Abstract for presentation at The 13th Australasian Remote Sensing and Photogrammetry Conference

In recent decades, substantial changes in the vegetation cover of Queensland, Australia, has led to national and international concerns regarding greenhouse gas emissions, loss of diversity and landscape degradation. Focusing on the mixed species forests and agricultural land near Injune, changes in land cover and vegetation clearing methods over the period 1972 to 2003 were documented using a combination of Landsat sensor data and farmer interviews. The temporal and spatial variations in clearing patterns as a function of physical and political factors were then investigated. The analysis indicated that clearing within the study area had accelerated prior to the introduction of the 1999 Vegetation Management Act and primarily on freehold land. Interviews with local farmers confirmed that chaining was the most common method of clearing with ring barking and stem injection occurring only in the late 1970s/early 1980s. Prior to 1990, most of the clearing had occurred in areas that were considered suitable for agricultural development, including areas of relatively level ground with fertile clay soils, as indicated by the dominance of Acacia harpophylla. However, subsequent clearance, prompted partly by political events, have focused on the less suitable terrain (steeper slopes) and on soils that are less fertile. As a result, a greater proportion of Eucalyptus woodland has been cleared and, large areas are entering phases of regeneration. The clearance patterns within the study area reflect those occurring throughout south-central Queensland. The paper critically evaluates the use of time-series datasets for determining the impacts of agricultural land management and policy and identifies ways in which maps generated from remotely sensed data can be better translated to activities on the ground. Opportunities for better detecting land management practices and associated changes in forest structure, biomass and species composition using a combination of optical and radar data are also presented.