Post-Fire Natural Regeneration of Conifer Seedlings

One of the myths used by the U.S. Forest Service to justify large post-fire clearcut logging projects after wildland fires on National Forest lands is their belief that mixed-conifer and ponderosa pine forests will not naturally regenerate (i.e., regrow on their own) in large high-intensity fire patches, due to lack of seed sources from live, mature trees or due to competition with native shrubs.

The scientific literature published to date strongly contradicts the Forest Service’s position, however relatively few data have been gathered in the interior of large high-intensity fire patches (those that are hundreds, or thousands, of acres in size). The Forest Service has exploited this information gap to justify enormous post-fire timber sales on National Forests in large fire areas, like the Rim fire, and has wasted millions of tax payer dollars replanting what their logging projects destroy.

This is why John Muir Project Director, Dr. Chad Hanson is conducting a major study of natural post-fire conifer regeneration, focusing on data collection within the interior areas of the largest high-intensity fire patches (which the Forest Service is targeting most heavily for its post-fire clearcutting projects).

So far he is finding abundant and vigorous natural conifer regeneration—especially pines—even in the middle of the very largest high-intensity fire patches. In fact the conifers are growing and thriving even where native shrubs cover 90% to 100% of the ground! This is likely because the native shrubs, which produce flowers that attract native insects which provide food for flycatching birds and bats, also fix nitrogen and replenish important soil nutrients, increasing soil productivity for all vegetation, including trees. Moreover, the shrubs may protect growing conifer seedlings and saplings from being eaten by deer, small mammals, and other herbivores. This should be no surprise, as the forests of the Sierra Nevada are fire dependent/fire adapted ecosystems and have been re-establishing themselves, on their own, for thousands of years.

Dr. Hanson is hoping to have a study published on this research in 2015.

Star Fire 2013 Gallery

Below are photos taken by Chad Hanson and field researcher Keegan Ramey on the Eldorado and Tahoe National Forests in 2013.

These photos were taken in high intensity fire patches within the Star Fire burn area, 12 years after the Star fire burned. The photos show vigourous natural conifer regeneration with saplings being between 10-20 feet tall, as well as native shrubs and oaks which help to create the robust complex early seral forest which succeeds high intensity fire.

McNally Fire 2014 Gallery

The photos below were taken 12 years after the McNally fire which burned on the Sequoia National Forest in 2002.

The photos show extensive native shrub growth (mostly whitethorn), but also reveal the naturally regenerating pine trees which are hiding among, and likely benefiting from, the shrub cover.

Rim Fire May 2014 Gallery

Below are photos taken by Chad Hanson on the Stanislaus National Forest within the Rim Fire area in May of 2014, just 7 months after the Rim Fire was extinguished.

The photos were taken in high intensity fire patches and document the natural conifer regeneration which was just starting at the beginning of the first growing season after the fire.

Rim Fire December 2014 Gallery

Below are photos taken in the largest high intensity fire patches on the Stanislaus National Forest in the Rim Fire area in December 2014, just 15 months after the fire was put out.

These photos show the continued growth of seedlings (they are much larger than in May), oaks that are stump sprouting (i.e., “dead” trees regrowing from their stumps) as well as the logging which kills the vast majority of these naturally regenerating seedlings.

View Figures

The figures below were created from data gathered in high intensity fire patches on the Stanislaus National Forest within the Rim Fire area.

These figure show that, contrary to the Forest Service’s assertions, natural conifer regeneration is robustly occurring even in the largest high intensity fire patches and appears to favor pine species (Jeffery Pine, Ponderosa Pine and Sugar Pine).