Influence of Geographic Distance on the Floristic Composition of the Miombo Savannah in Unango, Northern Mozambique

Abstract

Geographic distance results in population decline, influencing species richness, diversity and distribution. The aim of this research was to evaluate the influence of geography on the floristic composition in the Miombo Savannah in Unango the northern part Mozambique. The studied area was 1.8ha, where 20 sample units of 30m * 30m were established using systematic sampling with a distance of 20m and individuals with DBH ≥ 5 cm were measured. The description of species composition and distribution was evaluated using the Importance Value Index (IVI), diversity by the Shannon Index, and the influence of geographical distance on floristic similarity by the Mantel test. In the floristic survey a total of 999 individuals were sampled, belonging to 34 species distributed in 19 families, the Shannon index was 2.6 and in terms of number of species, the Fabaceae family was the most representative in the study area. The species with the highest importance index values in the study area were <i>Brachystegia spiciformis, Brachystegia boehmii, Uapaca kirkiana, Uapaca nitida, Julbernardia globiflora </i>and<i> Salix mucronata</i>. The Mantel test was not significant, showing that the geographical distance does not influence the floristic similarity within the forest formation on a local scale, other factors may have an influence on the similarity between areas such as climate, topography and soils.