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Zimbabwe: Landuse in Dry Tropical Savannas

Savanna - Landscape and Regional Ecosystem Model

Model objectives

Savanna aims at realistic, general and explanatory representations of ecological change. Itdoes not aim at giving descriptions of ecological status and neither does it aim at giving prescribed responses.

It's specific modeling objectives are:

  • Simulating extensive ecosystems occupied by ungulate herbivores
  • Simulating vegetation change in the absence of herbivore
  • Simuating interactions among functional groups (e.g. sun adapted herbs, shade tolerant herbs, shrubs, decidous and evergreen trees)

The explicit linkages among water and nutrient pools, primary production processess and plant population dynamics provide anwers that would be difficult to address with either a population dynamics or biomass model alone. Seasonal dynamics are important when it is critical to evaluate and manage ungulate populations in relation to inter-seasonal forage dynamics. Seasonal bottlenecks of low forage availability may be critical during winter, dry seasons or droughts. The model attempts to model these linkages to address the following issues;

  • Does competition for water use and light affect relative numbers of different functional groups of plants?
  • Is ungulate carrying capacity affected by changes in primary production?
  • How are vegetation and ungulate distributions and interactions related to water, soils and topography?

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