Mapping historical livestock grazing pressure in Queensland

Abstract

The comparison of historical livestock grazing maps can provide insights into the long term environment impacts of grazing upon different landscapes. The Queensland State Statistics (QSS) (1860-1949) describes at a district level, the numbers of cattle, horses and sheep providing a record of introduction and development of the sheep and cattle industry throughout Queensland. The livestock record from the QSS has been spatially defined to provide a history of pastoral land use in Queensland. To account for livestock change at local statistical areas, it was necessary to determine changes in statistical boundaries over time and to spatially distribute stock according to the statistical area that was described in the QSS. This was achieved by applying a stock distribution model (SDM) in order to calculate an estimated yearly stocking rate within each QSS district. In the absence of other data, the methodology presented displays a more accurate representation of stock movement and subsequent grazing during the Queensland’s development period. More importantly the data collected and standardised across the mapping units allows for the AussieGRASS (Australian Grassland and Rangeland Assessment by Spatial Simulation) model to extend its grazing modelling capacity to calendar years past 1950 for all areas of Queensland.