N is an important limiting factor for sustaining forest productivity.Climate warming may influence the soil N transformation and regulate the productivity of forest ecosystems.However,there are still knowledge gaps regarding how forest soil N cycling responds to climate warming,especially due to the lack of experimental evidence from subtropical regions.In this study,based on a soil warming experiment in subtropical Chinese-fir plantations,the rates of net soil N mineralization,net nitrification,nitrous oxide(N2O)emission,and inorganic N leaching at a soil depth of 0-20 cm were observed in situ.The results showed that the rates of soil N2O emissions and ammonium leaching did not differ significantly between the young and mature plantations.Mature plantations had higher net soil N mineralization,nitrification,and leaching rates than young plantations.Soil warming had no significant effect on the soil net N mineralization rate,net nitrification rate,or N2O emission rate.Although the amount of nitrate leached in young plantations was reduced by 38.7％under soil warming,nitrate leached in mature plantations and ammonium leached in both young and mature plantations showed no significant response to soil warming.Overall,soil warming failed to alter the net soil N transformation rates,N2O emission rate,or amount of inorganic N leaching,indicating that the net input and leaching loss of soil inorganic N did not respond positively to soil warming in subtropical forests.This study enhances our understanding of soil N cycles in subtropical forests under climate warming scenarios.
关键词
增温/亚热带杉木人工林/矿化/硝化/N2O排放速率/无机氮淋溶
Key words
warming/subtropical Chinese fir plantation/mineralization/nitrification/N2O emission rate/inorganic nitrogen leaching
维普
万方数据