Vegetation change associated with land-use in tropical dry forest areas of Western Mexico

Patterns of vegetation changes associated with land-use and successional pathways in areas occupied by tropical dry forest in Western Mexico were described. A diagram of vegetation states and transitions (events that promote the change) was constructed using Petri nets, a tool for graphic and mathematical modelling. This conceptual model was verified by analysing the perception of 28 settlers, using an environmental narrative method. Three main pathways of vegetation changes associated with land-use were detected: (i) forest replaced by agriculture in flatlands, (ii) pasture established on slopes, and (iii) wood extraction carried out without slash-and-burn on hill crests. If cultivated areas in flatlands and pasture fields on slopes are not continuously maintained by farmers, thorny vegetation develops within one to 3 years. If left untouched, this secondary vegetation becomes a low forest dominated by Acacia and Mimosa sp. persisting for at least 20 years.