Integration of Brigalow (Acacia Harpophylla) Vegetation with Dryland Cropping in South-East Queensland: Agronomic, Hydrological, Ecological and Goethean Perspectives

Melanie Bradley, University, My, Clyde Wild
Large tracts of brigalow (Acacia harpophylla F. Muell. ex Benth. Mimosaceae) vegetation once covered the Queensland Brigalow Belt. Over the last century, a significant reduction in brigalow coverage has taken place (> 90%), primarily a result of land clearing for agricultural development. Despite significant loss of brigalow and its associated biodiversity, potential exists for reversing the loss, avoiding further land degradation and promoting sustainable agricultural production, through the
more » ... tablishment of brigalow-cropping systems. Such land-use systems are characterised by deliberate integration of stands of regrowth and remnant brigalow vegetation with areas of dryland cropping. This landscape ecology study increased knowledge and understanding of brigalow-cropping systems using two complementary investigative approaches: (1) a conventional, reductionist, quantitative approach; and (2) a holistic, qualitative approach. The first approach was used to investigate brigalow-cropping systems from agronomic, hydrological and ecological perspectives. These perspectives provided insight into aspects of brigalow-cropping system function, structure and composition. The second approach looked at brigalow-cropping systems from the Goethean perspective. This latter perspective sought to understand brigalow-cropping systems on a 'whole-of-paddock' basis. Each perspective constituted a discrete study, with the studies done on properties located in the Tara Shire of south-east Queensland. Specifically, the agronomic perspective looked at tree-crop competition adjacent to stands of regrowth and remnant brigalow. It found that young brigalow regrowth (< 5 years since last disturbance) did not have a negative impact on adjacent cropping. However, older brigalow regrowth (> 10 years since last disturbance) and remnant brigalow vegetation had a significant, detrimental impact on adjacent production, with tree-crop competition zones ranging from 12–47 m. Both field measurements and simulation modelling (using the Agricu [...]
doi:10.25904/1912/195 fatcat:c6fc6hsymfgxvp6epsfrc2mllm