Reducing Crown Fire Hazard in Fire-Adapted Forests of New Mexico

Analysis of FIA data for New Mexico shows that 2.4 million acres of pon- derosa pine and dry mixed conifer forests rate high for fire hazard. A restoration treatment designed to address altered ecological conditions in these forests increased average crowning index (i.e., the wind speed necessary to maintain a crown fire) by 50 mph, compared to only 23 mph for a thin-from-below approach designed to reduce hazard. After we projected treated stands forward 30 years, only one-eighth of the acres receiving the thin-from-below treatment remained low hazard, com- pared to over half receiving the restoration treatment. ecent wildfires provide harsh testimony to the hazardous forest conditions that exist over large areas of New Mexico. The fires of 2000 are especially notable, not just in terms of acres burned, but particularly because of the significant damage to property and associated threats to people. There is now both the public support and political will for major initiatives to address this regional concern (Western Governors' Association 2001). For example, tens of millions of dollars have been distributed through the National Fire Plan, much of it dedicated to reducing hazardous fuels. How- ever, planning to address fire hazard at a strategic level requires understanding the forest conditions most vulnerable to fire and the effectiveness of alterna- tive hazard reduction treatments. Absence of a detailed, systematic, and uniform forest inventory for all acres and ownerships has heretofore precluded a comprehensive analysis of fire haz- ard in New Mexico. However, recent availability of Forest Inventory and Analysis (FIA) data, which are collected using consistent inventory protocols across all ownerships, made possible this strategic assessment of fire hazard at a statewide level. Objectives