HomeMy WebLinkAbout1.23 Noxious Weed Mgmt PlanNoxious Weed Management Plan
PDC Energy
Piceance Centralized Soil Treatment Facility
OLSSON
ASSOCIATES
OA Project No. 011 -2627
760 Horizon Drive, Suite 102 1 Grand Junction, CO 81506 1 TEL 970.263.7800 1 FAX 970.263.7456
INTEGRATED VEGETATION AND NOXIOUS WEED
MANAGEMENT PLAN
PROPOSED CENTRALIZED SOIL TREATMENT FACILITY SITE
GARFIELD COUNTY, COLORADO
Cover Photo: View of proposed centralized soil treatment facility site.
Prepared for:
Petroleum Development Corporation
1775 Sherman Street, Suite 3000
Denver, CO 80203
Prepared by:
WestWater Engineering
2516 Foresight Circle #1
Grans Junction.. O 81 A15
Michael Klish- Principal Environmental Scientist
October 2009
1.0 INTRODUCTION
1.1 Project Description
At the request of Petroleum Development Corporation (PDC), WestWater Engineering (WWE)
has prepared an Integrated Vegetation and Noxious Weed Management Plan for a proposed
centralized soil treatment facility site. The project site is located 6.8 miles east of Parachute,
Colorado in Sections 25, Township 6 South, Range 95 West (Figure 1). The project area lies
within Garfield County, Colorado, and is located on private land. Access to the project area is
currently available via U.S. Highway 6 east from Parachute onto a private access road.
The primary use of the site and adjacent area is natural gas extraction/development and wildlife
habitat. The general project area is currently undergoing natural gas development including well
drilling and the construction of pipelines and roads.
1.2 General Survey Information
Mapped soil types, as published by the Natural Resources Conservation Service (NRCS), U.S.
Department of Agriculture (USDA), were reviewed to determine the soil types and vegetation
characteristics of site and surrounding area (NRCS 2009).
Field inspections of the project area were conducted by WWE biologists on October 16, 2009.
WWE biologists surveyed the area in and around the site to identify vegetation communities and
to search for, identify, and map noxious weed species.
Vegetation types were determined through aerial photography, field identification of plants, and
on- the - ground assessment of plant abundance visible during the survey. Identification of plant
species was aided by using pertinent published field guides (Whitson et al. 2001, CWMA 2007,
Kershaw et al. 1998, Weber and Wittmann 2001). Photographs were taken of the general project
location, vegetation, terrain, and other specific biological findings. Locations of weeds and other
features included in this report were recorded with the aid of a handheld global positioning
system (GPS) receiver using NAD83/WGS84 map datum, with all coordinate locations based on
the Universal Transverse Mercator (UTM) coordinate system in Zone 12.
2.0 LANDSCAPE SETTING
2.1 Vegetation Communities
Vegetation communities around the project area have been disturbed by grazing use by livestock,
natural gas development, and Interstate 70. The area surrounding the site is dominated by
sagebrush shrublands with an understory of mixed forbs and grasses. Pinon juniper woodlands
are widely scattered on the hillsides and ridge -tops near the project area. Pinon juniper
woodlands are dominated by Utah juniper (Juniperus osteosperma) and occasional pinon pine
(Pinus edulis). Other vegetation observed in the area includes greasewood (Sarcobatus
vermiculatus), four -wing saltbush (Atriplex canescens), shadscale ( Atriplex confertifolia), and
yellow rabbitbrush (Chrysothamnus viscidiflorus) with cheatgrass (Bromus tectorum) and crested
WestWater Engineering Page 1 of 11 October 2009
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wheatgrass (Agropyron cristatum) throughout the understory. With the exception of western
wheatgrass (Pascopyrum smithii), very few native grasses were observed.
Approximately 30 percent of the centralized soil treatment facility parcel has been previously
disturbed by a pipeline Right -of -Way (ROW). Vegetation found along the pipeline ROW is
primarily composed of crested wheatgrass, kochia (Kochia scoparia), Russian thistle (Salsola
spp), and weedy annual mustards (family Brassicacea).
2.2 Soils
Soil types present in the project area are the loamy soils commonly found along alluvial fans and
valleys throughout Garfield and Mesa Counties. Mapped soil types, as published by the Natural
Resources Conservation Service (NRCS), U.S. Department of Agriculture (USDA), were
reviewed to determine the soil types and vegetation characteristics of the project site and
surrounding property (NRCS 2009).
Two soil types are found in the project area and include the following:
1. Nihill - Channery loam is a well drained soil with 6 -25 percent slopes.
2. Arvada loam is a well drained soil with 1 -6 percent slopes.
2.3 Terrain
The project area lies north of the Colorado River on an upland terrace. Terrain is relatively flat
at an elevation of approximately 5,200 ft above sea level. Steep slopes and low hills lie north of
the project site and are bisected by several dry washes.
3.0 NOXIOUS WEEDS
3.1 Introduction to Noxious Weeds
Noxious weeds are plants that are aggressive competitors when non - native to an area. Most have
come from Europe or Asia, either accidentally or as ornamentals that have escaped. Once
established in a new environment, they tend to spread quickly because the insects, diseases, and
animals that normally control them are absent. Noxious weeds are spread by man, animals,
water, and wind. Prime locations for the establishment of noxious weeds include roadsides,
construction sites, areas that are overused by animals or humans, wetlands, and riparian
corridors. Subsequent to soil disturbances, vegetation communities can be susceptible to
infestations of invasive or exotic weed species. Vegetation removal and soil disturbance during
construction can create optimal conditions for the establishment of invasive, non - native species.
Construction equipment traveling from weed - infested areas into weed -free areas could disperse
noxious or invasive weed seeds and propagates, resulting in the establishment of these weeds in
previously weed -free areas.
The Colorado Noxious Weed Act (State of Colorado 2005) requires local governing bodies to
develop noxious weed management plans. Both the State of Colorado and Garfield County
maintain lists of plants considered to be noxious weeds. The State of Colorado noxious weed list
includes three categories. List A species must be eradicated whenever detected. List B species
WestWater Engineering Page 3 of 11 October 2009
include weeds whose spread should be halted. List C species are widespread, but the State will
assist local jurisdictions which choose to manage those weeds.
The Garfield County Weed Advisory Board has compiled a list of 21 plants from the State list
considered to be noxious weeds within the county (Appendix A). The Garfield County Weed
Advisory Board has duties to:
1. Develop a noxious weed list,
2. Develop a weed management plan for designated noxious weeds, and
3. Recommend to the Board of County Commissioners that identified landowners submit an
integrated weed management plan for their properties.
3.2 Observations
Four Colorado State listed weed species are found at the site, one of which is listed by Garfield
County (Table 1 and Appendix A). One Colorado State B listed weed, Canada thistle (Cirsium
arvense), was observed in the project area. Three Colorado State C listed weeds were observed
in the project area and included downy brome (Bromus tectorum), halogeton (Halogeton
glomeratus), and redstem filaree (Erodium cicutarium).
The vegetative community in previously disturbed areas at the site was primarily composed of
common weed species that are not listed by the State of Colorado as noxious weeds. These
species include: kochia (Bassia prostrate), Russian thistle (Salsola spp.), tumble mustard
(Sisymbrium altissimum), and annual wheatgrass (Eremopyrum triticeum). Heavy infestations of
these weedy species were observed throughout the older disturbed areas of the site.
Table 1. Noxious Weeds Observed in the Proiect Area.
Common Name*
Scientific Name
USDA Symbol
1
Plant Type
General Location and Comments
Canada ThistleB
Cirsium arvense
CIAR4
Creeping
Perennial
Single plant on existing pipeline alignment.
Downy bromeL
Bromus tectorum
BRTE
Annual
Found throughout project area.
Halogetonc
Halogeton
glomeratus
HAGL
Annual
Found in dense patches along existing pipeline
alignment.
Red -stem filareeB
Erodium
cicutarium
ERCI6
Annual /Biennial
Found throughout freshly cleared pipeline ROW and
existing alignment.
* Government weed listing: Bold - Garfield County, Colorado. Superscript - Colorado State B or C list.
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October 2009
3.3 Integrated Weed Management
Control of invasive species is a difficult task. Care must be taken to prevent damage to desirable
plant species during treatments to prevent further infestations by other pioneer invaders. Weed
management is best achieved through a variety of methods over a long period of time including
inventory (surveys), direct treatments, prevention through best management practices,
monitoring of treatment efficiency, and subsequent detection efforts. Weed management is often
reserved to "control" of existing species and prevention of further infestations (existing and
novel species) rather than eradication. After successful and effective management, decreases in
infestation size and density can be expected, and after several years of successful management
practices, eradication is sometimes possible.
3.4 Prevention and Assessment of Noxious Weed Infestations
Weed management is costly and heavy infestations may exceed the economic threshold for
practical treatment. Prevention is especially valuable in the case of noxious weed management.
Several simple practices should be employed to prevent most weed infestations. The following
practices should be adopted for any activity to reduce the costs of noxious weed control through
prevention. The practices include:
• Prior to delivery to the site, equipment should be thoroughly cleaned of soils remaining
from previous construction sites which may be contaminated with noxious weeds.
• If working in sites with weed -seed contaminated soil, equipment should be cleaned of
potentially seed - bearing soils and vegetative debris at the infested area prior to moving to
uncontaminated terrain.
• All maintenance vehicles should be regularly cleaned of soil.
• Avoid driving vehicles through areas where weed infestations exist.
Assessment of the existence and extent of noxious weeds for an area is essential for the
development of an integrated management plan. This report provides an initial assessment of the
occurrence of noxious weeds for the project area. In order to continue effective management of
noxious weeds, further inventory and analysis is necessary to 1) determine the effectiveness of
the past treatment strategies, 2) modify if necessary the treatment plan, and 3) detect early
infestations of new species or locations and thus more economical treatments.
3.5 Treatment and Control of Noxious Weed Infestations
Invasive and noxious weeds commonly occur along ditches, creek corridors and adjacent
drainages (especially in riparian areas), abandoned fields, and disturbed areas such as well pads,
pipeline routes and roadsides.
It is recommended to continue monitoring the site to insure new infestations of noxious weeds do
not establish at the centralized soil treatment facility. Once an area has been cleared of
vegetation and the soil has been upturned this increases the vulnerability of the site to invasion
by noxious weeds. Noxious weeds establish in areas of disturbance due to the removal of
competitors and the optimal growing conditions that are created by disturbing a site.
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If noxious weeds are found in the future at the site it is important to know whether the target is
an annual, biennial, or perennial to select strategies that effectively control and eliminate the
target. Treatment strategies are different depending on plant type, which are summarized in
Tables 2 and 3. Herbicides should not always be the first treatment of choice when other
methods can be effectively employed.
Some weeds, particularly annuals and biennials, can develop resistance to herbicides. The ability
to quickly develop immunity to herbicides, especially when they are used incorrectly, makes it
imperative to use the proper chemicals at the correct time in the specified concentration
according to the product label. Most misuse is centered on excessive application, either in
frequency or concentration. This results in mostly top kill and resistant phenotypes.
Table 2. Treatment Strategies for Annual and Biennial Noxious Weeds
Target: Prevent Seed Production
1. Hand grub (pull), hoe, till, cultivate in rosette stage and before flowering or seed maturity. If seeds
develop, cut and bag seed heads.
2. Cut roots with a spade just below soil level.
3. Treat with herbicide in rosette or bolting stage, before flowering.
4. Mow biennials after bolting stage, before seed set. Mowing annuals will not prevent flowering but
can reduce total seed production.
(Sirota 2004)
Table 3. Treatment Strategies for Perennials
Target: Deplete nutrient reserves in root system, prevent seed production
1. Allow plants to expend as much energy from root system as possible, do not treat when first
emerging in spring, but allow growth to bud/bloom stage. If seeds develop, cut and bag if possible.
2. Herbicide treatment at bud to bloom stage or in the fall (recommended after August 15 when natural
precipitation is present). In the fall, plants draw nutrients into the roots for winter storage.
Herbicides will be drawn down to the roots more efficiently at this time due to translocation of
nutrients to roots rather than leaves. If the weed patch has been present for a long period of time,
another season of seed production is not as important as getting the herbicide into the root system.
Spraying in fall (after middle August) will kill the following year's shoots, which are being formed
on the roots at this time.
3. Mowing usually is not recommended because the plants will flower anyway; seed production should
be reduced. Many studies have shown that mowing perennials and spraying the re- growth is not as
effective as spraying without mowing. Effect of mowing is species dependent; therefore, it is
imperative to know the species and its basic biology. Timing of application must be done when
biologically appropriate, which is not necessarily convenient.
4. Tillage may or may not be effective. Most perennial roots can sprout from pieces only '/2" — 1" long.
Clean machinery thoroughly before leaving the weed patch.
5. Hand pulling is generally not recommended for perennial species unless you know the plants are
seedlings and not established plants. Hand pulling can be effective on small patches but is very labor
intensive because it must be done repeatedly.
(Sirota 2004)
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October 2009
3.6 Commercial Applicator Recommendations
A certified commercial applicator is a good choice for herbicide control efforts. Regulations
may require a Colorado licensed applicator. An applicator has the full range of knowledge,
skills, equipment, and experience desired when dealing with tough noxious weeds. Reclamation
farming services using multiple seed bin range drills and specialized related equipment is
available and should be used for reclamation seeding projects.
Common chemical and trade names may be used in this report. The use of trade names is
for clarity by the reader. Inclusion of a trade name does not imply endorsement of that
particular brand of herbicide and exclusion does not imply non - approval. Certified
commercial applicators will decide which herbicide to use and at what concentration
according to label directions. Landowners using unrestricted products must obey all label
warnings, cautions, and application concentrations. The author of this report is not
responsible for inappropriate herbicide use by readers.
3.7 Best Management Practices — Noxious Weeds
Construction: The following practices should be adopted for any construction project to reduce
the costs of noxious weed control and aid in prevention efforts. The practices include:
• Top soil, where present, should be segregated from deeper soils and replaced as top soil
on the final grade, a process known as live topsoil handling.
• In all cases, temporary disturbance should be kept to an absolute minimum.
• Equipment and materials handling should be done on established sites to reduce area and
extent of soil compaction.
• Disturbances should be immediately reseeded with the recommended mix in the re-
vegetation section.
• Topsoil stockpiles should be seeded with non - invasive sterile hybrid grasses, if stored
longer than one growing season.
• Prior to delivery to the site, equipment should be cleaned of soils remaining from
previous construction sites which may be contaminated with noxious weeds.
• If working in sites with weed -seed contaminated soil, equipment should be cleaned of
potentially seed - bearing soils and vegetative debris prior to moving to uncontaminated
terrain.
In areas with slope greater than 3 percent, imprinting of the seed bed is recommended.
Imprinting can be in the form of dozer tracks or furrows perpendicular to the direction of slope.
When utilizing hydro- seeding followed by mulching, imprinting should be done prior to seeding
unless the mulch is to be crimped into the soil surface. If broadcast seeding and harrowing,
imprinting should be done as part of the harrowing. Furrowing can be done by several methods,
the most simple of which is to drill seed perpendicular to the direction of slope in a prepared bed.
Other simple imprinting methods include deep hand raking and harrowing, always perpendicular
to the direction of slope.
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Herbicides: Annual and biennial weeds are best controlled at the pre -bud stage after
germination or in the spring of the second year. The species identified in the survey are
susceptible to commercially available herbicides. Selective herbicides are recommended to
minimize damage to desirable grass. Herbicide use in any riparian zones should be restricted to
formulations that are approved for such use. Non - selective aquatic glyphosate formulations (e.g.,
Rodeo®) can be used in riparian areas with little danger to the ground or surface water, but
desired grasses, forbs, shrubs and trees are susceptible to damage by direct contact.
Professionals or landowners using herbicides must use the concentration specified on the label of
the container in hand. Herbicides generally do not work better at higher concentrations. Most
herbicide failures observed by WWE are related to incomplete control caused by high
concentrations killing top growth before the active ingredient can be transported to the roots
through the nutrient translocation process. Most herbicide applications should use a surfactant if
directed on the herbicide label or other adjuvants as called for on the herbicide label.
Grazing: Grazing should be deferred, in reclaimed areas, until the desired grass species are
established.
Mechanical: Mechanical control with a hand tool (shovel etc.) is ideal for situations where
noxious weed infestations are low and visibility is good.
Alternative Methods: An alternative method, particularly where there is poor or destroyed
topsoil, is the application of vesicular - arbuscular mycorrhizal fungi, typically referred to as
AMF. These fungi, mostly of the genus Glomus, are symbiotic with about 80 percent of all
vegetation. Endo - mycorrhizal fungi are associated mostly with grasses and forbs and could be
helpful when reclaiming this project. In symbiosis, the fungi increase water and nutrient transfer
capacity of the host root system by as much as several orders of magnitude (Barrow and
McCaslin 1995).
Over - the - counter commercial products, which are better adapted to coating seeds when re-
seeding and treating roots of live seedling trees and shrubs at time of planting, come in powder
form and are available from many different sources. Some also come in granular form to be
spread with seed from a broadcast spreader. The best AMF products should contain more than
one species.
All Colorado State Forest Salida District tree and shrub plantings include the application of
AMF. According to District Forester Crystal Tischler, "AMF is worth it" (Tischler 2006). Most,
if not all, Colorado Department of Transportation re- vegetation /reseeding projects now require
use of AMF and BioSol, a certified by- product of the penicillin manufacturing process composed
primarily of mycelium. Compacted soils respond well to fossilized humic substances and by-
products called humates. These humates, including humic and fulvic acids, and humin were
formed from pre - historic plant and animal deposits and work especially well on compacted soils
when applied as directed.
4.0 REVEGETATION — RECLAMATION
4.1 Project Area
The project area is comprised of grasslands and desert shrublands, and sparsely vegetated
foothills. Successful reclamation of the project area is dependent upon soil type and texture,
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slope gradient and aspect, proper weed control, available water, and revegetation with suitable
plant species.
Based on the soil types, terrain, and the presence of noxious weeds in the project area, successful
reclamation is most likely if a seed mix of grasses and shrubs is used. The seed mix presented in
Table 4 is recommended. The suggested seed mix is based on BLM recommendation for the
elevation and vegetation type presently occurring in the project area (BLM 2008).
For best results and success, the recommended grass mixture reseeding should be done in
late autumn. The reseeding rate should be doubled for broadcast application (CNHP 1998).
Preferred seeding method is multiple seed bin rangeland drill with 110 soil preparation other than
simple grading to slope and imprinting and waterbars where applicable.
Alternative seeding methods include, but are not limited to:
• harrow with just enough soil moisture to create a rough surface, broadcast seed and re-
harrow, preferably at a 90 degree angle to the first harrow;
• hydro- seeding (most economical in terms of seed cost); and
• hand raking and broadcast followed by re- raking at a 90 degree angle to the first raking.
• These are not the only means of replanting the site. However, these methods have been
observed to be effective in similar landscapes.
After desired grasses are established and control of target weed species is successful, then
shrubs, forbs, and trees can be planted without concern for herbicide damage. Few native forb
seeds are available commercially as cultivars. Most are collected from natural populations.
Native shrubs and forbs often do not establish well from seed, particularly when mixed with
grasses. Past experience has shown that stabilizing the soil with grasses, accomplishing weed
control, and then coming back to plant live, containerized woody species in copses has been the
most cost effective method for establishing the woody species component of the plant
community.
For sites where soil disturbance will be temporary, grasses should be drilled after construction
activities cease and the equipment is removed from the site. After two years of controlling
weeds (with herbicides) and allowing the grasses to become established, forbs and woody
species should be inter - seeded or hand - planted to increase the diversity and value of the
reclamation plantings.
4.2 Reclamation Goals
Interim and final reclamation measures shall be consistent with those outlined in the Colorado
Oil and Gas Conservation Commission's (COGCC) amended rules, effective April 1, 2009
(COGCC 2009). These regulations are expected to fulfill Garfield County's requirements for
interim and final reclamation standards.
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Table 4. Suggested Seeding for Low - Elevation Salt- Desert Scrub /Basin Big Sagebrush
Common Name
Scientific Names
Variety
Season
Form
PLS
lbs /acre*
Plant Both of the Following (5% Each, 10% Total)
Fourwing Saltbush
Atriplex canescens
VNS
Shrub
2.5
Shadscale
Atriplex confertifolia
VNS
Shrub
2.0
and Two of the Following (25% Each, 50% Total)
Bottlebrush Squirreltail
Elymus elymoides, Sitanion hystrix
VNS
Cool
Bunch
3.4
Streambank Wheatgrass
Elymus lanceolatus ssp. psammophilus,
Agropyron riparium
Sodar
Cool
Sod - forming
4.2
Bluebunch Wheatgrass
Pseudoroegneria spicata
Secar
Cool
Bunch
4.7
and One of the Following (20% Total)
Indian Ricegrass
Achnatherum [Oryzopsis] hymenoides
Paloma, Rimrock
Cool
Bunch
3.7
Sandberg Bluegrass
Poa sandbergii, Poa secunda
VNS
Cool
Bunch
0.6
and One of the Following (10% Total)
Alkali Sacaton
Sporobolus airoides
VNS
Warm
Bunch
0.15
Salina Wildrye
Leymus salinus
VNS
Cool
Bunch
1.0
and One of the Following (10% Total)
Galleta
Pleuraphis [Hilaria] jamesii
Viva florets
Warm
Bunch/Sod-
forming
1.6
Sand Dropseed
Sporobolus cryptandrus
VNS
Warm
Bunch
0.05
*Based on 60 pure live seeds (PLS) per square foot, drill - seeded. Double this rate (120 PLS per square foot) if broadcast or hydroseeded.
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October 2009
5.0 REFERENCES
Barrow, J. R., and Bobby D. McCaslin. 1995. Role of microbes in resource management in arid
ecosystems. In: Barrow, J. R., E. D. McArthur, R. E. Sosebee, and Tausch, R. J., comps.
1996. Proceedings: shrubland ecosystem dynamics in a changing environment. General
Technical Report, INT- GTR -338, Ogden, Utah: U.S. Department of Agriculture, U.S.
Forest Service, Intermountain Resource Station, 275 pp.
BLM. 2008. Revisions to BLM energy office revegetation requirements. Bureau of Land
Management, Department of the Interior, Glenwood Springs.
CNHP. 1998. Native Plant Re- vegetation Guide for Colorado. Colorado Natural Heritage
Program, Caring for the Land Series, Vol. III, State of Colorado, Division of Parks and
Outdoor Recreation, Department of Natural Resources, Denver, 258 pp.
COGCC. 2009. Amended Rules. Colorado Oil and Gas Conservation Commission, Department
of Natural Resources.
CWMA. 2007. S. Anthony, T. D'Amato, A. Doran, S. Elzinga, J. Powell, I. Schonle, K. Uhing.
Noxious Weeds of Colorado, Ninth Edition. Colorado Weed Management Association,
Centennial.
Kershaw, L., A. MacKinnon, and J. Pojar. 1998. Plants of the Rocky Mountains. Lone Pine
Publishing, Auburn, Washington.
NRCS. 2009. Web Soil Survey, U.S. Department of Agriculture, Natural Resource Conservation
Service, URL: http://websoilsurvey.nrcs.usda.gov
Sirota, J. 2004. Best management practices for noxious weeds of Mesa County. Colorado State
University Cooperative Extension Tri River Area, Grand Junction, Colorado. URL:
http://www.coopext.colostate.edu/TRA/Weeds/weedmgmt.html
State of Colorado. 2005. Rules pertaining to the administration and enforcement of the Colorado
Noxious Weed Act, 35 -5 -1 -119, C.R.S. 2003. Department of Agriculture, Plant Industry
Division, Denver, 78 pp.
Tischler, Crystal. 2006. District Forester, Colorado State Forest Service, Salida. Personal
communication with Bill Clark, WestWater Engineering, Grand Junction, Colorado.
Weber, William A., and Ronald C. Wittmann. 2001. Colorado Flora, Western Slope.
Third Edition, University Press of Colorado, Boulder.
Whitson, T. D. (editor), L. C. Burrill, S. A. Dewey, D. W. Cudney, B. E. Nelson, R. D.
Lee, and R. Parker. 2001. Weeds of the West — 9th edition. Western Society of Weed
Science in cooperation with Cooperative Extension Services, University of Wyoming,
Laramie.
WestWater Engineering Page 11 of 11 October 2009
APPENDIX A
Garfield County Noxious Weed List
Species
Common name
Species
Code
Growth
Form'
Life
History 2
State "A"
List
State "B"
List
" State
C List
Garfield
List
Acroptilon repens
Russian knapweed
ACRE3
F
P
X
X
Aegilops cylindrica
Jointed goatgrass
AECY
G
A
X
X
Arctium minus
Common (Lesser) burdock
ARMI2
F
B
X
X
Cardaria draba
Hoary cress, Whitetop
CADR
F
P
X
X
Carduus acanthoides
Spiny plumeless thistle
CAAC
F
B, WA
X
X
Carduus nutans
Musk (Nodding plumeless) thistle
CANU4
F
B
X
X
Centaurea diffusa
Diffuse knapweed
CEDI3
F
P
X
X
Centaurea maculosa
Spotted knapweed
CEMA4
F
P
X
X
Centaurea solstitialis
Yellow starthistle
CESO3
F
A
X
X
Chrysanthemum
leucanthemum
Oxeye daisy
CHLE80
F
P
X
X
Cichorium intybus
Chicory
CIIN
F
P
X
X
Cirsium arvense
Canada thistle
CIAR4
F
P
X
X
Cynoglossum officinale
Houndstongue, Gypsyflower
CYOF
F
B
X
X
Elaeagnus angustifolia
Russian olive
ELAN
T
P
X
X
Euphorbia esula
Leafy spurge
EUES
F
P
X
X
Linaria dalmatica
Dalmatian toadflax, broad - leaved
LIDA
F
P
X
X
Linaria vulgaris
Yellow toadflax
LIVU2
F
P
X
X
Lythrum salicaria
Purple loosestrife
LYSA2
F
P
X
X
Onopordum acanthium
Scotch thistle
ONAC
F
B
X
X
Tamarix parvi fora
Smallflower tamarisk
TAPA4
T
P
X
X
Tamarix ramosissima
Salt cedar, Tamarisk
TARA
T
P
X
X
1 — Growth form: T = tree /shrub; F = forb /vine; G = graminoid 2 — Life history: A = annual; B = biennial; P = perennial; WA = winter annual
WestWater Engineering
Appendix A October 2009