Predictors of Plant Functional Traits in a Novel Ecosystem
Alexander Goetz1*, Anna A. Sher1, Annie L. Henry1, Eduardo González2
1Department of Biological Sciences, University of Denver, Denver, CO, USA; alexander.goetz23@du.edu
2Department of Biology, Colorado State University, Fort Collins, CO, USA
Understanding ecosystem changes due to the removal of invasive species require addressing not only taxonomic species composition but also ecosystem functioning via traits of individual plants. This proposed research explores how Tamarix spp. treatment, particularly biological control, impacts functioning of the surrounding plant community, specifically habitat for the endangered Southwestern willow flycatcher (Empidonax traillii extimus, abbr. SWFL). SWFL nesting habitat is associated with specific tree branching structures (a functional trait) and presence of water (an abiotic characteristic), not the presence of any particular species; it is as yet unknown whether restoration activities are producing such conditions. Our research asks: Which removal methods and site characteristics in formerly Tamarix dominated stands predict ecosystem function optimal for endangered bird habitat? To answer this question, I sampled specific leaf area (SLA; a trait correlated with several aspects of functional niche) and vertical biomass distribution (a coarse-scale proxy for branching structure) at 34 sites in Grand County, UT. Soil samples, geographic data and vegetation surveys were also collected at these sites. I found high variability in both SLA and vertical biomass distribution between sites and reaches. Comparison with the abiotic site condition variables showed a significant effect of soil electrical conductivity on vertical biomass distribution. Ecological function of novel ecosystems is particularly important in the context of evaluating land management outcomes; further results from this study seek to improve our understanding of the functional trajectory of degraded environments after restoration activity has occurred. Models constructed from our findings will seek to predict factors influencing desirable traits post-restoration, which will continue to be of high importance for SWFL management as climate change causes shifts in species ranges.