A study was conducted to assess carbon stocks in various forms and land-use types and reliably estimate the impact of land use on C stocks in the Nam Yao sub-watershed (19°05′10″N, 100°37′02″E), Thaila...A study was conducted to assess carbon stocks in various forms and land-use types and reliably estimate the impact of land use on C stocks in the Nam Yao sub-watershed (19°05′10″N, 100°37′02″E), Thailand. The carbon stocks of aboveground, soil organic and fine root within primary forest, reforestation and agricultural land were estimated through field data collection. Results re- vealed that the amount of total carbon stock of forests (357.62 ± 28.51 Mg·ha^-1, simplified expression of Mg (carbon)·ha^-1) was significantly greater (P〈 0.05) than the reforestation (195.25 ± 14.38 Mg·ha^-1) and the agricultural land (103.10 ± 18.24 Mg·ha^-1). Soil organic carbon in the forests (196.24 ± 22.81 Mg·ha^-1) was also significantly greater (P〈 0.05) than the reforestation (146.83 ± 7.22 Mg·ha^-1) and the agricultural land (95.09± 14.18 Mg·ha^-1). The differences in carbon stocks across land-use types are the primary consequence of variations in the vegetation biomass and the soil organic matter. Fine root carbon was a small fraction of carbon stocks in all land-use types. Most of the soil organic carbon and fine root carbon content was found in the upper 40-cm layer and decreased with soil depth. The aboveground carbon:soil organic carbon: fine root carbon ratios (ABGC: SOC: FRC), was 5:8:1, 2:8:1, and 3:50:1 for the forest, reforestation and agricultural land, respectively. These results indicate that a relatively large proportion of the C loss is due to forest conversion to agricultural land. However, the C can be effectively recaptured through reforestation where high levels of C are stored in biomass as carbon sinks, facilitating carbon dioxide mitigation.展开更多
文摘A study was conducted to assess carbon stocks in various forms and land-use types and reliably estimate the impact of land use on C stocks in the Nam Yao sub-watershed (19°05′10″N, 100°37′02″E), Thailand. The carbon stocks of aboveground, soil organic and fine root within primary forest, reforestation and agricultural land were estimated through field data collection. Results re- vealed that the amount of total carbon stock of forests (357.62 ± 28.51 Mg·ha^-1, simplified expression of Mg (carbon)·ha^-1) was significantly greater (P〈 0.05) than the reforestation (195.25 ± 14.38 Mg·ha^-1) and the agricultural land (103.10 ± 18.24 Mg·ha^-1). Soil organic carbon in the forests (196.24 ± 22.81 Mg·ha^-1) was also significantly greater (P〈 0.05) than the reforestation (146.83 ± 7.22 Mg·ha^-1) and the agricultural land (95.09± 14.18 Mg·ha^-1). The differences in carbon stocks across land-use types are the primary consequence of variations in the vegetation biomass and the soil organic matter. Fine root carbon was a small fraction of carbon stocks in all land-use types. Most of the soil organic carbon and fine root carbon content was found in the upper 40-cm layer and decreased with soil depth. The aboveground carbon:soil organic carbon: fine root carbon ratios (ABGC: SOC: FRC), was 5:8:1, 2:8:1, and 3:50:1 for the forest, reforestation and agricultural land, respectively. These results indicate that a relatively large proportion of the C loss is due to forest conversion to agricultural land. However, the C can be effectively recaptured through reforestation where high levels of C are stored in biomass as carbon sinks, facilitating carbon dioxide mitigation.