Wildfire and Spatial Patterns in Forests in Northwestern Mexico: The United States Wishes It Had Similar Fire Problems

Abstract

Knowledge of the ecological effect of wildfire is important to resource managers, especially from forests in which past anthropogenic influences, e.g., fire suppression and timber harvesting, have been limited. Changes to forest structure and regeneration patterns were documented in a relatively unique old-growth Jeffrey pine-mixed conifer forest in northwestern Mexico after a July 2003 wildfire. This forested area has never been harvested and fire suppression did not begin until the 1970s. Fire effects were moderate especially considering that the wildfire occurred at the end of a severe, multi-year (1999-2003) drought. Shrub consumption was an important factor in tree mortality and the dominance of Jeffrey pine increased after fire. The Baja California wildfire enhanced or maintained a patchy forest structure; similar spatial heterogeneity should be included in US forest restoration plans. Most US forest restoration plans include thinning from below to separate tree crowns and attain a narrow range for residual basal area/ha. This essentially produces uniform forest conditions over broad areas that are in strong contrast to the resilient forests in northern Baja California. In addition to producing more spatial heterogeneity in restoration plans of forests that once experienced frequent, low-moderate intensity fire regimes, increased use of US wildfire management options such as wildland fire use as well as appropriate management responses to non-natural ignitions could also be implemented at broader spatial scales to increase the amount of burning in western US forests.

Fuel and stand conditions in an isolated, unmanaged forest landscape in central Oregon

“…Our results support the broad consensus that forest fuel composition in western North America is highly variable at many spatial scales, especially in relatively unmanaged stands (Stephens et al 2008). Stand composition is often an insufficient estimator of fuel composition and total fuel load data may be an inadequate indicator for wildfire risk.…”

Forgetting fire: Traditional fire knowledge in two chestnut forest ecosystems of the Iberian Peninsula and its implications for European fire management policy

“…These results seem to replicate Minnich"s (1983) findings on the contrast between fire regimes in Baja California (Mexico) -where during the time of his study state fire suppression policies had never been implemented -and California (USA) where active state fire suppression policies had been a part of the landscape since the beginning of the 20 th century. These findings have been confirmed and further refined in posterior comparative studies of fire regimes in both countries (Stephens et al, 2008).…”

“…State fire exclusion policies seem to have, indeed, played an important role in determining the evolution of anthropogenic fire regimes not only in Spain but also throughout the world (Minnich, 1983;Kull, 2002;Seijo, 2005;Laris and Wardell, 2006;Stephens, 2008;Fernandes et al, 2014). Political scientists have hypothesized, for instance, that the same international governance rural development or environmental policies may have contrasting impacts depending on the relative "strength" or "weakness" of the implementing national state organizations (Migdal, 1988;Scott, 1999;Guha, 2000;Goldman, 2005;Seijo and Gray, 2012).…”

Historical and current landscape‐scale ponderosa pine and mixed conifer forest structure in the Southern Sierra Nevada

“…Periods of frequent fire in mixed-conifer and pine-dominated forests gave fire-resistant species a competitive advantage, allowing them to establish dominance (Stephens et al 2008). During ''fire-free'' or less frequent-fire periods, pines persisted due to their dominant positions in the forest canopy (Fulé et al 2009).…”

“…Throughout much of the drier, low-to midelevation coniferous forests in western North America fires historically burned at intensities that often left mature trees unaffected or scarred by fire, but seldom killed (Allen et al 2002, Collins andStephens 2007) even when preceded by multi-year drought (Stephens et al 2008). Mid-elevation forests in the Sierra Nevada, such as those historically dominated by ponderosa pine (Pinus ponderosa), Jeffrey pine (P. jeffreyi ), and other mixed conifer species commonly burned many times per century ( Van de Water and Safford 2011) and this produced generally open stand structures (Figs.…”