FY2023 FNCA Workshop on Climate Change (Evaluating the Carbon Emission from Forest Soils: ECEFS) project was held on December 12, 2023, online. This Workshop was hosted by Ministry of Education, Culture, Sports, Science and Technology (MEXT) of Japan.

The Workshop was attended by 32 participants from 8 FNCA member countries, namely, Bangladesh, China, Indonesia, Japan, Malaysia, Mongolia, the Philippines and Vietnam, including workshop staffs.

Workshop

The welcome address by Mr. OBATA Ryoji, MEXT, and the opening remarks by Dr. TAMADA Masao, FNCA Coordinator of Japan, were delivered. Then, the introduction by each Workshop participant followed and the workshop agenda was adopted.

Since this project has been started as a new project of FNCA from FY2023, an overview of the project was explained by Dr. NGAI Haruyasu, the project leader of Japan. Country reports on the current situation and future plans were delivered from six countries (Bangladesh, Indonesia, Malaysia, Mongolia, the Philippines and Vietnam).

Based on the current situation in each country, all participants discussed the experimental plans. The sampling methods of soil and gas that will be used for the analysis in this research were explained. The samples of each country should be sent to Japan, CO₂ gas, the soil and ¹⁴C will be analyzed in Japan. The data obtained through the analysis will be collected to construct a database. Furthermore, a wide-area evaluation by machine learning using this database will be conducted.

Session 1

Mr. OBATA, MEXT, gave the welcome address. He said, "Among the FNCA projects, this climate change project is led by Japan and has been restarted in 2023, and the reason for this is to respond to global warming and to reveal the dynamics of carbon dioxide in soil. Elucidating this will greatly contribute to understanding future climate change. Nine countries are participating in this project, and we very much welcome their participation." Afterwards, Dr. TAMADA, FNCA coordinator of Japan, remarked that this project had been adopted at the Coordinators Meeting (CDM) held in June, 2023, then started. He also noted that carbon dioxide emitted from soil is the main cause of global warming. Because CO₂ plays such an important role, there is an urgent need to construct a universal CO₂ emission model. FNCA projects are normally evaluated every three years, and this project is scheduled to be evaluated under the CDM at the end of FY2025. He expressed his hope that there would be a lively discussion in this workshop for developing a prototype database of CO₂ emissions.

Session 2

Dr. NAGAI, the project leader of Japan, provided an overview of this project. In the global carbon cycle in the terrestrial ecosystems, soil stores more than twice as much carbon as the atmosphere and releases carbon through microbial decomposition of soil organic carbon (SOC). So far, this carbon emission amount maintains the balance with that enters through photosynthesis by plants. However, global warming may accelerate the decomposition of SOC by microorganisms and increase the release of CO₂ from the soil to the atmosphere. Therefore, the models for predicting future climate change require accurate soil CO₂ emission models. Based on the above background, the project aims to understand the processes that drive carbon cycling in terrestrial ecosystems and their sensitivity to temperature increases, and to predict the feedback of carbon cycling to global warming. It was explained that the project would take six years to complete, with the ultimate goal being to develop an Asian-scale soil properties database and soil CO₂ emission model.

Session 3

Country reports were given by the participating countries.

Bangladesh

There are four major forest types in Bangladesh: 1) tropical evergreen to semi-evergreen forests (hill forests), 2) tropical moist deciduous forests (sala forests), 3) mangrove forests (natural mangroves and mangrove plantations), and 4) wetland forests. Satoyama also occupies an important part of the country, accounting for approximately 2.6 million hectares, or 17.4% of the country. Regarding soil types, Cambisols, Fluvisols, and Nitsols are the main soil types of tropical forests, mangroves, and deciduous forests, respectively. Additionally, mangrove forests store the highest amount of SOC. Among the soil types, Fluvisol and Graysol store most of this SOC.

Indonesia

The research center (BRIN) in Indonesia carries out research on a wide range of applications of radiation and isotopes (radiocarbons) in agriculture, hydrogeology, the environment, etc. Other than radiocarbon, the topic of FNCA is relatively new to our current research center. We intend to work with local parties who have more experience with this particular application. In addition, responses to a questionnaire conducted before the workshop regarding forest types and soil types were also explained.

Malaysia

We aim to understand the processes that drive carbon cycling in terrestrial ecosystems and to determine the SOC characteristics of forest soils in different locations and would like to conduct an analysis. However, there is a lack of equipment such as accelerated mass spectrometry (AMS), limited resources (particularly financial) to support basic science research, and soil sampling is dependent on other ongoing activities/projects.

Mongolia

For permafrost monitoring, there are currently more than 80 actively monitored boreholes distributed throughout Mongolia, and these boreholes are equipped with temperature data loggers that operate at 4-hour intervals. Despite occupying a large area (40% of the total area), the Gobi desert region has low organic carbon storage in the soil, and forests (9% of the total area) have a high storage capacity of 1510 mg despite its small area.

The Philippines

We have two research themes. One is the detection of stored carbon in the Philippine National Greening Program using stable isotope technology. This study assesses the impact of afforestation on soil carbon sequestration by comparing carbon pools to reference sites and identifying sources of soil carbon. Soil sample collection is carried out at four NGP sites (Lagro, Rodriguez, Payatas, lpo) and associated reference sites. The another one is the research on the effects of land use changes with the aim of understanding the dynamics of carbon sequestration and mineralization associated with land use changes in the Philippines. It is important to understand the dynamics of carbon sequestration and mineralization with land use change to address the challenges posed by land use change and the need for sustainable agriculture.

Vietnam

In Vietnam, the main cause of climate change such as global warming is an increase in the concentration of CO₂ in the atmosphere. Although industry is the main source of CO₂ emissions, emissions from the soil are also significant concern. Therefore, we aim to understand the processes that drive carbon cycling in terrestrial ecosystems (particularly soils) and their sensitivity to temperature increases, and to predict the feedback of carbon cycling to global warming. The project will collect and characterize soil organic carbon (SOC) in forest soil. The target areas are Nam Cat Tien National Park (forest type: deciduous broad-leaved trees, evergreen broad-leaved trees, soil type: acrisol, arissol, ferarisol) and Yok Don National Park (forest type: dry dipterocarp forest, semi-deciduous forest, evergreen forest, soil type: Acrysol, ferrasol, mainly red basaltic soil). The analysis is conducted by sampling from these two locations."

Session 4

Dr. KOARASHI from JAEA explained that the goal of this research was to provide scientific (and quantitative) insights into carbon cycle feedbacks to global warming in order to improve our ability to predict future climate change on Earth. He proposed the following five items for future implementation.

1. Measuring the CO₂ emission rate from various forest soils (surface layer 0 to 20 cm) throughout Asia [soil incubation]
2. Measuring the physicochemical, mineralogical, and organic matter properties of the soil, including ¹⁴C characteristics as an indicator of SOM turnover [soil analysis]
3. Building an Asian-scale database
4. Analyzing the relationship between CO₂ emission rate and soil properties to investigate the factors controlling CO₂ emission rate from forest soil
5. Developing a model to assess CO₂ emissions from Asian forests and future responses to global warming

In order to promote the above research, JAEA will develop an experimental kit and plan to distribute it to each country. This kit is used to collect soil samples. It also presents criteria for selecting locations for collecting soil samples, and in the first phase of this project, experiments will be conducted on samples from more than 50 locations in Asia, and ¹⁴C analysis of 40 soil samples.

Prior to this workshop, responses to a survey of participating countries were submitted from five countries (Indonesia, Kazakhstan, the Philippines, Thailand, and Vietnam), and the responses were organized and presented. Each of them was asked to response to the questions and to consider the things regarding the content.

Then, a time schedule for this project was shown as follows.

Until the end of March 2024

• The locations for research will be determined through further discussions between Japan and participating research teams.
• Develop an "experiment kit" and begin distributing it to participating research teams.

From April 2024 to October 2025

• Each research team will sequentially begin experiments using the kits at selected research locations while maintaining close contact with Japan.
• The research team will send soil and gas samples to Japan as soon as they are ready.
• The Japanese research team will conduct proper soil and gas analysis.

In December 2025

• By a database, analyzes the relationship between CO₂ emissions and environmental factors, and build a prototype model to estimate emissions.

Discussions were performed based on the research plan presented by Dr. KOARASHI.

Session 5

At the conclusion of the workshop, Dr. NAGAI announced that the next workshop would be held in Japan in 2024.