Header image

Utilising random forestsin the modelling of Eragrostiscurvula presencein an Australian grassland system | Dr Jed Brown

Tracks
Thursday, August 7, 2025
12:00 PM - 12:20 PM
Miconia Room

Speaker

Agenda Item Image
Dr Jed Brown
Lecturer
Charles Sturt University

Utilising random forestsin the modelling of Eragrostiscurvula presencein an Australian grassland system | Dr Jed Brown

Abstract

Eragrostis curvula is an agronomically and ecologically undesirable perennial tussock grass dispersed across Australia. The objective of this study is to investigate relationships of ecologically relevant abiotic variables with the presence of E. curvula at a landscape scale in the Snowy Monaro region, Australia. Through vegetation surveys across 21 privately owned properties and freely available ancillary data on E. curvula presence, we used seven predictor variables, including Sentinel 2 NDVI reflectance, topography, distance from roads and watercourses, and climate, to predict the presence or absence of E. curvula across its invaded range using a random forest (RF) algorithm. Assessment of performance metrics resulted in a pseudo-R² of 0.96, a kappa of 0.97, and an R² for out-of-bag samples of 0.67. Temperature had the largest influence on the model’s performance, followed by linear features such as highways and rivers. Highways’ high importance in the model may indicate that the presence or absence of E. curvula is related to the density of human transit, thus acting as a vector for E. curvula propagule dispersal. Further, humans’ tendency to reside adjacent to rivers may indicate that E. curvula’s presence or absence is related to human density and its potential to spread via water courses.

Biography

Dr Jed Brown is a vegetation ecologist and educator with a PhD specialising in invasive plants. Based in Port Macquarie, he teaches subjects relating to vegetation ecology and remote sensing at Charles Sturt University. Jed’s work focuses on understanding plant dynamics and addressing environmental challenges, with an emphasis on invasive species. He inspires students through hands-on fieldwork, ecological assessments, and innovative approaches to environmental data analysis. Passionate about bridging research and practice, Jed’s expertise in vegetation ecology contributes to advancing knowledge and fostering sustainable management of ecosystems.
loading