Subproject 1: Vegetation and rangeland dynamics and implications for policy


Aims:

In this subproject we focus on modelling the impacts of climate change and land use on vegetation dynamics and diversity in the Limpopo province.

Approach:
Our research addresses three key questions:
(1) How can we simulate functional diversity in the Limpopo province?
(2) How does climate change influence vegetation?
(3) How can management activities be optimized to minimize undesirable vegetation change under future climate conditions?

To answer these questions, we use the trait- and individual-based dynamic vegetation model aDGVM2 to simulate vegetation structure, composition, and dynamics in the study region. Application of the model to the study region requires prior customization, including changes and improvements of the representation of grasses and woody vegetation, specific parameterization of the model for the study region, and the development of new routines to simulate grazing, browsing, fuel wood extraction, and fire management. To date, the following tasks already have been accomplished or are work in progress:


  • We integrated multi-stemmed woody vegetation types and novel fire sub-models into the aDGVM2, which will allow us to investigate shrub encroachment.
  • A grazing model that conditions grazing impacts on traits and biomass of simulated grasses has been developed.
  • More flexible routines to describe crown architecture of trees are developed for more realistic simulations of fuel wood removal and browsing.
  • After successful integration of these sub-models, we will explore management policies for the Limpopo province.


Links to other subprojects:
As data-model integration is a prerequisite to reduce uncertainties of model projections, we use field data from the project partners in SP4, in particular from the DroughtAct experiment, to parameterize and calibrate the aDGVM2 model.