Evaluating herbivore management outcomes and associated vegetation impacts

Abstract

African savannas are characterised by temporal and spatial fluxes that are linked to fluxes in herbivore populations and vegetation structure and composition. We need to be concerned about these fluxes only when management actions cause the system to shift towards a less desired state. Large herbivores are a key attribute of African savannas and are important for tourism and biodiversity. Large protected areas such as the Kruger National Park (KNP) manage for high biodiversity as the desired state, whilst private protected areas, such as those adjacent to the KNP, generally manage for high income. Biodiversity, sustainability and economic indicators are thus required to flag thresholds of potential concern (TPCs) that may result in a particular set of objectives not being achieved. In large conservation areas such as the KNP, vegetation changes that result from herbivore impact, or lack thereof, affect biodiversity and TPCs are used to indicate unacceptable change leading to a possible loss of biodiversity; in private protected areas the loss of large herbivores is seen as an important indicator of economic loss. Therefore, the first-level indicators aim to evaluate the forage available to sustain grazers without deleteriously affecting the vegetation composition, structure and basal cover. Various approaches to monitoring for these indicators were considered and the importance of the selection of sites that are representative of the intensity of herbivore use is emphasised. The most crucial step in the adaptive management process is the feedback of information to inform management decisions and enable learning. Feedback loops tend to be more efficient where the organisation’s vision is focused on, for example, economic gain, than in larger protected areas, such as the KNP, where the vision to conserve biodiversity is broader and more complex.<p><strong>Conservation implications:</strong> In rangeland, optimising herbivore numbers to achieve the management objectives without causing unacceptable or irreversible change in the vegetation is challenging. This manuscript explores different avenues to evaluate herbivore impact and the outcomes of management approaches that may affect vegetation.</p><p><strong>How to cite this article:</strong> Grant, R.C.C., Peel, M.J.S. & Bezuidenhout, H., 2011, ‘Evaluating herbivore management outcomes and associated vegetation impacts’, <em>Koedoe</em> 53(2), Art. #1008, 15 pages. doi:10.4102/koedoe.v53i2.1008</p&gt

Browsing intensity of herbaceous forbs across a semi-arid savanna catenal sequence

“…During the past two decades, savanna management has shifted its focus from causes of ecosystem change, habitat homogeneity, equilibrium and carrying capacity to responses to change, heterogeneity, dynamic equilibrium and ecosystem redundancy perspectives (Rogers, 2003;Grant et al, 2011). The understanding and application of these concepts to the herbaceous layer are however, largely based upon findings from rangeland science, a discipline driven by agriculture (i.e.…”

Surface Moisture and Vegetation Cover Analysis for Drought Monitoring in the Southern Kruger National Park Using Sentinel-1, Sentinel-2, and Landsat-8

“…The monitoring of changes in vegetation structure and dynamics, which are influenced by external factors (e.g., droughts, fires, herbivory, etc.) is one of the essential components for the management of the Kruger National Park [19].…”

Diet and seasonal dispersal of extralimital giraffe at Sanbona Wildlife Reserve, Little Karoo, South Africa

“…Over the past two decades, large areas in South Africa have seen shifts in land use from agriculture to game farming, for either commercial hunting or ecotourism and the photographic safari industry (Vorster 2011). Most of these land owners base their management decisions on economic sustainability (Grant, Peel & Bezuidenhout 2011), often introducing extralimital species (Castley, Boshoff & Kerley 2001). Charismatic extralimital species, such as the South African giraffe, have been introduced to the Western and Eastern Cape due to their popularity among foreign tourists (Parker & Bernard 2005).…”