THE ANNUALIZATION OF PACIFIC NORTHWEST GRASSLANDS: IMPLICATIONS FOR ECOSYSTEM SERVICES

Grasslands in the western Pacific Northwest exist within a landscape largely dominated by agriculture and provide important ecosystem services including forage production, carbon storage, biodiversity, and pollinator services. Recent evidence suggests that climate change will facilitate a regime shift in these grasslands from their historically perennial-dominated state toward increasing exotic annual dominance. Such a regime shift could have widespread implications for the continued provisioning of key ecosystem services. The overarching goal of my proposed research isto understandthe ecosystem service implications of an annualization of PNW grasslands. An additional goal is to take a "translational ecology" approach toward this project, such that the right questions for stakeholders (i.e., farmers and ranchers) are asked and answered through the process. To achieve these goals, I will undertake the following objectives:I will conduct astudy at four natural grassland sites to identify how key ecosystem services vary with the degree of annual cover.I will conduct an experiment where I will identify whether grazing differentially affects ecosystem services provided byperennial versus annual pastures. I will use a "translational ecology" approach by working directly with a local farm to develop and tailor the grazing experiment to meet the farmer's interests and needs. For example, one of his objectives is to improve pollinator habitat and promote native biodiversity on his working lands, while maintaining an economically-viable pasture. Therefore, I will explore whether the addition of native seeds can be equally viable in the two pasture types and whether this could be used to offset some losses in ecosystem services.