Potential for post-fire recovery of greater-sage-grouse habitat

Authors: RIGINOS, CORINNA - Nature Conservancy; Monaco, Thomas; VEBLEN, K. - Utah State University; GUNNELL, KEVIN - Utah Division Of Wildlife Resources; THACKER, ERIC - Utah State University; DAHLGREN, DAVID - Utah State University; MESSNER, TERRY - Utah State University

Submitted to: Ecosphere
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 7/22/2019
Publication Date: 11/1/2019
Citation: Riginos, C., Monaco, T.A., Veblen, K.E., Gunnell, K., Thacker, E., Dahlgren, D., Messner, T. 2019. Potential for post-fire recovery of greater-sage-grouse habitat. Ecosphere. 10(11). https://doi.org/10.1002/ecs2.2870.
DOI: https://doi.org/10.1002/ecs2.2870

Interpretive Summary: In the Western United States, fire has become a significant concern in the management of big sagebrush (Artemisia tridentata Nutt.) ecosystems. This is largely due to large-scale increases in cover of the fire-prone invasive annual cheatgrass (Bromus tectorum L.) and concurrently, concerns about declining quantity and quality of habitat for the declining Greater Sage-grouse (Centrocercus urophasianus). The prevailing paradigm is that fire results in a loss of sage-grouse habitat on time scales relevant to management (i.e., 1-20 yrs), since sagebrush cover can take many more years to recover post-fire. However, fire can have effects that improve sage-grouse habitat, including stimulating perennial grass and forb production. The conditions under which fire results in the permanent loss or enhancement of sage-grouse habitat are not well-understood. We used long-term data from the Utah Division of Wildlife Resources Range Trend Project to assess short-term (1-4 year post-treatment) and long-term (6-10 years post-treatment) effects of fire on 16 sites' vegetation cover attributes relative to sage-grouse habitat vegetation guidelines. Sagebrush cover remained low post-fire at sites considered unsuitable for sage-grouse (<10%, initial sagebrush cover). In contrast, sagebrush cover decreased to <10% in the short-term post-fire at sites that had higher (>10%) pre-fire sagebrush cover, but by 6-10 years after fire most of these sites exhibited a recovering trajectory and two sites had recovered to >10% cover. Post-fire sagebrush cover was positively related to elevation. Across all sites, average perennial grasses and forbs increased in cover to approximately the habitat vegetation guidelines for sage-grouse. Cheatgrass cover did not change in response to fire, and increased perennial grass cover appears to have played an important role in suppressing cheatgrass. Our results indicate that, while fire poses a potential risk for sage-grouse habitat loss and degradation, burned sites do not necessarily need to be considred permanently altered, epecially if they are located at higher elevation with high sagebrush cover pre-fire and are reseeded with pernnial grasses and forbs post-fire to suppress annual grasses. However, our results confirm that fire at more degraded sites; e.g., those with <10% sagebrush cover, can result in cheatgrass-dominated landscapes and should be avoided.

Technical Abstract: In the Western United States, fire has become a significant concern in the management of big sagebrush (Artemisia tridentata Nutt.) ecosystems. This is largely due to large-scale increases in cover of the fire-prone invasive annual cheatgrass (Bromus tectorum L.) and, concurrently, concerns about declining quantity and quality of habitat for the declining Greater Sage-grouse (Centrocercus urophasianus). The prevailing paradigm is that fire results in a loss of sage-grouse habitat on time scales relevant to management (i.e., 1-20 yrs), since sagebrush cover can take many more years to recover post-fire. However, fire can have effecs that improve sage-grouse habitat, including stimulating perennial grass and forb production. The conditions under which fire results in the permanent loss or enhancement of sage-grouse habitat are not well-understood. We used long-term data from the Utah Division of Wildlife Resources Range Trend Project to assess short-term (1-4 year post-treatment) and long-term (6-10 years post treatment) effects of fire on 16 sites' vegetation cover attributes relative to sage-grouse habitat vegetation guidelines. Sagebrush cover remained low post-fire at sites considered unsuitable for sage-grouse (<10%, initial sagebrush cover). In contrast, sagebrush cover decreased to <10% in the short-term post-fire at sites that had higher (>10%) pre-fire sagebrush cover, but by 6-10 years after fire most of these exhibited a recovering trajectory and two sites had recovered to >10% cover. Post-fire sagebrush cover was positively related to elevation. Across all sites, average perenial grasses and forbs increased in cover to approximately the habitat vegetation guidelines for sage-grouse. Cheatgrass cover did not change in response to fire, and increased perennial grass cover appears to have played an important role in suppressing cheatgrass. Our results indicate that, while fire poses a potential risk for sage-grouse habitat loss and degradation, burned sites do not necessarily need to be considred permanently altered, especially if they are located at higher elevation with high sagebrush cover pre-fire and are reseeded with perennial grasses and forbs post-fire to suppress annual grasses. However, our results confirm that fire at more degraded sites; e.g., those with <10% sagebrush cover, can result in cheatgrass-dominated landscapes and should be avoided.