Re-introducing fire in sagebrush steppe experiencing decreased fire frequency: Does burning promote spatial and temporal heterogeneity?

Authors: Davies, Kirk; Bates, Jonathan - Jon

Submitted to: International Journal of Wildland Fire
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 4/17/2020
Publication Date: 5/7/2020
Citation: Davies, K.W., Bates, J.D. 2020. Re-introducing fire in sagebrush steppe experiencing decreased fire frequency: Does burning promote spatial and temporal heterogeneity? International Journal of Wildland Fire. 29(8):686-695. https://doi.org/10.1071/WF20018.
DOI: https://doi.org/10.1071/WF20018

Interpretive Summary: Fire has been excluded from many shrub-steppe communities largely because of current management policies. Fire, however, can be important in these ecosystems. We measured plant community response to re-introducing fire for 12 years post-fire. Re-introducing fire created spatial and temporal heterogeneity in vegetation in mountain big sagebrush-steppe. This suggests that management may need to include infrequent fire to maintain a diversity of plant communities.

Technical Abstract: Fire frequency has decreased in many shrub-steppe communities. Re-introducing fire may be needed to increase spatial and temporal variability in vegetation, but is often hindered by concerns of undesirable vegetation shifts arising from a lack of information on long-term effects of re-introduction fire in these communities after prolonged fire exclusion and other departures from historic conditions. We evaluated plant community response to re-introducing fire for 12 years post-fire in six mountain big sagebrush (Artemisia tridentata Nutt. ssp. vaseyana (Rydb.) Beetle) communities experiencing prolonged fire exclusion. Herbaceous biomass production was greater in burned compared to unburned areas for most of the duration of the study. Exotic annual grasses appeared to be problematic in the first eight years post-fire, but became inconsequential by the end of the study. Re-introducing fire promoted other shrubs (shrubs excluding sagebrush) that were probably inhibited by competition from sagebrush. Sagebrush cover and density remained low in burned areas for the duration of the study, because of limited recruitment in the first couple of years post-fire and herbaceous competition. Re-introducing fire appears to increase temporal and spatial heterogeneity in shrub-steppe communities experiencing prolonged fire exclusion and thereby, may be needed to maintain a diversity of plant communities.