Project lists

23.To Demonstrate the Development and Application of Standing-Tree Carbon Equations to Improve the Accuracy of Forest-Cover Carbon Stock Estimates in Thailand
20 Mar 2022     


As economies all over the globe have come together to commit to climate action and reducing or compensating for carbon emissions to combat climate change, it became clear that for proper reporting and accounting a multitude of data needs to be provided by each economy. Beyond accounting for carbon emissions like the burning of fossil fuels, emissions produced by transportation or emissions resulting from the production of goods, it was recognized that the carbon stored in forests needs to be properly accounted for as well. This is both because in the long term forests, often through forest restoration programs, can act as carbon sinks, or because deforestation would cause carbon release that should be part of an economy’s reported carbon emissions.  


While Thailand has now been reporting to the United Nations Framework Convention on Climate Change (UNFCCC) for a number of years, there is still some uncertainty about the accuracy of national estimates of Thailand’s forest cover carbon stocks, including incomplete reporting of carbon stocks and limited knowledge of the best method to assess carbon stocks. This, of course, affects the quality with which Thailand can assess its own contributions to climate change.


Thus in January 2017, APFNet funded a project spearheaded by Kasetsart University Faculty of Forestry (KUFF) to develop new standing-tree carbon equations that are expected to result in more accurate data about the forest carbon stocks. Subsequently, a pilot map of forest cover carbon stocks in the Ngao Demonstration Forest in Lampang Province will be developed, which can later be scaled up for the entire economy.


(Main Topic 1: Developing Standing-Tree Carbon Equations)


Taking Stock of Thailand’s Forests

In 1992 the researchers Pochai and Nanakorn developed local tree volume equations based on upper stem diameter measurements of standing trees. While a good tool at the time, those equations were developed for only one local area in northern Thailand using a small sample of trees. Additionally, only the DBH of the trees was used as an independent variable, while tree height – now the minimum standard for any volume equation – was simply not considered at all. Finally, sets of species were simply grouped together by tree family grouping them based on wood density, thus potentially skewing the accuracy of the equations. Yet subsequently those equations were applied on a national scale.


With the increasing importance of assessing carbon stocks accurately, these rough calculations were simply not enough anymore and need to be replaced. The new equations to be developed by KUFF will instead both incorporate total height and DBH and refine the base equations through taking base sample tree cores. This way the equations for major tree species groups subdivided by wood density in evergreen, mixed-deciduous and dry dipterocarp forests can be developed. Subsequently, a focus group will create a national action plan for the development of national standing-tree carbon equations for all the major species groups.


(Main Topic 2: Developing Forest Cover Carbon Stock Map)


Visualizing Carbon Stocks

Creating improved equations is certainly a great achievement on its own, however in order to ensure that those new estimates are actually used by policy makers, visual tools that combine the power of GIS and remote sensing with the new calculated data, need to be employed. In short, beyond the mere equations what policy makers really need are carbon stock maps. With such maps government officials can make better informed policy decisions, but also have a visual tool that displays forest carbon stocks across the economy.


As previously mentioned, due to the limited focus of the project it would not be possible to create maps for all of Thailand, as the current equations will only cover some of the major tree species groups. Thus, to nevertheless demonstrate the possibilities of such maps, a pilot map of the Ngao Demonstration Forest in Lampang Province will be developed using Landsat data with a basic 30x30 meter resolution on multi-spectral mode and one fine 15x15 resolution on panchromatic mode, considering the areas NDVI. Combined with various GIS data regression relationships between satellite data and ground data (collected during the development of the equations) the maps will then be developed.




Scaling it up

Both the newly calculated equations and carbon stock maps are only the start of a push to replace all of the old equations and maps on a national level. Thus, towards the end of the project a national workshop involving about 40 participants from relevant government and private agencies will be held to disseminate the knowledge and get more buy-in. Using this new methodology to create carbon stock equations during future national forest inventories carbon stocks can be calculated and displayed more accurately and help Thailand to meet its national and international reporting commitments and implement its strategic plan for sustainable forestry.



  • Developing standing-tree carbon equations to improve the accuracy of forest cover carbon stock estimates in Thailand



Project title: To Demonstrate the Development and Application of Standing-Tree Carbon Equations to Improve the Accuracy of Forest-Cover Carbon Stock Estimates in Thailand  [project ID:  2015P6-THA]

Supervisory agency:   Royal Forest Department, Bangkok, Thailand

Executing agency:   Kasetsart University, Faculty of Forestry, Bangkok, Thailand  

Budget in USD (total / APFNet grant): 253,345/199,045

Kick-off date & duration: 01/2017-12/2018

Target economy: Thailand

Site Location:   Ngao Demonstration Forest, Lampang Province, Thailand


- Provide accurate information on national forest carbon stocks to support informed sustainable forest management policy decision-making and balanced public debate on the benefits of forests in climate change mitigation. 

- To pilot-test the development of accurate standing-tree carbon equations and their application to the preparation of a forest-cover carbon stock map in the Ngao Demonstration Forest, Lampang Province.

Expected outputs:

- Methodology to construct new tree carbon equations developed and pilot-tested.

- Application of tree carbon equation to prepare a carbon cover map demonstrated.

- Action plan to construct and promote national standing-tree carbon equations prepared.

- Information and knowledge from the project disseminated among stakeholders.


Kasetsart University: Dr. Khwanchai Duangsathaporn (

APFNet: Anna Finke (; Sun Weina ( )