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Grant R.C.C.,Scientific Services Kruger National Park | Peel M.J.S.,Animal Production Institute | Bezuidenhout H.,Conservation Services
Koedoe | Year: 2011

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. Conservation implications: 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. © 2011. Source

Freitag S.,Scientific Services | Biggs H.,Conservation Services | Breen C.,University of KwaZulu - Natal
Ecology and Society | Year: 2014

Natural resource management is embedded within social-ecological environments and requires decisions to be taken within this broad context, including those that pertain to protected areas. This realization has led to South African National Parks adopting a strategic adaptive management approach to decision making. Through narrative, we show why and how this practice has progressively spread and evolved both within the organization and beyond, over the past two decades. A number of catalytic events and synergies enabled a change from reactive tactical management approaches to more inclusive forward-looking approaches able to embrace system complexity and associated uncertainty and change. We show how this long period of innovation has lead to an increased appreciation for the heterogeneous social-ecological system, and for the importance of constructing relationships and colearning, such that organizational transformation has enabled more legitimate and effective operation within an expanding and diversifying constituency. © 2014 by the author(s). Source

van Wilgen N.J.,Cape Research Center | Dopolo M.,Cape Research Center | Symonds A.,Conservation Services | Bester E.,Storms River Village Conservation Services | And 3 more authors.
Koedoe | Year: 2013

Resource harvesting is permissible within South African protected areas under certain conditions as part of benefit sharing that seeks to strengthen relationships with communities living adjacent to parks. However, not all resource use is authorized and little is currently known about what is harvested, or the extent and impacts of harvesting in parks. This limits capacity to monitor and set the boundaries for such use. This paper provides a checklist of resources harvested within each of 19 national parks managed by South African National Parks. Data were gathered by means of a question-based survey of park staff. A database detailing the parks from which each resource was harvested and its purpose(s) was compiled, representing the most comprehensive list of resources harvested from parks to date. A total of 382 harvested biological and biotic resources (284 terrestrial and 98 aquatic), used for a wide range of purposes, were identified across parks. Many of the resources, especially animals (96%), were harvested destructively. The strongest motivation for harvest was subsistence, although most resources were also used for financial gain through informal business. Although current data are not sufficient to determine harvest sustainability for most resources, better data and increased awareness of resource use activities will enable future research to this end. Conservation implications: The checklist of harvested resources provides critical baseline data for parks, which will facilitate assessment of park-specific priorities for research, monitoring and management action. © 2013. The Authors. Source

Foxcroft L.C.,Conservation Services | Foxcroft L.C.,Stellenbosch University | Pickett S.T.A.,Cary Institute of Ecosystem Studies | Cadenasso M.L.,University of California at Davis
Perspectives in Plant Ecology, Evolution and Systematics | Year: 2011

Numerous mechanisms driving alien plant invasions have been described in a rapidly growing body of literature. However these are frequently case specific, making generalizations across species and systems difficult. A number of conceptual approaches have been proposed to help synthesize the literature, stimulating healthy debate among scientists. We build on these syntheses, presenting an expanded framework that incorporates the processes contributing to invasions, and the context within which they must interact. We also provide a model template into which the framework we develop is incorporated, illustrating both with examples. Our general framework includes three contributing processes: these are (1) the characteristics of the introduced species, (2) system context, within which the invasion takes place, and (3) the features of the receiving habitat. System context refers to the influences arising outside of the receiving environment, both spatially and temporally. Each contributing process is comprised of specific mechanisms, drawn from literature on invasion ecology and other related fields. The framework invokes relevant mechanisms for a specific species or situation. Although, a number of frameworks already consider the characteristics of the invading species or those of the receiving habitat, they seldom include all possible characteristics of both. We propose that these approaches alone are inadequate to provide a comprehensive understanding of the invasion process, without explicitly examining the context within which the invasion takes place. The model template we present relates the contributing processes described for a particular invasion, to the change in habitat from one state to another. Each of the contributing processes defined in the framework modulates the degree to which the habitat is changed. We suggest that these additional tools and the explicit inclusion of all three contributing processes, provide for further synthesis and improved understanding of invasions by alien plants. © 2011 Perspectives in Plant Ecology, Evolution and Systematics. Source

Foxcroft L.C.,Conservation Services | Foxcroft L.C.,Stellenbosch University | Jarosik V.,Charles University | Jarosik V.,Academy of Sciences of the Czech Republic | And 4 more authors.
Conservation Biology | Year: 2011

Human land uses surrounding protected areas provide propagules for colonization of these areas by non-native species, and corridors between protected-area networks and drainage systems of rivers provide pathways for long-distance dispersal of non-native species. Nevertheless, the influence of protected-area boundaries on colonization of protected areas by invasive non-native species is unknown. We drew on a spatially explicit data set of more than 27,000 non-native plant presence records for South Africa's Kruger National Park to examine the role of boundaries in preventing colonization of protected areas by non-native species. The number of records of non-native invasive plants declined rapidly beyond 1500 m inside the park; thus, we believe that the park boundary limited the spread of non-native plants. The number of non-native invasive plants inside the park was a function of the amount of water runoff, density of major roads, and the presence of natural vegetation outside the park. Of the types of human-induced disturbance, only the density of major roads outside the protected area significantly increased the number of non-native plant records. Our findings suggest that the probability of incursion of invasive plants into protected areas can be quantified reliably. ©2010 Society for Conservation Biology. Source

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