The Clear Seasonal Difference of Carbon Flow in Teak Plantation in Northern Thailand

Abstract:

The amount of GHG emissions from deforestation and forest degradation in Tropical Asia regions became enormous. Thailand has the history that logged from natural forest and shifted to plantation such as rubber or teak. This tendency might also continue because of the presence of the neighboring country, which imports enormous timbers each year. And seasonal variation of rainfall amount in Thailand is very large as an effect of monsoon climate and Phenology changes clearly in deciduous forest. Thus, seasonal variation of CO₂ emissions from Teak plantation in Thailand might be larger compare to other tropical regions, but not enough researched. From the facts above mentioned, this study pursues to reveal the carbon flow in rainy and dry season in Teak plantation in Thailand and finally to reveal that which environmental factor controls soil respiration variation. The experiments were carried out in an even-aged teak (Tectona grandis) plantation located in Lampang Province, northern Thailand. The teak plantation was established in 1968. The amount of Carbon flow flux in rainy season and dry season were calculated using the data of soil respiration in 2007-2013, carbon flux above the canopy in 2006, litter fall amount in 2009, and above ground plant growth in 2006-2012. In rainy season (from June to September), GPP, above ground plant growth, litter fall, and soil respiration are 10700kgC/ha, 5046±1021kgC/ha, 835kgC/ha, and 6304±1664kgC/ha, respectively. TBCF was calculated by GPP and above ground plant growth as 5654kgC/ha. In dry season (from December to March), 2691kgC/ha, -806±373kgC/ha, and 2230kgC/ha, respectively. TBCF is 3497kgC/ha. Now, experiment of measuring root growth and withering is conducted. Soil respiration in rainy season is three times as large as that in dry season. And in dry season, the ratio of TBCF to GPP is much higher than that in rainy season.