Beneficial impacts of climate change on pastoral and broadacre agriculture in cool-temperate Tasmania

Abstract

Abstract. Although geographically small, Tasmania has a diverse range of regional climates that are affected by different synoptic influences. Consequently, changes in climate variables and climate-change impacts will likely vary in different regions of the state. This study aims to quantify the regional effects of projected climate change on the productivity of rainfed pastoral and wheat crop systems at five sites across Tasmania. Projected climate data for each site were obtained from the Climate Futures for Tasmania project (CFT). Six General Circulation Models were dynamically downscaled to~10-km grid cells using the CSIRO Conformal Cubic Atmospheric Model under the A2 emissions scenario for the period 1961-2100. Mean daily maximum and minimum temperatures at each site are projected to increase from a baseline period to 2085 (2071-2100) by 2.3-2.78C. Mean annual rainfall is projected to increase slightly at all sites. Impacts on pasture and wheat production were simulated for each site using the projected CFT climate data. Mean annual pasture yields are projected to increase from the baseline to 2085 largely due to an increase in spring pasture growth. However, summer growth of temperate pasture species may become limited by 2085 due to greater soil moisture deficits. Wheat yields are also projected to increase, particularly at sites presently temperature-limited. This study suggests that increased temperatures and elevated atmospheric CO 2 concentrations are likely to increase regional rainfed pasture and wheat production in the absence of any significant changes in rainfall patterns.

Management opportunities for boosting productivity of cool-temperate dairy farms under climate change

“…This is partly due to frost and other factors such as low solar radiation. Our results demonstrate that by 2050 pasture production in summer will likely be reduced as a result of further reductions in soil moisture and increases in vapour pressure deficit (Guobin and Kemp, 1992;Turner and Asseng, 2005), consistent with the previous findings of Phelan et al (2014) and Holz et al (2010) for Tasmanian pastures and Cullen et al (2009Cullen et al ( , 2012 for pasture in Victoria and New South Wales. Overall our results show that climate change between the baseline and 2050 will be beneficial for whole farm milk production since higher temperatures are conducive to greater pasture growth in winter and early spring, leading to greater annual biomass production.…”

“…The CFT modelling projections for Tasmania under the A2 emission scenario indicate temperature increases from 2.6°C to 3.3°C, and in some regions either positive or negative changes in annual rainfall of up to 100 mm per year . Previous studies of climate change impacts across the dairy regions of southeastern Australia have commonly focused on impacts on pasture and fodder crops (Bell et al, 2013;Cullen et al, 2009Cullen et al, , 2012Holz et al, 2010;Pembleton et al, 2013;Phelan et al, 2014). Cullen et al (2009Cullen et al ( , 2012 indicated that pasture production in cooltemperate climates would be relatively resilient to climate change, whilst Holz et al (2010) and Phelan et al (2014) suggest that the net effect of a warming climate would be beneficial for pasture growth.…”

“…The reliable production of high quality pasture in Tasmania reduces the demand for supplementary feed and provides a competitive advantage for the dairy industry in comparison to mainland Australia and international producers. Whilst the potential impacts of projected climate change on pasture production under future climates in Tasmania have previously been described (Bell et al, 2013;Cullen et al, 2008Cullen et al, , 2012Holz et al, 2010;Phelan et al, 2014), to date there has been little work undertaken to determine how climate change may impact more broadly on whole farm systems, such as effects on herd milk production and farm feed budgeting.…”

Quantification of the Impact of Temperature, CO2, and Rainfall Changes on Swedish Annual Crops Production Using the APSIM Model

“…Although it has not previously been applied for climate change scenario analysis in the context of Nordic countries, APSIM has an open source code, is supported by an active user and developer community, and most importantly, already includes useful submodules to simulate the crops assessed in this study and the effects of changes in precipitation and temperature on the phenology and yield of the crops. Examples of APSIM being used for such tasks include Pembleton et al (2016), Phelan et al (2014), or Bahri et al (2019).…”

Challenges for Simulating Growth and Phenology of Silage Maize in a Nordic Climate with APSIM

“…A wide number of crop models have been developed since the middle of the 20th century and the pioneering work of Cornelis Teunis de Wit [9,10]. Crop models can be used to perform various tasks such as predicting the effects of climate change on crops (e.g., [11][12][13]), optimization of farming practices for given soil-climate-crop combinations (e.g., [14,15]), understanding the environmental stresses experienced by crops (e.g., [16,17]) or to improve the knowledge of the physiological processes of a plant (e.g., [18]).…”