11 Oct 2018

Schönbeinstr. 6, lecture hall 00.003


Special Seminar by Dr. Matthew Prebble, Australian National University

"Ecosystem change on the Pacific Islands: botanical insights on the Anthropocene"


The lateness and prominence of human colonisation of the remote Pacific Islands makes them ideal places to investigate processes of global change and the consequences of human engagement. The recent entry of humans provides unique opportunities to assess the rate at which ecosystems and plant species adapted or failed to adapt to unprecedented disturbance, particularly fire and the introduction of crop production and associated exotic invasive species. The Pacific Islands are also the location of large scale fluctuating climate phenomena which strongly influence global and local climates, yet ecologists have continually portrayed this region, particularly prior to the advent of humans, as stable or in a state of equilibrium. Here, I attempt to summarise ongoing research which attempts to question some of these prevailing assumptions. Firstly, I examine the relationship between evidence for changes in rainfall (hydrogen isotopes) vegetation (palynology) and fire (charcoal particles) on islands within the South Pacific Convergence Zone and responses to ENSO, concentrating on near-time fossil records from wetlands. How coupled are these processes? Secondly, I examine evidence for the rapid adaptation or extinction of indigenous plants following the unprecedented rates of disturbance on these last landmasses to be colonized by humans. I present two island case studies, one examining the downstream ecological consequences of the removal of sea-birds, and another examining the adaptation then extinction of indigenous annual plants in crop production systems of differing intensity. Finally, I examine the opportunities for research in this region, as a proxy for global change, where the vestiges of early human-ecosystem interactions have yet to play out.

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