Fire ecology of Mexican pines and a fire management proposal

Abstract

Many Mexican pine ecosystems are characterized by great biological diversity and are strongly influenced by fire. We summarize fire ecology information for 35 taxa (including infraspecific taxa) in terms of nine types of fire traits: serotiny, seed germination after fire, grass stage, fast initial growth, thick bark, protected buds, self-pruning capacity, resprouting, and canopy recovery from scorch. The majority of Mexican pine species appear to be adapted to a predictable, stand-thinning fire regime. Current fire regimes are often altered from long-term historical patterns due to a combination of natural fires plus anthropogenic fires. Human-caused fires are the most common and burning practices have deep historic and socioeconomic roots. As a consequence, there are three main categories of fire conditions: (1) pine forests endangered by excessive anthropogenic fire (eventually leading to deforestation); (2) pine forests maintained by an appropriate fire regime; and (3) pine forests with insufficient fire or fire exclusion due to fire protection. For managers, conservationists, and landowners concerned with maintaining the important benefits associated with fire, such as fuel hazard reduction and nutrient cycling, different approaches are needed. While recognizing the difficult social and economic factors that foster forest degradation, we recommend basing fire management in pine forests upon a site-specific and species-specific understanding of the historical and ecological role of fire, trying to reduce excessive anthropogenic burning, maintain appropriate burning, and restore fire into fire-excluded forests. The interaction of fire with other resource uses, such as timber harvesting and livestock grazing, should also be balanced in a holistic ecosystem management approach. These changes must be made in the context of seeking alternative economic options for rural residents and by thoughtful planning to obtain as many ecological and economic benefits from fire as possible while minimizing negative impacts.