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Browsing by Author "Galvin, Kathleen A."

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    Addressing management questions for Ngorongoro Conservation Area, Tanzania, using the Savanna modelling system
    Boone, Randall B.; Coughenour, M.; Galvin, Kathleen A.; Ellis, J. (Oxford, UK: Blackwell Science Ltd, 2002)
    Ngorongoro Conservation Area (NCA), in northern Tanzania, is a multiple-use area of importance to Maasai pastoralists and wildlife conservation. We adapted the Savanna modelling system to the NCA, creating an Integrated Management and Assessment System that allows users to assess responses to alternative management actions. We used the system to conduct fifteen experiments reflecting potential management questions. Results suggest that: the distribution of rainfall throughout the year may have a greater impact on the ecosystem than its quantity; cattle may be near a carrying capacity determined not by forage limitations but because of disease risks; increasing survival and reducing disease in livestock yields greater returns than increasing birth rates; allowing livestock to graze in areas where they are currently excluded may lead to a slight increase in livestock populations, but sometimes leads to large declines in wildlife populations; few ecosystem effects were noted when households and cultivation were allowed to grow at 3% per year for 15 years; and when up to 5% of the study area was in cultivation, there were declines 16% in livestock and wildlife populations, except for elephants, which declined by 48%. Users may modify our experiments using tools we have developed, or address other NCA management questions.
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    An agro-pastoral household model for the rangelands of East Africa
    Thornton, Philip K.; Galvin, Kathleen A.; Boone, Randall B. (Amsterdam, Netherlands: Elsevier Science B.V., 2003)
    East Africa contains areas with some of the greatest large mammal biodiversity on the planet. These areas are key natural resources for the economic development of the region. They are also key areas for pastoralists who have co-existed with wildlife for millennia. Increasing populations, conflicts between wildlife and cattle, and the growth of agriculture, are all placing great pressure on these lands. This paper describes the development of a pastoralist socio-economic model that is linked to the Savanna ecosystem model. In this way, options and scenarios could be investigated for their impacts not only on the ecosystem but also on pastoralist households and their welfare. The model, named PHEWS (Pastoral Household and Economic Welfare Simulator), tracks the flow of cash and dietary energy in pastoralist households using a simple set of rules. The model was calibrated for the Ngorongoro Conservation Area (NCA), northern Tanzania. The results of two population increase scenarios are presented. Model results indicate that all households in NCA depend to some degree on outside sources of calories, and that pastoralist welfare in NCA, even with small amounts of agriculture allowed, is under severe pressure at current human population levels. Strengths and weakness of the model are discussed, and next steps in its application identified.
  • Climate variability and impacts on east African livestock herders: The Maasai of Ngorongoro Conservation Area, Tanzania
    Galvin, Kathleen A.; Thornton, Philip K.; Boone, Randall B.; Sunderland, Jennifer (Grahamstown, South Africa: NISC Pty Ltd, 2004)
    East African pastoral adaptation and vulnerability to climate variability and climate change is assessed, using data from decision-making processes and ecological data of the Maasai of Ngorongoro Conservation Area as an example. The paper uses integrated modeling, linking PHEWS, a household model, to SAVANNA, an ecosystem model to look at the effects of drought and a series of wet years on the well-being of Maasai pastoralists. Model results suggest that the ecosystem is quite resilient and suggests that the Maasai of the NCA are not very vulnerable to climate variability. However the economic situation in the NCA is precarious and food insecurity is prevalent without drought. The result is that drought has a very negative effect on people.