Chin J Plant Ecol ›› 2016, Vol. 40 ›› Issue (10): 1049-1063.DOI: 10.17521/cjpe.2016.0069

Special Issue: 碳水能量通量

• Research Articles • Previous Articles     Next Articles

Greenhouse gas fluxes of typical northern subtropical forest soils: Impacts of land use change and reduced precipitation

Hua JU1,2, Guo-Zhen SHEN2,*(), Ming-Zhe MA2, Jie-Lin GE2, Wen-Ting XU2, Chang-Ming ZHAO2, Qiu- Liang ZHANG1   

  1. 1College of Forestry, Inner Mongolia Agricultural University, Huhhot 010019, China
    and 2State Key Laboratory of Vegetation and Environmental Change, Institute of Botany, Chinese Academy of Sciences, Beijing 100093, China
  • Online:2016-10-10 Published:2016-11-02
  • Contact: Guo-Zhen SHEN

Abstract:

Aims It is important to study the effects of land use change and reduced precipitation on greenhouse gas fluxes (CO2, CH4 and N2O) of forest soils. Methods The fluxes of CO2, CH4 and N2O and their responses to environmental factors of primary forest soil, secondary forest soil and artificial forest soil under a reduced precipitation regime were explored using the static chamber and gas chromatography methods during the period from January to December in 2014. Important findings Results indicate that CH4 uptake of primary forest soil ((-44.43 ± 8.73) μg C·m-2·h-1) was significantly higher than that of the secondary forest soil ((-21.64 ± 4.86) μg C·m-2·h-1) and the artificial forest soil ((-10.52 ± 2.11) μg C·m-2·h-1). CH4 uptake of the secondary forest soil ((-21.64 ± 4.86) μg C·m-2·h-1) was significantly higher than that of the artificial forest ((-10.52 ± 2.11) μg C·m-2·h-1). CO2 emissions of the artificial forest soil ((106.53 ± 19.33) μg C·m-2·h-1) were significantly higher than that of the primary forest soil ((49.50 ± 8.16) μg C·m-2·h-1) and the secondary forest soil ((63.50 ± 5.35) μg C·m-2·h-1) (p < 0.01). N2O emissions of the secondary forest soil ((1.91 ± 1.22) μg N·m-2·h-1) were higher than that of the primary forest soil ((1.40 ± 0.28) μg N·m-2·h-1) and the artificial forest soil ((1.01 ± 0.86) μg N·m-2·h-1). Reduced precipitation (-50%) had a significant inhibitory effect on CH4 uptake of the artificial forest soil, while it enhanced CO2 emissions of the primary forest soil and the secondary forest soil. Reduced precipitation had a significant inhibitory effect on CO2 emissions of the artificial forest soil and N2O emissions of the secondary forest (p < 0.01). Reduced precipitation promotes N2O emissions of the primary forest soil and the artificial forest soil. CH4 uptake of the primary forest and the secondary forest soil increased significantly with the increase of soil temperature under natural and reduced precipitation. CO2 and N2O emission fluxes of the primary forest soil, secondary forest soil and artificial forest soil were positively correlated with soil temperature (p < 0.05). Soil moisture inhibited CH4 uptake of the secondary forest soil and the artificial forest soil (p < 0.05). CO2 emissions of the primary forest soil were significantly positively correlated with soil moisture (p < 0.05). N2O emissions of primary forest soil and secondary forest soil were significantly correlated with the nitrate nitrogen content (p < 0.05). It was implied that reduced precipitation and land use change would have significant effects on greenhouse gas emissions of subtropical forest soils.

http://jtp.cnki.net/bilingual/detail/html/ZWSB201610008

Key words: Mt. Shennongjia, precipitation reduction, land use change, emissions of CO2, uptake of CH4, emissions of N2O, environmental factors