Fine-scale habitat mapping of threatened reptiles in the Queensland Brigalow Belt using new generation radar remote sensing and high spatial resolution imagery

A project undertaken at the Australian Centre for Sustainable Catchments, University of Southern Queensland, and supervised by Dr Armando Apan.

Many of the habitat predictive models that ulitised satellite imagery have used relatively coarse-grained data. Thus, they are only useful where the organism of concern has habitat requirements that can be identified adequately at coarse scales. For the threatened reptiles of the Brigalow Belt, the identification and mapping of their habitat requires fine-scale resolution due to their habitat preferences. Reptiles require specific microhabitat characteristics within their preferred broad habitat type.

These microhabitat attributes will need sensors that are capable of providing information about vegetation structure, surface roughness, biomass, micro-topography, etc. at a fine scale. Previous studies using radar imagery have demonstrated that many of these variables can be extracted. However, as most of these radar sensors are either mounted on airborne systems or on satellite platforms that have implications on imagery costs or spatial resolution, their applications to fine-scale habitat mapping is limited or non-existent.

Our aim is to assess the ability of new radar imagery and high resolution multispectral imagery to estimate habitat attributes (metrics) associated with threatened reptiles of the Queensland Brigalow Belt. Specifically, the objectives are:

  1. to evaluate the relationships between habitat metrics collected from the field and those generated from radar-multispectral imagery, focusing on “yakka skink” (Egernia rugosa), and
  2. to develop a predictive habitat model by utilising field data, imagery, and thematic maps in a geographic information system (GIS) environment.

This study covers several innovative components: a) the first study on using high-resolution satellite imagery to map threatened reptile in the Brigalow Belt; b) a pioneering study to utilise ALOS radar imagery for wildlife habitat mapping in Australia; and c) a novel study that will attempt to evaluate (in the context of habitat mapping) the utility of space-borne sensors to map non-traditional variables like rock outcrops, fallen leaf-litter, branches, hollow logs, understorey old trees, surface roughness, etc.

This project offers great benefits to conservation planning and management. It will develop reptile habitat mapping techniques and will produce maps needed to secure and improve the long term survival of the species. Biodiversity conservation is an issue of regional, national and global significance. The yakka skink is listed as “Vulnerable” under

  1. the EPBC Act 1999, and
  2. the Queensland Nature Conservation Act 1992.

Figure 1: Yakka skink (Egernia rugosa), Brigalow Belt, Queensland

Figure 2: Brigalow stand, Erringibba National Park, Glenmorgan (Photo Dr. A. Apan)

Figure 3: SPOT 5 image of Glenmorgan area

Figure 4: Some reptiles can be found on piles of logs (Photo Dr. A. Apan)