Previous research funded by the Great Basin Native Plant Project found that bluebunch wheatgrass (Pseudoroegneria spicata) populations differed in traits important for adaptation to precipitation and temperature (St. Clair et al. 2013). From this work, 11 seed zones were delineated for the Interior Northwest including the Great Basin, Snake River Plain, Columbia Plateau, and Blue Mountains (St. Clair et al. 2013).
Forest Service scientists and their partners are investigating the efficacy of these seed zones by comparing differences in establishment, survival, and reproduction of bluebunch wheatgrass populations from local seed zones compared to non-local seed zones. We hypothesize that in the long-term, populations from local seed zones will better establish, survive, and reproduce than those from non-local seed zones.
Evaluate adaptation (i.e., establishment, survival, growth, and reproduction) of bluebunch wheatgrass populations from local seed zones relative to non-local seed zones.
Model adaptation as a function of source location and common garden climates.
Characterize traits and climatic factors important for adaptation.
Model effects of climate change on native populations and consequences of assisted migration for responding to climate change.
The results of this study will help land managers determine sources of bluebunch wheatgrass populations for post-fire restoration of an area. Population movement guidelines and associated seed zones can be adjusted based on results from this study and management objectives.
This study will also explore the consequences of changing climates for adaptation by substituting space for time to evaluate different populations in different climates. Results from this portion of the study will aid land managers in maintaining and restoring areas considering future climate changes. Long-term productivity and adaptation will be modeled to allow evaluation of trade-offs between different management options for current and future climates.
Scientists established a reciprocal transplant study in two broad regions each with eight seed zones and four to five wild populations from each seed zone. The two broad regions include: (1) a transect spanning the hot, dry climates of the lower Snake River Plain to the cool, somewhat wet climates of the transverse ranges of the Great Basin to the cold, dry climates of the upper Snake River Plain, and (2) a transect spanning the hot, dry climates of the Columbia Plateau to the cool, wet climates of the Blue Mountains to the cold, dry climates east of the Blue Mountains.
Eight common gardens were established in each transect with climate representative of the local seed zone. Each common garden was planted with bluebunch wheatgrass from each seed zones within the two regions along with one widely used variety and one selected germplasm. Common gardens will be managed to control weeds so establishment can be largely a function of local climate rather than differences among test sites in competing vegetation.
In the spring and summer of 2015 and 2016, monitoring and data collection for each of the 16 common gardens will occur. In the spring, plant survival, reproductive phenology, occurrence of herbivory, and presence of fungus will be recorded at each common garden. Weather data loggers will be placed at each common garden to record local temperature during the course of the study.
At each common garden, plant survival and reproduction will be recorded along with occurrence of herbivory and presence of fungus. Crown width, a measure of plant size, biomass, leaf width, and seeds per reproductive stalk will be measured for each plant. These measurements will be repeated in 2016 and continue for an indefinite length of time. Reporting of early results will be presented after the first two growing seasons (2015 and 2016).
St. Clair, J.B.; Kilkenny, F.F.; and Shaw, N.L. 2014. Progress on establishment of reciprocal transplant tests to study adaptation of bluebunch wheatgrass. Great Basin Native Plant Annual Meeting; 2014 March 17-18; Boise, ID. Presentation.
St. Clair, J.B.; Kilkenny, F.F.; and Shaw, N.L. 2014. Testing the efficacy of seed zones for bluebunch wheatgrass. Great Basin Native Plant Project Annual Meeting; 2014 March 17-18; Boise, ID.
St. Clair, J.B. 2014. Development and use of seed zones to ensure adapted plant materials for restoration: Introduction. Society of Ecological Restoration Regional Conference, Northwest and Great Basin Chapters; 2014 October 6-10; Redmond, OR.