Spring 2008 - Yosemite Conservancy

Above left: Yosemite’s original human inhabitants regularly set fire to the Valley floor to encourage the growth of grasses and oaks. Here,
their descendants use traditional methods to ignite a prescribed burn. Above right: Park staff monitor the progress of the prescribed burn.
tem as possible. Those tools have expanded to include not
only fire suppression, but fuels reduction and management
of naturally-ignited fires.
Fuels reduction can be accomplished in a variety of
ways. One method involves mechanically cutting up
brush, trees and downed logs, and either piling them
for burning or hauling them away. This technique can
reduce larger diameter fuels such as snags and downed
logs, but does not reduce levels of duff and smaller forms
of forest litter that have accumulated. Prescribed fire can
reduce fuels of all sizes but is a much riskier practice.
There is always the danger of a fire escaping planned
boundaries, while the resulting smoke can be a nuisance
or health threat. Before land managers burn, they develop
a prescribed burn plan based on a prescription: a set of
weather, fuel and resource parameters that are aimed at
achieving a particular goal.
All of this is made more complicated by fuels that have
accumulated over the past hundred years of successful fire
suppression. Fire introduced to such fuel-loaded landscapes
has the potential to burn too hot or for too long,
damaging the ecosystem’s ability to rejuvenate. While
early fire managers worried over how to put fires out,
determining which land management objectives are most
important and how to meet them are two of the most difficult
challenges that fire managers face today.
In the fall of 2005, the National Park Service conducted
a prescribed burn in a thirteen-acre wetland
meadow in Yosemite Valley. Like much of Yosemite Valley,
the meadow historically had been managed and used by
American Indians. These resources are still used by the
descendants of the Valley’s original inhabitants as well
as the Park’s Indian Cultural Demonstration Program.
A century and a half of fire suppression, however, had
allowed thatch to accumulate, invasive Himalayan
blackberry to spread into the meadow, and conifers to
encroach. The presence of an old road and its culvert further
accelerated these changes by disrupting the natural
flow of water through the area. The compounded effect
of changes to the natural fire regime and the altered
hydrology of the site threatened populations of traditionally
gathered plants, and posed a complex restoration
challenge.
The National Park Service coordinated with other
park partners, including the Yosemite Fund, Yosemite
Institute and local Native American tribes, to put together
a long-term restoration and research effort addressing
many of these concerns. Although the meadow was once
maintained by regular burning, fire alone was no longer
enough to restore the area with native plants. Scientific
literature reports that Himalayan blackberry will resprout
vigorously after burning, which in turn suggested that
removing the blackberry first was imperative. To determine
which approach would be most effective, park staff
and volunteers pulled the blackberry before the burn in
some areas and simply burned it in others. The study
would also track the response of traditionally gathered
plants to the different treatments.
The Park Service invited tribes having ancestral
cultural associations with park lands to participate in
the prescribed burn. The fire was lit using a traditional
friction method as representatives of the tribes offered
prayers and songs. The igniter rapidly rolled a pointed
stick between his hands with the point pressed firmly into
a plank of wood. When the heat had built sufficiently, the
stick tip was used to ignite a wad of shredded cedar bark
8 YOSEMITE ASSOCIATION, SPRING 2008