Measurement of ethylene and methane production in a temperate forest soil using inhibition of acetylene and carbon monoxide

Temperature effects on ethylene and methane production from temperate forest soils

“…Due to the incomplete inhibition by CO addition of the C 2 H 2 reduction activity, the C 2 H 4 evolution from forest soils was to some extent enlarged, which was smaller than the CH 4 evolution from oxic forest soils (P < 0.05) (Figure 2). This observation was in agreement with the results reported by Xu and Inubushi [15] , who reported that the larger in situ CH 4 production compared to C 2 H 4 production was observed under a temperate pine forest by using inhibition of C 2 H 2 and CO. Under the oxic conditions, addition of 2 kPa CO in the presence of c. 250 Pa C 2 H 2 did not affect the evolution of CH 4 from these forest soils at 5-35℃ and their corresponding Q 10 values (Figure 2(c), (d)).…”

“…As shown in previous studies, the addition of acetylene at concentrations more than 100 Pa C 2 H 2 could completely inhibit the consumption of C 2 H 4 and CH 4 by forest soils but did not affect the natural formation of C 2 H 4 and CH 4 in forest soils [15] . Hence, the evolution of C 2 H 4 and CH 4 from forest soils at 5-15℃ could completely result from C 2 H 4 and CH 4 production from soil.…”

“…The soil C 2 H 2 consumption with and without addition of 2 kPa CO significantly increased as temperature increased from 25 to 35℃; the percentile reduction of headspace C 2 H 2 concentrations relative to zero hour could reach from 40% to 65% at 35℃ whereas it was 10%-20% for the soil DII (Figure 1(b), (d)). This indicated that headspace C 2 H 2 concentrations under the experimental conditions always remained more than 100 Pa C 2 H 2 and could effectively inhibit the soil C 2 H 4 and CH 4 consumption at 25 and 35℃ [15] . Under the oxic conditions, there were almost the same Q 10 values of C 2 H 2 consumption by forest soils (Figure 1(a), (c)), which were larger than those of the CH 4 and C 2 H 4 consumption by the same soils (P < 0.05) (Xu et al, unpublished data).…”

“…However, there are few measurements of C 2 H 4 and CH 4 production from oxic soils and the mechanisms involved are not clear. The addition of N sources could induce a 5-fold larger increase in rates of in situ C 2 H 4 and CH 4 production beneath a temperate pine forest stand compared to those from the control [15] . These observations would promote one to study the CH 4 and C 2 H 4 production from forest topsoil and the mechanisms involved.…”

“…A series of laboratory incubation and field experiments have shown that CH 4 and C 2 H 4 production from forest soils under oxic conditions can be respectively measured by using inhibition of acetylene (C 2 H 2 ) and combination with carbon monoxide (CO) [12][13][14][15] . However, there are few measurements of C 2 H 4 and CH 4 production from oxic soils and the mechanisms involved are not clear.…”