Keeping a Forest Healthy

Burn Piles

Ever since a series of major forest fires hit our region, including the Caldor Fire which burned all the way from near Placerville to South Lake Tahoe, the issue of our overly dense forests leading to more conflagrations has been a top concern for the region. In fact, Tahoe Fund CEO Amy Berry says, “our number one priority is to remove trees from our forest. Simply put, we have too many trees, and if we don’t figure out how to lose some of them, we face the very real risk of losing all of them.” Considering that the Tahoe Fund has contributed to over 130 environmental improvement projects around Lake Tahoe in the last 13 years, and they’ve decided this is the most important issue, is a pretty strong statement.

To summarize the problem, these days it is common for an untreated area in Lake Tahoe to have 300 trees per acre. Historically, a healthy Sierra forest had just 25 trees per acre, which means we have a lot of work to do.

Fortunately, the agencies that control the land where Tahoe XC sits: California State Parks, the Tahoe City Public Utility District, The US Forest Service, and the California Tahoe Conservancy, have been busy for a number of years trying to reduce the number of trees per acre. This of course is not just to protect this important recreational resource that we know and love, but also to protect the neighboring communities of The Highlands and Cedar Flat. Multiple agencies are involved in the effort, all of whom use a variety of different techniques to ‘thin’ the forest.

The Tahoe Conservancy controls a parcel of land where the Green and Blue trails travel across. Several years ago they carried out a large-scale mechanical tree thinning operation on a large chunk of that land. At first, being accustomed to dense forest for so many years, the area looked bare, but after having learned that this open forest with large healthy trees is actually what a Tahoe forest used to look like, it forces us to see the density of surrounding areas in a different light. From a fire danger standpoint, making sure the tree canopies are not touching, greatly reduces the ability for a fire to quickly travel through the forest.

Next door to the Conservancy lands, the California State Parks have taken a different approach over the last decade. On smaller plots of land, they have thinned the forest via cutting smaller trees and creating piles that are later burned. After they burn the piles, they will go back and do a low intensity ground fire which not only reduces the fuel created by the trees, but also eliminates some of the flammable brush that has grown between the trees. The goal is to use many small controlled fires to reduce the impact of a larger fire.

In addition to reducing fire danger, prescribed burning can replicate what would naturally occur in the Sierra without human intervention. Historically, the Sierra ecosystem experienced small fires created by lightning, promoting a healthy forest. In fact, some plants will not germinate until after a fire has passed through. The Washoe tribe also created small fires to keep forests from getting too dense and encroaching on important meadow areas.

One day recently, around the end of September, I was headed to the Post Office in Tahoe City, when I noticed a large cloud of smoke coming from the area to the north of town. There was a moment of fear similar to the feeling I had when the Washoe Fire was roaring from the Sunnyside area towards Tahoe City in 2007 (the fire was ultimately stopped when it reached a recently thinned forest). When I saw the sign that it was a prescribed fire in the Burton Creek State Park, I was relieved, but it also reminded me of the long list of challenges faced by those trying to carry out prescribed burning operations.

If it is too dry or too windy there is danger of any prescribed burn getting out of control and for the public to express concern. If it is too wet or not windy enough, the fire will not burn well or the smoke will lay down and lead to smoky skies where we live. In the summer it is dry and hot, and for about four months or more in the winter the land is covered in snow. Neither of which are good times to burn. Prescribed burns in our forests are often managed by the same folks who fight forest fires, so when they are on the line they don’t have time to carry out prescribed burning operations, making the window for these operations even tighter.

So, perhaps what we should do when we see a prescribed burn in operation is say “Oh good, they finally found the right conditions and the staffing to pull off a burn. Keep up the good work.”