Burning and Wildfire
(Fire as a Tool in Saltcedar Management)
Bruce R. West
The Barstow Resource Area
has battled saltcedar (Tamerix ramosissima) in
Afton Canyon, located on the Mojave River 38 miles
northwest of Barstow, California, since 1992. Many
saltcedar control and riparian restoration elements, or
tools, have been utilized in this struggle to return the
canyon to a functioning riparian community. Fire has
proved to be an effective and important tool in this
long range riparian restoration project.
Prior to making a
commitment on a saltcedar control/riparian restoration
project, the site should be evaluated and your goals
assessed for reasonableness. Questions to ask would be:
- * Is the saltcedar
problem manageable with available current resources.
The resources to consider are personnel, funding,
equipment and material.
- * What natural resource
improvements are expected? Is open water your goal or
are there other priorities such as the restoration of
the riparian habitat more important. Oftentimes
several related resource improvements are anticipated.
- * What saltcedar
control and riparian restoration methods would work
best in your situation?
A management goal of
controlling saltcedar to manageable levels and improving
the functioning ecological condition of the riparian
habitat in Afton Canyon was first identified in the
Afton Canyon Area of Critical Concern (ACEC) Management
Plan. The management actions developed to reach this
management goal primarily include the removal of
saltcedar and revegetation of the treatment area with
native plants. The principal rationale considered in the
Afton Canyon Restoration Project, as stated by the ACEC
plan, was to improve wildlife habitat within the canyon
In preparation for the
initial prescribed burn, photo monitoring plots were
established within the dense, mature saltcedar of the
proposed burn area. The photo plot locations were
extremely difficult to access because of the thick
saltcedar. The plots were within monoculture stands of
saltcedar that had developed heavy accumulations of
branches, woody material and thick duff. The duff was
deposited on the branches as well as on the soil
surface. Other actions undertaken prior to the
prescribed burn were the construction of fire breaks
around native trees and the building of fire fuel
jackpots. These jackpots consisted of stacked cut, and
other, woody materials utilized as initial ignition
points to provide a high intensity energy source to
pre-heat nearby material, help get the fire going and
create a fire wind.
The initial date for the
prescribed management burn in Afton Canyon was November,
1991. This period was chosen because it was assumed that
the saltcedar would be dormant, fuel moistures would be
fairly low and temperatures/humidity would be moderate.
As with many well laid plans, the saltcedar would not
ignite. The winter rains began shortly thereafter, and
the burn was on indefinite hold. On the last day of
July, 1992 we tried again. The jackpots were lit and
soon the saltcedar was an inferno! The high
temperatures, light winds and low humidity provided
ideal conditions for the prescribed burn. The flame
lengths reached approximately 100 feet, threatening the
native trees located within the fire breaks.
The fire was very
effective. All that remained standing were larger
blackened saltcedar stems and trunks. The smaller
branches, duff, leaves and decadent limbs were all
consumed. The fire visibly opened the burn area allowing
the soil to be clearly seen between the blackened
standing material. The fire encompassed approximately 80
percent of the proposed burn area. The areas where the
fire didn't carry were usually in younger age stands
and/or near the perimeter of the wet "green strip" where
fewer combustible materials were available and moisture
levels were higher.
The intensity of the fire
was very high, killing the saltcedar outright in some
areas and scorching many of the native trees that we had
tried to protect. It was found that, to protect existing
native trees, firebreaks must exceed 100 feet. Some of
the above ground portions of the native trees survived
and most that didn't resprouted basally. The resprouted
willows are currently between ten and fifteen feet in
height and growing. The results demonstrate that the
initial contribution gained from the use of fire on
saltcedar is that it opens the very dense stands to
allow access for the spraying of resprouts.
The burned saltcedar began
to basally resprout within a month following the burn.
Different age classes and sizes of the burned saltcedar
had different degrees of accessibility. The more tree
like stands with larger, well spaced standing material
were easier to access for herbicide application than the
more closely spaced and younger age "thickets."
Application of herbicide to the resprouts began
approximately one month following the burn.
The herbicide was applied
using backpack and other hand carried pump sprayers. The
saltcedar resprouted very quickly and grew very rapidly,
six feet in a period of a few months, so it was
imperative that the resprouts were promptly treated with
herbicide. We learned that the larger the resprouts, the
more time and herbicide it takes to spray each resprout.
We recommend that saltcedar resprouts should be sprayed
immediately upon their appearance, though this often
requires several spray treatment sweeps. For this
initial burn, it is estimated that our initial treatment
of saltcedar resprouts was 80 percent successful.
The herbicide used for
initial resprout treatment was Pathfinder, a pre-mixed
Dow-Elanco product with trichlorpyr as the active
ingredient and petroleum distillate as the carrier. We
have since switched to the more benign Pathfinder II
with its vegetable oil-based carrier. Along with other
human comfort problems, the petroleum based carrier in
the original Pathfinder caused the rubber gaskets and
hoses in the compression pump sprayers to weaken and
fail. In the future, we are also considering using
Rodeo, a Monsanto product, for saltcedar control that is
specifically labelled for water use.
Mother Nature sometimes
changes the plans of mere mortals. In the winter months
following the burn and herbicide treatment, the Mojave
River had one of its more substantial flood flows. This
changed the landscape of the canyon bottom. In some
areas the high water scoured out much of the small,
wispy saltcedar, while in other areas there was soil
deposition and the burying of uprooted saltcedar. Our
burn treatment area was located on a terrace and was
unaffected except for some soil deposition and small
channelized flows. The impacts to other areas of our
restoration area were both beneficial and detrimental.
The fresh soil deposition created ideal pole planting
sites but also covered piles of saltcedar which would
later come to life. This flood also washed upstream
portions of untreated saltcedar into downstream treated
In the spring of 1994,
following the flood event and a year of herbicide
treatment, we began our restoration effort. From January
through March we harvested and planted several hundred
Fremont cottonwood (Populus fremontii) and
Goodings willow (Salix nigra var. goodingii)
poles in and around the burn area. BLM staff, prison
inmates and high school volunteers all helped in this
The poles were placed in
augured holes approximately three to five feet deep;
most poles reached the water table. Our success from
these first pole plantings was not very good with only
ten percent survival. We later found that plantings were
more successful near the edges of the burn, in areas
where there was more deposition from the flood and where
saltcedar was cleared using the cut stump method, rather
than a burning technique.
Native plants propagated
naturally following the burn. Chinese pusley (Heliotropium
convolvulaceum var. californicum), kochia (Kochia
americana) and other site stabilizing plants quickly
established. Native trees that were burned in the fire
also began to resprout. Mesquite trees vigorously
resprouted only to be attacked by rabbits and other
small mammals. The willows, which presently are
approaching 20 feet in height, also vigorously
resprouted. Following the burn and subsequent flood,
cattails, sedges and other wetland plants popped up
everywhere within the wetland and marsh areas. Later,
arrowweed (Pluchea sericea) and quailbush (Atriplex
lentiformis) became established.
The burn also opened up
the canyon to wildlife. Says phoebe (Sayornis saya)
are now observed regularly enjoying the increased
visibility, openness, snag perches and grass/forb
meadows. Bobcats (Lynx rufus), bighorn sheep (Ovis
canadensis), coyotes (Canis latrans) and many
other species of birds and wildlife now enjoy the canyon
and the increased open water.
Cottonwood trees planted
in 1994, within areas of heavy soil deposition and
protected from the wind and blowing sand, have thrived.
Whereas, survival of cottonwood/willow poles in wind
exposed areas has been relatively low. Trees in
sheltered locations have reached heights greater than 15
feet. As stated above, this is the exception. Although
the survival rate for our cottonwood/willow pole
plantings have been lower than anticipated, this
disappointment is not deterring current, or future,
restoration efforts. We are continuing our saltcedar
control and riparian restoration efforts in Afton
Canyon. Our latest pole planting effort, during winter
and spring of 1996, totaled approximately 2,500 trees.
To date, well over 5,000 native cottonwood and willow
poles have been placed in the Afton Canyon project area,
with survival rates gradually increasing.
The construction of
riparian enclosure fence is another tool that has been
utilized in the Afton Canyon restoration effort. The
present project area is in an active grazing allotment.
In the past it has also experienced heavy off-road
vehicle use. The constant soil disturbance from these
activities created ideal seed beds for salt cedar
germination. Physical damage to native and planted
cottonwood/willow poles also was occurring.
Additionally, native plantings were being grazed by
cattle and crushed by vehicles. In the spring of 1995 a
riparian enclosure fence was constructed to control
these activities within the treatment area.
The vision of a sprouting
saltcedar next to a young cottonwood pole leafing out
symbolizes the struggle taking place between the native
plant community and the invading exotic plants. We in
the Barstow Resource Area believe that some selected
degraded riparian habitats can be returned to
functioning condition by controlling the saltcedar and
through the stated revegetation/restoration efforts.
Native plant communities need help and we intend to keep
working in Afton Canyon until our saltcedar nemesis is
When the Afton Canyon
Restoration project began many people commented that we
were crazy even to attempt a saltcedar control on such a
large scale; "It can't be done", "You're wasting your
time," they said. Well, the war certainly hasn't been
won, but we intend to keep fighting.
In conclusion, it is hoped
that this report provides a little more insight into the
Afton Canyon Restoration Project and how fire is being
used as one tool in saltcedar control and riparian
restoration. There are still many questions on the use
of fire and follow-up restoration, as well as,
revegetation of burned areas. Primary among the
- * What do you do about
boron and salt accumulation in burned saltcedar
- *Are there easier ways
to treat saltcedar resprouts?
There is a need for more
research into fire behavior, fire history and the
revegetation of saltcedar burns. Even with these
questions, it appears that prompt herbicide treatment
after the prescribed burning and/or wild fire in
saltcedar is an excellent tool to consider in the
treatment of mature, dense saltcedar stands.