Understanding dominant factors related to non-native plant invasions into mountain environments are imperative for the development of effective conservation strategies in mountain ecosystems. Mountain environments are currently among the least invaded ecosystems, however, these biodiversity hotspots are increasingly under threat of exotic plant invasion. The objectives of this study were to identify important factors associated with non-native species distributions along elevation gradients, and to quantify the extent to which dominant non-native species composition was structured by geographic distance as opposed to environmental variation. We conducted a complete understory vascular plant survey in summer 2012 along three roads located in the Wallowa Mountain Range of northeastern Oregon. Non-native species were primarily concentrated at the low elevation sites with moderate to high disturbance levels, and species richness declined linearly with increasing elevation. Multivariate analyses indicated that elevation, disturbance, precipitation, and canopy openness were important correlates of non-native plant community structure. Distance from road (0-100m) had little influence on non-native plant distributions, indicating that potential road associated influences on non-native plant distributions extend at least 100 meters from roadsides. Environmental variation was more important than geographical distance for structuring non-native species composition. Collectively, these data suggest that future shifts in climate, and disturbance regimes are likely to influence the potential for established low elevation species to penetrate into higher elevation sites.
Oral presentation and poster titles, abstracts, and authors from the Society for Range Management (SRM) Annual Meetings and Tradeshows, from 2013 forward.