Effect of Simulated Acid Rain on Potential Carbon and Nitrogen Mineralization in Forest Soils

• Published in: Pedosphere Vol. 18; no. 4; pp. 503 - 514
• Main Authors: OUYANG, Xue-Jun, ZHOU, Guo-Yi, HUANG, Zhong-Liang, LIU, Ju-Xiu, ZHANG, De-Qiang, LI, Jiong
• Format: Journal Article
• Language: English
• Published: South China Botanic Garden, Chinese Academy of Sciences, Guangzhou 510650 China 01.08.2008; Graduate School of the Chinese Academy of Sciences, Beijing 100049 (China)%South China Botanic Garden, Chinese Academy of Sciences, Guangzhou 510650 China
• Subjects: 有机氮; 有机碳; 森林土壤; 矿化作用; organic N; simulated acid rain; forest soils; mineralization; organic C
• ISSN: 1002-0160; 2210-5107
• DOI: 10.1016/S1002-0160(08)60041-7

Acid rain is a serious environmental problem worldwide. In this study, a pot experiment using forest soils planted with the seedlings of four woody species was performed with weekly treatments of pH 4.40, 4.00, 3.52, and 3.05 simulated acid rain （SAR） for 42 months compared to a control ofpH 5.00 lake water. The cumulative amounts of C and N mineralization in the five treated soils were determined after incubation at 25 ℃ for 65 d to examine the effects of SAR treatments. For all five treatments, cumulative CO2-C production ranged from 20.24 to 27.81 mg kg^-1 dry soil, net production of available N from 17.37 to 48.95 mg kg^-1 dry soil, and net production of NO3-N from 9.09 to 46.23 mg kg^-1 dry soil. SAR treatments generally enhanced the emission of CO2-C from the soils; however, SAR with pH 3.05 inhibited the emission. SAR treatments decreased the net production of available N and NO3-N. The cumulative CH4 and N2O productions from the soils increased with increasing amount of simulated acid rain. The cumulative CO2-C production and the net production of available N of the soil under Acmena acuminatissima were significantly higher （P 〈 0.05） than those under Schima superba and Cryptocarya concinna. The mineralization of soil organic C was related to the contents of soil organic C and N, but was not related to soil pH. However, the overall effect of acid rain on the storage of soil organic matter and the cycling of important nutrients depended on the amount of acid deposition and the types of forests.