The effect of forest management on trace gas exchange at the pedosphere–atmosphere interface in beech (Fagus sylvatica L.) forests stocking on calcareous soils

Abstract

The effect of forest management (thinning) on in situ carbon dioxide (CO 2 ), methane (CH 4 ) and nitrous oxide (N 2 O) trace gas exchange between soil and atmosphere was studied in three consecutive years at three beech forest sites, which differ in aspect [southwest (SW), northeast (NE), northwest (NW)]. At all sites adjacent thinning plots (''T'') and untreated control plots (''C'') were established. Measurements at the SW and NE sites covered the years 4-6 after thinning while at the NW site measurements covered the year before and the first 2 years after thinning. Mean N 2 O fluxes were <3 lg N 2 O-N m À2 h À1 at all plots except for the newly thinned NWT plot. CH 4 uptake was rather low, too. Very low CH 4 oxidation rates during dry periods are explained by physiological drought stress for CH 4 oxidizers. Heterotrophic litter decomposition constitutes the largest part of total soil respiration. On the whole, no significant positive or negative effects of the silvicultural treatment on the magnitude of CO 2 -, CH 4 -and N 2 O-trace gas exchange could be observed at the SW site 4-6 years after thinning. Also at the NE site, no effects of thinning on CO 2 and N 2 O fluxes could be demonstrated. However, at this site a significant moisture-induced lower CH 4 uptake could be shown. At the NW site forest management led to a dramatic increase in N 2 O emissions in the first two summers after thinning and to distinct effects on CO 2 emissions and CH 4 uptake in the first year after the felling. The unambiguous effects of thinning at the NW site are mainly related to higher C input by dead residues leading to enhanced mineralization activity, to a shift in the competition for nutrients favoring microorganisms as compared to trees and to changes in the soil water availability at the thinned plot. Considering the data obtained from the NE and SW site we expect that with the development of an understorey vegetation at the NW site the observed effects on the magnitude of trace gas exchange due to thinning will continue to decline in the following years. Our results implicate that it is indispensable to take account of the effects of forest management in order to accurately calculate trace gas emission inventories for the investigated forest ecosystem in case thinning took place immediately before.

Long-term effects of clear-cutting and selective cutting on soil methane fluxes in a temperate spruce forest in southern Germany

“…This may be ascribed to the fact that these values were determined about three years after logging. A significant increase in soil water content as a result of the reduction of evapotranspiration and hence water uptake by trees has been documented not only in clear-cutting studies (Castro et al, 2000;Zerva and Mencuccini, 2005), but also in a study on forest selective cutting (Dannenmann et al, 2007), which is consistent with our findings.…”

“…Published studies on the effect of forest selective cutting on soil CH 4 flux were rather scarce, especially for long-term data, and sometimes contradictory. Dannenmann et al (2007) reported a distinct decrease in soil CH 4 uptake in the first year after thinning of a beech forest, but no significant changes of CH 4 fluxes at another nearby site 4e6 years after selective cutting. One laboratory study done by Bradford et al (2000) showed a significantly higher CH 4 uptake in soil cores from a selectively logged oak forest site than that from an undisturbed site.…”

“…In view of the huge spatial and temporal variability of environmental factors and the limited number and restricted temporal coverage of long-term field measurements, the annual CH 4 sink of temperate forest soils is still afflicted with a high degree of uncertainty, ranging from 0.01 to 0.64 g CH 4 m À2 yr À1 (Smith et al, 2000;Dutaur and Verchot, 2007). Forest selective cutting and clear-cutting are the management practices most frequently used for silvicultural rotation and timber harvesting worldwide (Zerva and Mencuccini, 2005;Dannenmann et al, 2007). There is a growing number of studies pointing out that forest clear-cutting might cause a reduction in soil CH 4 consumption (Kagotani et al, 2001;Huttunen et al, 2003;Saari et al, 2004), or even switch of soils from being net CH 4 sinks to being net sources (Castro et al, 2000;Zerva and Mencuccini, 2005) by altering the biotic and abiotic factors (e.g.…”

“…Sullivan et al (2008) reported that methane uptake was not affected by selective cutting in ponderosa pine forest soils within one year of management. A study by Dannenmann et al (2007) showed that forest selective logging led to a distinct reduction in CH 4 uptake in the first year after tree felling, but no significant effects of selective cutting on the magnitude of CH 4 exchange could be observed at another site 4e6 years after felling. However, an increased net CH 4 consumption after selective logging has also been reported by Bradford et al (2000), who carried out a laboratory incubation study by collecting intact soil cores from Grizedale Forest, UK.…”

Thinning in artificially regenerated young beech stands

“…Abetz & Ohnenus 1999;Tarp et al 2000;Bastien et al 2005;Boncina et al 2007;Hein et al 2007;Štefančík 2013a) but also in the frame of other forest services. Thinning in beech stands is important for the cycles of carbon (Borys et al 2013) and nitrogen (Nahm et al 2006;Dannenmann et al 2007a), and also climate (Le Goff & Ottorini 1993;Cescatti & Piutti 1998;Barna 2000Barna , 2001Lemoine et al 2002;Dannenmann et al 2007b;Štefančík 2008). The positive effect of thinning on beech stands (higher increment, longer growth period compared to unthinned stands) under the climate change was confirmed by van der Maaten (2013).…”