The impact of shifting agriculture on the availability of non-timber forest products: the example of Sabal yapa in the Maya lowlands of Mexico

Understanding the effect of agriculture on the availability of non-timber forest products (NTFP) is currently relevant. Many landscapes are dominated by agricultural fields and fallow lands, so we should understand the status of NTFP in these landscapes. We studied the availability of leaves of xaan palm trees (Sabal yapa Wright ex Beccari) in the shifting cultivation systems among the Yucatec Maya in Mexico. The mature leaves of this species of palm have been widely used for roofing since prehispanic times until present days; in the year 2000, approximately 90,000 people used S. yapa in Quintana Roo, and 360,000 used Sabal spp. in the Yucatán peninsula. This palm is managed by Maya farmers who spare palm trees when clearing a forest patch to turn it into maize fields (milpa). We compared the population structure and leaf production rate in different stages of the shifting cultivation cycle (milpa, fallow lands and forest), and quantified the domestic leaf demand in the village of X-Maben, state of Quintana Roo. In addition, we projected future availability of xaan leaves, and estimated the period after which this might not be sufficient enough to cover the local demand of some villages and municipalities of Quintana Roo. Our results suggest that one of the consequences of shifting cultivation is the decrease in the availability and quality of this NTFP. Decreasing availability is a result of variations in population structure and leaf production rates between agriculture and forest patches. These negative effects may increase as agriculture becomes more intensive. Currently, the complete mosaic landscape created by this practice still offers sufficient resources for the local inhabitants in many communities. Besides, this NTFP has a high commercial potential in the tourist area. Our study suggests that the harvest of S. yapa in natural systems is sustainable for nine more decades and will be compatible with shifting cultivation as long as land tenure remains communal, there are long fallow periods and other factors remain unchanged.