HomeMy WebLinkAboutNative Grass Project 2
Native Grass Establishment - Project #2
Prepared by Marty Main
Introduction
Establishment of native grasses has been identified as a priority by the City of
Ashland within active forest and resource management of their lands. This endeavor
provides several potential benefits for the lands, particularly as regards (1)
encouragement of less flammable forest vegetation, and (2) re-establishment of native
species and communities of vegetation.
An initial attempt to establish native grasses on the site of a newly cleared
whiteleaf manzanita brushfield was undertaken in the autumn of 1998. This endeavor
has been described in the document "Native Grass Establishment in a Newly Cleared
Brushfield" (Main, 1998). This paper will describe a similar attempt to establish
native grasses on a second site, with slightly different environmental conditions,
disturbance history, pre- and post-treatment vegetational conditions, native grass
establishment techniques, and research protocols. This paper is most appropriately
used in conjunction with the original paper previously described.
Site and Project Description
The project study site is located on approximately one acre of City of Ashland
ownership immediately west (across Granite Street) of the Granite Street ReseIVoir
(intersection of Granite and Glenview Streets) in upper Lithia Park. This is about
one mile from the Crowson ReseIVoir site seeded in autumn of 1998. Elevation of
this site is approximately 2,200 feet. Slopes are primarily 15 to 40 percent easterly
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aspects. Soils are derived from decomposed granitic parent material, primarily of the
Shefflein soil series (Soil SUIVey of Jackson County Area, Oregon, USDA Soil
Conservation SeIVice, 1993). Annual precipitation is 20 to 25 inches.
Prior to treatment, this site was dominated by a dense, early seral vegetation
including mixed conifers (primarily Douglas-fir and ponderosa pine), hardwoods
(primarily Pacific madrone, California black oak, and Oregon white oak), and
numerous understory brush species (including whiteleaf manzanita, deerbrush
ceanothus, poison oak, snowberry, and others). Scattered overstory conifers to 20
inches DBH overtopped a dense layer of all of the above, creating a relatively
uniform, dense, highly wildfire-prone vegetational structure. This site was earmarked
for fuels treatment to reduce wildfire potential. Thinning and brushing, piling and
burning was completed in late October, 1999, successfully reducing vegetational
densities and creating a much less wildfire-prone vegetational structure. An
unplanned underburn of the site additionally occurred on November 6, 1999. Fire
intensities were primarily low in this fire, typical of the type that may have been
expected prior to Euroamerican settling of southern Oregon. Flame lengths were
generally four feet or less, and duff layers were left largely intact. Damage to residual
post-treatment trees was minimal, although some mortality may occur in the next
several years.
Treatment
The underburned area was seeded on November 10, 1999, approximately two
3
weeks after the original pile burning and four days after the unplanned underbum.
Three species of native grasses, generously provided by the Medford District of the
Bureau of Land Management, were seeded by hand:
Native Grasses Amount (grams)
Poa scabrella 1,632
(lower Table Rock seed source)
Festuca idahoensis 2,305
Elymus Glaucus 2,205
Combined, these amounts covered approximately 0.84 acres, corresponding to a
seeding rate of 14.6 pounds per acre.
Within the treatment area, five repe'titions of three treatment types were
delineated on-the-ground. In three of the five repetitions, three adjacent plots were
delineated: (1) seeding directly into a bum pile, (2) seeding into an underburned (but
not pile burned) plot, and (3) control plot in which no grass seed was applied. In the
remaining six plots (two repetitions of three plots), no seed was applied. Of these six
plots, three were located in bum piles and three located in underburned only sites.
Although a light rain occurred on the day prior to seeding, a good soaking
rain encouraging seed germination did not occur for another week or so. In addition,
the seeding date was very late to expect good germination due to decreasing
temperature that can cause mortality and/or frost heaving of young, developing
seedlings.
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Monitoring
The various treatments will be monitored over the next several years to
determine subjective and/or objective differences. Perhaps most importantly, this
study will hopefully allow the opportunity to compare germination and growth in
adjacent pile burned and underburned sites. The entire site should, like the Crowson
ReseIVoir study site, offer an excellent, easily accessible location to visually assess the
effectiveness of the above-described treatments.
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