My objective is to develop mathematical and modelling approaches
to quantifying the impact of ecosystem events (e.g. fire, flood,
drought) on semi-arid grasslands in the Pilbara region of Western
Australia. The methodology utilises time series of remotely-sensed
imagery of Themeda triandra (Forskall) tussock grasslands,; data
has been collected by the Ecosystems Research Group at UWA twice a
year since 1996 and comprising 1280 images of 1m x 1m quadrats.
Ecological theory can be used to generate spatio-temporal models
of vegetation dynamics, including those incorporating fire. These
models can then be fitted to the image data via an ad hoc
statistical modelling technique that uses Monte Carlo simulation.
This research is important because assessment of the stability and
resilience of ecosystems would be enhanced if the impact of a
particular sequence of ecosystem events on, say, vegetation
productivity, could be accurately quantified and/or predicted.
Output of validated models may then be used for short term
predictions of system behaviour and defining relationships between
patterns and process, pertinent to exploring interactions among
multiple ecosystem events. For example, the ecological impact of
fire will be dependent on the timing of previous fires and the
recent patterning of rainfall, drought and biomass. Empirical
understanding of the impact of such interactions on vegetation
dynamics will permit a rigorous comparison of alternative
management scenarios in highly complex systems.
Project Link: B 4.2 Multi-scale patterns in
ecological processes and fire regime impacts
PhD Thesis Link: Image-based modelling of pattern dynamics in a semiarid
grassland of the Pilbara, Australia
