|MUNSON, SETH - Us Geological Survey (USGS)|
|BRADFORD, JOHN - Us Geological Survey (USGS)|
|BUTTERFIELD, BRADLEY - Northern Arizona University|
|GUNNELL, KEVIN - Utah Division Of Wildlife Resources|
Submitted to: Restoration Ecology
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 2/4/2019
Publication Date: 1/31/2019
Citation: Copeland, S.M., Munson, S.M., Bradford, J.B., Butterfield, B.J., Gunnell, K.L. 2019. Long-term plant community trajectories suggest divergent responses of native and non-native perennials and annuals to vegetation removal and seeding treatments. Restoration Ecology. 27(4):821-831. https://doi.org/10.1111/rec.12928.
Interpretive Summary: Vegetation management treatments (such as seeding and vegetation removal) are common across the intermountain US, yet their long-term impacts on plant communities are unclear due to lack of consistent widespread monitoring. We analyzed the effects of treatments, climate, and weather variability on plant community characteristics over time using a dataset of 491 sites with and without vegetation removal and seeding treatments across the state of Utah over a 20-year period. Our results suggest that community properties frequently targeted by management treatments, such as the amount of non-native annual cover and cover of native perennials, may take several years to decades to recover and are highly influenced by climate and weather variability. Managers may need to consider monitoring over time periods of 10 years or more, and including environmental variation, in assessments of vegetation response to treatments in this region.
Technical Abstract: Land managers frequently apply vegetation removal and seeding treatments to restore ecosystem function following woody plant encroachment, invasive species spread, and wildfire. However, the long-term outcome of these treatments is unclear due to a lack of widespread monitoring. We quantified how vegetation removal (via wildfire or management) with or without seeding and environmental conditions related to plant community composition change over time in 491 sites across the intermountain western United States. Most community metrics took over 10 years to reach baseline conditions post-treatment, with the slowest recovery observed for native perennial cover. Total cover was initially higher in sites with seeding after vegetation removal than sites with vegetation removal alone, but increased faster in sites with vegetation removal only. Seeding after vegetation removal was associated with rapidly increasing non-native perennial cover and decreasing non-native annual cover. Native perennial cover increased in vegetation removal sites irrespective of seeding and was suppressed by increasing non-native perennial cover. Seeding was associated with higher non-native and native species richness across the monitoring period as well as initially higher, then declining, total species richness. Several cover and richness recovery metrics were positively associated with mean annual precipitation and negatively associated with mean annual temperature, whereas relationships with weather extremes depended on the lag time and season. Our results suggest that key plant groups, such as native perennials and non-native annuals, respond to restoration treatments at divergent time-scales and with different sensitivities to climate and weather variation.