fire severity

Morel mushrooms are globally distributed, socially and economically important reproductive structures produced by fungi of the genus Morchella. Morels are highly prized edible mushrooms and significant harvests are collected throughout their range, especially in the first year after fire, when some morel species fruit prolifically.

Many recent wildfires in ponderosa pine (Pinus ponderosa Lawson & C. Lawson) - dominated forests of the western United States have burned more severely than historical ones, generating concern about forest resilience. This concern stems from uncertainty about the ability of ponderosa pine and other co-occurring conifers to regenerate in areas where no surviving trees remain.

Fire regime characteristics in North America are expected to change over the next several decades as a result of anthropogenic climate change. Although some fire regime characteristics (e.g., area burned and fire season length) are relatively well-studied in the context of a changing climate, fire severity has received less attention.

Mixed-severity fires are increasingly recognized as common in Pseudotsuga forests of the Pacific Northwest and may be an important mechanism for developing or maintaining their structural diversity and complexity. Questions remain about how tree mortality varies and forest structure is altered across the disturbance gradient imposed by these fires.

Recent large scale mountain pine beetle (Dendroctonus ponderosae Hopkins, MPB) outbreaks have created concern regarding increased fuel loadings and exacerbated fire behavior and have prompted a desire to understand the effects of sequential disturbances on the landscape.

Fuel accumulation and climate shifts are predicted to increase the frequency of high-severity fires in ponderosa pine (Pinus ponderosa) forests of central Oregon. The combustion of fuels containing large downed wood can result in intense soil heating, alteration of soil properties, and mortality of microbes.

Determining how the frequency, severity, and extent of forest fires are changing in response to changes in management and climate is a key concern in many regions where fire is an important natural disturbance.

There is considerable interest in evaluating whether recent wildfires in dry conifer forests of western North America are burning with uncharacteristic severity—that is, with a severity outside the historical range of variability.

Fire severity maps are an important tool for understanding fire effects on a landscape. The relative differenced normalized burn ratio (RdNBR) is a commonly used severity index in California forests, and is typically divided into four categories: unchanged, low, moderate, and high.

Wildfire has been an important process affecting the Earth's surface and atmosphere for over 350 million years and human societies have coexisted with fire since their emergence. Yet many consider wildfire as an accelerating problem, with widely held perceptions both in the media and scientific papers of increasing fire occurrence, severity and resulting losses.