Short-term temporal changes of soil carbon losses after tillage described by a first-order decay model

Forest-peat fires are notable for their difficulty in estimating carbon losses. Combined carbon losses from tree biomass and peat soil were estimated at an 8 ha forest-peat fire in the Moscow region after catastrophic fires in 2010. The loss of tree biomass carbon was assessed by reconstructing forest stand structure using the classification of pre-fire high-resolution satellite imagery and after-fire ground survey of the same forest classes in adjacent areas. Soil carbon loss was assessed by using the root collars of stumps to reconstruct the pre-fire soil surface and interpolating the peat characteristics of adjacent non-burned areas. The mean (median) depth of peat losses across the burned area was 15 ± 8 (14) cm, varying from 13 ± 5 (11) to 20 ± 9 (19). Loss of soil carbon was 9.22 ± 3.75–11.0 ± 4.96 (mean) and 8.0–11.0 kg m−2 (median); values exceeding 100 tC ha−1 have also been found in other studies. The estimated soil carbon loss for the entire burned area, 98 (mean) and 92 (median) tC ha−1, significantly exceeds the carbon loss from live (tree) biomass, which averaged 58.8 tC ha−1. The loss of carbon in the forest-peat fire thus equals the release of nearly 400 (soil) and, including the biomass, almost 650 tCO2 ha−1 into the atmosphere, which illustrates the underestimated impact of boreal forest-peat fires on atmospheric gas concentrations and climate.

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Temporal Changes in Pollen Grain Concentration Predict Short-Term Clinical Outcomes in Acute Coronary Syndromes

Heart Lung and Circulation ◽

10.1016/j.hlc.2021.06.045 ◽

2021 ◽

Vol 30 ◽

pp. S112

Author(s):

O. Al-mukhtar ◽

S. Vogrin ◽

S. Noaman ◽

E. Lampugnani ◽

D. Dinh ◽

...

Keyword(s):

Clinical Outcomes ◽

Acute Coronary Syndromes ◽

Temporal Changes ◽

Pollen Grain ◽

Short Term ◽

Coronary Syndromes

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Short-term impact of crop diversification on soil carbon fluxes and balance in rainfed and irrigated woody cropping systems under semiarid Mediterranean conditions

Plant and Soil ◽

10.1007/s11104-021-05101-w ◽

2021 ◽

Author(s):

María Martínez-Mena ◽

Carolina Boix-Fayos ◽

Efrain Carrillo-López ◽

Elvira Díaz-Pereira ◽

Raúl Zornoza ◽

...

Keyword(s):

Soil Carbon ◽

Carbon Balance ◽

Climate Change Mitigation ◽

Cropping Systems ◽

Crop Diversification ◽

Short Term ◽

Soil C ◽

Soil C Balance ◽

Woody Crop ◽

Change Mitigation

Abstract Purpose Diversification practices such as intercropping in woody cropping systems have recently been proposed as a promising management strategy for addressing problems related to soil degradation, climate change mitigation and food security. In this study, we assess the impact of several diversification practices in different management regimes on the main carbon fluxes regulating the soil carbon balance under semiarid Mediterranean conditions. Methods The study was conducted in two nearby cropping systems: (i) a low input rainfed almond (Prunus dulcis Mill.) orchard cultivated on terraces and (ii) a levelled intensively irrigated mandarin (Citrus reticulata Blanco) orchard with a street-ridge morphology. The almond trees were intercropped with Capparis spinosa or with Thymus hyemalis While the mandarin trees were intercropped with a mixture of barley and vetch followed by fava bean. Changes caused by crop diversifications on C inputs into the soil and C outputs from the soil were estimated. Results Crop diversification did not affect soil organic carbon stocks but did affect the carbon inputs and outputs regulating the soil carbon balance of above Mediterranean agroecosystems. Crop diversification with perennials in the low-input rainfed woody crop system significantly improved the annual soil C balance in the short-term. However, crop diversification with annual species in the intensively managed woody crop system had not effect on the annual soil C balance. Conclusions Our results highlight the potential of intercropping with perennials in rainfed woody crop systems for climate change mitigation through soil carbon sequestration.

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Towards a representation of priming on soil carbon decomposition in the global land biosphere model ORCHIDEE (version 1.9.5.2)

Geoscientific Model Development ◽

10.5194/gmd-9-841-2016 ◽

2016 ◽

Vol 9 (2) ◽

pp. 841-855 ◽

Cited By ~ 15

Author(s):

Bertrand Guenet ◽

Fernando Esteban Moyano ◽

Philippe Peylin ◽

Philippe Ciais ◽

Ivan A Janssens

Keyword(s):

Organic Matter ◽

Soil Organic Matter ◽

Soil Carbon ◽

Global Scale ◽

Soil Incubation ◽

First Order ◽

Carbon Decomposition ◽

Litter Manipulation ◽

Global Land ◽

Biosphere Model

Abstract. Priming of soil carbon decomposition encompasses different processes through which the decomposition of native (already present) soil organic matter is amplified through the addition of new organic matter, with new inputs typically being more labile than the native soil organic matter. Evidence for priming comes from laboratory and field experiments, but to date there is no estimate of its impact at global scale and under the current anthropogenic perturbation of the carbon cycle. Current soil carbon decomposition models do not include priming mechanisms, thereby introducing uncertainty when extrapolating short-term local observations to ecosystem and regional to global scale. In this study we present a simple conceptual model of decomposition priming, called PRIM, able to reproduce laboratory (incubation) and field (litter manipulation) priming experiments. Parameters for this model were first optimized against data from 20 soil incubation experiments using a Bayesian framework. The optimized parameter values were evaluated against another set of soil incubation data independent from the ones used for calibration and the PRIM model reproduced the soil incubations data better than the original, CENTURY-type soil decomposition model, whose decomposition equations are based only on first-order kinetics. We then compared the PRIM model and the standard first-order decay model incorporated into the global land biosphere model ORCHIDEE (Organising Carbon and Hydrology In Dynamic Ecosystems). A test of both models was performed at ecosystem scale using litter manipulation experiments from five sites. Although both versions were equally able to reproduce observed decay rates of litter, only ORCHIDEE–PRIM could simulate the observed priming (R2 = 0.54) in cases where litter was added or removed. This result suggests that a conceptually simple and numerically tractable representation of priming adapted to global models is able to capture the sign and magnitude of the priming of litter and soil organic matter.

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Can we model observed soil carbon changes from a dense inventory? A case study over England and Wales using three versions of the ORCHIDEE ecosystem model (AR5, AR5-PRIM and O-CN)

Geoscientific Model Development ◽

10.5194/gmd-6-2153-2013 ◽

2013 ◽

Vol 6 (6) ◽

pp. 2153-2163 ◽

Cited By ~ 10

Author(s):

B. Guenet ◽

F. E. Moyano ◽

N. Vuichard ◽

G. J. D. Kirk ◽

P. H. Bellamy ◽

...

Keyword(s):

Soil Carbon ◽

Net Primary Productivity ◽

Soil Depth ◽

Carbon Mineralization ◽

Ecosystem Model ◽

Climate Trends ◽

England And Wales ◽

Carbon Decomposition ◽

Plant Soil ◽

Carbon Losses

Abstract. A widespread decrease of the topsoil carbon content was observed over England and Wales during the period 1978–2003 in the National Soil Inventory (NSI), amounting to a carbon loss of 4.44 Tg yr−1 over 141 550 km2. Subsequent modelling studies have shown that changes in temperature and precipitation could only account for a small part of the observed decrease, and therefore that changes in land use and management and resulting changes in heterotrophic respiration or net primary productivity were the main causes. So far, all the models used to reproduce the NSI data have not accounted for plant–soil interactions and have only been soil carbon models with carbon inputs forced by data. Here, we use three different versions of a process-based coupled soil–vegetation model called ORCHIDEE (Organizing Carbon and Hydrology in Dynamic Ecosystems), in order to separate the effect of trends in soil carbon input from soil carbon mineralization induced by climate trends over 1978–2003. The first version of the model (ORCHIDEE-AR5), used for IPCC-AR5 CMIP5 Earth System simulations, is based on three soil carbon pools defined with first-order decomposition kinetics, as in the CENTURY model. The second version (ORCHIDEE-AR5-PRIM) built for this study includes a relationship between litter carbon and decomposition rates, to reproduce a priming effect on decomposition. The last version (O-CN) takes into account N-related processes. Soil carbon decomposition in O-CN is based on CENTURY, but adds N limitations on litter decomposition. We performed regional gridded simulations with these three versions of the ORCHIDEE model over England and Wales. None of the three model versions was able to reproduce the observed NSI soil carbon trend. This suggests either that climate change is not the main driver for observed soil carbon losses or that the ORCHIDEE model even with priming or N effects on decomposition lacks the basic mechanisms to explain soil carbon change in response to climate, which would raise a caution flag about the ability of this type of model to project soil carbon changes in response to future warming. A third possible explanation could be that the NSI measurements made on the topsoil are not representative of the total soil carbon losses integrated over the entire soil depth, and thus cannot be compared with the model output.

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Estimating temporal changes in soil carbon stocks at ecoregional scale in Madagascar using remote-sensing

International Journal of Applied Earth Observation and Geoinformation ◽

10.1016/j.jag.2016.09.002 ◽

2017 ◽

Vol 54 ◽

pp. 1-14 ◽

Cited By ~ 34

Author(s):

C. Grinand ◽

G. Le Maire ◽

G. Vieilledent ◽

H. Razakamanarivo ◽

T. Razafimbelo ◽

...

Keyword(s):

Remote Sensing ◽

Soil Carbon ◽

Temporal Changes ◽

Carbon Stocks ◽

Soil Carbon Stocks

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Soil carbon release responses to long-term versus short-term climatic warming in an arid ecosystem

10.5194/bg-2019-236 ◽

2019 ◽

Author(s):

Hongying Yu ◽

Zhenzhu Xu ◽

Guangsheng Zhou ◽

Yao Shou

Keyword(s):

Soil Temperature ◽

Soil Carbon ◽

Field Experiments ◽

Arid Ecosystems ◽

Organic Carbon Content ◽

Climatic Warming ◽

Short Term ◽

Desert Steppes ◽

Carbon Release

Abstract. Climate change severely impacts grassland carbon cycling, especially in arid ecosystems, such as desert steppes. However, little is known about the responses of soil respiration (Rs) to different warming magnitudes and watering pulses in situ in desert steppes. To examine their effects on Rs, we conducted long-term moderate warming, short-term acute warming and watering field experiments in a desert grassland of Northern China. While experimental warming significantly reduced Rs by 32.5 % and 40.8 % under long-term and moderate and short-term and acute warming regimes, respectively, watering pulses stimulated it substantially. Warming did not change the exponential relationship between Rs and soil temperature, whereas the relationship of Rs with soil water content (SWC) was well fitted to the Gompertz function. The soil features were not significantly affected by either long-term or short-term warming regimes, respectively; however, soil organic carbon content tended to decrease with long-term climatic warming. This indicates that soil carbon release responses strongly depend on the duration and magnitude of climatic warming, which may be driven by SWC and soil temperature. The results of this study highlight the great dependence of soil carbon emission on warming regimes of different durations and the important role of precipitation pulse during growing season in assessing the terrestrial ecosystem carbon balance and cycle.

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REVIEW Soil carbon release responses to long-term versus short-term climatic warming in an arid ecosystem

10.5194/bg-2019-236-rc2 ◽

2019 ◽

Author(s):

Anonymous

Keyword(s):

Soil Carbon ◽

Arid Ecosystem ◽

Climatic Warming ◽

Short Term ◽

Carbon Release

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