March 2023 - 36

Mastication is an effective method of conifer control where tree material needs to be reduced to a high density of trees.
(Photo by Willow Bish/WGFD)
Mechanical treatments include
chainsaw cutting and heavy
equipment work. One of the
more commonly used heavy
equipment methods involves
using equipment to grind tree
material down. This method,
called mastication, is effective
at reducing fuel loads.
weeds. Burning is typically a better option for
treatment on sites that receive higher precipitation
and cooler weather, rather than dry,
warm sites because of the low rate of recovery
and higher risk of weed invasion on drier sites.
Lastly, timing windows for burning may be
extremely short, making it difficult to effectively
plan and implement treatments. Unfortunately,
due to the complexities involved
with planning these projects and the lack of
contractors available to conduct prescribed
burns on private land, this method is not used
as often as managers would like.
Mechanical treatments include chainsaw
cutting and heavy equipment work. One of
the more commonly used heavy equipment
methods involves using equipment to grind
tree material down. This method, called mastication,
is effective at reducing fuel loads. It
is a useful treatment method in areas where
tree material needs to be reduced due to a
high density of trees or for access reasons,
such as for large herbivores, like cattle or
elk, or humans. In some cases, the mulch
left from mastication may be so thick that it
inhibits understory vegetation. Mastication
methods can't be utilized in areas with difficult
access, such as steep slopes, rocky areas,
rough terrain or areas that are far from roads
or do not allow for vehicles of any kind. Areas
with moist soils aren't the best candidates
36 | March 2023
for heavy equipment work because there is
a high likelihood of damage to vegetation
and soil structure. Timing of treatment may
minimize disturbance concerns by operating
later in summer or early fall when the ground
is drier or in the winter on frozen ground.
Mastication may miss small trees, seedlings
and low-lying branches which may require
follow-up treatment or shortens the lifespan
of the project. Heavy equipment methods
can be costly and are not cost-effective on
sites with low density trees.
Chainsaw treatments are typically the
most adaptable of all methods. They can be
used on areas that are difficult to access with
equipment and can be implemented with
a high degree of precision to follow land
ownership boundaries or to respect other
restrictions. Timing of chainsaw treatments
is typically flexible, which allows for a large
window of treatment that effectively increases
the amount of work that can occur each year.
This method typically does not disturb soil or
other vegetation and is often less disruptive
to wildlife. Similar to heavy equipment work,
this method may also miss small trees, seedlings
and low-lying branches which requires
follow-up treatment or shortens the lifespan
of the project.
IT'S CUT, NOW WHAT?
There are several techniques for cutting
and handling tree material when utilizing
chainsaw treatments. These include lop and
scatter, cut and pile and jackstraw/hinging.
The lop and scatter technique involves
cutting down trees and reducing the tree
material so it's closer to the ground. The
vegetative debris left on the ground, called
slash, can protect soil from erosion, provide
microsites for increased moisture accumulation
and protect desirable vegetation from
excessive herbivory, or browsing by animals
feeding on plants, by limiting access to the
site for some time. Dense tree sites may result
in too much slash, which limits understory
vegetation growth. However, as trees break
down and needles drop, understory vegetation
growth becomes less inhibited. Similarly, the
fire hazard may increase in the first few years
before needles from the trees drop and the
risk decreases over time. Lop and scatter can
be cost-effective, but large trees and high tree
density raises costs. This technique is often
used in low-density sites. Lop and scatter is
frequently used as a technique to prepare a site
for future prescribed burns. Trees can be cut

March 2023

Table of Contents for the Digital Edition of March 2023