Fire Effects and Fire Ecology

Wildfires change plant communities by reducing dominance of some species while enhancing the abundance of others. Detailed habitat-specific models have been developed to predict plant responses to fire, but these models generally ignore the breadth of fire regime characteristics that can influence plant survival such as the degree and duration of exposure to lethal temperatures.

The results of this synthesis illustrate several important lessons. First, current forest structure is the result of decades of fire-suppression activities, and so restoration will require multiple treatments to bring forests to within the range of historic variation.

Dry forests throughout the United States are fire-dependent ecosystems, and much attention has been given to restoring their ecological function. As such, land managers often are tasked with reintroducing fire via prescribed fire, wildland fire use, and fire-surrogate treatments such as thinning and mastication.

A first-of-its-kind study, conducted in a forest of old-growth ponderosa pine and white fir in Oregon’s Crater Lake National Park, explored the relationships among seasonal prescribed burning, an array of soil attributes, and mycorrhizal fungal fruiting patterns.

By collecting information on fuel loading, fuel consumption, fuel moisture, site conditions and fire weather on fires in a variety of shrubland types, researchers are developing a fuller knowledge of shrubland fire effects.

Knowing when, where and how fire should be applied is critical for land managers planning to use fire prescriptively for land management goals, or allowing fires ignited naturally to burn. Myriad variables need to be taken into consideration to determine how fire will consume different fuels.

Technology is playing an increasingly pivotal role in the efficiency and effectiveness of fire management. The First Order Fire Effects Model (FOFEM) is a widely used computer application that predicts the immediate or ‘first-order’ effects of fire: fuel consumption, tree mortality, emissions, and soil heating.

Prescribed burning may be conducted at times of the year when fires were infrequent historically, leading to concerns about potential adverse effects on vegetation and wildlife. Historical and prescribed fire regimes for different regions in the continental United States were compared and literature on season of prescribed burning synthesized.

The Fire and Fire Surrogate (FFS) project is a large long-term metastudy established to assess the effectiveness and ecological impacts of burning and fire “surrogates” such as cuttings and mechanical fuel treatments that are used instead of fire, or in combination with fire, to restore dry forests.

Antelope bitterbrush is a dominant shrub in many interior ponderosa pine forests in the western United States. How it responds to prescribed fire is not well understood, yet is of considerable concern to wildlife and fire managers alike given its importance as a browse species and as a ladder fuel in these fire-prone forests.