WWETAC Projects

Project Title:  Threat assessment of non-native perennial grasses to the ecology and management of National Grasslands in the Northern Great Plains

Principal Investigator:   Jack L. Butler, USFS Rocky Mountain Research Station, Forest & Grassland Research Laboratory, Rapid City, SD

jackbutler[at]fs.fed.us

Collaborators:   Nebraska National Forests & Grasslands, Chadron, NE; Pawnee National Grasslands, Greeley, CO; Thunder Basin National Grassland, Douglas, WY; Dakota Prairie (Little Missouri National Grassland, Grand River National Grassland, Cedar River National Grassland, and Sheyenne National Grasslands), Bismarck, ND

Key Issues/Problem Addressed:                              

National Grasslands are large, diverse, and mostly intact native ecosystems that provide a wide variety of outputs and resource values.  Approximately 86% of the 3.8 million acres of National Grasslands are located within the Northern Great Plains States of CO, NE, WY, SD, and ND, and may represent the last, large tracts of native short- and mixed-grass prairie in the United States.  However, the structural and functional integrity of native grasslands are being threatened by intensive agriculture, urban and energy development, unmanaged recreation, and climate change. 

Invasive plants are some of the more common threats that pose distinctive challenges to the ecology and management of the National Grasslands. Because of the recognized ecological and economic impacts of invasive plants on natural ecosystems, several financial, logistical, technical, and legal mechanisms are often in place to manage invasive plant infestations.  In contrast, three relatively common, non-native perennial grass species (smooth brome, crested wheatgrass, and Kentucky bluegrass), widely sown for livestock forage or restoration in the Northern Great Plains grasslands, are generally not recognized as invasive in the United States.  However, a number of studies, primarily from researchers in Canada, document cases where these species have escaped cultivation, invaded native grasslands, and adversely impacted native species diversity. The collective evidence strongly indicates that these 3 non-native, perennial grasses have slowly and inexorably transformed relatively large tracts of Northern Great Plains native grasslands, and this transformation has largely gone unnoticed in the United States. 

Setting and Approach:  

The first step of Phase I will involve preparing a comprehensive literature review and synthesis on the biology, ecology, and management of smooth brome, Kentucky bluegrass, and crested wheatgrass in relation to northern Great Plains prairies.   Vegetation inventory and monitoring information with respect to these 3 species and their native constituents will be solicited from each National Grassland.  Finally, when appropriate, vulnerability assessments will be developed that describe how the natural/semi-natural/tame grassland matrix on the National Grasslands may be affected by projected changes in climate.  The main objective of Phase II (FY2013) of the proposed project is to expand coverage to include lands near and adjacent to the National Grasslands  and National Park Service lands.

Progress to Date:            

A draft version of the literature review on non-native perennial grasses is currently under review.

Impacts/Applications:  

The expected outcome will be research and management that is strategically focused on National Grasslands issues that may adversely impact the diversity, productivity, and sustainability of what may be the last, large tracts of native grasslands in the United States.

WWETAC ID:      FY11NG103