Carbon stocks and flows
Overview: Difference between stocks and flows
A grazing paddock is a dynamic system, not a static one. To understand how a paddock functions, it is important to understand the role of the element carbon as it flows through different paths after it enters the paddock.
Carbon is a carrier of energy through a natural system. As it moves, carbon takes different forms – such as animals, plant leaves, plant roots, soil organic matter. These different forms contain carbon in different chemical combinations and their individual carbon-containing molecules flow through the system at different rates. Carbon keeps flowing above ground as well as below ground, including through commercial livestock.
Carbon compounds in a paddock can be loosely classified into short-term (labile), medium-term and long-term, though there is a continuum. The dynamic nature of carbon is not revealed by spot measurements taken at a point in time, commonly referred to as ‘stocks’. Considering soil carbon, the technique used for measurement uses a 2mm sieve that removes about a third of grass roots which are labile carbon. Soluble carbon, the fastest flowing carbon, is outside the measurement process.
Short-term carbon, which accounts for the bulk of carbon flows, moves through the landscape by ongoing interchange between plants, animals, soil and atmosphere. This exchange powers the health of the paddock generally and pastoral productivity in particular. The volume of flowing carbon in a paddock reflects recent land management decisions.
On the other hand, the level of long-term carbon is a consequence of past decision-making. Long-term soil carbon is important for paddock health , even though it moves at an extremely slow speed and its level is slow to change. It is not responsible for short-term changes in paddock health or productivity. Short term improvements in paddock health and productivity are driven by the short-term carbon introduced in the first phase of carbon flows. Also, the carbon in long-term soil carbon has to start the journey as short-term carbon in the first phase of carbon flows.
Long-term soil carbon has become prominent in public debate because of climate change policy and carbon trading. Payments to landholders in the form of carbon credit schemes for storing carbon apply only to long-term forms of carbon, because short-term carbon flows cannot be secured. However, payments in the form of stewardship incentives can be justified for management changes that increase the flow of carbon and so improve paddock and catchment condition. The two purposes are distinct and different metrics are needed to assess them.
The concept of carbon flows highlights the ongoing nature of carbon transfers; whereas the alternative concept of carbon stocks (a measurement at one point in time) is a static one and says little about what is driving changes in the health of the landscape or the relative significance of past and current management decisions.
An understanding of carbon flows leads into recognition of the importance of timing when managing stock on a pastoral property. Timing of grazing was central to Alan Lauder’s book Carbon Grazing.
Thinking dynamic ‘carbon flows’ rather than static ‘carbon stocks’ leads to a better understanding of how a paddock functions and needs to be managed.
“Carbon Grazing” – the book
Alan Lauder’s book Carbon Grazing – The Missing Link, published in 2008, will shortly be available on this website. An update to the book is also available. Printed copies of the second printing have sold out.
“Unsettled Science: Timing the Harvest of Carbon Flows”
Alan Lauder published a Short Communication in Volume 119 of the Proceedings of the Royal Society of Queensland pointing out the importance of supporting research based on paddock observations by non-credentialled scientists. Copies of this article can be purchased online from Informit (free to Society members).
“The sequence of actions in the conduct of science, and then typically its acceptance and implementation, are referred to as Scientific Method and then objective meritocratic formation of policy. In the modern world it includes evidence – hypothesis – experiment – conclusions – peer review – publication – transfer to policy – and finally its communication to practical managers. However, this sequence does not always proceed in a logical and orderly fashion. For a range of reasons, important evidence can remain un-investigated and even if scientifically validated, conclusions can remain un-implemented.”
Columns – Why carbon flows
Alan Lauder has published a series of columns explaining the dynamics of pastoral landscapes.They have appeared first on the website of Soils for Life.
Column 1: What is the most fundamental thing a producer has to get right?
Column 2: Has extension focused on the wrong aspect of carbon when discussing decision making?
Column 3: Restarting carbon flows to repair a degraded claypan.
Column 4: Why carbon suddenly turned up in extension.
Column 5: How moving carbon carries energy.
Column 6: Think carbon before nitrogen.
Please consult the Carbon Grazing website for further information.
As to the future, Alan Lauder is keen to establish an outreach to pastoralists, to share his knowledge of both science and the paddock, but sponsorship funding is lacking. He is also willing to answer genuine inquiries from pastoralists, scientists or extension officers. Sponsors willing to discuss supporting Alan’s research or outreach; or inquirers keen to know more about his methods are invited to contact him.
About Alan Lauder
Member Alan Lauder was a successful rural producer with thirty years’ experience of property management in Queensland’s south-western pastoral zone. He built extensive networks in the scientific community to gain a ‘big picture’ understanding of how landscapes function and how different regimes for managing livestock affect landscapes. This understanding extends to greenhouse outcomes and water catchment outcomes.
In 1997, he was funded to conduct a $272,000 Drought Regional Initiative project on his property. The project perfected a method of building the health and resilience of grazing landscapes. While a wool grower, he produced the world’s first guaranteed prickle-free jumper, supplying David Jones and Country Road. While still on the property, the Queensland Government used him as one of ten case studies in their publication, Graziers’ Experiences in Managing Mulga Country. He spoke at the 1999 International Rangeland Congress and was invited to speak at the Grootfontein Research Institute in South Africa. He is lead author of the peer-reviewed paper “Offsetting methane emissions – An alternative to emission equivalence metrics”. Alan was nominated for the McKell National Landcare Award and was a Deakin Lecture series presenter in Melbourne in 2010. In 2015 he was invited to speak to ranchers on the five main Hawaiian islands.