tree communities and species associations were classified along altitudinal gradients of Amani Nature Reserve (ANR) and Udzungwa Mountains (UMF). The plots were sampled from the two mentioned sites and classified separately. In addition, tree communities were named based on dominant and diagnostic species. Along climate gradient, four and five distinct plant communities were identified in ANR and UMF respectively. The communities consisted of typical Miombo species in the lowland forests (lower slopes) of the UMF. Zonation of the tree communities corresponded to a range of edaphic factors. The communities of ANR responded to sand, loamy sand, and sandy clay soil types, while in UMF the communities correlated with sandy loam and loamy sand soil types. All communities correlated with acidic soils in ANR and UMF. This study advances the understanding of drivers of plant community distribution in EAMs and other tropical ecosystems. Variation findings reported in some of the previous studies might be due to different sampling approaches and variables (environmental factors) used in the analysis.