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HomeMy WebLinkAboutOrder 006 - Weed Control DistrictDeschutes County Board of Commissioners 1300 NW Wall St., Suite 200, Bend, OR 97701-1960 (541) 388-6570 - Fax (541) 385-3202 - www.deschutes.org AGENDA REQUEST & STAFF REPORT For Board Business Meeting of Wednesday, April 6, 2011 DATE: March 29, 2011 FROM: Dan Sherwin Road Department 541-322-7135 TITLE OF AGENDA ITEM: Consideration of Board signature of Order No. 2011-006, Continuing Deschutes County as a Weed Control District. PUBLIC HEARING ON THIS DATE? No BACKGROUND AND POLICY IMPLICATIONS: Order No. 2011-006 adopts an updated noxious weed list (Exhibit A of the Order), and continues Deschutes County as a Weed Control District that was originally established by Order No. 2002-037 in 2002. The Oregon Department of Agriculture periodically updates the State noxious weed list, and this update to the County's noxious weedlist will bring the list in conformance with the State's list. Under this Order, the Board continues to authorize declaring that certain noxious weeds not be allowed to go to seed within the Deschutes County Weed Control District. The Weed Control District shall continue to destroy noxious weeds and prevent the seeding and spread of such other weeds and plants subsequently declared noxious. The Board appoints the Deschutes County Road Department Director as the County Weed Inspector to carry out actions authorized and required under ORS 569.350 to 569.495. The Road Department Director may also delegate his authority to assistants as Weed Inspectors. A noxious weed list shall be published, describing the District and naming weeds to be destroyed and prevented from producing weeds within the District. Enforcement shall generally follow the Enforcement Procedures (attached for reference). Under ORS 569.400, the County Weed Inspector and duly appointed assistants may enter upon land or premises, and perform any act authorized by this Order, and is also authorized to file with the County Clerk an itemized statement of expenses necessarily incurred, including the wage of the Weed Inspector. FISCAL IMPLICATIONS: None. Order No. 2011-006 is neither a fiscal nor a funds obligation document. RECOMMENDATION & ACTION REQUESTED: Move approval and signature of Order No. 2011-006, adopting the updated noxious weed list and continuing Deschutes County as a Weed Control District. ATTENDANCE: Dan Sherwin and Paul Stell, Weed Board Advisory Chair DISTRIBUTION OF DOCUMENTS: Copy to Dan Sherwin, Road Department REVIEWED LEGAL COUNSEL For Recording Stamp Only BEFORE THE BOARD OF COUNTY COMMISSIONERS OF DESCHUTES COUNTY, OREGON An Order Continuing Deschutes County as a Weed Control District * ORDER NO. 2011-006 * WHEREAS, pursuant to ORS 570.515 and Order No. 2002-037 the Board of County Commissioners declared Deschutes County a Weed Control District; and WHEREAS, the Board has been and continues to be authorized to declare certain weeds and plants noxious for the purposes of ORS 569.350 to 569.495; and WHEREAS, the Board is authorized to appoint one or more weed inspectors to carry out the purposes of ORS 569.350 to 569.495 and to take such other actions as authorized and appropriate to eradicate noxious weeds on private and public property; now therefore, THE BOARD OF COUNTY COMMISSIONERS OF DESCHUTES COUNTY, OREGON, HEREBY ORDERS as follows: Section 1. That Deschutes County, as described in ORS 201.090 has been since March 28, 2002 and shall continue to be a Weed Control District for the purpose of destroying noxious weeds and of preventing the seeding and spread of such other weeds and plants as a governing body may, for the purposes of ORS 569.350 to 569.495, declare noxious. The name of the District shall be the "Deschutes County Weed Control District." Section 2. The Board hereby appoints the Deschutes County Road Department Director as the County Weed Inspector to carry out the actions authorized and required pursuant to ORS 569.350 to 569.495. Section 3. The Weed Inspector shall cause to be published the Notice, marked Exhibit A, attached hereto and by this reference incorporated herein, describing the District and naming the weeds to be destroyed and to be prevented from producing seed within the District. This Notice shall be published in The Bulletin once each week for two consecutive weeks. The Weed Inspector is authorized and directed to enforce the provisions of ORS 569.350 to 569.495 immediately after the last publication and this Notice. Enforcement shall generally follow the Enforcement Procedure set forth on Exhibit B, attached hereto and incorporated herein. Section 4. Pursuant to ORS 569.400, the County Weed Inspector and such assistants as the Weed Inspector may employ, may enter upon land or premises and do any act authorized by this order, and is further authorized to file with the County Clerk an itemized statement of expenses necessarily incurred, including the wages of the Weed Inspector, in accordance with ORS 569.400. Section 5. Deschutes County Clerk is hereby authorized and directed to have printed a sufficient number of copies of ORS 569.445 and 569.450 and deliver such copies upon request to owners or operators of machinery described in ORS 569.445 and 569.450. Page 1 of 2 ORDER 2011-006 Section 6. Except as otherwise provided herein, the Weed Control District established by the Board in 2002 is and shall continue in full force and effect. Nothing contained in this Order shall be construed as terminating or rendering invalid Order No. 2002-037 or any actions, proceedings or decisions brought or made pursuant to Order No. 2002-037. Section 7. This order becomes effective upon adoption. Dated this day of , 2011 BOARD OF COUNTY COMMISSIONERS TAMMY BANEY, CHAIR ANTHONY DeBONE, VICE -CHAIR ATTEST: Recording Secretary ALAN LINGER, COMMISSIONER Page 2 of 2 ORDER 2011-006 EXHIBIT A NOTICE FORMATION OF DESCHUTES COUNTY WEED CONTROL DISTRICT The Board of County Commissioners' of Deschutes County, Oregon ("Board") has declared that Deschutes County, described in ORS 201.090, to be a Weed Control District. The district shall be known as the "Deschutes County Weed Control District." The following described weeds are declared to be noxious weeds and plants, and such weeds are to be destroyed, prevented and prevented from producing seeds within the District: "A" Rated Weeds African rue Buffalobur + common houndstongue dyer's woad - false brome giant cane hydrilla leafy spurge + meadow knapweed - Mediterranean sage + medusahead rye + musk thistle - orange hawkweed + perennial pepperweed + purple loosestrife + rush skeletonweed Russian knapweed + Scotch thistle + squarrose knapweed sulfur cinquefoil saltcedar tamarix + tansy ragwort + whitetop; hoary cress + wild carrot + yellow starthistle - Page 1 of 3 — Exhibit A to Order No. 2011-006 Peganum harmala Solanum rostratum Cynoglossum officinale Isatis tinctoria Brachypodium sylvaticum Arundo donax Hydrilla verticillata Euphorbia esula Centaurea pratensis Salvia aethiopis Taeniatherum caputmedusae Carduus nutans Hieracium aurantiacum Lepidium latifolium Lythrum salicaria Chondrilla juncea Acroptilon repens Onopordum acanthium Centaurea virgata Potentilla recta Tamarix ramosissima Senecio jacobaea Lepidium draba Daucus carota Centaurea solstitialis "B" Rated Weeds Canada Thistle + dalmation toadflax + diffuse knapweed + kochia (annual) + myrtle spurge + poison hemlock + puncturevine + ribbon grass + Russian thistle + Scotch broom + spotted knapweed + yellow toadflax or "butter and eggs" + yellow flag iris + "C Rated Weeds bur buttercup + bull thistle + cheat grass ( Downy brome) + common mullein + dodder + field bindweed + filaree redstem + horseweed + poverty sumpweed + quackgrass + South American waterweed + spiny cocklebur + St Johnswort + sweet clover(s) -Only on Right of Ways + Western Water -hemlock / + Cirsium arvense Linaria dalmatica Centaurea diffusa Kochia scoparia Euphorbia myrsinites Conium maculatum Tribulus terrestris Phalaris arundinacea Salsola spp. Cytisus scoparius Centaurea biedersteinii Linaria vulgaris Iris pseudacorus Ranunculus testiculatus Cirsium vulgare Bromus tectorum Verbascum thapsus Cuscuta spp. Convolvulus arvensis Erodium cicutarium Conyza Canadensis Iva axillaries Agropyron repens Elodea densa Xanthium spinosum Hypericum perforatum Melilotus officinalis Cicuta douglasii+ Currently in the County All known populations have been treated Natives but Poisonous to Animals or Humans The Board has appointed a County Weed Inspector who has the power to enforce ORS 569.350 to 569.495 including the right to enter upon land or premises and destroy noxious weed or control them in such manner as will destroy all seeds of such noxious weeds. The County Weed Inspector is authorized to place liens upon real property to recoup the expenses (including the wages of the Weed inspector) necessarily incurred in the destruction of noxious weeds. Page 2 of 3 — Exhibit A to Order No. 2011-006 Every person, firm or corporation owning or occupying land within Deschutes County shall destroy or prevent the seeding on such land any noxious weeds within the meaning of ORS 569.350 to 569.495 or declared to be noxious by the Board no weed declared noxious shall be permitted (to produce seed) by the owner or occupier of land. Publication: THE BULLETIN , 2011 BOARD OF COUNTY COMMISSIONERS FOR DESCHUTES COUNTY, OREGON TAMMY BANEY, Chair Page 3 of 3 — Exhibit A to Order No. 2011-006 EXHIBIT B ENFORCEMENT PROCEDURES DESCHUTES COUNTY NOXIOUS WEED CONTROL 1. When a noxious weed infestation is brought to the attention of the County Weed Inspector an inspection of the site is warranted. It is the County's goal to have landowners comply with State weed laws and it is the intent for the Weed Inspector to assist landowners in achieving compliance. 2. Each contact, attempt to contact, and the results of that contact shall be documented. 3. The inspector shall visit the property and make an assessment of the infestation. If unable to make a determination from the public right of way the inspector shall make reasonable effort to contact the property owner or agent prior to entry as permitted in ORS 569.380. A reasonable effort may be a personal contact while at the site, a phone call, a notice left at the dwelling, or a certified letter. 4. If the inspector believes the property contains noxious weeds, the inspector shall either personally serve notice on the property owner or occupant, or post notice in three conspicuous places on the land. The notice shall contain: the date of service, the name of the weed or weeds growing on the land, and a statement setting forth that the weeds must be destroyed within a specified time of not less than two days or more than 10 days (as determined by the inspector) from the date of service. The notice may contain an invitation to the property owner or occupant to visit with the inspector for clarification of any requirements relative to noxious weed abatement, alternative methods of achieving compliance and an agreement by which the property owner will control the noxious weeds by a date certain, together with follow up inspection. 5. If follow up inspection reveals that the noxious weeds have not been adequately or effectually controlled or not controlled as agreed upon then a citation may be issued, by a person duly authorized to cite for a violation, and served on the owner or occupant in accordance with applicable law. Each day that the noxious weeds are permitted to set seed may be considered a separate violation. 6. If the follow up inspections reveal compliance with the agreed upon treatment the inspector should continue to inspect the property for 1 and '/2 growing seasons to verify that the noxious weeds are no longer growing or producing seed. Exhibit B to Order No. 2011-006 February 22, 2011 To: Deschutes County Board of Commissioners From: Deschutes County Weed Advisory Board Subject: Deschutes County 2011 Noxious Weed List Commissioners, Weed Advisory Board 61150 SE 27th St • Bend, Oregon 97702 [541) 322-7135 • FAX (541) 388-2719 Submitted for your approval is the 2011 Noxious Weed List. Two additional noxious weeds should be added to the list. They are giant cane ( giant reed) Arundo donax which will be designated as a "A" rated weed and ribbon grass, Phalaris arundinacea designated as a "B" rated weed. These two noxious weeds are a concern that they may enter into rivers, riparian areas and irrigation systems and spread throughout Deschutes County. See attached information about these weeds. Sincer Paul Stell Weed Board Chair Attachments DESCHUTES COUNTY WEED LIST Deschutes County Weed Policy and Classification System "NOXIOUS WEED" means any weed designated by the Deschutes County Board of Commissioners that is injurious to public health, agriculture, range, recreation, wildlife, or any public or private property; any weed that impacts and displaces desirable vegetation, such as Threatened and Endangered Plant Species, wildlife habitat, and livestock. It is acknowledged that certain noxious weeds have become so thoroughly established and are spreading so rapidly on state, county, and federally owned lands, as well as on private land, that they may have been declared by Oregon Revised Statue 570.505 to be a menace to public welfare. Steps leading to eradication where possible, are necessary. It is further recognized that the responsibility for such eradication and/or intensive control rests not only on the private landowner and operator, but also the county, state and federal government. Noxious Weed Control Rating System Noxious Weeds, for the purpose of this system, shall be designated "A", "B" or "C" 1. An "A" designated weed is: a priority noxious weed designated by the Deschutes Weed Board as a target weed species on which the Weed Control District will comply with a state wide management plan and/or implement a county wide plan for intensive control and monitoring. An "A" rated weed may also be a weed of known economic or ecological importance which occurs in small enough infestations to make eradication/containment possible; or one that is not known to occur here, but its presence in neighboring counties make future occurrence here seem imminent. Recommended Action: Infestations are subject to intensive control when and where found. 2. A "B" designated weed is: a weed of economic importance, which is both locally abundant and abundant in neighboring counties. Recommended Action: Moderate control and or monitoring at the county level. 3. A "C" designated weed is: a weed that has the potential to cause harm to agriculture production and transportation systems. Recommended Action: Control and monitoring at the county level. This list is available, upon request, to the public from the Deschutes County Weed/Vegetation Manager, 322-7135. 2011 ,t w Oregon Department of Agriculture Plant Pest Risk Assessment for Giant Reed Arundo donax L. February 2011 Name: Giant reed (Arundo donax); a.k.a. giant cane, Spanish reed Family: Grass (Poaceae) Purpose: Arundo donax was evaluated in 2007 and placed on the Oregon Department of Agriculture (ODA) Watch List. ODA and the Oregon State Weed Board (OSWB) are reevaluating Arundo due to the current interest in using Arundo as a biomass energy crop potential for production in Oregon. Findings of this Assessment and Recommendations: Using a rating system adapted from United States Department of Agriculture, Animal and Plant Health Inspection Services, Plant Protection and Quarantine Weed Risk Assessment Guidelines, Arundo donax scored 41 out of a potential score of 90 (moderate B -listing). Using the ODA Noxious Weed Rating System, it scored 16 out of 25 (low A -listing). This low score, even with its limited distribution in Oregon, is attributed to its lack of seed production, lower risk of natural spread, limited economic impacts, lack of health impacts, capacity to control, and probability of detection. Literature clearly indicates that Arundo is a serious invader of tropical and warm temperate environments. What is less clear, is its ability to become invasive in colder temperate zones. and the Bear Creek near Medford, Oregon The Noxious Weed Control Program recommends that Arundo donax remain on the ODA Watch List, allowing for a Control Area Order to be established in Morrow and Umatilla Counties under ORS 570.405, which would allow continued review and research on a limited production level. Plant Pest Risk Assessment, ODA Page 1 of I6 Introduction: Arundo donax, is considered a serious weed in California and the Southwest. Due to the proximity of weedy populations in California and an increased use as an ornamental in the late 1990's, it was evaluated in a 2007 risk assessment by ODA. Currently, only one escaped population has been found in Oregon. The findings of the 2007 risk assessment determined that Arundo should be placed on the ODA Watch List and undergo additional evaluation. The 2007 findings where based on field observations of Arundo growing in southern Oregon and the Willamette Valley. It was observed to only grow vigorously in Jackson County along Bear Creek in Medford. No eastern Oregon ornamental plantings or escaped populations where reported or observed. (ODA 2007). The Plant Epidemiology and Risk Analysis Laboratory, Center for Plant Health Science and Technology of the United States Department of Agriculture, Animal Plant Health Inspection Service, Plant Protection and Quarantine (USDA-APHIS-PPQ) reviewed the 2007 plant pest risk assessments of Arundo donax. Overall, they agree with the general conclusion of the assessment that Arundo donax is a weed of concern. Although, they would have given Arundo a slightly higher score and made the statement "The key question is would it be invasive in Oregon's climate?" (USDA-APHIS-PPQ 2011). They provided a recommendation that ODA consider more carefully how widely and extensively it is cultivated in Oregon, and evaluate the opportunities it has and has not had for escaping. The USDA-APHIS-PPQ evaluation used a process that includes a very basic climate matching tool to evaluate the geographic potential of a species in the United States. The analysis suggests that 55.9% of the U.S. is suitable for the growth of this species (Figure 1), including most of Oregon. However, just because it can grow in most of Oregon, doesn't mean that it would be invasive there. (USDA-APHIS-PPQ 2011). Figure I. Climatically suitable areas for the growth of A. donax in the United States, USDA-PPQ 2011. In Oregon, the feasibility of large-scale production and using Arundo as an alternative energy source is being reviewed by Portland General Electric (PGE) to fuel the Boardman coal-fired power plant in Morrow County. The issue has renewed the urgency in evaluating its invasiveness in Oregon and whether it qualifies to be included as a State Listed Noxious Weed. Plant Pest Risk Asscstiment, ODA Page 2 of 16 World Distribution: It is native to the Asian subcontinent and introduced to Europe several thousand years ago (Benton 2005). Arundo donax can now be found in most tropical and warm temperate geographic area due to human introduction. Naturalized populations are reported from North and South America, Asia, Australia, New Zealand and the Pacific Islands (Haflinger and Scholz 1981). Arundo is prevalent throughout the southwest United States from California to Florida. The degree to which Arundo is naturalized and problematic in each country or region is mixed. Growth Habits and Reproduction: Arundo donax is one of the world's largest herbaceous grasses growing in dense compact masses and reaching heights of 20 feet. Canes develop leaves that are alternate growing up to 2 feet in length and 2 inches wide. Fleshy, almost bulbous creeping rootstocks anchor deep into the soils and form dense root masses. Arundo tolerates all types of soils and thrives especially well in sandy or moist well -drained soils commonly found in riparian zones subjected to annual flooding (Hoshovsky 1986). It prefers flood plains and riparian areas (Hoshovsky 1986). Steep -banked river systems or non -fluctuating waterways offer less opportunity for establishment (Dudley 2000). The edges of wetlands and marshes can provide adequate moisture for survival. Although Arundo is capable of establishing at springs and in uplands where there is adequate moisture (Dudley 2000). Arundo does not thrive in soils that are waterlogged or submerged year-round. Populations established in riparian zones can creep outward into drier to droughty soils utilizing deep -growing roots to gather subsurface water during the dry season. Roadsides and non -irrigated lands make poor habitats for Arundo establishment and spread. Arundo is a species of tropical and warm temperate zones. It is hardy to Zone 6 (Bir 2010). The grass grows vigorously in tropical to warm temperate climates where it produces perennial canes. In colder temperate zones, canes are not perennial and die back or become ragged during winter. Arundo is affected by cold spells and freeze events early in the growing season. These events stunt the grass and can prevent it from reaching its full biological potential. Dormant plants are resistant to moderate freezing temperatures. New growth is impacted by frost events that stunt overall height (Hoshovsky 1986). Severe cold winter temperatures coupled with low soil moisture might be expected to kill or injure dormant roots, limiting its range in colder temperate zones. Flowers are produced on large plume -like panicles between March and September, but fertile seeds are extremely rare. DNA analysis demonstrates that the genetic diversity of Arundo in both Europe and North America is low and indicates that the populations are in fact large clones (Mariani, Cabrini et.al. 2010). The lack of genetic variability is the leading cause of seed sterility. Vegetative reproduction from roots is the primary source of spread in both Europe and North America. All material testing in North America was determined to be of a single clone imported in the 1500's and is genetically identical to Western European populations (Ahmad, Liow et.al. 2008). Stems are not a major factor in reproduction. In southern latitudes, older stems two years or more, develop nodal tissue capable of producing roots if buried with adequate moisture (Ceotto, di Candillo 2010). Stems deposited downstream in debris piles or silt can establish and root. In northern latitudes, such as the Pacific Northwest, stems rarely develop into two-year culms due to cold winter temperatures. Plant l'c,,1 R.,1<:\ ()I).A 01 16 First-year stems do not develop nodal tissue capable of rooting (Ceotto, di Candillo 2010). Factors Contributing to Spread: Humans have played a significant role in the distribution and spread of Arundo in North America for nearly 400 years. The first introductions were in California in the early 1500's by Spanish missions. Arundo was used for animal pens, basket weaving and windbreaks. Other early introductions are attributed to the French (Bir 2010). From these early introductions, plantings were intentionally established in waterways for erosion control. Root fragments can be easily stored and transported with little care. Sharing and use of plant material continued throughout the southwest and has lead to the invasive problems of today. Figure 2. Invasive populations of Arundo in the U.S., Bugwood 2010 The majority of escaped populations reported as invasive occur in the southern half of the United States (Figure 2). Information regarding more northern escaped populations and its invasiveness in northern latitudes in not well documented. Further expansion in the United States can be expected if Arundo proves to be a viable bioenergy source. Ornamental plantings may contribute to spread by being introduced into riparian areas through dumping of yard debris or by being intentionally planted next to streams by homeowners who are unaware of the potential problems. Animals are causal agents of spread, though Arundo produces a host of compounds that serve to discourage grazing or insect feeding. Pacific Northwest Observations: Gardeners and producers have some experience with Arundo in the Pacific Northwest. A five -acre plantation established near Junction City (Lane County Oregon) grew poorly in the clay soils normally utilized for grass seed production and was removed in 2009. The Lane County plot was established to determine Arundo's suitability as an energy crop. The planting did not thrive after several years of growth. Lane County Planting 2008 Plant Pest Risk Assessrncnt, ODA Page 4 of 16 Small patches exist in landscapes and water gardens throughout the Northwest, including a xeric garden in a city park in Yakima, Washington where it is reported as doing well (Jacobson per. comm. 2011). Such plantings are not common and only one escaped population has been observed or reported in the Northwest. It does not appear to be aggressively spreading from ornamental plantings in the Willamette Valley and it is not clear if it will be invasive in the colder winter environment of Eastern Oregon. The climate of Jackson, Josephine, Coos and Curry Counties in southwest Oregon and the mid- Columbia River counties of Gilliam and Umatilla may provide sufficient temperatures to enable giant reed to grow vigorously and the ability to spread laterally. Oregon's only escaped population was identified in 2006 on Bear Creek near Medford; it has since been eradicated (French pers. comm. 2006). Plantings established in 2003 and 2006 in Prosser, Washington serves as the most reliable source for information concerning the vigor of plants growing east of the Cascades in the Pacific Northwest. The 2006 plantings diminished in vigor and density during the time it was maintained. Plant mortality during the winter of 2008 averaged 83 percent. It is speculated that this may be due to a shallow planting of the rootstock or insufficient water going into the winter season. The plantings were removed in 2009. (Stevens, Parker et.al. 2008) Positive Economic Impact: Arundo donax is a highly versatile plant that has been cultivated for over 5,000 years (Perdue 1958). The recent sharp rise in petroleum prices, climate change, energy security, and a desire for greener energy has increased global interest in biofuels. The Oregon legislature and U.S. Congress have signed renewable energy bills into law that promote and provide incentives for developing and using renewable resources for energy. Arundo has the ability to produce large quantities of biomass per acre and is being studied as a promising alternative energy source. Many countries are looking at biofuels as a key to help reduce reliance on foreign oil, lowering emissions of greenhouse gases and meeting economic development goals (Demirdas 2007). Historically Arundo has played an important role in the development of music in Western culture (Perdue 1958). The hollow stems are used widely for flutes, pipes, clarinets, and bagpipes. Reeds for woodwind instruments are made from the culms and no satisfactory substitute had been developed. Canes and leaves provide an important source of building materials for roofing, shelter, shreens and fencing (Bir 2000). Arundo has been planted widely for windbreaks, erosion control and as an ornamental. It makes high quality paper and is used for the production rayon in Italy (Duke 1983). Arundo is grown commercially in Mediterranean Europe, South America, Caribbean Islands, and China. In Oregon, it is a minor nursery crop and can be found for sale and used as an accent plant in landscapes and water gardens. Negative Economic Impact: Economic impacts are documented in California and the Southwestern resulting from flood damage, water loss, structural damage, and increased fire hazard. Arundo canes can create large debris piles that threaten the structural integrity of bridges and other in -stream structures that require expensive removal and cleanup following flood events. In some cases, Arundo completely dominates streams and flood channels forcing waters to cut away from the main channel. Water in the desert southwest is often in short supply. Plant Pest Risk Assessiriunl. ODA Arundo removes large amounts of in -stream and groundwater that could be used for irrigation, drinking water, native plants, and wildlife. Compared to native plants, it consumes three times as much the water. In the Santa Ana River alone, Arundo consumes an estimated 56,200 acre-feet of water annually with a estimated value of $18 million (Orange County Water District 2003). Ecological Impacts: Streamside and riparian impacts occur from aggressive annual growth and the ability of giant reed to spread laterally by rhizomes to form monotypic stands that displace native species. Arundo donax dramatically alters the ecological processes in riparian systems and ultimately transforms most riparian habitats towards pure stands of alien grass. By current estimates there are tens of thousands of acres of Arundo along the major coastal drainage systems of southern California (Bell 1997). Studies of native plant richness in areas invaded by Arundo show greatly decreased native plant cover (Cushman, Gaffney 2010), with willows, cottonwoods and streamside shrubbery suffering the most. Many species of migratory songbirds including the threatened southwestern willow flycatcher and Bell's vireo require these native plants for feeding, nesting and cover (Humple, Geupel 2002). When Arundo invades their numbers decline. Additionally, native insects required by these songbirds for food no longer exist in sufficient numbers to sustain reproductive populations (Herrera and. Dudley 2003). In addition to impacts on wildlife food webs through trophic level simplication, Arundo is believed to have microclimate effects on stream temperature through reduction in shading. Leaf litter quality also decreases reducing food sources for aquatic invertebrates (Beerling, Dawah 1993). Aerial view of Arundo near Eagle Pass, Texas, along the Rio Grande Probability of Early Detection: Most regions of Oregon have active weed control programs, watershed councils, or Soil and Water Conservation Districts that are actively engaged in early detection of invasive species. Arundo is a large easily detected plant even in early stages of establishment. An informed public and weed professionals can readily identify and report this plant. Control: Control requires the killing or removal of the root -mass. Small populations of Arundo can be removed manually but care must be taken to completely remove all root fragments. Large-scale control programs require treatment with a systemic herbicide and appropriate timing to achieve effective control. The most effective treatment is a foliar application of glyphosate applied at 3-5% solution mid-August to early November prior to dormancy (Spencer et.al. 2008). Plant Pest Risk. Assessment, ODA Page 6 of 1. Large infestations covering many river miles present challenges and many methods of vegetation removal are employed with varying degrees of success; these include prescribed fire, heavy machinery, mowing and cutting. Control costs using glyphosate applications can reach $20,000 per hectare (Mack 2008). The United States Department of Agriculture -Agricultural Research Service (USDA -ARS) is investigating four insects as classical weed biological control agents. Each of the four attacks giant reed at a different place. The scale insect, Rhizaspidiotus donacis, attacks the root; the wasp Tetramesa romana attacks the main stem; the Arundo fly Cryptonevra spp. feeds the inside of the new shoots; and the leaf sheath miner, Lasioptera donacis, attacks the leaves. The Arundo wasp, was released in Texas in 2009, the first natural enemy to be employed against Arundo donax (Agriculture Research 2009). 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