Long-term plant community dynamics following Russian olive removal and vegetation restoration

Authors: WONKKA, CARISSA - University Of Florida; McGranahan, Devan; Muscha, Jennifer; Branson, David; Campbell, Joshua; West, Natalie

Submitted to: Restoration Ecology
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 7/6/2025
Publication Date: 7/21/2025
Citation: Wonkka, C.L., McGranahan, D.A., Muscha, J.M., Branson, D.H., Campbell, J.W., West, N.M. 2025. Long-term plant community dynamics following Russian olive removal and vegetation restoration. Restoration Ecology. Article e70148. https://doi.org/10.1111/rec.70148.
DOI: https://doi.org/10.1111/rec.70148

Interpretive Summary: Russian olive is an invasive tree impacting riparian areas across the western United States. It is frequently removed as part of riparian restoration, but restoration success is not assured. Planting and seeding vegetation after removal is often thought necessary because the tree removal causes disturbance to the existing vegetation. We experimentally assessed the long-term impact of Russian olive removal and replanting native plants with different plant functional groups on rates of invasion and reinvasion and native plant cover. We found that planting and seeding treatments reduced perennial grass invasion, but did not provide invasion resistance against other invasive plants or enhance native shrub and tree cover. As such, unless the primary post-removal goal is preventing non-native perennial grass reinvasion, and not to increase native riparian woody species abundance or pollinator resources, our data suggest revegetation, especially planting native trees and shrubs, might not be worth the cost.

Technical Abstract: Eleagnus angustifolium (Russian olive) is a non-native tree invading riparian areas across the western United States. It is frequently the target of restoration through removal, but restoration success has been variable and reinvasion and secondary invasion can occur in restored areas. Revegetation following removal is often considered necessary to reduce secondary invasion because of the substantial soil disturbance involved with tree removal. We experimentally assessed the long-term impact of Russian olive removal and subsequent revegetation with different plant functional groups on ecological function in an invaded riparian ecosystem. We found that revegetation treatments reduced perennial grass invasion, but did not provide invasion resistance against other invasive plants or enhance native shrub and tree cover. As such, unless the primary post-removal goal is preventing non-native perennial grass reinvasion, but is instead to increase native riparian woody species abundance or pollinator resources, our data suggest revegetation, especially planting native trees and shrubs, might not be worth the cost.