S. Jantawong et al. / EnvironmentAsia 12(3) (2019) 12-22

EnvironmentAsia 12(3) (2019) 12-22 DOI 10.14456/ea.2019.41 EnvironmentAsia ISSN 1906-1714; ONLINE ISSN: 2586-8861 The international journal by the Thai Society of Higher Education Institutes on Environment

Impacts of Land Use Changes on Carbon Stocks, Greenhouse Gas, and Carbon Economic Value of Agriculture, Forestry and Other Land Use (AFOLU) Sector in Coastal Area of Yi San Sub-District, Samut Songkhram Province, Thailand between 2001 and 2015

Sopana Jantawong1*, Nipon Tangtham2, Puntip Jongkroy3

1Sustainable Land Use and Natural Resource Management Program, the Graduate School, Kasetsart University, Bangkok, Thailand 2 Forestry Research Center, Faculty of Forestry, Kasetsart University, Bangkok, Thailand 3 Department of Geography, Faculty of Social Sciences, Kasetsart University, Bangkok, Thailand

* Corresponding author: [email protected] Received: June 28, 2018; Revised: December 30, 2018; Accepted: June 17, 2019

Abstract

The objectives of this research were to 1) study changes in land use of Agriculture, Forestry and Other Land Use (AFOLU) sector using GIS application as a tool for accounting land use type area for each given periods, 2) to estimate the amount of carbon stocks, and carbon dioxide emissions and removals from changes of 6 land use types (mangrove forest, cropland, grassland, wetlands, settlements, and aquaculture land) which were evaluated under the standard method of the 2006 IPCC Guideline for National Greenhouse Gas Inventories, and 3) to evaluate the economic value of carbon dioxide based on existing carbon price in California Carbon Market. The result showed that between 2001 and 2015 in Yi San Sub-district, Samut Songkhram Province, different types of land use were changed from aquaculture to mangrove forest (974.37 ha), followed by mangrove forest to aquaculture (770.75 ha), respectively. Mangrove forests increased in carbon stocks due to biomass growth of 50,730.63 tC and the large proportions of decrease in carbon stocks in biomass were from aquaculture land as -21,735.14 tC. The estimation of total carbon dioxide emissions was +123,043.83 tCO2 and total carbon dioxide removals were -190,409.73 tCO2. The land use with the highest carbon dioxide emission was the aquaculture land (+81,696.64 tCO2), followed by the grassland (+35,058.26 tCO2) and settlements (+5,509.30 tCO2), respectively. The land use with the highest amount of carbon dioxide removal was the mangrove forest (-186,012.28 tCO2), followed by the cropland (-2,257.41 tCO2) and grassland (-2,140.04 tCO2), respectively. The highest gain of economic value from CO2 removals was the mangrove forest (2,808,785.43 USD) followed by cropland (22,314.48 USD). The highest economic loss from CO2 emissions was the aquaculture land (1,233,619.26 USD) followed by the grassland (497,065.12 USD) and settlements (83,190.43 USD), respectively. As a result, those land use changes can reduce global warming potential (GWP) up to -67,365.90 tCO2e and increase the net total carbon economic value as 1,017,225.09 USD.

Keywords: Land Use Changes; Carbon Stocks; Carbon Economic Value; AFOLU Sector; Coastal Area; Samut Songkhram Province; Thailand

12 S. Jantawong et al. / EnvironmentAsia 12(3) (2019) 12-22 1. Introduction 2006 IPCC guidelines in the AFOLU sector. The result that Nan Province, Udon Thani Global warming and climate change has Province and Bangkok was identified as a CO2 been widely recognized as a major global issue emission source. The proportions of emissions as it threatens to alter the natural environment, in Nan were larger than CO2 emission due to the disrupt the well-being of society, and deter conversions of forest land to the various types economic development. (IPCC, 2007). The of cropland. In contrast, Surat Thani Province greenhouse gases concentrations in the was considered as a carbon sink due to the large atmosphere have been proportionally emitted coverage of the forest land and perennial crop from the human activities as shown in the (Miphokasap, 2017). changes of land use pattern (IPCC, 2006). The Coastal areas play an important role in Agriculture, Forestry and Other Land Use the global carbon cycle and therefore changes (AFOLU) sector plays a central role for food in land use could affect this role. Changes security and sustainable development, it is in land use influence the amount of carbon one of the four major sources (energy sector, storage in vegetation and soil thereby either industrial processes and product use sector, releasing CO2 to, or removing it from, the agriculture, forestry and other land use sector, atmosphere (Jong et al., 2010). In Thailand, and waste sector) of GHGs, particularly of mangrove forests are found mainly along the carbon dioxide (CO2) (IPCC, 2006). At a global coastal area. Some local communities like scale of GHGs emissions by economic sector, the those in Yi San Sub-district have developed AFOLU sector is the largest emitting sector after a sustainable mangrove plantation for the the energy sector that accounted for 24% and purpose of charcoal production (Kridiborworn 35%, respectively, of the total emissions (IPCC, et al., 2012). Yi San Sub-district is located in 2014), but that if no further mitigation measures the coastal zone of Amphawa District, Samut and technical efficiency improvements are Songkhram Province, central Thailand. The first implemented, future emissions may further private mangrove forest plantation in Thailand increase by up to 30% by 2050 (Tubiello et al., started in Yi San in 1907 and it is known as 2014). a source of best quality mangrove charcoal Between 1990 and 2005, Thailand had production (Department of Marine and Coastal the 24th largest greenhouse gas emissions Resources, 2009). In 1987, the mangrove forest in the world, the 6th in Asia, and the 2nd in was approximately 50% which was degraded Southeast Asia. The highest greenhouse gas by intensive shrimp farming. When shrimp emission was the energy sector (73.13%), farming was unsuccessful, some locals turned followed by the agriculture, forestry and other to commercial mangrove plantation business land use (AFOLU) sector (15.89%) and the as a new source of income. The mangrove areas industrial processes and product use sector have slightly increased recently (Department (9.55%), respectively (The Joint Graduate of Marine and Coastal Resources, 2009; School of Energy and Environment, 2012; The Kridiborworn et al., 2012; Choosak, et al., 2016). Thailand Research Fund, 2016). The AFOLU The objectives of this research are 1) sector is unique among the sectors considered to study changes in land use of Agriculture, in this volume, since the mitigation potential is Forestry and Other Land Use (AFOLU) sector derived from both an enhancement of removals 2) to estimate the amount of carbon stocks, of GHGs, as well as reduction of emissions carbon dioxide emissions and removals from through management of land and livestock changes of 6 land use types (mangrove forest, (IPCC, 2014). cropland, grassland, wetlands, settlements, The spatial inventory of CO2 emissions and aquaculture land, and 3) to evaluate the and removals during 2007-2012 resulting from economic value of carbon dioxide based on carbon stock change in biomass from land use existing carbon price. The success of this and land use changes in Thailand based on the study will lead to an awareness of stakeholders

13 S. Jantawong et al. / EnvironmentAsia 12(3) (2019) 12-22 to recognize the impacts of greenhouse gas mangrove areas have slightly increased recently emissions from land use changes. The results (Department of Marine and Coastal Resources, shall also provide a database on greenhouse gas 2009; Kridiborworn et al., 2012; Choosak, et al., inventories, trend of greenhouse gas emissions 2016). and reduction of greenhouse gas from land use changes for policy makers and optimization of 2.2 Research methodology framework land use in coastal area during economic, social Data analysis and evaluation were divided and environmental development in the future. into four main parts of accounting land use changes, changes in carbon stocks, the CO2 2. Materials and Methods emissions and removals, and the amount of economic value were illustrated in Figure 2. 2.1 Study site Yi San Sub-district (centered at 13º 2.2.1 Re-arranging land use categories and 16ʹ-13º 19ʹ N 99º 52ʹ-99º 56ʹ E) is located classification of land use changes based on the in the coastal zone of Amphawa District, 2006 IPCC guidelines in the AFOLU sector Samut Songkhram Province, central Thailand The spatial layers (scale 1: 50,000 in (Figure 1). The first private mangrove forest 2001 and scale 1: 25,000 in 2006, 2009, 2011, plantation in Thailand started in Yi San in 2012, 2015) of land use categories which were 1907 and it is known as a source of best quality interpreted from satellite image, aerial photo mangrove charcoal production (Department and ground survey operated by the Land of Marine and Coastal Resources, 2009). Local Development Department (LDD, 2017) were people were dependent on these forests for used as the activity data source. However, five goods and services such as aquaculture and main land use categories (urban and built- charcoal production. Mangrove plantations up land, agricultural land, forest land, water of Rhizophora apiculata was once common body, miscellaneous) of LDD differ from those (Community-Based Research Division, of the 2006 IPCC guidelines. Thus, it needs 2009; Ratanavilaisakul, 2010). In 1987, the to re-arrange the land use categories to be mangrove forest was approximately 50% which consistent. The six land categories (forest land, was degraded by intensive shrimp farming. cropland, wetlands, grassland, settlements, When shrimp farming was unsuccessful, other land) based the 2006 IPCC guidelines some locals turned to commercial mangrove were subdivided into land remaining in the plantation business as a source of income. The same category and converted from one category

Figure 1. Study site in Yi San Sub-district, Samut Songkhram Province, Thailand Source: Google Earth (2018)

14 S. Jantawong et al. / EnvironmentAsia 12(3) (2019) 12-22

Table 1. Land use categories and sub-categories based on the 2006 IPCC guideline

to another. Each land category was further are categorized into wood harvesting, and losses subdivided into sub-categories as illustrated in from natural disturbances such as fire and Table 1. flooding (IPCC, 2006).

2.2.2 Estimation of annual carbon stocks (2) in biomass changes 1) The emissions and removals of CO2 Where: ΔCB = annual change in carbon for the AFOLU sector, based on change in stocks in biomass (the sum of above-ground ecosystem C stocks, are estimated for each land and below-ground biomass) for each land sub- use categories including both land remaining category, considering the total area, tC/yr, ΔCG in the same category and land converted to = annual increase in carbon stocks (Gain) due another land use for all subdivisions of land area to biomass growth for each land sub-category, category, carbon stock changes were separately considering the total area, tC/yr, ΔCL = annual calculated and summarized in six land use decrease in carbon stocks (Loss) due to biomass categories (IPCC, 2006) as shown in Equation loss for each land sub-category, considering the (1). total area, tC/yr

(1) 2.2.3 Estimation of CO2 emissions and removals Where: ΔC is carbon stock change, Convert C to CO2 emissions and removals AFOLU is Agriculture, Forestry and Other as shown in Equation (3). Land Use, FL is Forest Land (in this study FL is specified for Mangrove Forest), CL is (3) Cropland, GL is Grassland, WL is Wetlands, SL is Settlements, and OL is Other Land (in this Where: ΔCB = Annual carbon stock study OL is specified for Aquaculture Land) changes, Conversion factor = 44/12 (IPCC, 2006), Molecular weights: C = 12g/mol, O = 16 2) Annual carbon stock changes in each g/mol, CO2 = 44 g/mol. land use type can be calculated using the Gain- Loss method. The Gain-Loss Method requires 2.2.4 Evaluation of the economic value the biomass carbon loss to be subtracted from Evaluation of the economic value of the biomass carbon gain as shown in Equation carbon dioxide in this study was based on (2). Gain can be attributed to biomass growth existing carbon price in California Carbon at above and below ground components. Losses Market as shown in Equation (4)

15 S. Jantawong et al. / EnvironmentAsia 12(3) (2019) 12-22 mangrove forest expansion (approximately (4) 204.91 ha) and reduction of shrimp farming area (approximately 353.87 ha) during the past 3. Results and Discussion 14 years led to a greater potential of land use as a source of carbon storage as illustrated in 3.1 Distribution of land use and land conversions Figure 4 and in Supplementary Table 1. (ha) in Yi San Sub-district, Samut Songkhram Province, Thailand during 2001-2015 3.2 Amount of carbon stocks (tC) and CO2 The main proportions of land use emissions and removals (tCO2) from land use and categories in Yi San Sub-district, Samut land use changes in Yi San Sub-district, Samut Songkhram Province were aquaculture and Songkhram Province, Thailand for each period mangrove forest, respectively. The result showed during 2001-2015 that during 2009-2015, mangrove forest area In this study, the calculations of carbon continuously increased, while the area of stocks in biomass changes indicate that land aquaculture declined as illustrated in Table 2 uses in Yi San Sub-district, Samut Songkhram and Figure 3. Distribution of land use in the Province were as the carbon sink. This is mainly past was consistent with data in Supplementary because of the large coverage of mangrove Table 1 and it was found that between 2006 forest. The mangrove forest area, both land and 2015, different types of land use especially remaining and other land uses conversions to aquaculture were changed to mangrove forest. mangrove forest during 2001-2015 can increase Expansion of mangrove forest was driven by the in carbon stocks due to biomass growth with the failure of shrimp culture. total values of 50,730.63 tC. In contrast, during Between 2001 and 2015, the different types 14 years period, the loss of mangrove forest was of land use in the study area were changed from mainly caused by the conversions to aquaculture aquaculture to mangrove forest (974.37 ha), which resulted in the large proportions of the followed by mangrove forest to aquaculture decrease in carbon stocks in biomass with the (770.75 ha), respectively, the proportion of land values of -21,735.14 tC as illustrated in Figure conversion to another land use was highest 5 and in Supplementary Table 2. (21.59%) during the 2001-2006, followed by Over the period 2001-2015, AFOLU, during 2006-2009 (14.15%), and 2012-2015 net total carbon dioxide emissions of Yi San (6.03%), respectively. It can be concluded that Sub-district, Samut Songkhram Province were

Figure 2. Research Methodology Framework

16 S. Jantawong et al. / EnvironmentAsia 12(3) (2019) 12-22

Figure 3. Trend of land use distribution (ha) in Yi San Sub-district, Samut Songkhram Province, Thailand during 2001-2015

Figure 4. Land use category conversion in coastal area of Yi San Sub-district, Samut Songkhram Province, Thailand from 2001 to 2015 (unit: ha). The number 1 to 6 in each bar chart represent the area change of mangrove forest, cropland, grassland, wetlands, settlements, and aquaculture land respectively.

17 S. Jantawong et al. / EnvironmentAsia 12(3) (2019) 12-22

+123,043.83 tCO2 and net total carbon dioxide plays an important role in mitigating global removals were -190,409.73 tCO2. The land warming by CO2 removal up to -190,409.73 use with the highest carbon dioxide emission tCO2. If without mangrove area, the total CO2 was the aquaculture land (+81,696.64 tCO2), removal would drop to only -4,397.45 tCO2 followed by the grassland (+35,058.26 tCO2) and the proportions of CO2 emissions in Yi San and settlements (+5,509.30 tCO2), respectively. Sub-district were larger than CO2 removals as The land use with the highest amount of carbon +118,646.38 tCO2 causing GHG problem in the dioxide removal was the mangrove forest atmosphere as illustrated in Figure 6. (-186,012.28 tCO2), followed by the cropland This study is consistent with other research (-2,257.41 tCO2) and grassland (-2,140.04 that indicate the importance of deforestation tCO2), respectively (Table 3). During 2001- and conversion of mangrove ecosystems that 2006, the largest carbon dioxide emission have been predicted to result in significant source was aquaculture land (+58,413.61 tCO2). carbon emissions. The potential emissions from In contrast, 2012-2015, the largest carbon the conversion of mangroves to shrimp ponds dioxide removal by sink was mangrove forest are among the largest measured carbon dioxide (-41,812.22 tCO2) (Supplementary Table 3). In emissions from land use in the tropic. (Kauffman Table 3, the result showed that mangrove forest et al., 2014). The conversion, restoration and use

Table 2. Distribution of land use (ha) in Yi San Sub-district, Samut Songkhram Province, Thailand during 2001-2015

Table 3. Carbon dioxide absorption (tCO2) caused by land use changes in Yi San Sub-district, Samut Songkhram Province, Thailand during 2001-2015

18 S. Jantawong et al. / EnvironmentAsia 12(3) (2019) 12-22

Figure 5. Carbon stock in biomass change caused by land use category conversion in coastal area of Yi San Sub-district, Samut Songkhram Province, Thailand between 2001 and 2015 (unit: tC). The number 1 to 6 in each bar chart represent respective different land cover change paths, namely, mangrove forest, cropland, grassland, wetlands, settlements, and aquaculture land.

Table 4. Carbon economic value (USD and THB) of CO2 emissions and removals (tCO2) in Yi San Sub-district, Samut Songkhram Province, Thailand during 2001-2015

19 S. Jantawong et al. / EnvironmentAsia 12(3) (2019) 12-22 of mangrove forest in eco-engineering solutions by the given carbon price from California for coastal protection provide a promising Carbon Dashboard is voluntary carbon market, strategy, delivering significant capacity for equal to 15.10 USD/tCO2 (March 29, 2018) climate change mitigation and adaptation (Thailand Greenhouse Gas Management (Duarte et al., 2016). Organization, 2018). Results of the study showed that during 2001-2015 the gain of 3.3 Valuation of CO2 emissions and removals in highest carbon value from CO2 removals was Yi San Sub-district, Samut Songkhram Province, the mangrove forests (2,808,785.43 USD), Thailand for each period during 2001-2015 followed by cropland (22,314.48 USD). In Valuation of CO2 emissions and removals contrast, the loss of highest carbon value

Figure 6. Carbon dioxide emissions and removals from remaining land use and category conversion in coastal area of Yi San Sub-district, Samut Songkhram Province, Thailand between 2001 and 2015 (unit: tCO2). The number 1 to 6 in each bar chart represent respective different land cover change paths, namely, mangrove forest, cropland, grassland, wetlands, settlements, and aquaculture land.

20 S. Jantawong et al. / EnvironmentAsia 12(3) (2019) 12-22 from CO2 emissions was aquaculture land knowledge generated can be beneficial to support (1,233,619.26 USD), followed by grassland environmentally sustainable communities along (497,065.12 USD) and settlements (83,190.43 the coast. USD), respectively as illustrated in Table 4. Acknowledgement 4. Conclusion The researcher is grateful to the Sustainable In this study, we present the changes in Land Use and Natural Resource Management land use of Agriculture, Forestry and Other Land Program, the Graduate School, Kasetsart Use (AFOLU) sector using GIS application as a University for a Doctoral Degree scholarship. tool for accounting land use type area for each given periods, the amount of carbon stocks, and References carbon dioxide emissions and removals from changes of 6 land use types (mangrove forest, California Carbon Dashboard. Carbon price. cropland, grassland, wetlands, settlements, Available from: http://calcarbondash.org/ and aquaculture land) under the standard 2018; [Accessed 21th April 2018]. method of the 2006 IPCC, and valuation of Choosak S, Thongjoo C, Chaichana R. Ecological carbon dioxide based on existing carbon price. roles of commercial mangrove plantation The result showed that in Yi San Sub-district, forests for benthic macroinvertebrate Samut Songkhram Province, changes of land communities in Thailand. Applied Ecology use influences terrestrial CO2 sources and sinks. and Environmental Research. 2016; 14(2): It could be summarized from the results that 421-432. mangrove forests were identified as a CO2 sink Community-Based Research Division. Sub due to the highest increase in carbon stocks and global assessment-ecosystem services, the highest carbon economic gains. In contrast, human well-being and sustainable aquaculture land was considered as a CO2 development in Samut Songkhram emission source since most areas of mangrove Province. Bangkok, Thailand. 2009. (In forest, cropland, and grassland were converted Thai). to aquaculture. Thus, it caused decrease in Department of Marine and Coastal Resources. carbon stock and losses of the highest economic Yi San: Thailand ,s first private mangrove value. GIS based spatial inventory and carbon forest plantation. Bangkok, Thailand. economic value are beneficial to provide a 2009. (In Thai). database on greenhouse gas inventories status, Durate MC, Losada IJ, Hendriks IE, Mazarrasa trend of greenhouse gas emissions and reduction I, Marba N. The role of coastal plant of greenhouse gas from land use changes for communities for climate change mitigation policy makers and optimization of land use in and adaptation. Nature Climate Change. coastal area in the context of economic, social 2016; 3: 961-968. and environmental development at the level of Google Earth. Yi San Sub-district, Amphawa Sub-district, coastal area or different levels in the District, Samut Songkhram Province. future. However, the uses of the default emission Available from: http://maps.google.com/ and stock change factors for calculating CO2 maps 2018 [Accessed 21th May 2018]. emissions and removals were not consistent IPCC. IPCC guidelines for national greenhouse with the actual carbon stock in the specific gas inventories volume 4 agriculture, location. Thus, the practical emission factors forestry and other land use. Hayama, should be made available by considering to the Japan. 2006. vegetation types, age of trees, and environment IPCC. Summary for Policymakers. In: Solomon conditions. According to our findings, together S, Qin D, Manning Chen MZ, Marquis M, with additional investigation on livelihood, Averyt KB, Tignor M, Miller HL, editors. social aspects, and other environmental aspects, Climate change 2007: The physical science

21 S. Jantawong et al. / EnvironmentAsia 12(3) (2019) 12-22 basis. Contribution of working group I [Accessed 21th April 2018]. to the fourth assessment report of the The Joint Graduate School of Energy and Intergovernmental Panel on Climate Environment. The greenhouse gas Change. New York: Cambridge University inventory from agriculture report. Press; 2007. Bangkok, Thailand. 2012. (In Thai). IPCC. Agriculture, Forestry and Other Land The Thailand Research Fund. Thailand second Use (AFOLU). Chapter 11. In: Climate ,s second assessment report on climate change 2014: mitigation of climate change. Bangkok, Thailand. 2016. (In Change. contribution of working group Thai).Tubiello FN, Salvatore M, Cóndor III to the fifth assessment report of the Golec RD, Ferrara A, Rossi, S, Biancalani, Intergovernmental Panel on Climate R, Federici S, Change (Eds: Edenhofer O, Pichs- Jacobs H, Flammini A. Agriculture, Forestry Madruga R, Sokona Y, Farahani E, Kadner and Other Land Use Emissions by Sources S, Seyboth K, Adler A, Baum I, Brunner and Removals by Sinks, 1990-2011 S, Eickemeier P, Kriemann B, Savolainen Analysis. ESS Working Paper No. 2. Rome: J, Schlömer S, Stechow CV, Zwickel T, FAO; 2014 Available from: http://www.fao. Minx JC. New York: Cambridge University org/docrep/019/i3671e/i3671e.pdf 2014 Press; 2014. [Accessed 15th April 2018]. Kauffman JB, Heider C, Norfolk J, Payton F. Carbon stocks of impact mangroves and emissions arising from their conversion in the Dominican Republic. Ecological Applications. 2014; 24(3): 518-527. Kridborworn P, Chidthaisong A, Yuttitham M, Tripetchkul S. Carbon sequestion by mangrove forest planted specifically for charcoal production in Yeesarn, Samut Songkram. Journal of Sustainable Energy and Environment 2012; 3: 87-92. Land Development Department. Land Use Map of Samut Songkhram Province in 2001 scale 1:50,000 and Land Use Map of Samut Songkhram Province in 2006, 2009, 2011, 2012, 2015 scale 1:25,000. Bangkok, Thailand. 2017. (shape file). Miphokasap P. Spatial inventory of CO2 emissions and removals from land use changes in Thailand. Chemical Engineering Transactions. 2017; 56: 13-18. Ratanavilaisakul R. Study of coexistence of people with mangrove forest and wisdom of using resources for economics benefits in the Yi San community, Samut Songkhram Province. RMUTP Research Journal. 2010; 4(1): 102-114. Thailand Greenhouse Gas Management Organization. Carbon credit and carbon market. Available from: http:// carbonmarket.tgo.or.th/#weekly 2018

22