Date: Tuesday 30 May 2017
5.15pm Refreshments in Room 1175A, John Dedman Building, ANU http://campusmap.anu.edu.a
My research interests are broadly in ecological statistics, in which I explore the relationship between the environment and the spatial distribution of a species or species communities.
In particular, I explore methods for species distribution models, in which the goal is to predict the intensity of a species as a function of various environmental variables. Much of my work involves the use of presence-only data, a form of citizen science in which the available data are the locations of reported sightings, with no corresponding information regarding species absences. The use of presence-only data creates a number of challenges in model fitting and interpretation. One such issue is the effect of non-uniform sampling effort: certain regions may be more surveyed than others in presence-only data sets, and failing to account for such differences leads to biased inference. Another issue is that of spatial dependence: there are a number of reasons why reported locations may not be independent of each other, and understanding these reasons is crucial in appropriately modelling the data.
I also consider techniques to perform model selection in the context of species distribution models. As data describing environmental conditions continues to become available for an increasing number of environmental variables across finer spatial resolutions, it is important to consider which of these variables should be included in the model.
I have developed an approach to species distribution modelling which accounts for these challenges called “PPM-LASSO”, in which point process models are fitted with a Lasso-type penalty to simultaneously perform model selection and improve predictive performance. I have built tools to fit these models in the R package ppmlasso available on CRAN.
Recently, I have explored fitting models that make use of multiple data types including presence-absence data collected through systematic surveys. My current research aims to tackle the question of how to best combine these data types to account for their various properties.