Contribution of autotrophic and heterotrophic respiration to soil CO2 efflux in Chinese fir plantations

2011 ◽  
Vol 59 (1) ◽  
pp. 26 ◽  
Author(s):  
Dalun Tian ◽  
Guangjun Wang ◽  
Yuanying Peng ◽  
Wende Yan ◽  
Xi Fang ◽  
...  
Keyword(s):  
Southern China ◽  
Relative Proportion ◽  
Soil Co2 Efflux ◽  
Chinese Fir ◽  
Heterotrophic Respiration ◽  
Co2 Efflux ◽  
Strongly Correlated ◽  
Soil Co2 ◽  
Soil C ◽  
Soil C Cycling

Soil respiration (Rs) is overwhelmingly the sum of autotrophic respiration (Ra, root and rhizosphere) and heterotrophic respiration (Rh, microbes and soil fauna). Separating Rs into Ra and Rh components is a major challenge but necessary for understanding the implications of environmental change on soil C cycling and sequestration. In this study, a trenching method was employed to partition Rs sources in Chinese fir plantations in Southern China. Soil CO2 efflux (FCO2) rates were measured using an infrared gas analyser system with soil chambers at the trenched and untrenched (Control) plots from January 2007 to December 2008. Soil temperature (Tsoil) and soil water content (Wsoil) were also measured at the plots during the study period. The results showed that the mean soil FCO2 rate from trenched plots (0.88 ± 0.12 µmol m–2 s–1, mean ± s.e.) was significantly lower than that from untrenched plots (1.22 ± 0.18 µmol m–2 s–1) (P < 0.001) during the study period. Compared with Ra, Rh made a major contribution to annual flux of Rs in Chinese fir forests. The relative proportion of Rh to Rs averaged 76 and 69% in 2007 and 2008, respectively. The seasonal changes of Ra to Rs ratio ranged from 13 to 56% with a mean of 33%. The annual mean Rs was 455 ± 249 gC m–2 year–1 in the study site for the study period, of which Rh and Ra were 330 ± 219 and 125 ± 65 gC m–2 year–1, respectively. Both Rs and Rh was strongly correlated with Tsoil at a 5-cm depth, while Ra had no relationship with Tsoil. Temporal variation in Wsoil had little effect on Rs and Rh. The results indicated that the fluxes of Ra and Rh were controlled by different factors and the microbial communities, compared with roots, were likely more sensitive to global warming in affecting soil C fluxes in Chinese fir ecosystems in subtropical regions.

scholarly journals Partitioning of soil CO<sub>2</sub> efflux in un-manipulated and experimentally flooded plots of a temperate fen

2012 ◽  
Vol 9 (5) ◽  
pp. 5287-5319
Author(s):  
S. Wunderlich ◽  
W. Borken
Keyword(s):  
Water Table ◽  
Carbon Stock ◽  
Relative Proportion ◽  
Soil Co2 Efflux ◽  
Heterotrophic Respiration ◽  
Co2 Efflux ◽  
Gradual Change ◽  
Soil Co2 ◽  
Rhizosphere Respiration ◽  
Growing Seasons

Abstract. Peatlands store large amounts of organic carbon, but the carbon stock is sensitive to changes in precipitation or water table manipulations. Restoration of drained peatlands by drain blocking and flooding is a common measure to conserve and augment the carbon stock of peatland soils. Here, we report to what extent flooding affected the contribution of heterotrophic and rhizosphere respiration to soil CO2 efflux in a grass-dominated mountain fen, Germany. Soil CO2 efflux was measured in three un-manipulated control plots and three flooded plots in two consecutive years. Flooding was achieved by permanent irrigation during the growing seasons. Radiocarbon signatures of CO2 from different sources including soil CO2 efflux, incubated peat cores and live grass roots were repeatedly analyzed for partitioning of soil CO2 efflux. Additionally, heterotrophic respiration and its radiocarbon signature were determined by eliminating rhizosphere respiration in trenched subplots (only control). In the control plots, rhizosphere respiration determined by 14C signatures contributed between 47 and 61% during the growing season, but was small (4%) immediately before budding. Trenching revealed a smaller rhizosphere contribution of 33% (2009) and 22% (2010) during growing seasons. Flooding reduced annual soil CO2 efflux of the fen by 42% in 2009 and by 30% in 2010. The reduction was smaller in 2010 mainly through naturally elevated water level in the control plots. A 1-week interruption of irrigation caused a strong short-lived increase in soil CO2 efflux, demonstrating the sensitivity of the fen to water table drawdown near the peat surface. The reduction in soil CO2 efflux in the flooded plots diminished the relative proportion of rhizosphere respiration from 56 to 46%, suggesting that rhizosphere respiration was slightly more sensitive to flooding than heterotrophic respiration. We conclude that the moderate decrease in rhizosphere respiration following flooding arises from a gradual change in vegetation in this fen ecosystem.

scholarly journals Partitioning of soil CO<sub>2</sub> efflux in un-manipulated and experimentally flooded plots of a temperate fen

2012 ◽  
Vol 9 (8) ◽  
pp. 3477-3489 ◽  
Author(s):  
S. Wunderlich ◽  
W. Borken
Keyword(s):  
Water Table ◽  
Carbon Stock ◽  
Relative Proportion ◽  
Soil Co2 Efflux ◽  
Heterotrophic Respiration ◽  
Co2 Efflux ◽  
Soil Co2 ◽  
Rhizosphere Respiration ◽  
Growing Seasons ◽  
Elevated Water

Abstract. Peatlands store large amounts of organic carbon, but the carbon stock is sensitive to changes in precipitation or water table manipulations. Restoration of drained peatlands by drain blocking and flooding is a common measure to conserve and augment the carbon stock of peatland soils. Here, we report to what extent flooding affected the contribution of heterotrophic and rhizosphere respiration to soil CO2 efflux in a grass-dominated mountain fen in Germany. Soil CO2 efflux was measured in three un-manipulated control plots and three flooded plots in two consecutive years. Flooding was achieved by permanent irrigation during the growing seasons. Radiocarbon signatures of CO2 from different sources including soil CO2 efflux, incubated peat cores and live grass roots were repeatedly analyzed for partitioning of soil CO2 efflux. Additionally, heterotrophic respiration and its radiocarbon signature were determined by eliminating rhizosphere respiration in trenched subplots (only control). In the control plots, rhizosphere respiration determined by 14C signatures contributed between 47 and 61% during the growing season, but was small (4 ± 8%) immediately before budding. Trenching revealed a smaller rhizosphere contribution of 33 ± 8% (2009) and 22 ± 9% (2010) during growing seasons. Flooding reduced annual soil CO2 efflux of the fen by 42% in 2009 and by 30% in 2010. The reduction was smaller in 2010 mainly through naturally elevated water level in the control plots. A one-week interruption of irrigation caused a strong short-lived increase in soil CO2 efflux, demonstrating the sensitivity of the fen to water table drawdown near the peat surface. The reduction in soil CO2 efflux in the flooded plots diminished the relative proportion of rhizosphere respiration from 56 to 46%, suggesting that rhizosphere respiration was slightly more sensitive to flooding than heterotrophic respiration.

scholarly journals Elevated Tropospheric Ozone Concentration Alters Soil CO2 Emission: A Meta-Analysis

2021 ◽  
Vol 13 (8) ◽  
pp. 4571
Author(s):  
Enzhu Hu ◽  
Zhimin Ren ◽  
Sheng Xu ◽  
Weiwei Zhang
Keyword(s):  
Tropospheric Ozone ◽  
Co2 Emission ◽  
Meta Analysis ◽  
Co2 Enrichment ◽  
Terrestrial Ecosystems ◽  
Soil Co2 Efflux ◽  
Co2 Efflux ◽  
Soil Co2 ◽  
Soil C ◽  
Soil Co2 Emission

Elevated tropospheric ozone (O3) concentration may substantially influence the below-ground processes of terrestrial ecosystems. Nevertheless, a comprehensive and quantitative understanding of O3 impacts on soil CO2 emission remains elusive, making the future sources or sinks of soil C uncertain. In this study, 77 pairs of observations (i.e., elevated O3 concentration treatment versus control) extracted from 16 peer-reviewed studies were synthesized using meta-analysis. The results depicted that soil CO2 efflux was significantly reduced under short-term O3 exposure (≤1 year, p < 0.05), while it was increased under extended duration (>1 year, p < 0.05). Particularly, soil CO2 emission was stimulated in nonagricultural ecosystems, in the free-air CO2 enrichment (FACE) experiment, and in the soils of lower pH. The effect sizes of soil CO2 efflux were significantly positively correlated with experimental duration and were significantly negatively correlated with soil pH, respectively. The ozone effect on soil CO2 efflux would be enhanced at warm temperatures and high precipitation. The duration of O3 exposure was the fundamental factor in analyzing O3 impacts on soil CO2 emission.

Different responses of stem and soil CO2 efflux to pruning in a Chinese fir (Cunninghamia lanceolata) plantation

Trees ◽  
2015 ◽  
Vol 29 (4) ◽  
pp. 1207-1218 ◽  
Author(s):  
Qingpeng Yang ◽  
Lanlan Liu ◽  
Weidong Zhang ◽  
Ming Xu ◽  
Silong Wang
Keyword(s):  
Soil Co2 Efflux ◽  
Chinese Fir ◽  
Cunninghamia Lanceolata ◽  
Co2 Efflux ◽  
Soil Co2

scholarly journals Continuous measurement of soil CO<sub>2</sub> efflux in a larch forest by automated chamber and concentration gradient techniques

2010 ◽  
Vol 7 (1) ◽  
pp. 1345-1375
Author(s):  
N. Liang ◽  
T. Hirano ◽  
Z.-M. Zheng ◽  
J. Tang ◽  
Y. Fujinuma
Keyword(s):  
Concentration Gradient ◽  
Soil Co2 Efflux ◽  
Larch Forest ◽  
Heterotrophic Respiration ◽  
Large Temperature ◽  
Gradient System ◽  
Co2 Efflux ◽  
Soil Co2 ◽  
Gradient Approach ◽  
Chamber Technique

Abstract. Winter measurements of soil CO2 effluxes are few because such measurements are difficult when the ground is snow-covered, limiting the ability of chamber systems to characterize soil CO2 effluxes accurately year-round. In this study, we used two systems for continuous measurements of soil CO2 effluxes in a larch forest in northern Japan: (1) a 16-channel automated soil chamber system with eight chambers for measuring soil CO2 efflux and eight chambers for measuring heterotrophic respiration during snow-free periods, and (2) a soil CO2 concentration gradient system used year-round, including when the ground was snow-covered. During the warm season, the gradient approach yielded systematically higher CO2 effluxes than the automated chamber technique, whereas it yielded lower CO2 effluxes during the cold season. As a result of this bias (p<0.001), the annual soil CO2 efflux estimated by the automated chamber was 959 g C m−2 (of which 57% was contributed by heterotrophic respiration), whereas the efflux estimated by the gradient approach was 1040 g C m−2. Because of the fast-response infrared gas analyzer adopted for the chamber technique, the soil CO2 efflux response to the onset of rain was detected immediately and the efflux returned to pre-rain values several hours after the rain had stopped. Rain events accounted for about 24 g C m−2 (about 2% of the annual soil CO2 efflux). The gradient system successfully measured the soil CO2 effluxes when the ground was snow-covered (9 December to 17 April), when they ranged from 0.40 to 0.70 μmol m−2 s−1. Total CO2 efflux from the snowpack estimated by the gradient technique approached 73 g C m−2, corresponding to about 7% of the annual soil CO2 efflux. The Q10 coefficient of the soil CO2 efflux showed large seasonal variation, mainly because of the large temperature sensitivity of root respiration.

Responses of Soil CO2 Efflux to Precipitation Pulses in Two Subtropical Forests in Southern China

2011 ◽  
Vol 48 (6) ◽  
pp. 1182-1188 ◽  
Author(s):  
Qi Deng ◽  
Guoyi Zhou ◽  
Shizhong Liu ◽  
Guowei Chu ◽  
Deqiang Zhang
Keyword(s):  
Southern China ◽  
Soil Co2 Efflux ◽  
Co2 Efflux ◽  
Soil Co2 ◽  
Subtropical Forests ◽  
Precipitation Pulses
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