Seeding locally sourced native compared to introduced bunchgrasses post-wildfire in frigid Wyoming big sagebrush communities

Authors: Davies, Kirk; Boyd, Chad

Submitted to: Restoration Ecology
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 3/17/2021
Publication Date: 3/23/2021
Citation: Davies, K.W., Boyd, C.S. 2021. Seeding locally sourced native compared to introduced bunchgrasses post-wildfire in frigid Wyoming big sagebrush communities. Restoration Ecology. 29(5). Article e13397. https://doi.org/10.1111/rec.13397.
DOI: https://doi.org/10.1111/rec.13397

Interpretive Summary: There is widespread disagreement over seeding native compared to introduced bunchgrasses after fire in sagebrush communities to increase perennial grasses and decrease exotic annual grasses. We compared drill-seeding native and introduced bunchgrasses after wildfire in sagebrush communities. Seeding native and introduced bunchgrasses both increased bunchgrass abundance and cover, but bunchgrasses increased more with seeding introduced bunchgrasses. Introduced bunchgrasses also limited exotic annual grasses, but seeding native bunchgrasses did not. The results of this study will be useful to land managers, restoration practitioners, and rangeland scientists.

Technical Abstract: Perennial grasses are often seeded after disturbances to provide ecosystem services and prevent invasive plant dominance. However, there is widespread disagreement over the use of native compared to introduced grasses. In Wyoming big sagebrush (Artemisia tridentata Nutt. ssp. wyomingensis Beetle & A. Young) communities, introduced wheatgrasses are often seeded after wildfires because they are less expensive, more available, and establish better than widely available native species. However, locally sourced native bunchgrasses, which likely have adaptations to local conditions, have not been compared to introduced wheatgrasses. We compared drill-seeding locally sourced native bunchgrasses and introduced wheatgrasses after wildfire in frigid Wyoming big sagebrush communities for 3'years. Seeded native and introduced bunchgrasses both increased bunchgrass abundance and cover, even though precipitation was below average the first year post-seeding. Seeding introduced wheatgrasses, however, increased bunchgrass cover and abundance more than seeding native bunchgrasses. Seeding introduced wheatgrasses also limited exotic annual grass abundance and cover, but seeding locally sourced native bunchgrasses did not. Native bunchgrasses are slow growing, thus may limit exotic annual grasses in time. Alternatively, additional treatments, such as exotic annual grass control, may be needed to improve their success. The establishment of seeded native bunchgrasses in Wyoming big sagebrush in a below-average precipitation year is a promising result and suggests further research to improve seeded native vegetation success is warranted. The greater establishment of introduced wheatgrasses and their ability to limit exotic annual grasses suggests that successful introduced species may serve as a model for guiding trait selection in native species.