Field trip to the National Forest Reserve area, including Pak Chong and Mu Si forests, Nakhon Ratchasima province from 24-25 April 2025

Field trip to Khun Mae Tha National Forest Reserve, Chiang Mai province from 30 April to 1 May 2025

From April to May 2025, the Climate, Coastal and Marine Biodiversity (CCMB) project, implemented by GIZ Thailand, collaborated with the Office of the National Land Policy Board (ONLB) and Kasetsart University, the project consultant, on a joint visit to the case study areas in two provinces to support carbon sink assessment and guidelines on ONLB land. The purpose of the visit was to study land use patterns and collect soil samples to assess carbon sequestration, or carbon sink potential.

A carbon sink is a natural or artificial reservoir that absorbs and stores carbon dioxide (CO₂) from the atmosphere. It can be classified into three main types:

1. Terrestrial (Ground) Carbon Sink
2. Geologic (Underground) Carbon Sink
3. Oceanic Carbon Sink

This site visit focused on terrestrial and geologic carbon sinks. Key factors that enhance an area’s ability to sequester carbon include promoting natural ecosystem growth and conserving existing resources, such as through reforestation, afforestation, and the restoration of agricultural land, which also contributes to increased carbon capture.

Based on these components, the selected areas in different provinces with varying contexts serve as case studies for comparing land use patterns between monoculture and mixed farming. The goal was to develop land management guidelines for ONLB areas and to analyse the carbon sequestration potential of each land use pattern.

The selected areas were: (1) the National Forest Reserve in Pak Chong and Mu Si forests, Sung Noen district, Nakhon Ratchasima province, and (2) the National Forest Reserve in Khun Mae Tha forest, Mae Tha subdistrict, Mae On district, Chiang Mai province. These areas were chosen because they have shifted from monoculture farming to cultivating trees and other economically valuable crops such as coffee, and mixed agriculture. This transformation can serve as a model for enhancing carbon storage in the development of ONLB areas.

The National Forest Reserve area, including Pak Chong and Mu Si forests, Nakhon Ratchasima province

From 24-25 April 2025, the team visited representatives from Ban Dong Mafai Community-based Arabica and Macadamia Coffee Enterprise, who initiated the use of the area by engaging nearby communities and showcasing various types of agricultural plots.

In addition, soil samples were collected to analyse soil particle density and assess soil carbon sequestration. The samples were taken from various types of agricultural areas, as follows:

1. Mono-crop field (cassava): This area represents mono-crop farming, where farmers alternate between planting cassava and corn each year, without changing the overall cultivation pattern or implementing crop rotation.
2. Fruit plantation (mangoes): This area represents a single-crop orchard model, where mango cultivation has been continuously practiced for approximately 20 years.
3. Mixed coffee plantation: This plantation includes coffee alongside various other plants, such as macadamia, longan, and herbs, as well as forest and economic trees. It has been in operation for over 20 years.

In this regard, Kasetsart University, the project consultant, plans to collect additional data to gather comprehensive information on the area’s agricultural patterns.

Khun Mae Tha National Forest Reserve, Chiang Mai province
During the visit between 30 April and 1 May 2025, the team spoke with representatives of the Subdistrict Administrative Organisation and local farmers about the area’s history and land use.

This region is rich in plant biodiversity and ecosystems, particularly near the watershed forest. Such richness is the result of strong community collaboration and effective land management, which has developed into a cooperative system. This system not only provides sustainable income for the villagers but has also attracted private sector investment, helping expand household-level industries into thriving local enterprises.

In this study, soil samples were collected for analysis of soil particle density and assessment of soil carbon sequestration. The samples were taken from various agricultural areas, as follows:

1. A mixed mango plantation, where mangoes are grown alongside other plants such as pineapples and various herbs between the mango rows, and has been in operation for approximately 39 years.
2. Longan monoculture refers to the cultivation of only one variety of longan.
3. A longan mixed plantation, where longans are grown alongside other plants such as avocados, guavas, pineapples and more, and has been in operation for approximately 20 years.
4. Mixed vegetable plots consist of a variety of vegetables and have been in operation for approximately 23 years.

This field visit was a key component of the CCMB project’s objectives. The consultant team conducted a survey to study the geographic and social characteristics of the area, collecting data on land use and soil samples. This information will be used to develop guidelines for assessing soil carbon sequestration, enhancing carbon sequestration potential, and providing recommendations for development models in the ONLB area to improve carbon sequestration and generate additional co-benefits.

The development model for the ONLB area to be presented by the consultant will be based on a sustainable, low-carbon agriculture approach. This model will serve as a key mechanism to strengthen the linkages between nutrition, agriculture, and the promotion and preservation of environmental quality – including biodiversity conservation. It will also support the ONLB’s operations, making them more efficient and environmentally friendly.

The carbon sink assessment and guidelines on ONLB land will be included as part of the Carbon Sink Roadmap – Thailand’s strategic plan to enhance carbon absorption sources. This initiative aims to help achieve the goals set under the Nationally Determined Contribution 3.0 (NDC 3.0), which targets reducing greenhouse gas emissions to below 270 million tons of carbon dioxide equivalent by 2035 and increasing carbon sinks in the forestry and land use sectors to 120 million tons by 2037.

For more information on the CCMB project, visit https://www.thai-german-cooperation.info/th/climate-coastal-and-marine-biodiversity-ccmb/