Different harvest intensity and soil CO2 efflux in sessile oak coppice forests

Abstract

Soil CO2 efflux accounts for about 45-80% of total ecosystem respiration and is therefore an important part of the ecosystem carbon cycle. Soil CO2 efflux has been poorly studied in forests managed in the ancient coppicing manner. In our study, soil CO2 efflux, temperature, and moisture were measured in sessile oak stands with different harvesting intensity (control: 0% intensity; V1: 75%; V2: 80 %; V3: 85%; and V4: 100%) during the fifth and sixth years after harvesting. Soil CO2 efflux was in the range 2-8 µmol CO2 m -2 s -1 and indicated an increasing pattern with increasing harvesting intensity. The slope of that pattern became less steep from the fifth to the sixth year after harvesting, thus indicating gradual recovery of soil carbon dynamics in the coppiced stand toward the equilibrium state existing before harvesting. Temperature sensitivity of soil CO2 efflux ranged between 2.1 and 2.8, with the lowest values measured in the control stand. Soil CO2 efflux in the control stand was more sensitive to changes in soil moisture than was that on harvested plots. By our calculations, 6.2 tC ha -1 was released from the control stand and 6.2-6.8 tC ha -1 from the harvested stands during the sixth year after harvesting. If mean temperature were to rise by 1 °C, the amount of soil carbon released would increase by 7.7% in the control stand and, depending on harvesting intensity, by 9.0-10.8% in the harvested stands.

Effect of tree harvest, silvopastoral practices, and microclimate conditions on forest floor CO2 efflux in a sessile oak (Quercus petraea agg. [Matt.] Liebl.) forest

“…3), so it is variable in time. We also observed that harvest increased soil water content, and that is consistent with other studies (Londo et al 1999;Čater and Simončič 2010;Darenova et al 2016). The largest differences in SWC between control and harvested plots were observed during the first half of the first season after harvest.…”

Effect of coppicing, thinning and throughfall reduction on soil water content and soil CO₂ efflux in a sessile oak forest

“…Q 10 in the mature forest was the lowest compared to the coppiced stands. This finding is consistent with the previous study of Darenova et al (2016) who observed lower Q 10 in a high forest than in a coppice, which was sparser than on our experimental plots. From this result we can speculate, that in mature forest soil CO 2 efflux there is a higher proportion of root respiration Table 3.…”

“…R 2 of these relationships was always higher than 0.80, which confirms that soil temperature was a driving factor of temporal dynamics of R S at this site during periods without soil water limitation. The parameter of temperature sensitivity of R S (Q 10 ) ranged between 1.85 and 2.56 among the plots, which is comparable to recent findings for oak forests (Darenova et al 2016;Luan et al 2011;Rey et al 2002). Q 10 in the mature forest was the lowest compared to the coppiced stands.…”

“…As shoots of the coppice are growing, assimilation of the aboveground biomass is getting restored and the effect of harvest on soil respiration declines. Darenova et al (2016) suggested that it takes about 10 years for R S to be restored to the pre-harvest levels in their study oak coppice forest. The absence of a significant difference in R 10 between mature and unthinned coppice (after eight years of harvest) forest stands might be attributed to a possible disappearance of decomposition of debris and dead root.…”

Effect of different dolomitic limestone dosages on soil respiration in a mid-altitudinal Norway spruce stand

“…Within the forest stand close to the experimental plots, the continuous measurements of soil CO2 efflux were carried out applying an automated closed (non-steadystate through-flow) system (developed at the Global Change Research Institute in Brno, CZ) with six chambers. The design and installation were described by Darenova et al (2016). Within each chamber, the soil temperature (thermometers PT-100 ® , Treston a.s., CZ) was measured simultaneously with soil CO2 efflux at the depth of 1.5 cm.…”