The Cambrian

Weather, not tree density, determines fire behavior

There are now about 66 million dead trees in the forests of California. The main cause being drought and bark beetles. Intuitively, one would think this would increase the fire hazard in the forest.

However, among forest researchers, there is overwhelming consensus that weather (hot, dry, windy conditions) determines how wildland fires behave, not the density of dead trees or snags.

Cambria’s weather, in contrast, is generally cool, moist and only on occasion windy.

Trees larger than a few inches in diameter are not consumed in fires: Only the outer bark is burnt up, and so the majority of dead trees in the forest do not significantly influence fire behavior. Besides, once trees die, combustible oils begin to dissipate and the needles fall making it more, not less, difficult for flames to spread through the forest canopy.

Snag levels not a factor in fire speed

Many studies have been done with regard to this issue. In 2015, a study published in Proceedings of the National Academy of Sciences found that high snag levels had no effect on the rate of fire spread in conifer forests of the western U.S., including California.

Cambria’s Monterey pines are an example of a conifer forest. In 2016, another group of researchers found that forests with high snag levels actually tend to burn less intensely than forests with low snag numbers.

The only reason for harvesting dead snags and “dying” trees is for commercial profit or when money is involved. The sale of the dead and dying trees in the public’s forests is usually well below the value of the lumber harvested and therefore reaping a great profit for the timber industry.

The harvesting of these trees is also detrimental to the health of the forest. When trees die a natural death because of drought, native beetles or fire, the snags and downed logs contribute to forest rejuvenation through nutrients dissipated into the soil and become microhabitats for wildlife. Birds, mammals, reptiles and fish all use snags and logs for food, nesting or shelter.

Stumps don’t benefit ecosystem

Logging only leaves stumps, which produce none of these benefits. In the long run, logging will only degrade our forests and, ironically, lead to even more tree deaths. This ignorant, shameless and crass economic opportunism will destroy our forest ecosystems.

Our forests are the lungs of the earth, in that they remove the carbon dioxide from the atmosphere and add oxygen.

We should be planting more trees and harvesting only at a sustainable rate. Unfortunately, our current economic system demands that we harvest in an environmentally unsustainable manner.

All of this should be kept in mind when managing our forest in Cambria. A forest management plan has already been formulated. All that needs to be done is for local government to officially implement it.

John Zinke of Cambria is a retired physician and secretary for Greenspace – the Cambria Land Trust.

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