Research Projects

Completed Research

Regan DJ, Woodruff KJ, Davis AS. 2012. Propagation protocol for mountain huckleberry (Vaccinium membranaceum). Native Plants Journal 13(1):14-18.
We present some techniques for producing Vaccinium membranaceum Douglas ex Torr. (Ericaceae) from seeds in a container nursery. We use a novel container-to-container transplant system to grow robust seedlings to a marketable size sooner than was possible with past practices.

Woodruff KJ, Regan DJ, Davis AS. 2012. Propagation protocol for bigtooth maple (Acer grandidentatum Nutt.). Native Plants Journal 13(3):191-194.
We present our techniques for producing Acer grandidentatum Nutt. (Aceraceae) from seeds in a container nursery. Our combination of warm, moist treatment and stratification yields acceptable germination of 50%, and our use of Jiffy peat pellets allows us to reorganize plants by height during the 1-y growing season, which maximizes the number of deliverable seedlings.

Herriman KR & Davis AS. 2012. Cold Hardiness in Wyoming Big Sagebrush Seedlings: Implications for Nursery Production and Outplanting. Ecological Restoration, 30(2), 101-102.
Restoration of sagebrush ecosystems has only recently been emphasized due to the loss of increasingly valued native communities, but plant establishment has focused predominantly on direct seeding. Once established, Wyoming big sagebrush maintains a relatively high rate of persistence; however, seedling establishment can be erratic, and there have been numerous failures from direct seeding. Germination and establishment can be low due to seed quality, animal foraging, water stress, and inadequate light or temperature conditions.  Planting nursery-grown sagebrush seedlings could provide a more effective method of restoring sagebrush ecosystems, especially when cost and availability of locally adapted seeds are considered. Although the initial cost of planting with seedlings is higher than that of direct seeding, largely due to costs associated with nursery production and material, this strategy may prove to be more cost effective over time. Container seedlings have greater establishment success in cold, arid site conditions, while establishment on direct-seeded field sites can be unpredictable and uneven. We initiated a study to characterize the level of cold hardiness of Wyoming big sagebrush across a period of seedling production with the aim of improving overall seedling quality for restoration of degraded sites.

Kildisheva OA, Dumroese RK, and Davis AS. 2011. Overcoming dormancy and enhancing germination of Sphaeralcea munroana seeds. HortScience 46(12): 1672-1676.
The results of a series of experiments involving a variety of dormancy-breaking treatments indicate that Munro's globemallow [Sphaeralcea munroana (Douglas) Spach] seeds are physically dormant, possess a cap-like structure in the occlusion of the water gap, which inhibits imbibition, and can be artificially dislodged through boiling water scarification. The highest germination capacity (93%) was achieved by mechanical scarification of previously stored seeds. Exogenous application of a gibberellin solution and cold stratification failed to enhance germination compared with scarification alone, indicating an absence of additional dormancy types. These results should improve the usefulness of this drought-tolerant perennial for landscaping and restoration given its effectiveness in soil stabilization, tolerance to a variety of soil types, extreme temperatures, and ecological importance.