Soil Organic Carbon Pools under Different Land Use Patterns along Dongjiang River Valley of Guangdong Province, China

Soil organic carbon (SOC) content and density (SOCD) were studied under six land use patterns of Natural forest, Schima superba plantation, Coniferous forest, Bamboo forest, Orchard, and Abandoned land in the Dongjiang River valley of Guandong province, China. The results showed that surface soil (0 similar to 25 cm) organic carbon content and soil organic carbon density had significant difference (P < 0.01) among the six different land use patterns. Soil organic carbon content and density were characterized by the descending order as: Natural forest (26.67 +/- 0.79 g.kg(-1)) > Schima superba planted forest (21.1 +/- 0.79 g.kg(-1)) > Bamboo (20.9 +/- 0.53 g.kg(-1)) > Coniferous forest (15.65 +/- 0.93 g.kg(-1)) > Orchard (15.22 +/- 0.61 g.kg(-1)) > Abandoned land (8.69 +/- 0.38 g.kg(-1)), and Natural forest (67.16 +/- 2.31 kg.m(-2)) > Bamboo (60.08 +/- 1.53 kg.m(-2)) > Schima superba plantation (52.8 +/- 1.86 kg.m(-2)) > Coniferous forest (47.17 +/- 2.66 kg.m(-2)) > Orchard (43.03 +/- 1.56 kg.m(-2)) > Abandoned land (31.48 +/- 1.2 kg.m(-2)), respectively. Natural forest was the highest in both soil organic carbon content and soil organic carbon density, and Abandoned land the lowest. The findings suggested that a close-to-nature way of afforestation and forest management played an important role in increasing forest carbon sinks.