Forests managed by industry are more likely to feed

The chances of high severity forest fire were almost once higher on industrial private land than on public forests, a new study revealed. Forests managed by wood companies were more likely to present the conditions that megafires love – dense stands of trees regularly spaced with continuous vegetation connecting the canopy.

Research, led by the University of Utah, the University of California in Berkeley and the United States Forest Service, is the first to identify how extreme weather conditions and forest management practices have a joint impact on the severity of the shooting. Taking advantage of a single LIDAR data set, the authors created three -dimensional cards from public and private forests before five forest fires were going 1.1 million acres in northern Sierra Nevada, California.

The study is published in the journal World change biology.

In periods of extreme time, the density of the stems – the number of trees per acre – has become the most important predictor of high severity fire. Even faced with the acceleration of climate change, the way we manage the earth will make a difference.

“This is a really full of hope, because it means that we can adjust the way we manage these landscapes to have an impact on how fires are going through them,” said Jacob Levine, postdoctoral researcher to U and the main study of the study.

“The strategies that reduce density by enlightening small and mature trees will make forests more robust and resilient to be drawn in the future.”

In a study in 2022, Levine and the collaborators found that the gravity of the fire was generally higher in private forests. They also discovered the extensive risks to nearby areas, but not to private industry, threatening the desert, small landowners and urban areas in their shadows.

This new study is the first to identify the underlying forest structures that make high severity fires more likely in certain regions than in others.

Lidar unlocks the secrets of the forest structure

The National Forest of Plumas, the northern study area of Sierra Nevada in California, is emblematic of the broader trend of the occurrence and severity of forest fires. Mixed coniferous forests in the region are adapted to periodic and weak fires to the average severity that have gone to vegetation, creating large spaces between trees.

Efforts to increase wooden resources have led the US government to implement fire suppression policies in the 1800s, including the ban on controlled burns that Aboriginal peoples have practiced for millennia. In the absence of natural fire cycles and indigenous burns, modern forests have more fodder to supply high severity fires, defined as a fire that kills more than 95% of the over-greene trees.

The National Forest of Plumas is a mosaic of private industrial and public property, and 70% of the study area was burned in five massive forest fires between 2019 and 2021, including the largest unique fire in the recorded history of California, the Dixie Fire. On the original level, a unique data set had been collected a year before the region’s burn.

In 2018, the US Forest Service, the Geological Survey and the National Aeronautics and Space Administration interviewed the National Forest of Plumas and the surrounding private land using airborne flights and management detection (LIDAR). The Lidar sensors draw billions of lasers in the landscape below, which bounce on the grass, shrubs, young plants, tree awnings and other forest structures with high precision.

“We have a really detailed image of what the forest immediately looked like before these massive fires. This is an incredibly precious thing to have,” said Levine. “Understanding the forest structures that lead to high severity fire allows us to target attenuation strategies to get a big shooting problem while producing enough wood to meet market demand.”

Private public management strategies

Wood companies focus on maximizing profits and the supply of a sustainable wood source, a precious resource for society and an economic engine for rural communities. Most of the plantations practice the forest – cuttings of an area and replanting the trees in a closely packed grid. After 80 to 100 years, they start again, leaving a patchwork of dense stands of similar age and size.

“You can think of stacking a bunch of matches together in a grid – which will burn much better than if these matches are dispersed like smaller clusters,” said Levine.

“A larger fire can easily reach the canopy in dense forests. Then it tears a tree after another, throwing pieces of kilometers of material burning in advance. This is another story.”

The objectives of public land are more varied, requiring the management of pasture, leisure, catering, wood and fauna production corridors. They are also liable to the public, which hinders their ability to carry out active management. Environmental organizations often continue to stop the proposed projects that would eliminate trees to clarify density.

Although the study shows that private industrial land is worse, private and public agencies have a lot of room for improvement to protect the forests of our country. Most trees in Sierra Nevada lack adaptations to recover from high severity fires, which leads to more and more our forests that turn into shrubs and meadows.

“This has major implications for wood, but also for sequestration of carbon, water quality, fauna and leisure housing,” said Levine.

“Shrubs and meadows can be beautiful, but when we think of Sierra Nevada, we imagine majestic forests. Without major changes in forest management, future generations could inherit a landscape that looks very different from that we cherish today.”