Sickleweed on the Fort Pierre National Grassland: An Emerging Threat

Authors

Jack L. Bulter, US Forest Service, Rocky Mountain Research Station, Forest and Grassland Research LaboratoryFollow
Stefanie D. Wacker, US Forest Service, Rocky Mountain Research Station, Forest and Grassland Research Laboratory

Date of this Version

6-2012

Document Type

Article

Citation

The Prairie Naturalist 45:28–38; 2013

Comments

Published by the Great Plains Natural Science Society. Used by permission.

Abstract

We report the first detailed field survey of sickleweed (Falcaria vulgaris L.) in the United States. Sickleweed is native to Europe, the Mediterranean, Asia Minor, and Iran and was first reported in the United States in 1922. It is listed by the Nebraska Invasive Species Council as a Category II invasive plant species. In recent years, abundance and distribution of sickle- weed has increased dramatically in and around the Fort Pierre National Grassland (FPNG), South Dakota. Management of such a rapidly expanding population is hampered by a general lack of baseline information on the biology and ecology of sickleweed. We used an environmental gradient approach to describe the abundance and distribution of sickleweed on the FPNG and found that sickleweed colonization and expansion may be largely driven by small and large scale disturbances that create gaps in ground cover (bare soil and total vegetative cover plus litter), reduced diversity (H’), and altered competitive relationships with western wheatgrass. Minimizing disturbances that create gaps in litter and vegetative cover, decrease diversity, increase bare soil, and alter the dominance of western wheatgrass may reduce the colonization and expansion of sickleweed.