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ARS Home » Pacific West Area » Burns, Oregon » Range and Meadow Forage Management Research » Research » Publications at this Location » Publication #341710
Title: Evaluating a seed technology for sagebrush restoration across an elevation gradient: support for bet hedging

Author
item Davies, Kirk
item Boyd, Chad
item MADSEN, M - Brigham Young University - Idaho
item KERBY, J - Nature Conservancy
item HULET, A - University Of Idaho

Submitted to: Rangeland Ecology and Management
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 7/17/2017
Publication Date: 1/5/2018
Citation: Davies, K.W., Boyd, C.S., Madsen, M.D., Kerby, J., Hulet, A. 2018. Evaluating a seed technology for sagebrush restoration across an elevation gradient: support for bet hedging. Rangeland Ecology and Management. 71(1):19-24. https://doi.org/10.1016/j.rama.2017.07.006.
DOI: https://doi.org/10.1016/j.rama.2017.07.006

Interpretive Summary: Sagebrush restoration is needed across vast areas, especially after large wildfires, to restore important ecosystem services. We compared broadcast seeding seed pillows (a seed enhancement technology) with bare seed in two years across a burned elevation gradient. We found no evidence that seed pillows improved sagebrush establishment and growth compared to bare seed across the entire elevation gradient. Though our results suggest that seed pillows do not increase the likelihood of successful sagebrush restoration, they were successful at times when bare seed was not and vice-a-verse. This suggests that seeding both bare seed and seed pillows may be a better method to increase the probability of sagebrush restoration success, essentially bet hedging.

Technical Abstract: Big sagebrush (Artemisia tridentata Nutt.) restoration is needed across vast areas, especially after large wildfires, to restore important ecosystem services. Sagebrush restoration success is inconsistent with a high rate of seeding failures, particularly at lower elevations. Seed enhancement technologies may overcome limitations to restoration success. Seed pillows are one such technology designed to improve seed-soil contact in broadcast seedings by providing a favorable medium for seedling establishment and growth. Seed pillows have shown promising results in greenhouse studies; however, they have not been evaluated in the field. We compared broadcast seeding seed pillows with bare seed in two years across a large, burned elevation gradient. We found no evidence that seed pillows improved sagebrush establishment and growth across the elevation gradient compared to bare seed. Though our results suggest that seed pillows do not increase the likelihood of successful sagebrush restoration, they were successful at times when bare seed was not and the same was true for bare seed. One of the two treatments was successful at 50% of the elevations over the two seeding years. This suggests that seeding both bare seed and seed pillows may be a better method to increase the probability of success, essentially bet hedging. If both methods were used and seeding occurred in both years, success would have been 86%. Sagebrush density and cover varied by elevation. In the first year seeding, sagebrush density and cover generally increased with increasing elevation. In the second year seeding, sagebrush density and cover was greatest at the lowest and highest elevations. We speculate that at the lower elevations an unusually wet spring combined with limited herbaceous vegetation provided an ideal environment for sagebrush establishment and growth. Our results also demonstrate, counter to common assumptions, that lower elevations sagebrush seedings can be successful.