Mapping change in key soil properties due to climate change over south-eastern Australia

Soil Research ◽  
2019 ◽  
Vol 57 (5) ◽  
pp. 467 ◽  
Author(s):  
Jonathan M. Gray ◽  
Thomas F. A. Bishop

Climate change will lead to altered soil conditions that will impact on plant growth in both agricultural and native ecosystems. Additionally, changes in soil carbon storage will influence carbon accounting schemes that may play a role in climate change mitigation programs. We applied a digital soil mapping approach to examine and map (at 100-m resolution) potential changes in three important soil properties – soil organic carbon (SOC), pH and sum-of-bases (common macro-nutrients) – resulting from projected climate change over south-eastern Australia until ~2070. Four global climate models were downscaled with three regional models to give 12 climate models, which were used to derive changes for the three properties across the province, at 0–30 and 30–100 cm depth intervals. The SOC stocks were projected to decline over the province, while pH and sum-of-bases were projected to increase; however, the extent of change varied throughout the province and with different climate models. The average changes primarily reflected the complex interplay of changing temperatures and rainfall throughout the province. The changes were also influenced by the operating environmental conditions, with a uniform pattern of change particularly demonstrated for SOC over 36 combinations of current climate, parent material and land use. For example, the mean decline of SOC predicted for the upper depth interval was 15.6 Mg ha–1 for wet–mafic–native vegetation regimes but only 3.1 Mg ha–1 for dry–highly siliceous–cropping regimes. The predicted changes reflected only those attributable to the projected climate change and did not consider the influence of ongoing and changing land management practices.

Soil Research ◽  
2019 ◽  
Vol 57 (7) ◽  
pp. 805
Author(s):  
Jonathan M. Gray ◽  
Thomas F. A. Bishop

Climate change will lead to altered soil conditions that will impact on plant growth in both agricultural and native ecosystems. Additionally, changes in soil carbon storage will influence carbon accounting schemes that may play a role in climate change mitigation programs. We applied a digital soil mapping approach to examine and map (at 100-m resolution) potential changes in three important soil properties – soil organic carbon (SOC), pH and sum-of-bases (common macro-nutrients) – resulting from projected climate change over south-eastern Australia until ~2070. Four global climate models were downscaled with three regional models to give 12 climate models, which were used to derive changes for the three properties across the province, at 0–30 and 30–100 cm depth intervals. The SOC stocks were projected to decline over the province, while pH and sum-of-bases were projected to increase; however, the extent of change varied throughout the province and with different climate models. The average changes primarily reflected the complex interplay of changing temperatures and rainfall throughout the province. The changes were also influenced by the operating environmental conditions, with a uniform pattern of change particularly demonstrated for SOC over 36 combinations of current climate, parent material and land use. For example, the mean decline of SOC predicted for the upper depth interval was 15.6 Mg ha–1 for wet–mafic–native vegetation regimes but only 3.1 Mg ha–1 for dry–highly siliceous–cropping regimes. The predicted changes reflected only those attributable to the projected climate change and did not consider the influence of ongoing and changing land management practices.


2011 ◽  
Vol 62 (3) ◽  
pp. 223 ◽  
Author(s):  
Allison Aldous ◽  
James Fitzsimons ◽  
Brian Richter ◽  
Leslie Bach

Climate change is expected to have significant impacts on hydrologic regimes and freshwater ecosystems, and yet few basins have adequate numerical models to guide the development of freshwater climate adaptation strategies. Such strategies can build on existing freshwater conservation activities, and incorporate predicted climate change impacts. We illustrate this concept with three case studies. In the Upper Klamath Basin of the western USA, a shift in land management practices would buffer this landscape from a declining snowpack. In the Murray–Darling Basin of south-eastern Australia, identifying the requirements of flood-dependent natural values would better inform the delivery of environmental water in response to reduced runoff and less water. In the Savannah Basin of the south-eastern USA, dam managers are considering technological and engineering upgrades in response to more severe floods and droughts, which would also improve the implementation of recommended environmental flows. Even though the three case studies are in different landscapes, they all contain significant freshwater biodiversity values. These values are threatened by water allocation problems that will be exacerbated by climate change, and yet all provide opportunities for the development of effective climate adaptation strategies.


2007 ◽  
Vol 58 (12) ◽  
pp. 1167 ◽  
Author(s):  
R. J. Eckard ◽  
D. F. Chapman ◽  
R. E. White

Nitrogen (N) fertiliser use on dairy pastures in south-eastern Australia has increased exponentially over the past 15 years. Concurrently, imports of supplementary feed onto dairy farms have increased, adding further nutrients to the system. These trends raise questions about the environmental effects of higher nutrient inputs to dairy farms. To gauge possible effects, annual N balances were calculated from an experiment where N inputs and losses were measured for 3 years from non-irrigated grass/clover pastures receiving either no N fertiliser (Control) or 200 kg N/ha applied annually as ammonium nitrate or urea. Estimated total N inputs, averaged over the 3 years, were 154, 314, and 321 kg N/ha.year for the control, ammonium nitrate, and urea treatments, respectively, while N outputs in meat and milk were 75, 99, and 103 kg N/ha.year, respectively. The corresponding calculated N surplus was 79, 215, and 218 kg N/ha.year for the 3 treatments, respectively, and the ratio of product N/total-N inputs for the 3 treatments ranged from 50% in the control to 32% for both N treatments. Total N losses averaged 56, 102, and 119 kg N/ha.year, leaving a positive N balance of 23, 112, and 99 kg N/ha.year for the control, ammonium nitrate, and urea treatments, respectively. The ratio of product N/total-N inputs or the N surplus may be useful in monitoring the efficiency of conversion of N into animal products and the potential environmental effect at a whole-farm scale. However, additional decision support or modelling tools are required to provide information on specific N losses for a given set of conditions and management inputs. Given the large range in N losses there is opportunity for improving N-use efficiency in dairy pastures through a range of management practices and more tactical use of grain and N fertiliser.


2009 ◽  
Vol 18 (5) ◽  
pp. 575-585 ◽  
Author(s):  
Ralph Mac Nally ◽  
Gregory Horrocks ◽  
Hania Lada ◽  
P. Sam Lake ◽  
James R. Thomson ◽  
...  

2017 ◽  
Vol 68 (12) ◽  
pp. 2366 ◽  
Author(s):  
Paul I. Boon

The distribution and productivity of mangroves is directly affected by a wide range of climatic drivers, including temperature, frost, rainfall, evaporation and storm activity, which, in turn, influence a suite of secondary drivers, including changes in freshwater run-off and sediment supply, groundwater dynamics and inter-species competitiveness. The highest-latitude expression of mangroves globally is at Millers Landing, Victoria (38°45′S), and because the vigour and productivity of mangroves across much of Victoria is thought to be limited by low winter temperatures and the incidence and severity of frosts, it is likely that mangroves will be among the first plant communities to be affected by climate change in coastal south-eastern Australia. An increase in plant vigour is likely, but there are almost no historical data with which to compare current rates of primary production. An extension of mangroves to higher latitudes on the mainland is impossible because of the geomorphology of the land that lies further to the south. Small-scale changes in distribution, including the progressive encroachment of mangroves into coastal saltmarsh, are likely to be among the clearest indications of the response of mangroves to a warming climate. Increased effort into tracking changes in mangrove vigour, productivity and distribution is clearly warranted.


Geoderma ◽  
2022 ◽  
Vol 405 ◽  
pp. 115442
Author(s):  
Bin Wang ◽  
Jonathan M. Gray ◽  
Cathy M. Waters ◽  
Muhuddin Rajin Anwar ◽  
Susan E. Orgill ◽  
...  

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