Influence of nitrogen and carbon dioxide on ethylene and methane production in two different forest soils

Jena

1998

S. 227-237

4 Abb., zahlr. Lit. Ang.

Bandaufführung

9224S

59256

The impact of nitrogen and CO2 on ethylene and methane production was investigated in two different forest soils. The soils were adjusted to a water tension of 30 kPa. Nitrogen was added in the form of KNO3 or (NH4)2SO4 and CO2 was added in 5 different concentrations. To half of the samples, C2H2 was added to inhibit ethylene uptake. After 0, 24, and 96 hours, ethylene and methane concentrations were measured by gas chromatography. Ethylene net production increased with increasing N and CO2 concentrations. In the presence of acetylene, ethylene production was unaffected by the investigated amendments. Therefore, we suppose that the increasing ethylene net production rates are due to decreasing ethylene uptake rates. In the deciduous forest soil, there was no ethylene net production rate, as uptake rates exceeded production rates. Methane net production rates in the spruce forest soil increased with increasing N additions possibly due to a lowered C:N ratio and a decreased methane oxidation. Ethylene production rated in the presence of acetylene were slightly enhanced. In the deciduous forest soil, methane uptake rates decreased with nitrogen possibly due to the inhibition of the methanemonooxygenase. CO2 seemed to increase methane production in the presence of acetylene but had no significant effect on methane net production. Acetylene might serve as a substrate for methanogenesis.