YEAR ONE: Control of Brachypodium sylvaticum and Restoration of Rare Native Upland Prairie Habitat at Butterfly Meadows

Our project goal is to protect and restore rare Willamette Valley upland prairie habitat at Butterfly Meadows (Benton County) from invasion by the noxious weed Brachypodium sylvaticum (false brome).

Native prairies, which once dominated the landscape of the Willamette Valley, are considered among the rarest of Oregon’s ecosystems and are in critical need of conservation. One of the largest remaining parcels of native upland prairie, Butterfly Meadows (Benton County), is being invaded by Brachypodium sylvaticum. This site is one of the three most important remaining habitats for the Fender’s blue butterfly and Kincaid’s lupine, listed as Endangered and Threatened respectively. We propose to develop and implement herbicide treatments that control Brachypodium sylvaticum without harming native prairie vegetation. We will also develop and implement measures to reestablish native species from seed after removal of Brachypodium sylvaticum. Conifers and mature shrubs that have encroached on the meadow, both on the edge and in the complex, will be removed by mechanical means or girdling.

We propose to construct a buffer zone between the boundary of Butterfly Meadows and the neighboring intact forest and recently clear-cut areas, which are continuing sources of seed of Brachypodium sylvaticum invading Butterfly Meadows. This buffer zone will extend into both Starker Forest owned portions and OSU owned portions.

To determine the success of control of Brachypodium sylvaticum and woody species and restoration of native vegetation, we will monitor changes in abundance of Brachypodium sylvaticum, woody species, and native vegetation. We will use monitoring results to adjust future Brachypodium sylvaticum control measures and native vegetation restoration measures as needed.

This report describes the completion of the objectives applicable to phase one of this project:

Objective 2a Conduct pilot studies of herbicide control of Brachypodium sylvaticum and of potential adverse effects on native vegetation.

Objective 3 Conduct experimental studies of reestablishment of native species after removal of Brachypodium sylvaticum. Although objective 3 is part of phase two, scheduled for fall 2003, this report describes steps taken in preparation for its implementation in fall 2003 and spring 2004.

Objective 4 Remove encroaching woody species.

Objective 5a and 5b Construct buffer between Butterfly Meadows and source of Brachypodium sylvaticum propagules; Plant native species to replace Brachypodium sylvaticum in the buffer.

Objective 6c and 6d Monitor success of Brachypodium sylvaticum control in the buffer zone and the establishment of native species and adapt management strategies based on monitoring results; Monitor success of increasing abundance of Fender’s blue butterfly adults.