Attempting to restore mountain big sagebrush (Artemisia tridentata ssp. vaseyana) four years after fire

Authors: Davies, Kirk; Bates, Jonathan - Jon; HULET, APRIL - University Of Idaho

Submitted to: Restoration Ecology
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 1/10/2017
Publication Date: 9/28/2017
Citation: Davies, K.W., Bates, J.D., Hulet, A. 2017. Attempting to restore mountain big sagebrush (Artemisia tridentata ssp. vaseyana) four years after fire. Restoration Ecology. 25(5):717-722. https://doi.org/10.1111/rec.12505.
DOI: https://doi.org/10.1111/rec.12505

Interpretive Summary: Recovery of mountain big sagebrush after fire is a priority in western North America because of its value to wildlife. Seeding sagebrush can promote recovery, but is an additional cost that may not always be needed. Therefore, it may be beneficial to only seed after sagebrush recovery has been determined to be limited. We evaluated seeding sagebrush four years post-fire when sagebrush recovery was determined to be inadequate. Seeding sagebrush four years after fire did not accelerate sagebrush recovery. Seeded sagebrush likely failed to establish because of competition from herbaceous vegetation that had four years to increase after fire. Though it would be beneficial to only seeded sagebrush when needed, our results suggest postponing seeding until monitoring has determined that recovery is inadequate may not be advisable.

Technical Abstract: Restoration of shrubs is increasingly needed throughout the world because of altered fire regimes, anthropogenic disturbance, and over-utilization. The native shrub mountain big sagebrush (Artemisia tridentata Nutt. ssp. vaseyana (Rydb.) Beetle) is a restoration priority in western North America because of its value to wildlife. One of the principal threats to mountain big sagebrush is encroachment by western juniper (Juniperus occidentalis ssp. occidentalis Hook) and other conifers. Prescribed fire is frequently applied to control juniper, however, sagebrush recovery after fire can be variable. Seeding sagebrush after fire can hasten sagebrush recovery; however, seeding is not always necessary. Therefore, it may be advantageous to monitor post fire recovery to determine if seeding is needed. However, the effect of seeding sagebrush several years after fire is unknown. We evaluated seeding mountain big sagebrush four years after prescribed fire controlled junipers at five sites. Sagebrush cover (< 0.5%) and density (< 0.07 plants·m-2) was low in seeded plots and did not differ from unseeded controls in the three post-seeding years. We, therefore, conclude that seeding sagebrush four years after fire did not accelerate sagebrush recovery. Herbaceous vegetation was also similar between treatments. We speculate that seeded sagebrush failed to establish because of competition from herbaceous vegetation that had four years to recover after fire. Though it would be beneficial to only seed sagebrush when needed, our results suggest postponing seeding until monitoring has determined that recovery is inadequate may not be advisable. We suggest researchers investigate methods to improve predicting sagebrush recovery to allow for seeding, when needed, before the first post-fire growing season.