Glinka, Clare B , Chai, Tzu , Hawkes, Christine V. .
Invasion Legacies Impede Restoration of Ecosystem Processes.
The impacts of invasive plants can persist beyond their removal through persistent effects on soil microbial communities and ecosystem processes. These invasion legacies can impede restoration efforts at both the community and ecosystem level. In abandoned pastures in central Florida, we experimentally removed vegetation from areas dominated by two non-native grasses. These were compared to nearby intact native shrubland sites representing the former vegetation of the converted pastures and our current restoration target. We focused on how invasion legacies affect the recovery of ecosystem processes and their microbial drivers. To this end, we followed both soil biogeochemistry and soil microbial communities. For biogeochemistry, we tracked pools of carbon and nitrogen in soil and soil microbial biomass. We found that, over two years, both soil carbon and nitrogen remain elevated by >30% in previous pasture soils, regardless of invasive species removal. Microbial biomass carbon and nitrogen were also up to three times higher in invaded sites than in the native shrubland. For microbes, we tracked the abundance and composition of the main components of the biological soil crusts that dominate the soil surface in these sites: algae, cyanobacteria and fungi. Algae were more abundant in sites with higher soil moisture and a lower ratio of C:N in microbial biomass. In contrast, fungi were more abundant in sites with a higher ratio of C:N in microbial biomass. The abundance of cyanobacteria was generally more similar across the native and pasture sites, suggesting different drivers compared to algae and fungi. Based on our preliminary DNA-based characterization of these microbial communities, composition also differs among the restoration treatments with strong dissimilarity among former pastures and native sites. Biogeochemical resilience in these sites may depend on our ability to restore microbial drivers, which may require active management.
Log in to add this item to your schedule
1 - University of Texas at Austin, Section of Integrative Biology, 1 University Station, Austin, TX, 78705
Presentation Type: Poster:Posters for BSA Sections
Location: Event Tent/Cliff Lodge
Date: Tuesday, July 28th, 2009
Time: 5:30 PM