Rebecca Hamilton

PhD Candidate

Madsen Building (F09), Room 358
Email:

Supervisor
Dr. Dan Penny

Associate Supervisor
Assoc. Prof. Tom Hubble

Research

PhD Title: Ecosystem resilience and climate surprises: Examining the response of tropical dry forests to past extremes in the Asian Monsoon.

Background:

There is rising concern that human disturbances, including the suppression of natural system dynamics, reduction in taxonomic diversity and enhanced rates of greenhouse warming, are interacting to increase both the likelihood of abrupt climatic shifts, and the sensitivity of ecosystems to such external forcing events by reducing ecosystem resilience. These processes may interact to instigate ecological regime shifts, compromising the capacity of receiving ecosystems to provide essential services that are critical to sustaining human well-being. Improving our ability to make predictions about the current and likely future resilience of ecosystems to external climatic extremes and internal disturbance is therefore of critical social and scientific relevance.

Anticipating the future stability of tropical forests is particularly important not only because they host a large proportion of the planet’s genetic diversity and support economies in the most populous region, but also because the instigation of ecological regime shifts within these ecosystems may induce global impacts via broad-scale feedback processes. The threshold dynamics of the tropical forests of mainland south-east Asia have been particularly under researched, yet these systems have been subjected to multiple abrupt shifts in the behavior of the Asian monsoon over millennia – a system predicted to become more unstable during the 21st century.

This project seeks to retrospectively assess how mainland south-east Asian dry forests have responded to variations in monsoon intensity since the mid-Holocene in order to gauge how resilient or sensitive they may be to future changes of a similar magnitude. This will be achieved by establishing proxy records of ecological, land use and climatic change from the application of palynological techniques to sediment cores extracted from several closed-catchment crater lakes in the Ratanakiri province of north-east Cambodia.

Research Projects

  • 2012-present: Lake sediment palaeo-environmental reconstruction of Cambodian tropical dry forests (part of the Cambodian Crater Lake Project [CCLP]).
  • 2010-2011: Palaeo-ecological history of Lachlan Nature Reserve, Centennial Park, Sydney.