Evaluating the Influence of Topography on Species Diversity, Distribution and Composition of Forests in Central Vietnam

Abstract

Objectives: This study focused on evaluating the influence of topography conditions on species richness, diversity, distribution and species composition as dependent variables at different micro topographic attributes in Central Vietnam. Methods/Statistical Analysis: Trees with diameter at breast height ≥6.0 cm of 90 quadratic plots (1000 m2 ) were inventoried to assess species richness, diversity, and distribution. Scatterplot Matrices: Pairs-sample Test was applied to evaluate the multiple correlations between ranked elevations and slopes with dependent variables. The composition of most abundant, dominant species including Importance Value Index at the midpoint of each topographic attribute was compared with those of the entire topographic attribute. Findings: A total of 4297 tree individuals were recorded representing 122 species from 47 families. We found a significant difference of species richness, diversity, stem density and basal area in different topographic attributes (p < 0.05). The lower elevation and shallower slope had more species richness and diversity than those in the higher elevation and steeper slope. Elevation had more influence on the distribution of species, stand density, species diversity, basal area and family than those of the slope. The species composition between slopes was not remarkably distinguishable which helps to confirm that slopes do not contribute to species distribution, composition. Fagaceae, Myrtaceae, Lauraceae, Cannabaceae, Meliaceae, Sapindaceae, Dipterocarpaceae, Leguminosae, Burseraceae and Malvaceae were the most dominant. The composition of the most abundant and dominant species at the midpoint plots objected to those of the entire topographic attribute. Difference of species composition between elevations may have subjected due to disturbance or successional processes of different forest ecological habitats in the current study area. Application/Improvements: Mapping micro-site natural forest disturbances based topographic conditions of dominant, endemic species for conservation and management of different ecological habitats with support of highresolution satellite images.Keywords: Composition, Central Vietnam, Species Diversity, Topography