C&N Dynamics PDF Print E-mail

Improving long-term predictions of carbon and nutrient dynamics in Australia’s agro-ecosystems


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Project overview


Predictive modelling of carbon and nutrient dynamics in Australian vegetation and soils is critical to effectively plan sustainable land and ecosystem management strategies, to develop evidence-based policy, including policies for climate change adaptation and mitigation, and to improve understanding of ecosystem function and response to environmental and management factors such as climate, cultivation practices, stocking rate and fire.  However, the value of predictions depends on how well the models can simulate the real world, that is, observed ecosystem characteristics and measured changes.

A number of different models have been applied to Australian agro-ecosystems to predict carbon and nutrient flows at scales ranging from continental to regional and local.  The outputs have, in some cases, varied markedly due to differences in the model assumptions and parameterisation, and this has made interpretation difficult.


Working Group Overview: The C&N Dynamics Working Group will address the critical need for datasets from long-term monitoring of well-managed experimental sites in a format that can be used for model calibration, verification and uncertainty assessment thus contributing to improved model performance and confidence in predictions for management and policy applications.

In three workshops high-quality agro-ecosystem datasets for biophysical models will be assembled and tested in the main models used in Australia. Researchers with data from selected long-term trials will work with modellers and end-users from industry and policy.  The focus is on agro-ecosystems because they not only represent over 60% of Australia’s land mass but are areas where changes have occurred in the past and where there is a capacity for management to influence future changes in carbon and nutrient balance.

Potential applications of the enhanced predictive modelling of carbon and nutrient dynamics include (but are not limited to) climate change policies, and sustainability and continued productivity of Australia’s food and fibre production.

Brigalow Catchment

Brigalow Catchment Study - Aerial shot of the taken in June 2007 (courtesy of Craig Thornton). The leucaena catchment is in the upper left, the virgin brigalow scrub catchment is immediately beneath it, the cropping catchment is centre of screen and the grazing catchment is on the right. The actual monitored catchment areas sit within each of these larger "treatment" areas.

Hermitage Trial
Hermitage Long-Term Tillage Trial near Warwick, Queensland (28o12’S, 152o06’E)


For further enquiries about this group please contact the Principal Investigator, This e-mail address is being protected from spambots. You need JavaScript enabled to view it



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Products and outcomes



Final report


FINAL REPORT available for download

Download PDF




Since the last meeting the group has presented their work at a couple of meetings, one of which was the CCRSPI 2012 Conference



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Modelling package with YouTube video


The group, with funding from the Australian National Data Service (ANDS) inspired the development of a tool that "simplifies the environmental modelling process by assisting scientists to upload their data, run modelling tools and share it with others."


It is called Semaphore, and focusses on biogeochemical changes in the ecosystem. Test it out by clicking on this link –SEMAPHORE– and watch the video here.




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Workshop Reports



Workshop 1 Report (27 – 29 April 2011)

The first of three Workshops planned for the C & N Dynamics Working Group which was held at the ACEAS meeting room immediately after Easter was very successful.  The workshop brought together a highly experienced and diverse group with expertise ranging from on-ground soil and vegetation measurement to biophysical model development and policy and industry applications of environmental information.  They represented extensive experience from Australia and overseas, including Prof. Richard Conant from Colorado State University and QUT, a widely recognised expert in soil carbon sequestration modelling.  The Workshop offered a rare opportunity for 3 days interaction between experts who share interests in understanding the functionality of agro-ecosystems for long term sustainability and productivity.

L-R Leigh Hunt (CSIRO, Ecosystem Sciences), Ryan Farquarson (CSIRO, Land and Water), Ed Charmley (CSIRO, Livestock Industries), Beverley Henry (Institute for Sustainable Resources, QUT), Cameron Allan (Southern Livestock, Meat and Livestock Australia, Vic), Craig Thornton (Qld Department of Environment and Resource Management), David Rowlings (Queensland University of Technology), Ram Dalal (Qld Department of Environment and Resource Management), Murray Uncovich (University of Adelaide), Andrew Moore (CSIRO, ACT), Peter Grace (Institute for Sustainable Resources, QUT), John Carter (Queensland Centre for Climate Change Excellence, DERM), Richard Conant (Institute for Sustainable Resources, QUT and Colorado State University).


The focus of our Working Group is improving access to high quality data for understanding and predicting carbon and nitrogen dynamics, a key to ecological health and agricultural productivity. We are focussed particularly on the extensive rangelands (about 80% of Australia’s land area) where we know that practices such as clearing, cultivation, burning and grazing livestock have changed the stocks and flows of carbon and nitrogen and that this in turn has resulted in emissions to the atmosphere of the greenhouse gases, carbon dioxide, methane and nitrous oxide.  Development of climate change policies is adding urgency and value to the ACEAS investment in the C&N Dynamics Working Group.


During presentations on long term agricultural trials and model capability, it was exciting for Workshop 1 participants to see greater opportunities to work together. It was also rather daunting, however, to recognise the work that will be involved in compiling, formatting and documenting data from research sites such as the Hermitage Trial where there are 42 years of yield and soil C and N measurements comparing tillage, crop residue management and N fertiliser practices.  Dr Andrew Moore from CSIRO used his APSIM experience to lead a discussion that achieved agreement on a draft format for assembling data and metadata to facilitate its use in a range of models.  The format will be trialled initially for Brigalow Catchment Study where Craig Thornton has been assembling an enormous amount of data collected since 1965.  Participants will meet again in September to start testing the data as inputs to modelling, and to build on the collaborations that were initiated in Workshop 1 and also over a very enjoyable dinner at South Bank.



Workshop 2 Report (13 – 15 September 2011)


Workshop 2 of the C & N Dynamics Working Group was held in the ACEAS rooms in Brisbane with our diverse mix of experts in data collection and field trials, modelling, research and end-user applications for policy and industry issues. Complementing the Australian researchers we were fortunate to have the participation of three international experts:  Dr Bill Parton and Prof Rich Conant (Colorado State University) and Dr Steve Del Grosso (USDA, Fort Collins) all of whom have expertise in modelling and have published extensively on carbon and nitrogen dynamics in rangelands and croplands.  Their experience in working with NCEAS in the US using long-term trials to calibrate and validate models provided very valuable input to the workshop and broadened the mentoring experience for the postgraduate and early career scientists in our Working Group.


The achievements of the workshop include:


1. Key Presentations:

  • Bill Slattery from DCCEE providing an update of the current policy developments; and
  • Data custodians of the long-term trials at Brigalow Catchment, Hermitage, Kidman Springs and Wambiana provided an overview of progress towards developing model-ready datasets.
  • Andrew Moore led a discussion on a draft ‘standard template’ data format trialed using the Brigalow Catchment Study datset.

2. Collating datasets and metadata for at least three long-term trials: During the Workshop good further progress was made on the datasets.  ACEAS funding for technical assistance to enable further progress on some data will allow additional data to be included.  Metadata development will use fields consistent with TERN protocols.


3. Initial model testing of collated data: Pairing of data custodians with modellers proved a valuable opportunity for initial testing of the suitability of collated data from each site.


4. Developing a work plan for the period up to Workshop 3 in early December: Major follow-up tasks include (a) posting datasets and Metadata on the C&N Dynamics Working Group Wiki and (b) undertaking test model runs.


Workshop 2 summary evaluation:

  • The arrangements and logistics all worked smoothly thanks to ACEAS staff (who even arranged the laser light show to coincide with our dinner!).
  • Workshop 2 successfully built on the foundations of Workshop 1.  An enormous amount of time and effort put in by some members ensured data, templates and modelling capacity were available to work on.
  • The group is working very effectively with all (including the two new members who replaced those who had to withdraw due to new jobs) making a valuable contribution.
  • A Century Training Workshop which was arranged at QUT to follow Workshop 2 provided training by Dr Bill Parton and Cindy Keough (CSU) in Century and DayCent models. This was attended by 22 researchers from Australia and New Zealand including six Working Group members.

We have received very positive feedback for the potential of the Working Group to make a contribution to Australia’s capacity to model C and N dynamics in Australian agro-ecosystems to support environmental, agricultural and policy objectives but there is a probably a general under-appreciation of the time and effort required to collate, locate and quality check the large datasets being assembled.


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Workshop 2 group shot


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Workshop 3 Report (5-7 December 2011)


Two major challenges facing Australia (and the World) today are:


1. How to manage agro-ecosystems, i.e. those lands managed either intensively or extensively, for long-term sustainable food and fibre production while conserving biodiversity and other natural resource values; and

2. How to mitigate the impacts of future climate change by decreasing greenhouse gas emissions and increasing carbon sequestration in landscapes.


Better understanding of the C&N Dynamics in agro-ecosystems has the potential to make a significant contribution to addressing these challenges. Therefore our Working Group aimed to take some small steps towards contributing to the knowledge underpinning better policy and management decisions for these questions.


Carbon and Nitrogen cycling is fundamental to the health of all agro-ecosystems. In order to be able to model the C and N flows and stocks and how they are affected by management practices we need better data from long-term controlled trials and understanding of treatments that have led to measured differences. In addition to capturing high quality data and supporting meta-data from selected long-term trials the C&N Dynamics working group initiated a process of model comparison which can lead to improvements in capacity to model processes. This will assist in analysis of model outcomes that can support such applications as:


A. Understanding the impact of different management practices e.g. till vs no-till cropping on soil organic carbon levels

B. Understanding linkages between carbon and nitrogen levels in soils and the influence on N loss pathways from agricultural lands so that these processes can be better represented in models and hence in tools for land managers, e.g. to minimise N loss through leaching and run-off that can affect systems such as the Great Barrier Reef.

C. Consistency in modelling of soil carbon change in farming lands with the national greenhouse gas inventory and hence to developing tools that could enable farmers to participate in the Carbon Farming Initiative and Carbon markets.

D. Developing good management practices for land management for long-term sustainability and high productivity by better understanding of impacts on soil carbon and nitrogen dynamics, e.g. the impact of early vs late season burning in grazed savannahs; the impact of high vs low stocking rates in different seasons. Development of these practices contribute to combating the risk of land degradation.


These are the big picture goals. In reality we have developed a few high-quality well-documented datasets that can be used for model validation and enable better model representation of selected Australian agro-ecosystems. There is a long way to go to realise the full benefits but believe strongly in the value of what we are trying to achieve.


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Left to right: Craig Thornton, Leigh Hunt, Richard Conant, Bill Slattery, Andrew Moore, Beverly Henry, Stephen Reeves, Murray Uncovich, Bill Parton and Steve Clark. (absent: David Rowlands, Peter Grace) Apologies: John Carter, Ram Dalal, Robyn Cowley


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Last Updated on Sunday, 08 February 2015 16:12