Title : Phytosociological analysis and physiognomic profiling of Osara natural vegetation using “M-Tree” mobile application technology
Abstract:
Vegetation plays a vital role in maintaining ecological balance and supporting biodiversity within terrestrial ecosystems. Floristic composition refers to the identity, richness, abundance, and distribution of plant species within a vegetation community, whereas physiognomic structure describes the physical organization of vegetation based on characteristics such as growth form and vertical height stratification. This study assessed the phytosociological characteristics and physiognomic structure of the natural vegetation of Osara, Kogi State, Nigeria, using the M-Tree mobile application. Field sampling was conducted in five plots within the Osara natural vegetation. A total of 71 woody individuals in 19 species distributed among 16 plant families were inventoried, comprising both tree and shrub growth forms. Species diversity was assessed using the Shannon-Wiener diversity index, maximum diversity (Hmax), and Margalef’s richness index (D). Physiognomic structure was assessed from woody plant height measurements obtained using the M-Tree application, with species height relationships examined through hierarchical cluster analysis. The results revealed variation in species richness and abundance among the five plots. Species richness ranged from 13 species in Plots 1 and 2 to 19 species in Plot 5, while the Shannon-Wiener diversity index ranged from 1.5570 in Plot 4 to 2.3617 in Plot 2. Plot 3 recorded a Shannon-Wiener index of 2.0920, while Plot 5 recorded 2.2572. Margalef’s richness index ranged from 2.0567 to 3.9415, indicating variation in species richness among the sampled plots. The overall mean Shannon-Wiener index was 2.1205, with a mean Margalef’s species richness index of 3.0998. The height-based analysis revealed distinct vertical strata: an understorey layer (approximately 4-12 m), a sub-canopy layer (15-25 m), and an emergent/canopy layer (45-68 m). The cluster analysis further grouped species according to similarities in their mean height, providing an indication of their vertical relationships within the vegetation community. The findings provide a quantitative description of the floristic composition, ecological importance, species diversity, and vertical structural organization of Osara natural vegetation. The study establishes baseline information that can support vegetation monitoring, biodiversity assessment, and sustainable management of the natural vegetation.
Key Words: Species Richness, Plant Height, Importance Value Index, Quantitative description.
