According to the United Nations REDD Programme, the implementation of Reducing Emissions from Deforestation and forest Degradation (REDD) projects can occur effectively if a “transparent, comparable, coherent, complete and accurate measurement, reporting and verification (MRV) national systems are developed and implemented.” Leader of the UNEP Carbon Benefits Project at Michigan State University, Dr David L. Skole and his team demonstrated, at the recent IUFRO-FORNESSA Regional Congress, their new tool called An Enterprise On-Line Carbon Measurement, Reporting, and Verification (MRV) Tool. The tool uses a number of widely available GIS and database management software together with up-to-date allometric equations for monitoring carbon projects.
Allometric equations for measuring baseline carbon stocks are continually updated, both at a large regional level and also at a local level, and participants were able to see two examples of corrections to the equation. The scientists from the World Agroforestry Centre and other institutions were hopeful that innovative equations geared towards improving the calculation of total carbon mass (biomass) for any given land size may ultimately improve the reliability of MRV tools and help farmers take full responsibility for REDD+ projects running on their properties.
REDD+ projects are those that are set up to encourage stakeholders usually rural smallholder farmers to conserve forests or trees by giving them financial incentives. Regions like Brazil’s Amazon forest still get the bulk of REDD+ projects because REDD was initially set up to target high forest cover regions. Since the ‘+’ was added to REDD, other regions with lower forest cover have the opportunity to take advantage of co-benefits such as improved biodiversity and livelihoods while reducing deforestation and forest degradation.
Unfortunately, the African continent has low forest cover overall so REDD+ investors generally assume the continent has low biomass (carbon mass) volume. Dr David Skole suggested that the problem lies in the difficulties project implementers experience when setting up, monitoring and evaluating REDD+ projects. He said an online system for managing REDD+ projects that can give very accurate measurements of carbon stocks will encourage more investors and farmers in Africa to participate in REDD+ projects. In his opinion, the MRV tool will ease real time monitoring and evaluating of carbon projects.
Dr Skole alluded that it is especially critical to encourage African farmers to partake in the carbon market because the bulk of the markets biomass is set to come from places such as open woodlands and from regeneration systems such as agroforestry. Indeed more farmers are being encouraged to grow trees on farms in order to reduce emissions from land-use-change. “A total of about 450 Pentagrams of carbon (PgC) are released annually around the world with about 124 PgC due to land-use-change which represents 60% in tropical areas and 40% in temperate areas.”
All presenters agreed that the end goal is to be able to use high resolution satellite images to accurately measure the amount of biomass in any landscape and have a tool such as the MRV to monitor carbon stocks in real time. A major challenge in realizing this goal is the formulation of allometric equations. These equations help translate satellite images of tree canopies into biomass values.
“We think there is more carbon on farms than what is generally predicted by general national level allometric equations,” said Dr David Skole.
According to Dr David MacFarlane, Associate Professor of Forestry at Michigan State University (MSU), the basic problem is “standing trees cannot be weighed and therefore biomass must be predicted from dimensional measurements of trees, based on allometric scaling principles, regardless of the way tree or forest information is gathered.”
His team created a tree form factor for correcting general allometric equations. Once extensively tested, the correction factor could improve the accuracy and accessibility of the online MRV tool for farmers. Using his tree form factor that takes into account the tree form and wood density, Dr MacFarlane claimed that his equations can produce results that are arguably nationally consistent and locally accurate.
Unfortunately, there is a price to pay for the improved equation accuracies. The drive towards robust yet nationally consistent models is often costly both in economic and ecological terms. As an example, destructive sampling which is the process of cutting down trees in order to measure tree parameters, has been shown to be ecologically destructive over a larger area.
“Locally developed, species-specific equations are always the most accurate, national scale inventories [biomass measures] need to employ robust and nationally consistent models while mitigating the high economic and ecological cost of destructive sampling over large areas,” said Dr MacFarlane.
To this end, World Agroforestry Centre Scientist Shem Kuyah has worked with other scientists in exploring other ways of improving the accuracy of local data without felling trees. His study used a non-destructive technique known as Fractal Branch Analysis (FBA) to see how its accuracy compared with the destructive methods for calibrating regional tree biomass equations. FBA uses the symmetry and geometry of tree branches relative to the major stem.
Shem told congress participants that FBA is a very good method for estimating above-ground biomass in landscapes containing specific type of tree species such as those that can be found in forest plantations. It will be sometime before his FBA-based equations can be used to calculate biomass values within mixed species landscapes such as agroforestry systems.