Questions about the Forests of Yosemite: fire suppression and reforestation.

[Paschale]

When I visited Yosemite this summer, I heard a lot about the history of the forests, and the history of forest management.  One of our guides talked about old journal entries where people wrote that there was little to no undergrowth in much of the forests, amongst the old growth forests.  It was said that men on horse could ride amongst the trees at a full gallop and have no need to slow down for undergrowth.  The thought was that nature provided regular, natural fires to "clean" out the underbrush, while allowing the old growth trees to survive.  The lack of well established undergrowth essentially caused the fires to simply burn out due to lack of fuel, as well as preventing the fires from becoming so hot that they lit the old growth trees completely aflame.

I found a reference to this openness in a book called "In the Heart of the Sierras" from 1888.

"Still our course is upward, until we have reached a long stretch of elevated table-land that, for timber, is not excelled in any portion of the State. Large sugar-pine trees, Pinus Lambertiana; from five to ten feet in diameter, and over two hundred feet in height, devoid of branches for sixty or a hundred feet, and straight as an arrow, everywhere abound. Besides these there are thousands of yellow pines, Pinus ponderosa; Douglas firs, Abies Douglasii; and cedar, Libocedrus decurrens; that are but little, if any, smaller or shorter than the sugar-pines. These forests are not covered up with a dense undergrowth, as at the East, but give long and ever-changing vistas for the eye to penetrate."

The guide stated to us that the fire suppression practices of the past century had allowed the brush to make a stronghold that is unnatural, and which leads to the devastating forest fires that have taken place in Yosemite in the past 50 or so years.  It's certainly no longer a case of the forests not having much undergrowth!

Anyone have any thoughts on this?

Here's a whole webpage dedicated to this idea.

[jon12345]

Fire suppression is blamed for a lot of forest fires.  By not removing fuel build that could be removed by low intensity fires it becomes easier and easier for a fire to get out of hand.  Removing fire from an ecosystem will eventual change the whole ecology of a site as well.

[Ron Scott]

Smokey Bear has done his job "too well". ;) The National Park system does have a "Let Burn Policy" on wild fire starts however.

[Tillaway]

Years of both old logging practices and fire suppression has greatly changed the whole ecosytem of much of the wests inland forests.  Usually you find predominately true fir stands growing where there used to be Ponderosa Pine, Douglas Fir and Larch.  The true fir was in the understory story prior to logging and was released when the overstory was cut.  Fire suppression allowed the true fir to survive and dominate the site.  The fires kept the true fir dominating the landscape as it does now in much of the west. 

[tmullen]

 I run a wildland fire engine company about 30 miles out side of the park and work with the parkies on a regular basis. ( this does not make me an expert ).
The park does have a wildfire use program that alows natural lighting fire to burn in certain ares of the park. The valley and main vista areas are still in a wildfire exculsion zone were all fires are suppressed. In those areas the park is doing prescribed burns and mechanical tratments. The let burn policy has come under close scrutiny the past several years due to the air shed flowing down to the central valley.The city of Modesto has been under smoke for as long as 3 months because of the wild fire use fires in the high country of Yosemite. The problem took 100 years of fire suppression to create but the public thinks we can fix it in 10.

tmullen

[Paschale]

I run a wildland fire engine company about 30 miles out side of the park and work with the parkies on a regular basis. ( this does not make me an expert ).

tmullen, this sounds pretty interesting.  What's a "wildland fire engine company" all about?  I'd enjoy hearing some more about what you do!   8)