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A project funded by the Joint
Fire Science Program
Piñon-juniper woodlands have
expanded beyond their historical range in the western United States,
due partly to land
management practices such as fire suppression that began with settlements
of the region in the late 1880s. This woodland expansion has replaced
sagebrush steppe vegetation, leading to decreased wildlife habitat,
soil seedbanks, and plant species diversity, and increased potential
for soil erosion and high intensity crown fire. In an attempt to
restore historical conditions, "post-settlement" trees
have been removed to free resources for sagebrush steppe vegetation
to become re-established. This was intitially done by chaining landscapes
to uproot all trees, but this method had many undesirable effects
including extreme soil disturbance and the creation of even-aged
piñon-juniper stands, and is rarely done now on public lands.
More recently, mechanical and chemical thinning methods have replaced
chaining, often followed by seeding and/or burning. Unfortunately,
the cost-effectiveness and ecological effects of various combinations
of thinning, seeding, and burning remain mostly unknown, making it
difficult for land managers to develop effective management plans.
The need for this information is greater now than ever, because of
recent plans to apply large-scale fuel treatments across the Western
United States, a region dominated by sagebrush-steppe and piñon-juniper
vegetation.
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