Aussie Grass: Australian Grassland and Rangeland Assessment by Spatial Simulation

Abstract

Defining drought, categorising current droughts, and assessing grassland and rangeland sustainability in a quantitative and scienti:fic manner are important national issues for Australian State and Commonwealth governments, landholders and agribusiness. A challenge for ecologists and modellers of Australia's grasslands and rangelands is to integrate biological models, geographic information systems, satellite imagery, economics, climatology and visual high-performance computing into readily available products that can provide monitoring and prediction advice in near real-time.The QDNR systems approach to the management of native grasslands recognises that drought occurs at a regional scale, and that impacts on livestock and natural resources can be forecast using simple models of soil water, plant growth and animal performance. Our vision for a comprehensive Australian Gmssland and Rangeland Assessment System (Aussie GRASS) is one that consists of the best combination of minfall analyses, seasonal climate forecasts, satellite and terrestrial monitoring, and simulation models of relevant biological processes. This will provide a rational basis for largescale management decisions by graziers, extension workers, land resource managers, bureaucmts and politicians. Aussie GRASS products are currently used within the Queensland government for drought declaration assessments and applications for Drought Exceptional Circumstances.The Aussie GRASS national spatial modelling framework allows agricultural simulation models to be run at a continental scale on a 0.05 degree 05 km) grid. The simulation model currently in use by the Aussie GRASS project is the GRASP pasture model developed for tropical native pastures in Queensland by QDPI and QDNR. In the latest Aussie GRASS project, other regional models are being examined for their applicability to areas such as the southem winter perennial grass zone, chenopod shrublands or the high minfall temperate zone. 330 The Queensland version of the Aussie GRASS model is currently used to produce data for a monthly report -A Summary of Seasonal Conditions in Queensland. Model outputs are used in conjunction with recorded and forecast rainfall, satellite imagery, Southern Oscillation Index and current drought declarations to build a comprehensive picture of the current and future seasonal conditions impacting on primary producers. Other numerous outputs from the model can be produced and tailored as required.

Sustainable management for rangelands in a variable climate: evidence and insights from northern Australia

“…pasturesfromspace.csiro.au/, but major difficulties exist in its application in large, diverse rangeland paddocks (G. Bastin, personal communication). Real-time simulation models could also be used to predict pasture growth from antecedent rainfall in a manner similar to the national AussieGrass system (Carter et al, 2000;McKeon et al, 2009). However, the detailed model parameterisation and data input required would make this methodology unsuitable for most managers (R. A.…”

Australian drought: the interference of multi‐spectral global standing modes and travelling waves

“…Grazing enterprises have been developed over time against a background of relatively high variability in both rainfall and commodity prices (McKeon et al, 1990). History also tells a story of degradation episodes associated with extreme drought (Carter et al, 2000) that devastates the flora and fauna, and the regional economy every 20 years or so (Table I). Many of these degradation episodes led to major government inquiries and intervention.…”

“…To provide forecasts of pasture growth and degradation risk, an operational nationwide prediction system called Aussie GRASS (Carter et al, 2000) has been developed, with forecasting skill dependent on the predictability of the El Niño-southern oscillation (ENSO) climate signal (Stone et al, 1994). Yet, its applicability is limited to specific regions and specific seasons.…”

Learning from episodes of degradation and recovery in variable Australian rangelands

“…30). This improving understanding has led to various pastoralistsupported packages like Grazing Land Management (31) and the development of a national drought alert system (32). Second, national drought policy also continues to evolve, triggered by a major review in 1990.…”

“…(ii) Alert systems, at both local and regional scales, that use improved climatic understanding (19) and resource monitoring (33) to provide warnings of the potential for degradation episodes (32), taking account of the longer-term climatic cycles and trends that are beyond the likely experience of current managers. Forecasting rainfall and climate risk at 1-to 10-year time scales remains a high priority, to understand and warn of the impacts of quasi-decadal, bidecadal, and climate change signals.…”