Effects of Precious Tree Introduction into Moso Bamboo Forests on Soil Carbon and Nitrogen Pools

Forest type conversion is an important factor affecting soil carbon (C) and nitrogen (N) pools. Planting precious trees in moso bamboo forest is an important measure taken to establish a mixed forest due to the vulnerable ecological functioning of moso bamboo forest. However, the ways in which soil C and N pools in moso bamboo forest are affected by precious tree introduction are still unclear. A pure moso bamboo forest (BF), a bamboo forest interplanted with Phoebe chekiangensis (BPC), and a bamboo forest interplanted with Taxus wallichiana var. mairei (BTW) were selected. Soil organic C (SOC), total N, microbial biomass C (MBC), microbial biomass N (MBN), water-soluble organic C (WSOC), water-soluble organic N (WSON), and litter C and N concentrations were determined. Our results showed that the concentrations of SOC and N in BF were significantly lower than those in BPC and BTW. The total SOC and N concentrations decreased with increasing soil depth, and they were significantly higher at 0-20 cm than those at 20-40 cm and 40-60 cm. The biomasses of litters and their concentrations of C and N were increased after planting precious trees in moso bamboo forest, and they were significantly lower in BF than in BPC and BTW. In addition, precious tree introduction also improved the concentrations of soil MBC, MBN, WSOC, and WSON. To conclude, planting precious trees in moso bamboo forest significantly increased SOC and N concentrations at soil depths of 0-60 cm.