Where are the 'bad fires' in West African savannas? Rethinking burning management through a space-time analysis in Burkina Faso

摘要

In Sudanian savannas, frequent fires are required to maintain a mix of trees and grasses. After a century of long conflict over fire utilisation and resource management, arising from colonial scientists reacting against traditional practice, fire has become a management tool used to shape tropical vegetation. Many examples show that fire is allowed and used in protected areas, and more recently, tolerated in West African countrysides. If fires are no longer viewed as evil' for African landscapes, fire setting remains a problem. Nowadays, fire ecology and the savanna concept focus on fire seasonal temporality, and create a new and more specific category of contested fires, or late-season fire, referred to in this paper as bad fires'. This specific category generally conceives fire as a biophysical element, which leads to savanna degradation. This paper examines the reality of bad fires' in the Western Burkina Faso through a space-time analysis to investigate the existence of an annually seasonal pattern of fires created by peasants. Using spatial association (I_Moran) on active fire MODIS products, we are able to demonstrate a deterministic regional pattern occurring over six years (from 2004 to 2009). Results of this study confirm the importance of a close study of fire in its temporal dimension with respect to temporality in burning practices. Conclusions show that the details of timing in fire-setting are key and also bring us new perspectives to understanding fire collective management at a local scale and new elements for climate modelling at a global scale.