RUSSIAN OLIVE HAS SIMILAR GROWTH AND NODULATION RESPONSES AS OTHER ACTINORHIZAL SPECIES TO SOIL N AND LIGHT
The invasive exotic tree, Russian olive ( Elaeagnus angustifolia ) elevates soil N concentrations, is associated with higher exotic plant cover underneath its canopy, and has the potential to form self-replicating stands that prevent cottonwood regeneration. Additionally, it fills a previously unoccupied niche in western riparian ecosystems because it can recruit and grow in the shaded conditions found underneath cottonwood canopy. Russian olive’s tolerance to low light availability and high soil N concentration is unusual for actinorhizal species. To elucidate if Russian olive symbiosis with actinobacteria is less influenced by light availability and soil N concentrations than other actinorhizal species, we conducted a greenhouse study comparing Russian olive growth and nodulation to 3 Alnus and 2 other Elaeagnus species (all actinorhizal) across a gradient of shading and substrate N concentrations. We hypothesized that Russian olive nodulation, N fixation, and growth would be more tolerant to shading than these other species. Contrary to our expectations, Russian olive performed similarly to the other species, suggesting that differences in in the ability to fix atmospheric N in low light conditions do not explain its ability to invade areas underneath cottonwood canopies.
Graham Tuttle (Primary Presenter/Author), Colorado State University, firstname.lastname@example.org;
Gabrielle Katz ( Co-Presenter/Co-Author), Metropolitan State University of Denver, email@example.com;
Andrew Norton ( Co-Presenter/Co-Author), Colorado State University, firstname.lastname@example.org;