James Cook University

Brigid McCallum

1998

Woody weed encroachment and grassland decline is a contentious issue within rangeland management. The debate over the relationship between the two is further complicated by the lack of knowledge of pre-European vegetation. Moorrinya National Park provided an ideal location to investigate anecdotal evidence of woody weed encroachment and to document the nature of native grassland change at a small scale. The analysis of both anecdotal and historical evidence at this site will help contribute to an understanding of short and long term vegetation change.

During the course of the project, a time-series of black and white aerial photography was interpreted and ground-truthed in the field. Grassland boundaries for the years 1951, 1969 and 1980 were mapped and digitised using spatial analysis techniques. This was to allow for the determination of the rate of grassland change, the patterns of grassland expansion and contraction, and the distribution of woody plant species since 1951. Future directions of research will focus on causal factors such as fire and grazing.

At present very limited mapping material exists for Moorrinya National Park and so the small scale of the black and white aerial photos has been a challenge. Staff of the Department of Environment and CSIRO have been invaluable in providing assistance in this area.

Supervisors:

Dr Jon Luly, JCU
Dr Ross Hynes, CRC/JCU