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ARS Home » Pacific West Area » Burns, Oregon » Range and Meadow Forage Management Research » Research » Publications at this Location » Publication #354113
Title: Herbaceous biomass response to prescribed fire in juniper-encroached sagebrush steppe

Author
item Bates, Jonathan - Jon
item Davies, Kirk
item BOURNOVILLE, JUSTIN - Us Forest Service (FS)
item Boyd, Chad
item O'CONNOR, RORY - Kansas State University
item SVEJCAR, TONY - Oregon State University

Submitted to: Rangeland Ecology and Management
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 8/8/2018
Publication Date: 1/9/2019
Citation: Bates, J.D., Davies, K.W., Bournoville, J., Boyd, C.S., O'Connor, R., Svejcar, T.J. 2019. Herbaceous biomass response to prescribed fire in juniper-encroached sagebrush steppe. Rangeland Ecology and Management. 72(1):28-35. https://doi.org/10.1016/j.rama.2018.08.003.
DOI: https://doi.org/10.1016/j.rama.2018.08.003

Interpretive Summary: The increase in piñon-juniper reduces forage and browse for livestock and big-game. We measured herbaceous standing crop and yield by life-form in two mountain big sagebrush communities (MTN1, MTN2) and a Wyoming/basin big sagebrush (WYOBAS) community for 6 years following prescribed fire treatments to control western juniper. Forage availability for livestock and wild ungulates more than doubled. The additional forage provided on burned areas afford managers with greater flexibility to rest and treat additional sagebrush steppe where juniper is expanding as well as rest or defer critical seasonal habitat for wildlife such as sage grouse.

Technical Abstract: Western juniper (Juniperus occidentalis Hook.) has expanded and infilled in sagebrush steppe plant communities the past 130 to 150 years in the northern Great Basin. The increase in juniper reduces forage and browse for livestock and big-game. We measured herbaceous standing crop and yield by life-form in two mountain big sagebrush communities (MTN1, MTN2) and a Wyoming/basin big sagebrush (WYOBAS) community for 6 years following prescribed fire treatments to control western juniper. Lifeforms were Sandberg’s bluegrass (Poa secunda J. Presl), perennial bunchgrasses, cheatgrass (Bromus tectorum L.), perennial forbs, and annual forbs. Perennial forbs were further sorted into mat forming forbs and tall forbs. MTN1 and WYOBAS communities were rated as early-successional (phase 1) and MTN2 communities were rated as mid-successional (phase 2) woodlands prior to treatment. Prescribed fires killed all juniper and sagebrush in the burn units. Total herbaceous and perennial bunchgrass yields increased 2 to 2.5-fold compared to unburned controls. Total perennial forb yield did not differ between burn treatments and controls in all 3 plant communities. Tall perennial forb yield was 1.6 and 2.5-fold greater in the WYOBAS and MTN2 burned sites than controls. Mat forming perennial forb yields declined by 80 to 90 % after burning compared to controls. Cheatgrass yield increased in the burned WYOBAS and MTN2 communities and at the end of the study represented 10 and 22% of total yield, respectively. Annual forbs increased and were mainly comprised of native species on the MTN1 and MTN2 communities and non-native species on the WYOBAS community. Forage availability for livestock and wild ungulates more than doubled. The additional forage provided on burned areas afford managers with greater flexibility to rest and treat additional sagebrush steppe where juniper is expanding as well as rest or defer critical seasonal habitat for wildlife such as sage grouse.