Ongoing recovery of native ant assemblages following landscape-scale removal of the non-native Argentine ant from Santa Cruz Island, California
Neil Tsutsui, Professor
Environmental Science, Policy and Management
Applications for Fall 2024 are closed for this project.
The experimental removal of introduced species can provide unparalleled opportunities to examine community reassembly. Invader-removal experiments, for example, can clarify how recovery is influenced by processes acting within a given system or alternatively reflects processes acting at larger spatial scales. Despite the obvious value of such studies, surprisingly few examine recovery above the level of single-species populations. Introduced ants can displace native ant species, but no long-term, large-scale removal experiment has ever been performed to test how native ant communities reassemble after the removal of numerically and behaviorally dominant introduced ants.
Here we report on the ongoing recovery of native ant assemblages following landscape-scale removal of the non-native Argentine ant from Santa Cruz Island, California. Large-scale treatments concluded in 2016, and ant assemblages on treatment plots show unambiguous signs of recovery. Species richness and colony abundance on treatment plots have steadily increased – compared to comparable measures on control plots – since the conclusion of treatments. Moreover, the composition of native ant assemblages on treatment plots has increasingly converged on the core area where control plot assemblages cluster in two-dimensional ordination space. In addition to quantifying recovery with respect to abundance and diversity, we are examining recovery in terms of genetic diversity, trophic position, and ecological function. We are continuing to quantify recovery on an annual basis, but observed responses to date (six years following the end of treatments) indicate that native ant assemblages have the capacity to recover following invader removal but only if recovery is measured over temporal scales that are commensurate with the life history of focal native species.
Role: The undergraduate involved in this work will help conduct laboratory work to investigate the recovery of genetic diversity of ant assemblages as they reassemble following Argentine ant removal. Laboratory work will entail DNA extractions, library preparations, and potentially bioinformatic data analysis.
Day-to-day supervisor for this project: Ida Naughton, Post-Doc
Hours: 6-8 hrs
Related website: https://nature.berkeley.edu/tsutsuilab/
Biological & Health Sciences Environmental Issues