WELD COUNTY WEED MANAGEMENT PLAN

Transcription

1 WELD COUNTY WEED MANAGEMENT PLAN INTRODUCTION Weeds are plants that cause economic or ecological damage in both croplands and rangelands, create health problems for humans or animals, crowd out native vegetation, are undesirable where they are growing, and are generally difficult to control or eradicate. These include noxious, invasive, and pest species (Adams County 2015, USFWS 2013, Weld County Government 2019). Weeds are easily spread through seeds or other regenerative plant parts and are notoriously successful generalists in a variety of macro and micro ecosystems (Petit and Fried 2012, USFWS 2013). The spread of weeds can be attributed to numerous avenues, including construction. Construction projects are known to increase infestation by creating areas of disturbed ground where weeds thrive through movement of contaminated equipment and vehicles, and by increasing access for contaminated people and animals across uncontaminated lands (USFWS 2013). The pervasiveness of weeds across the United States and their deleterious effects on resources has encouraged government regulation as well as construction weed-control practices. (RMM) is developing natural gas pipeline projects throughout northeastern Colorado and in Weld County. The pipeline projects typically require trenching or boring and include supporting pipeline infrastructure. Development often includes access roads, bore pull back areas, and additional work spaces as needed. RMM will typically seek a 50-foot permanent rights-of-way (ROW) with an additional 30-foot temporary construction ROW for construction access. Pipelines and the associated infrastructure have been designed to minimize new disturbance by placement adjacent to roadways and other existing linear utility ROWs. RMM is committed to eliminating the introduction of weeds and preventing the spread of weeds along pipeline ROWs within Weld County and other Colorado counties. In order to minimize noxious and other weeds regulated by the Colorado Noxious Weed Act of 1990 supported by the Weld County Weed Division Tasks and Platte Invasives Endeavor (PIE) Plan of 2008, this (WMP) provides general information and documents the process used to identify, assess, and minimize the spread of noxious and other weeds before, during, and after pipeline installation. DESIGNATED WEED SPECIES The State of Colorado lists 78 noxious and/or invasive weed plant species (State of Colorado 2018). Colorado weed species, including those in Weld County, are separated by pervasiveness near the bottom of this WMP. Colorado statewide List A species are designated by the Commissioner for eradication. There are 25 List A species. Colorado statewide List B weed species are species for which the Commissioner, in consultation with the state noxious weed advisory committee, local governments, and other interested parties, develops and implements state noxious weed management plans designed to stop the continued spread of these species. There are 37 List B species. 1

2 Colorado statewide List C weed species are species for which the Commissioner, in consultation with the state noxious weed advisory committee, local governments, and other interested parties, will develop and implement state noxious weed management plans designed to support the efforts of local governing bodies to facilitate more effective integrated weed management on private and public lands. The goal of such plans will not be to stop the continued spread of these species but to provide additional education, research, and biological control resources to jurisdictions that choose to require management of List C species. There are 16 List C species. WELD COUNTY NOXIOUS WEEDS Weld County Weed Division is tasked to educate the public, mow and spray, and ensure that all landowners in Weld County control the designated noxious weeds on their property. Weld County weed species designated as noxious are; Absinth wormwood (Artemisia absinthium), black henbane (Hyoscyamus niger), bull thistle (Cirsium vulgare), Chinese clematis (Clematis orientalis), common mullein (Verbascum thapsus), dalmation toadflax (Linaria spp.), dames rocket (Hesperis matronalis), houdstongue (Cynoglossum officinale), leafy spurge (Euphorbia esula), musk thistle (Carduus nutans), myrtle spurge (Euphorbia myrsinites), Russian knapweed (Acroptilon repens), Scotch thistle (Onopordum acanthium), and yellow nutsedge (Cyperus esculentus; Weld County 2019). INVASIVE WEED SPECIES PLANNING, PREVENTION, AND MONITORING The Weld County Weed Management Team (WMT) will be consulted during the planning phase of the pipeline prior to construction. This consultation will help to inform RMM of best management practices for weed planning, spread prevention, and monitoring. In addition to measures recommended by the Weld County WMT, prior to construction, RMM will complete the following tasks. Educate and train contractor personnel on weed occurrence, identification, infestation pathways, and mitigation. Design a site footprint avoiding unnecessary soil disturbance where possible. Use methods that prevent weed colonization by minimizing exposure to seed dispersal vectors and susceptibility to infestation during on-site inspection. Conduct soil and vegetation assessments. Treat all noxious weeds and invasive species. Dispose of contaminated objects according to recommendations by the WMT. In addition to measures recommended by the Weld County WMT, during to construction, RMM will do the following. Post weed awareness messages at strategic locations so that they are visible to all workers. Minimize soil disturbance where possible. Prevent weed germination and establishment by retaining native vegetation around the site. Locate and use weed-free staging areas. 2

3 Ensure equipment remains free of noxious weed seeds/propagules when entering the construction area or moving between locations of known infestation by avoiding these locations and/or regularly washing/brushing down equipment. Accept only certified weed-free materials and inspect seed, straw, mulch (including wattles, straw bales, dams, etc.), and gravel. Maintain topsoil stockpiles in a weed-free condition through treatment and use of sterile and/or desired native cover crops. Treat all noxious weeds and invasive species. Dispose of contaminated objects according to recommendations by the WMT. In addition to measures recommended by the Weld County WMT, post-construction, RMM will do the following. Treat all noxious weeds and invasive species. Dispose of contaminated objects according to recommendations by the WMT. Revegetate with a diversity of native grasses and simple forbs. Seed mixtures used will be prescribed by the surface landowner and/or at the recommendation of the Weld County WMT. Maintain topsoil stockpiles in a weed-free condition through treatment and use of sterile and/or desired native cover crops. Accept only certified weed-free materials and inspect seed, straw, mulch (including wattles, straw bales, dams, etc.), and gravel. Incorporate field-wide vegetation monitoring by trained, knowledgeable personnel. Monitor disturbed areas annually. Conduct monitoring in late spring to assess new germination and allow for immediate response. Determine a plan of action based on evaluation status. Document species and size of infestations. INVASIVE WEED SPECIES CONTROL ACTIONS Noxious weeds and invasive non-desirable species will be controlled along all pipelines and associated project areas. Vegetation monitoring by trained personnel (detection and analysis) during all project phases and pre-construction consultation with the Weld County WMT will dictate the control measures required for the project. Control actions under consideration include the following. Spraying activities Chemical selection will be based on documented success of specific species and recommendation by the WMT. All chemicals will be applied according to label directions to ensure environmental safety, chemical efficacy, and cost-effective treatment. Spraying will start in late spring after target weeds are large enough and temperatures are conducive for effective control herbicide uptake and continue until all project locations are effectively treated. Treated sites will be monitored for effectiveness and reapplication administered where and when required based on monitoring reports. Completion of treatment is expected by late summer prior to onset of viable plant seeding. Bare ground application Bare ground will be maintained around equipment and facilities to control weeds and prevent fire hazards. All chemicals will be applied according to label directions 3

4 to ensure environmental safety, chemical efficacy, and cost-effectiveness. Bare ground control measures will begin in early spring after snow melt and continue until all sites are effectively treated, no later than late spring. Designated Colorado Noxious Weed Species Common Name Scientific Name Recommended Control Measure Class A (25) African rue Peganum harmala Herbicide, may use physical removal Bohemian knotweed Polygonum x bohemicum Camelthorn Alhagi maurorum Immediate removal, herbicide Common crupina Crupina vulgaris Herbicide Cypress spurge Euphorbia cyparissias Constant physical removal, maybe herbicide Dyer's woad Isatis tinctoria Constant physical removal, maybe herbicide Elongated mustard Brassica elongata Herbicide, may use physical removal Flowering rush Butomus umbellatus Herbicide, may use physical removal Giant knotweed Polygonum sachalinense Giant reed Arundo donax Herbicide, may use physical removal Giant salvinia Salvinia molesta Constant physical removal, herbicide Hairy willow herb Epilobium hirsutum Hydrilla Hydrilla verticillata Herbicide Japanese knotweed Polygonum cuspidatum Physical removal Meadow knapweed Centaurea nigrescens Physical removal Mediterranean sage Salvia aethiopis Medusahead Taeniatherum caputmedusae Myrtle spurge Euphorbia myrsinites Herbicide, may hand pull small infestations Orange hawkweed Hieracium auranatiacum Herbicide, may hand pull small infestations, push out with grasses Parrrotfeather Myriophyllum aquaticum Herbicide, may use physical removal Purple loosestrife Lythrum salicaria Rush skeletonweed Chodrilla juncea Constant hand pulling, no tilling or mowing, herbicide Squarrose knapweed Centaurea virgata Tansy ragwort Senecio jacobaea Hand pulling, herbicide Yellow star-thistle Centaurea solstitialis Physical removal, herbicide, prescribed burning Class B (37) Absinth wormwood Artemisia absinthium Herbicide, may use physical removal Black henbane Hyoscyamus niger Herbicide, may use physical removal Bouncingbet Saponaria officinalis Herbicide, may use physical removal Bull thistle Cirsium vulgare Herbicide, may use physical removal Canada thistle Cirsium arvense Herbicide, may use physical removal Chinese clematis Clematis orientalis Herbicide, may use physical removal Common tansy Tanacetum vulgare Herbicide, may use physical removal Common teasel Dipsacus fullonum Herbicide, may use physical removal Corn chamomile Anthemis arvensis Herbicide, may use physical removal Cutleaf teasel Dipsacus laciniatus Dalmatian toadflax, broadleaved Linaria dalmatica 4

5 Common Name Scientific Name Recommended Control Measure Dalmatian toadflax, narrowleaved Linaria genisitifolia Dame's rocket Hesperis matronalis Diffuse knapweed Centaurea diffusa Herbicide, may use physical removal Eurasian watermilfoil Myriophyllum spicatum Hoary cress Cardaria draba Houndstongue Cynoglossum officinale Jointed goatgrass Aegilops cylindrica Physical removal, herbicide, prescribed burning Leafy spurge Mayweed chamomile Euphorbia esula Anthemis cotula Moth mullein Verbascum blattaria Herbicide, may use physical removal Musk thistle Carduus nutans Herbicide, may use physical removal Oxeye daisy Leucanthemum vulgare Perennial pepperweed Lepidium latifolium Constant hand pulling, no mowing, herbicide required long-term Plumeless thistle Carduus acanthoides Constant hand pulling, no tilling or mowing, herbicide Russian knapweed Acroptilon repens Herbicide, may use physical removal Russian olive Elaeagnus angustifolia Saltcedar Tamarix spp. Herbicide, may use physical removal, flooding Scentless chamomile Tripleurospermum perforatum Herbicide, may use physical removal Scotch thistle Onopordum tauricum Herbicide, may use physical removal Spotted knapweed Centaurea stoebe Herbicide, may use physical removal Spotted x diffuse knapweed hybrid Centaurea x psammogena = C. stoebe x C. diffusa spp. micranthos Herbicide, may use physical removal Sulfur cinquefoil Potentilla recta Constant hand pulling, no tilling or mowing, herbicide Wild caraway Carum carvi Constant hand pulling, no tilling or mowing, herbicide Yellow nutsedge Cyperus esculentus Yellow toadflax Linaria vulgaris Herbicide, may use physical removal Yellow x Dalmatian toadflax hybrid Class C (16) Linaria vulgaris x L. dalmatica Bulbous bluegrass Poa bulbosa Chicory Cichorium intybus Common burdock Arctium minus Common mullein Verbascum thapsus Herbicide, may use physical removal Common St. Johnswort Hypericum perforatum Constant hand pulling, no tilling or mowing, herbicide Downy brome/cheatgrass Bromus tectorum Constant hand pulling or mowing, herbicide required longterm Field bindweed Convolvulus arvensis Halogeton Halogeton glomeratus Johnsongrass Sorghum halepense Herbicide, may use physical removal Perennial sowthistle Sonchus arvensis Tilling, hand pulling, sparing use of herbicide Poison hemlock Conium maculatum Physical removal and/or herbicide Puncturevine Tribulus terrestris Physical removal, may use herbicide Quackgrass Elymus repens Redstem filaree Erodium cicutarium Physical removal, may use herbicide 5

6 Common Name Scientific Name Recommended Control Measure Velvetleaf Abutilon theophrasti Herbicide, may use physical removal Wild proso millet Panicum miliaceum Source: State of Colorado 2017, USDA

7 REFERENCES Adams County Noxious Weeds. Available online at: Accessed January 15, Petit, S., & Fried, G Patterns of weed co occurrence at the field and landscape level. Journal of Vegetation Science, 23(6), U.S. Department of Agriculture (USDA) Field Guide for Managing Annual and Biennial Invasive Weeds in the Southwest. Available online at: Accessed January 15, U.S. Fish and Wildlife Service (USFWS) Weeds. Available online at: Accessed January 15, Weld County Government Weed Management. Available online at: Accessed January 15,