New Mexico’s ecosystems have evolved and have been shaped by fire

 

Eytan Krasilovsky

 

The Forest Stewards Guild prides itself on its mission and principles1 which put the needs of the forest first, and state that the “well-being of human society is dependent on responsible forest management that places the highest priority on the maintenance and enhancement of the entire forest ecosystem.”

 

With this mission and these principles, the Guild’s Southwest Program implements long-standing forest resilience, fire-adapted communities and forest stewards youth corps programs. These principles are the roots of all of our members’ forest stewardship ethic, which aligns our organization with land ethic of Aldo Leopold and the Aldo Leopold Foundation. As part of a Guild meeting, I was able to visit the Aldo Leopold Foundation and the famous “shack” where much of his groundbreaking writing took place. I learned from Leopold’s grandchildren how they care for the land guided by their grandfather’s land ethic. Their approach and that of the foundation is rooted in the famous quote, “Game can be restored by the creative use of the same tools which have heretofore destroyed it—axe, plow, cow, fire and gun… 2” For natural resource managers today, the land ethic means that intact, functioning ecosystems are needed to support varied habitats. In the Southwest, the tools to accomplish this are much the same as when Leopold served on the Carson National Forest in Tres Piedras: the axe and fire.

 

In the March 2017 issue of Green Fire Times, I called for fire-adapted communities and resilient landscapes and described how New Mexico’s ecosystems have evolved and have been shaped by fire, and that as a result, we need to learn to live with and adapt to the presence of wildfire. This is aligned with the Aldo Leopold Foundation’s current land care advice for woodland owners.3 

 

The science of tree rings provides another line of evidence to further support the use of these tools. Forests provide exceptionally detailed histories through their tree rings. Researchers have collected thousands of tree ring records that help us understand Southwestern forests. The University of Arizona is a world leader in tree-ring research, or dendrochronology. Their website4 provides a great introduction to this fascinating science. Tree rings keep an objective record of droughts, climate changes, insect outbreaks and fires. These events are recorded in the tree rings as differences in ring width or visible fire scars. If a fire kills all the trees in an area, tree rings can tell researchers when the new generation started to grow (and hence the date and size of the severe fire).

 

Tree rings tell us that before large-scale European settlement our ponderosa pine trees survived many fires, which passed through forests as often as every four years. With all the lightning the Southwest receives each year this is hardly surprising. These fires burned quickly through the forest with small flames, leaving behind a relatively small number of large trees with grassy meadows in between.5 The trees that survived had less competition for water, nutrients and light, so they were healthier, able to withstand drought and insect outbreaks. Frequent fires also maintained good living conditions for many animals, especially ones that prefer open forests such as northern goshawks, turkey, elk and kestrels.6

 

The Santa Fe watershed tree-ring records collected by Dr. Ellis Margolis and his team record a fire every four years on average.7 Tree-ring records from the Santa Fe watershed also show a fire in 1685 that burned across a wide area. While this fire scarred many trees and probably killed many small trees, the tree rings show medium and larger trees survived, grew faster and were healthier after the fire.

 

Tree rings also show how successful fire suppression was in the 20th century. Few if any fire scars were recorded during the last 100 years. Without the fire ponderosa pine forests were adapted to, they became less healthy. Wildlife biologists and rare plant experts have documented how the lack of fire negatively impacted animals and plants. Moreover, the dense forests that our suppression of fire has created are at high risk of a very different, very destructive kind of wildfire. Wildfires like the 2011 Las Conchas fire that killed every tree across thousands of acres are absent from the tree-ring records or the early General Land Office surveys that crossed New Mexico around 1880. Unfortunately, unless we return fire to its natural role in forests, these large, high-severity fires are predicted to become more common.

 

My March 2017 call for fire-adapted communities and resilient landscapes in these pages was rooted in the sciences of fire ecology and dendrochronology and aligned with Leopold’s land ethic and the Forest Stewards Guild mission and principles.

 

Eytan Krasilovsky is the southwest director of the Forest Stewards Guild.

 

 

Footnotes:

 

1 Read more about Guild principles here: www.forestguild.org/mission-principles.

2 Leopold, Aldo. 1933. Game Management. University of Wisconsin Press.

3 Aldo Leopold Foundation Land Care Program. www.aldoleopold.org/teach-learn/classes-workshops/land-care/.

4 University of Arizona Laboratory of Tree Ring Research. http://ltrr.arizona.edu/about/treerings. 

5 Friederici, P., ed. (2003). Ecological restoration of southwestern Ponderosa pine forests. Washington, D.C., Island Press.

6 Graham, R. T., McCaffrey, S., and Jain, T. B. (2004). “Science basis for changing forest structure to modify wildlife behavior and severity.” General Technical Report, RMRS-GTR-120.

7 A 700-year history of fire and streamflow: Santa Fe watershed, New Mexico.
http://swfireconsortium.org/wp-content/uploads/2012/06/Margolis_Tree-Rings.pdf

 

 

 

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