Af-Range Background

Af-Range is an assessed application of L-Range to the continent of Africa that can simulate vegetation and herbivore dynamics through space and time. Being derived from G-Range, the background provided for that model applies.

Providing G-Range for download to users anywhere in the world has been rewarding; the software has been downloaded hundreds of times. Years of expereince making custom applications of the Savanna ecosystem model suggested to me that people would download G-Range, adjust the application to suit their area of interest, and reasses the application before using it to address research questions. But that is not what has happened. Most people have used the G-Range results from Boone et al. (2018) directly in their work, and others have used the G-Range model unchanged to address new questions.

Among the outcomes from Boone et al. (2018) and from several other analyses is that Africa will be among the regions in the World most stressed by climate changes. Among other stressors are human population growth, changes in pastoralism, policy challenges, and fragmentation of landscapes. We therefore sought to apply L-Range to all of Africa and to use the most up-to-date spatial data available. Special effort has been put to assessing the outcome, with assessment reports provided along with the software so that users may judge if the tool is representing reality sufficiently well to address their questions of interest. We also sought to include herbivores directly in the application. We wished to simulate the entire continent, regardless of land cover type;some types will be simulated better than others, as reported in assessment.

A suite of spatial data inform Af-Range, with sources pending the publication of the tool's description. The landscape is divided into 47 units derived from our detailed analysis of a long series of images of Normalized Difference Vegetation Indices ( Boone 2020), such that the landscape units - some large and some small - have similar trends in the quantity and timing of primary production. Livestock populations come from the Gridded Livestock of the World database from the Food and Agriculture Organization, except for camels and donkeys. Those and distributions of wildlife will be detailed in a forthcoming puplication. Fire is represented across the continent, in-line with rates of burning drawn from remotely-sensed images.