Song Qing-Ni, Yang Qing-Pei, Liu Jun, Yu Ding-Kun, Fang Kai, Xu Pei, He Yu-juan
Jiangxi Agricultural University, Nanchang, China.
Ying Yong Sheng Tai Xue Bao. 2013 Feb;24(2):338-44.
By the methods of space-time substitution and PVC tube closed-top in situ incubation, this paper studied the soil mineralized-N content, N mineralization rate, and N uptake rate in Phyllostachys edulis-broadleaf mixed forest (PBMF) formed by P. edulis expansion and its adjacent evergreen broadleaf forest (EBF) in Dagangshan Mountain of Jiangxi Province, China. There existed the same spatiotemporal variation trend of soil total mineralized-N (TMN) content between the two forests. The annual average N mineralization rate was slightly lower in PBMF than in EBF. In PBMF, soil N mineralization was dominated by ammonification; while in EBF, soil ammonification and nitrification were well-matched in rate, and soil nitrification was dominated in growth season (from April to October). The N uptake by the plants in PBMF and EBF in a year was mainly in the form of NH4+-N, but that in EBF in growth season was mainly in the form of NO3- -N. These findings indicated that the expansion of P. edulis into EBF could promote the ammonification of soil N, weakened soil nitrification and total N mineralization, and also, increased the NH4+-N uptake but decreased the NO3- -N and TMN uptake by the plants.
通过时空替代法和PVC管封顶原位培养法，研究了中国江西省大岗山毛竹扩张形成的毛竹-阔叶林混交林（PBMF）及其相邻常绿阔叶林（EBF）土壤矿质氮含量、氮矿化率和氮吸收速率。两种森林土壤总矿质氮（TMN）含量存在相同的时空变化趋势。PBMF年平均氮矿化率略低于EBF。在PBMF中，土壤氮矿化以氨化作用为主；而在EBF中，土壤氨化作用和硝化作用速率相当，且在生长季（4月至10月）土壤硝化作用占主导。PBMF和EBF植物一年中的氮吸收主要以NH4+-N形式，但EBF生长季主要以NO3--N形式。这些结果表明，毛竹向EBF扩张可促进土壤氮的氨化作用，削弱土壤硝化作用和总氮矿化作用，同时增加植物对NH4+-N的吸收，但减少对NO3--N和TMN的吸收。
