Impact of the Invasive Alien Species, Lantana Camara (L). on Native Vegetation in Northern Gonarezhou National Park, Zimbabwe

Abstract

This study assessed the impact of Lantana camara invasion on native vegetation in Northern Gonarezhou National Park (GNP), Zimbabwe. Stratified random sampling was used with three categories; uninvaded, moderately invaded and heavily invaded. The distribution of L. camara in Northern Gonarezhou National Park was mapped using GIS. Soil properties and vegetation attributes were assessed in each category. L. camara was mainly distributed within the riparian vegetation and in the low-lying areas of Northern GNP. A total of 41 native woody species and 27 native herbaceous species were identified in the study area. Significant differences (ANOVA, P<0.05) in soil nitrogen, phosphorus, potassium and moisture among the three categories were noted. Soil nitrogen and phosphorus levels were highest in the heavily invaded category and lowest in the uninvaded category. Soil potassium and moisture levels were highest in the uninvaded category and lowest in the heavily invaded. For native vegetation attributes; basal area, canopy cover, herbaceous cover, woody plant density, species diversity (H�) and species richness (S) varied significantly (ANOVA, P<0.05) among the categories of L. camara intensity. These variables were highest in the uninvaded category and lowest in the heavily invaded category. The uninvaded category was the most diverse (H�=1.875) while the heavily invaded category was the least diverse (H�=1.334). Edaphic factors influenced plant species structure and composition in northern GNP. The significant differences in soil and vegetation variables suggest that L. camara is altering soil properties and native vegetation structure and composition in GNP to the detriment of wildlife management. Active management of L. camara in Gonarezhou National Park is therefore urgently required for wildlife and biodiversity conservation in the area.