Rangeland Ecology & Management

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INTERACTIONS BETWEEN VENTENATA DUBIA AND FIRE IN THE PACIFIC NORTHWEST BUNCHGRASS PRAIRIE.
Author
Perren, JoAnna
Morris, Lesley
Endress, Bryan A.
Taylor, Robert V.
Averett, Josh
Naylor, Bridgett
Publisher
Society for Range Management
Publication Year
2016
Body

Ventenata dubia is a relatively new invasive annual grass to the Intermountain West that has spread rapidly across seven western states (CA, OR, ID, WY, WA, UT, MT). Fire has a well-documented connection to the spread and increase of other annual species, such as cheatgrass, but the invasion dynamics between V. dubia and fire are unstudied. Our overall objective in this study was to examine the relationship of fire with the spread of V. dubia in the Pacific Northwest Bunchgrass Prairie. Given the influence of fire on the spread and increase of other annual grasses in the region (e.g., cheatgrass), we expected that fire would also assist V. dubia in similar ways. To test this idea, we resurveyed 77 plots across the Zumwalt Prairie Preserve where frequency and cover of V. dubia had been recorded in 2008. Twelve of these plots were known to have burned in the last 15 years. We then asked if V. dubia had increased across all sites between 2008 and 2015, if it had increased more in sites that had burned versus unburned sites over the 7 years, and if there was more V. dubia on burned or unburned sites in 2008 or 2015. We found that frequency of V. dubia had doubled and cover had also significantly increased across all of our plots over the 7 years regardless of whether or not they had burned. Likewise, fire did not significantly effect frequency or cover of V. dubia between burned and unburned plots within the same year. Our findings suggest that fire is not a driving factor in the spread and increase of V. dubia in this region and that it can continue to invade in the absence of wildfire as a disturbance.

Language
English
Resource Type
Text
Document Type
Conference Proceedings
Conference Name
SRM Corpus Christi, TX