Title:
Assessment of the impacts of chemical de-bushing on herbaceous vegetation and grond-dwelling invertebrate communities at Neudamm Farm
Author(s):
Publication Year:
2020
Abstract:

This study aimed at assessing the impacts of chemical de-bushing on herbaceous plants and ground-dwelling invertebrates at Neudamm farm. Three experimental sites (camp’s 5, 6 and 7) treated in 2015, 2016 and 2017 respectively with a general purpose arboricide were selected alongside one (camp 4) untreated site. Pitfall traps were placed under 15 Senegalia mellifera trees which were strategically selected in each site. Three quadrates, two placed contiguous under the canopy and one outside the canopy of fifteen Senegalia mellifera trees were used to identify and record the herbaceous plants. The herbaceous species diversity was higher in the control camp than in the other camps (H= 29.285, d.f = 3, p < 0.000), while the ground- dwelling invertebrate diversity (H= 2.497, d.f = 3, p < 0.5) and Family richness (H = 0.285, d.f = 3, p =0.963) did not differ significantly between the camps. However, species richness was higher in camp 5 (treated in 2016) than in the control camp (H= 13.085, d.f = 3, p < 0.000). The HCA on binary data separated the herbaceous plant species into 6 clusters and the pitfall traps into 7 clusters indicating the significant changes in herbaceous species and invertebrate family composition due to chemical treatment, among other factors. Grass biomass was higher in camp 5 (p < 0.001) and the control camp had the highest ground cover (H= 8.5 and p- value= 0.037). This study has shown that arboricides have significant direct negative effect on herbaceous vegetation and, to a lesser extent, on the ground- dwelling invertebrates. Keywords: herbaceous vegetation, invertebrates, arboricides, bush encroachment, species, composition and biodiversity.

Place:
University of Namibia
Type:
MSc Thesis
Item Type:
Thesis
Language:
en