Bush encroachment and the effect of grazing on species composition in Coastal Thornveld of Eastern Cape
1Simphiwe P Nobatyi, 1Keletso Mopipi and 2Ayodele T Odularu
1Department of Livestock and Pasture Science, Private Mail Bag X1314, University of Fort Hare, Alice, South Africa.
2Department of Chemistry, Private Bag X1314, University of Fort Hare, Alice, South Africa.
feature
Grassroots
August 2017
Vol. 17, No. 3
34
Table 1: Example of 1000-seed weights of different grass species
C
hallenges of bush encroachment resulted in reduction of grazing abilities of farm animals within and outside South
Africa. This research involved an experimental approach of using browsing goats and occasional fire as treatments in Bathurst Research Farm. Responses received from herbaceous and woody plants were measured using step-point and field plot methods, respectively. Results collected as data were analyzed using statistical means of ANOVA. In summary, the use of fire coupled with goats prior growing season does not only reduce bush phytomass as a result of decrease in species heights but also encourages herbage production and available browsing material.
Keywords: Bush encroachment, grazing goats, occasional fire, species composition.
Introduction
Grazing potentials of South African savannahs has been rejected due to bush encroachment (Daskin et al. 2016). This has led to limitation in the production of livestock (Reed et al. 2015). Encroachment involves the invasion of grasslands by woody species (O’ Connor et al. 2015). Bush encroaching species have negative effects on livestock because of their chemical and physical defences (Mkhize et al. 2015). Areas affected by bush encroachment have reduced productivity of forage resources and consequently, lower profitability compared to non-encroached areas (Oldeland et al. 2010; Kgosikoma et al. 2013; Gray and Bond 2013). In South African savannahs, woody vegetation involves not only browsing livestock and, game species, but also production of firewood, charcoal, construction timber and woodcarvings (Singh & Sureja 2006; Colgan et al. 2012). Factors contributing to bush encroachment are either elimination of grazing species or exclusion of fires (Kgosikoma et al. 2013; O’ Connor et al. 2015). Goats can be regarded as a primary browser when there is sufficient browse to provide 85% of the goat’s diet, especially in the Valley Bushveld (Aucamp 1976; Nyamukanza 2008). In cases where browsing animals like goats graze in bush dense areas, the function of fire will be the reduced and bushes at available heights are maintained at acceptable states for the browsing animals (Nyamukanza 2008). This study aims to assess the effect of goats’ grazing in controlling bush encroachment and