Cooperative Agreement F23AC02188

TALL WHITETOP (LEPIDIUM LATIFOLIUM), ALSO KNOWN AS PERENNIAL PEPPERWEED, IS A STATE LISTED NOXIOUS WEED THAT HAS INFESTED RIPARIAN FOREST, WETLANDS, AND WET MEADOWS IN PAHRANAGAT VALLEY, IN LINCOLN COUNTY, NEVADA. INVASIVE PLANTS AFFECT THE AMOUNT OF NATIVE FORAGE AVAILABLE BY OUTCOMPETING OR REPLACING NATIVE PLANTS. THIS IMPACTS WILDLIFE HABITAT AND POPULATIONS INCLUDING MULE DEER, ENDEMIC FISH, ENDANGERED BIRDS, AND MIGRATORY WATERBIRDS. IN ADDITION, TALL WHITETOP HURTS LOCAL ECONOMIES BY DEGRADING PRIVATE RANCH LANDS. IN PAHRANAGAT VALLEY, PRIVATE LANDS OCCUR UPSTREAM OF PAHRANAGAT NATIONAL WILDLIFE REFUGE. THE REFUGE RECEIVES ITS WINTER WATER RIGHTS THROUGH THE PAHRANAGAT DRAIN WHICH ALSO TRANSPORTS WEED SEEDS ONTO THE REFUGE. THE GOAL OF THIS PROJECT IS TO SUPPRESS THE GROWING INFESTATIONS OF TALL WHITETOP ON PRIVATE PASTURELAND AND WET MEADOWS UPSTREAM OF THE REFUGE. TREATMENTS WILL START ALONG THE PAHRANAGAT DRAIN, BETWEEN THE REFUGE AND THE TOWN OF ALAMO.ON THE REFUGE, THE ENDANGERED SOUTHWESTERN WILLOW FLYCATCHER (EMPIDONAX TRAILII EXTIMUS) BREEDS IN A COTTONWOOD AND WILLOW FOREST WHICH HAS BEEN DESIGNATED AS CRITICAL HABITAT. TALL WHITETOP HAS BECOME ESTABLISHED ADJACENT TO THIS FOREST, THREATENING ITS BIOLOGICAL INTEGRITY. IN ADDITION, IN THE MARSHES ON THE REFUGE, ENDANGERED YUMA RIDGEWAYS RAIL (RALLUS LONGIROSTRIS YUMANENSIS) ARE OCCASIONALLY DETECTED. THE RIPARIAN FORESTS, WET MEADOWS, AND PASTURES ON THE PRIVATE LAND, PROVIDE HABITAT FOR A VARIETY OF MIGRATORY BIRD SPECIES, INCLUDING LUCYS WARBLER (OREOTHLYPIS LUCIAE), SUMMER TANAGER (PIRANGA RUBRA), AND YELLOW WARBLER (SETOPHAGA PETECHIA). THE GOAL IS THAT BY AUGUST 2025, AT LEAST 80 ACRES OF TALL WHITETOP ON PRIVATE LANDS UPSTREAM OF THE REFUGE WILL RECEIVE TREATMENT WITH AN EFFECTIVENESS RATE OF 75-90 . THIS WILL HELP IMPROVE IMPORTANT CONSERVATION TARGETS ON THE REFUGE, BENEFITTING THE LISTED SPECIES AND MIGRATORY BIRDS THAT USE THIS HABITAT. TALL WHITETOP WILL BE TREATED WITH HERBICIDE BEFORE IT GOES TO SEED. THE OPTIMAL TIME TO TREAT WILL BE LATE SPRING OR EARLY SUMMER BEFORE THE MONSOON SEASON STARTS.OTHER PROJECT PARTNERS INCLUDE PAHRANAGAT NATIONAL WILDLIFE REFUGE AND THE PAHRANAGAT VALLEY COOPERATIVE WEED MANAGEMENT AREA. THE REFUGE OBTAINED INVASIVE SPECIES GRANT AND IS CONTRIBUTING FUNDS TO THIS PROJECT. THEY WILL ALSO BE TREATING 70 ACRES OF TALL WHITETOP ON THE REFUGE OVER THE NEXT SEVERAL YEARS. MEMBERS OF THE PAHRANAGAT VALLEY CWMA WILL HELP DETECT TALL WHITETOP ON PRIVATE LANDS IN THE VALLEY AND WILL WORK WITH LANDOWNERS TO GET THEM TO PARTICIPATE IN THE PROJECT AND TO SIGN LANDOWNER AGREEMENTS.