Fire History in Ponderosa Pine and Mixed-Conifer Forests of the Jemez Mountains, Northern New Mexico

Touchan, Ramzi; Swetnam, Thomas

We reconstructed fire history in ponderosa pine and mixed-conifer forests across the Jemez Mountains in northern New Mexico. We collected fire-scarred samples from nine ponderosa pine areas and four mesic mixed-conifer areas. An additional collection was obtained from a bristlecone pine stand in the Sangre de Cristo Mountains. We also reconstructed December-June precipitation from ponderosa pine tree-ring indices that were developed from four different watersheds in northern New Mexico. Prior to 1900, ponderosa pine forests were characterized by high frequency, low intensity surface fire regimes. The mixed-conifer stands sustained somewhat less frequent surface fires, along with patchy crown fires. In both ponderosa pine and mixed-conifer forests precipitation was significantly reduced in the winter-spring seasons preceding fire events. In addition, winter-spring precipitation during the third year preceding major fire years in the ponderosa pine forest was significantly increased. This study provides baseline knowledge concerning the ecological role of fire in ponderosa pine and mixed conifer forests. This information is vital to support ongoing ecosystem management efforts in the Jemez Mountains.