Effect of biomass cutting on soil CO2 efflux in a sandy grassland

2020 ◽  
Author(s):  
Marianna Papp ◽  
Szilvia Fóti ◽  
Krisztina Pintér ◽  
Zoltán Nagy ◽  
János Balogh
Keyword(s):  
Soil Respiration ◽  
Carbon Allocation ◽  
Ecosystem Respiration ◽  
Gross Primary Production ◽  
Organic Carbon Content ◽  
Co2 Efflux ◽  
Belowground Carbon Allocation ◽  
Belowground Carbon ◽  
High Organic Carbon Content ◽  
Sandy Grassland

<p>Carbon storage in grassland ecosystems is realized mostly belowground. The changes in the management activities of grasslands also influence the below-ground carbon stocks. Soil carbon-dioxide efflux (Rs) takes a major part of the ecosystem’s carbon cycle. R<sub>s</sub> includes the respiration of different components. Rs gives 60-80% of ecosystem respiration or 40-60% of gross primary production. It is known from the literature that respiration is affected by abiotic (temperature (Ts), soil water content (SWC)) and the biotic factors.</p><p>In our study we investigated the biotic one, namely the belowground carbon allocation on soil respiration. The study was performed in a semi-arid sandy grassland at Bugac (Kiskunság National Park, Hungary). The vegetation of the pasture was dominated by Festuca pseudovina, Carex stenophylla and Cynodon dactylon and the soil is a chernozem type soil with high organic carbon content.</p><p>The soil CO<sub>2</sub> effluxes were measured continuously by an automated soil respiration system consisted of 10 soil respiration chambers. The chambers measured 3 different experimental plots. Data was collected in every half-hour from each chamber for 6 days before the cutting event. After the cutting data was recorded from 1) non-cut, 2) half cut and 3) completely removed treatments also for 6 days. The study was repeated under laboratory conditions (constant temperature, illumination, humidity) on grass patches planted in pots. We observed that the respiration in half cut and completely removed treatments increased after they were cut off. The proportion of respiration after cutting in the completely removed treatment reduced to 85% compared to the control one. Our results highlight that the soil respiration is largely affected by belowground carbon allocation.</p>

Belowground carbon allocation in forests estimated from litterfall and IRGA-based soil respiration measurements

2002 ◽  
Vol 113 (1-4) ◽  
pp. 39-51 ◽  
Author(s):  
E.A Davidson ◽  
K Savage ◽  
P Bolstad ◽  
D.A Clark ◽  
P.S Curtis ◽  
...  
Keyword(s):  
Soil Respiration ◽  
Carbon Allocation ◽  
Belowground Carbon Allocation ◽  
Belowground Carbon

scholarly journals Distinct patterns in the diurnal and seasonal variability in four components of soil respiration in a temperate forest under free-air CO<sub>2</sub> enrichment

2011 ◽  
Vol 8 (10) ◽  
pp. 3077-3092 ◽  
Author(s):  
L. Taneva ◽  
M. A. Gonzalez-Meler
Keyword(s):  
Soil Respiration ◽  
Seasonal Variability ◽  
Ecosystem Respiration ◽  
Co2 Efflux ◽  
Diurnal Variability ◽  
Soil C ◽  
Free Air ◽  
C Cycle ◽  
Strong Control ◽  
Average Contribution

Abstract. Soil respiration (RS) is a major flux in the global carbon (C) cycle. Responses of RS to changing environmental conditions may exert a strong control on the residence time of C in terrestrial ecosystems and in turn influence the atmospheric concentration of greenhouse gases. Soil respiration consists of several components oxidizing soil C from different pools, age and chemistry. The mechanisms underlying the temporal variability of RS components are poorly understood. In this study, we used the long-term whole-ecosystem 13C tracer at the Duke Forest Free Air CO2 Enrichment site to separate forest RS into its autotrophic (RR) and heterotrophic components (RH). The contribution of RH to RS was further partitioned into litter decomposition (RL), and decomposition of soil organic matter (RSOM) of two age classes – up to 8 yr old and SOM older than 8 yr. Soil respiration was generally dominated by RSOM during the growing season (44% of daytime RS), especially at night. The contribution of heterotrophic respiration (RSOM and RL) to RS was not constant, indicating that the seasonal variability in RR alone cannot explain seasonal variation in RS. Although there was no diurnal variability in RS, there were significant compensatory differences in the contribution of individual RS components to daytime and nighttime rates. The average contribution of RSOM to RS was greater at night (54%) than during the day (44%). The average contribution of RR to total RS was ~30% during the day and ~34% during the night. In contrast, RL constituted 26% of RS during the day and only 12% at night. About 95% of the decomposition of soil C older than 8 yr (Rpre-tr) originated from RSOM and showed more pronounced and consistent diurnal variability than any other RS component; nighttime rates were on average 29% higher than daytime rates. In contrast, the decomposition of more recent, post-treatment C (Rpre-tr) did not vary diurnally. None of the diurnal variations in components of RH could be explained by only temperature and moisture variations. Our results indicate that the variation observed in the components of RS is the result of complex interaction between dominant biotic controls (e.g. plant activity, mineralization kinetics, competition for substrates) over abiotic controls (temperature, moisture). The interactions and controls among roots and other soil organisms that utilize C of different chemistry, accessibility and ages, results in the overall soil CO2 efflux. Therefore understanding the controls on the components of RS is necessary to elucidate the influence of ecosystem respiration on atmospheric C-pools at different time scales.

scholarly journals Spatial and temporal variation of CO<sub>2</sub> efflux along a disturbance gradient in a <i>miombo</i> woodland in Western Zambia

2011 ◽  
Vol 8 (1) ◽  
pp. 147-164 ◽  
Author(s):  
L. Merbold ◽  
W. Ziegler ◽  
M. M. Mukelabai ◽  
W. L. Kutsch
Keyword(s):  
Soil Respiration ◽  
Soil Temperature ◽  
Temporal Variation ◽  
Carbon Content ◽  
Ecosystem Respiration ◽  
Spatial And Temporal Variation ◽  
Co2 Efflux ◽  
Forest Reserve ◽  
Disturbance Gradient ◽  
Total Ecosystem Respiration

Abstract. Carbon dioxide efflux from the soil surface was measured over a period of several weeks within a heterogeneous Brachystegia spp. dominated miombo woodland in Western Zambia. The objectives were to examine spatial and temporal variation of soil respiration along a disturbance gradient from a protected forest reserve to a cut, burned, and grazed area outside, and to relate the flux to various abiotic and biotic drivers. The highest daily mean fluxes (around 12 μmol CO2 m−2 s−1) were measured in the protected forest in the wet season and lowest daily mean fluxes (around 1 μmol CO2 m−2 s−1) in the most disturbed area during the dry season. Diurnal variation of soil respiration was closely correlated with soil temperature. The combination of soil water content and soil temperature was found to be the main driving factor at seasonal time scale. There was a 75% decrease in soil CO2 efflux during the dry season and a 20% difference in peak soil respiratory flux measured in 2008 and 2009. Spatial variation of CO2 efflux was positively related to total soil carbon content in the undisturbed area but not at the disturbed site. Coefficients of variation of efflux rates between plots decreased towards the core zone of the protected forest reserve. Normalized soil respiration values did not vary significantly along the disturbance gradient. Spatial variation of respiration did not show a clear distinction between the disturbed and undisturbed sites and could not be explained by variables such as leaf area index. In contrast, within plot variability of soil respiration was explained by soil organic carbon content. Three different approaches to calculate total ecosystem respiration (Reco) from eddy covariance measurements were compared to two bottom-up estimates of Reco obtained from chambers measurements of soil- and leaf respiration which differed in the consideration of spatial heterogeneity. The consideration of spatial variability resulted only in small changes of Reco when compared to simple averaging. Total ecosystem respiration at the plot scale, obtained by eddy covariance differed by up to 25% in relation to values calculated from the soil- and leaf chamber efflux measurements but without showing a clear trend.

scholarly journals Partitioning of canopy and soil CO<sub>2</sub> fluxes in a pine forest at the dry timberline across a 13-year observation period

2020 ◽  
Vol 17 (3) ◽  
pp. 699-714
Author(s):  
Rafat Qubaja ◽  
Fyodor Tatarinov ◽  
Eyal Rotenberg ◽  
Dan Yakir
Keyword(s):  
Soil Respiration ◽  
Primary Productivity ◽  
Pinus Halepensis ◽  
Ecosystem Respiration ◽  
Carbon Accumulation ◽  
Dry Forest ◽  
Mean Annual Precipitation ◽  
Co2 Uptake ◽  
Belowground Carbon Allocation ◽  
Observation Period

Abstract. Partitioning carbon fluxes is key to understanding the process underlying ecosystem response to change. This study used soil and canopy fluxes with stable isotopes (13C) and radiocarbon (14C) measurements in an 18 km2, 50-year-old, dry (287 mm mean annual precipitation; nonirrigated) Pinus halepensis forest plantation in Israel to partition the net ecosystem's CO2 flux into gross primary productivity (GPP) and ecosystem respiration (Re) and (with the aid of isotopic measurements) soil respiration flux (Rs) into autotrophic (Rsa), heterotrophic (Rh), and inorganic (Ri) components. On an annual scale, GPP and Re were 655 and 488 g C m−2, respectively, with a net primary productivity (NPP) of 282 g C m−2 and carbon-use efficiency (CUE = NPP ∕ GPP) of 0.43. Rs made up 60 % of the Re and comprised 24±4 %Rsa, 23±4 %Rh, and 13±1 %Ri. The contribution of root and microbial respiration to Re increased during high productivity periods, and inorganic sources were more significant components when the soil water content was low. Comparing the ratio of the respiration components to Re of our mean 2016 values to those of 2003 (mean for 2001–2006) at the same site indicated a decrease in the autotrophic components (roots, foliage, and wood) by about −13 % and an increase in the heterotrophic component (Rh∕Re) by about +18 %, with similar trends for soil respiration (Rsa∕Rs decreasing by −19 % and Rh∕Rs increasing by +8 %, respectively). The soil respiration sensitivity to temperature (Q10) decreased across the same observation period by 36 % and 9 % in the wet and dry periods, respectively. Low rates of soil carbon loss combined with relatively high belowground carbon allocation (i.e., 38 % of canopy CO2 uptake) and low sensitivity to temperature help explain the high soil organic carbon accumulation and the relatively high ecosystem CUE of the dry forest.

scholarly journals A GLOBAL TREND IN BELOWGROUND CARBON ALLOCATION: COMMENT

Ecology ◽  
1998 ◽  
Vol 79 (5) ◽  
pp. 1822-1825 ◽  
Author(s):  
Knute J. Nadelhoffer ◽  
James W. Raich ◽  
J. D. Aber
Keyword(s):  
Carbon Allocation ◽  
Belowground Carbon Allocation ◽  
Global Trend ◽  
Belowground Carbon
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