Impact of the invasive shrub, Lantana camara L. on soil properties in Nairobi National Park, Kenya

Abstract

Lantana camara L. (Verbenaceae) is an invasive shrub of global significance in the conservation of biodiversity in terrestrial ecosystems. The invasive species has profound impact on soil ecosystems due to its allelopathic and litter accumulation effect. This study tested for its impact on soil properties in Nairobi National Park (NNP) by randomly sampli ng soil from the invaded and un-invaded sites in three habitats namely forest, riverine and shrub-gr assland using the Modified Whittaker plot design. Six plots were laid in the forest, four in the riverine and eight in the shrub-grassland. Ten samples were collected at invaded and ten at un-invaded sites per habitat totaling to sixty which were obtained and analysed. Two-way analysis of variance (ANOVA) resu lts indicated significant differences in the values of soil pH, the concentrations of magnesium, calcium and potassium between the invaded and un- invaded sites and their levels were higher in in vaded sites. Also magnesi um, calcium and potassium varied significantly across the forest, riverine and shrub-grassland. These results suggest that L. camara can improve the nutrient levels of soil and therefore influence nutrient cycling resulting to making the ground better for its growth and this might explain the capacity of the invasive species to outcompete the native ones.