Fire Health Main

This model combines stand density index (SDI), basal area loss, drought
stress, and insect and disease surveys using an equal weight overlay. SDI determines
the relative density of a stand, and was used in this model to identify where the
density of small diameter trees is high. Basal area loss is defined as "the
expectation that, without remediation, 25 percent or more of the standing live basal
area of trees greater than 1 inch in diameter will die over the next 15 years
(starting in 2005)." For the purposes of the New Mexico State Assessment, the basal
area loss data layer represents areas of dense forest/woodlands with large diameter
trees expected to experience mortality from insect and disease. SDI and basal area
loss data layers were derived as a part of the 2006 National Insect and Disease Risk
Map (NIDRM) and based on New Mexico's Forest Inventory Analysis Data from 1987-1999.
Moisture stress depicts percent of normal precipitation for winter precipitation
from 2006-2008 and was derived from PRISM precipitation data. Insect and disease
outbreaks data was limited to past occurrence flyover data for western spruce
budwrom and western tent catepillar and are based on USFS Forest Health Aerial
Survey data from 1987-2008 .