Chin J Plant Ecol ›› 2011, Vol. 35 ›› Issue (3): 275-283.DOI: 10.3724/SP.J.1258.2011.00275

• Research Articles • Previous Articles     Next Articles

Plant functional type effects on methane uptake by soils in typical grasslands of Inner Mongolia

LIU Wei1,2,*(), WANG Ji-Ming3, WANG Zhi-Ping1   

  1. 1State Key Laboratory of Vegetation and Environmental Change, Institute of Botany, Chinese Academy of Sciences, Beijing 100093, China
    2Graduate University of Chinese Academy of Sciences, Beijing 100049, China
    3Anhui Provincial Key Laboratory of the Conservation and Exploitation of Biological Resources, College of Life Sciences, Anhui Normal University, Wuhu, Anhui 241000, China
  • Received:2010-05-31 Accepted:2010-11-12 Online:2011-05-31 Published:2011-03-02

Abstract:

Aims Methane (CH4) is an important atmospheric trace gas contributing to global warming and atmospheric chemistry. Aerated soils are a biological sink for atmospheric CH4. Our objectives were to quantify CH4 uptake by soils in typical grasslands of Inner Mongolia and examine the effects of plant functional type on the uptake.
Methods We used static chamber sampling and gas chromatography measurement to examine the effects of four plant functional types (PFTs) ― perennial rhizome forbs (PR), perennial bunchgrass (PB), perennial forb (PF) and annuals and biennials (AB) ― on CH4 uptake by aerated soils.
Important findings CH4 uptake by soils showed seasonal change related to soil water content and temperature. Over most of observed periods in 2008 and 2009, there were no significant differences in soil CH4 uptake rates among the various PFTs. During rapid plant growth in August, however, there were significant differences in the soil CH4 uptake rates. The soil CH4 uptake rates were lower with PBs. AB and PF increased the uptake of CH4 by soils, while PR and PB had little influence. Soil physico-chemical factors such as temperature, water content and gas diffusion affect CH4 uptake. Differences in CH4 uptake rates by soils may be explained using these environmental factors affected by PFTs. With regard to trace gas, PFT has prominent effects on this ecosystem. Sub-dominant species and companion species (AB and PF), by regulating soil microbe and environmental factors, have important and irreplaceable roles on the uptake of CH4 by soils.

Key words: CH4 oxidation, grassland ecosystem, greenhouse gas, plant community, Xilin River Basin