A new approach to simulate peat accumulation, degradation and stability in a global land surface scheme

2021 ◽  
Author(s):  
Sarah Chadburn ◽  
Eleanor Burke ◽  
Angela Gallego-Sala ◽  
Noah Smith
Keyword(s):  
Carbon Cycle ◽  
Land Surface ◽  
Soil Column ◽  
Organic Matter Content ◽  
Matter Content ◽  
Organic Layer ◽  
Earth System ◽  
Peat Accumulation ◽  
New Approach ◽  
The Uk

<p>Representing peatlands in global Earth System Models (ESMs) is a major challenge, but a crucial one since peatlands represent a significant component of the global carbon cycle.</p><p>Here we present the first ESM implementation of peat accumulation and degradation that integrates both organic and mineral soils in a single formulation, implemented in JULES - the land-surface component of the UK Earth System Model (UKESM). In this scheme, the soil column is able to expand with the addition of new organic material and to subside as this material decomposes, with variable organic layer thickness, which means that peat can appear and disappear within the landscape without a need for a prescribed peatland fraction.</p><p>Thermal and hydraulic characteristics of the soil are dynamically updated depending on the organic matter content and its level of decomposition, using relationships derived from observations. This scheme captures important feedbacks within the soil, such as the way that peatlands - once formed - can be self-sustaining even under conditions where they would not form today. It also captures the loss of carbon and soil structure when peatlands are drained. We demonstrate this behaviour in the model.</p><p>This provides a new approach for improving the simulation of organic and peatland soils, and associated carbon-cycle feedbacks in ESMs.</p><p>The key remaining challenges for simulating global peatlands are to realistically distribute water around the landscape, in order to represent topographically-controlled peatlands, and to develop appropriate peatland vegetation types.</p>

Mobility of metsulfuron-methyl in tropical soils

Soil Research ◽  
1997 ◽  
Vol 35 (6) ◽  
pp. 1291 ◽  
Author(s):  
B. S. Ismail ◽  
K. Kalithasan
Keyword(s):  
Organic Matter ◽  
Soil Column ◽  
Organic Matter Content ◽  
Tropical Soils ◽  
Matter Content ◽  
Fresh Weight ◽  
Downward Movement ◽  
Natural Conditions ◽  
Metsulfuron Methyl ◽  
Rainfall Total

The mobility of metsulfuron-methyl in 5 soil series with different organic contents was determined in a greenhouse as well as under natural conditions. In these studies, the movement and biological activity of metsulfuron-methyl were determined by the bioassay method using long bean as a bioassay species. Bioactivity and movement of the herbicide down the soil profile were inversely related to the organic matter content of the soil. Phytotoxic levels of metsulfuron-methyl were restricted to the 10-cm depth of the column containing Selangor Series soil except when it received 40 mL of water daily (depth, 10–15 cm). In Munchung Series, the phytotoxic level was also mainly in the 5–10 cm layer. However, when the column received 40 mL daily or every 4 days, the residue was detected in 15–20 cm and 10–15 cm zones, respectively. The phytotoxic level moved downward to the 20–25 cm layer both in Sogomana and Holyrood Series when 40 mL of water was given daily. A phytotoxic level of metsulfuron herbicide was detected in the 20–25 cm layer when the soil column containing Serdang Series was leached with 40 mL of water every 4 days or with 20 mL daily; the phytotoxic level was detected at a depth of 25–30 cm when this soil was watered daily with 40 mL. The downward movement of metsulfuron under natural conditions showed a pattern similar to that found under simulated conditions. Phytotoxic effects of the residue could be detected in the 25–30 cm and 15–20 cm zone of Serdang and Holyrood Series, respectively, after exposure to 20 days of rainfall (total 111·9 mm). Phytotoxic residue in both Sogomana and Munchung Series soil was detected in the 10–15 cm layer, and in the 5–10 cm layer for Selangor Series soil, after exposure to 20 days of rainfall. After exposure to 40 days of rainfall (total 152·8 mm) under natural conditions, the residue could be detected in the 15–20 cm layer of Selangor Series. The phytotoxic level moved deeper in soil with low organic matter after exposure to 40 days of rainfall. Fresh weight reduction was greater in the 20–30 cm layer in Serdang Series than in the top layer.

scholarly journals Modelling Holocene carbon accumulation and methane emissions of boreal wetlands – an Earth system model approach

2013 ◽  
Vol 10 (3) ◽  
pp. 1659-1674 ◽  
Author(s):  
R. J. Schuldt ◽  
V. Brovkin ◽  
T. Kleinen ◽  
J. Winderlich
Keyword(s):  
Land Surface ◽  
Ice Cores ◽  
Methane Emissions ◽  
Earth System Model ◽  
Carbon Accumulation ◽  
System Model ◽  
Surface Model ◽  
Earth System ◽  
Max Planck ◽  
Peat Accumulation

Abstract. Since the Last Glacial Maximum, boreal wetlands have accumulated substantial amounts of peat, estimated at 180–621 Pg of carbon. Wetlands have significantly affected the atmospheric greenhouse gas composition in the past and will play a significant role in future changes of atmospheric CO2 and CH4 concentrations. In order to investigate those changes with an Earth system model, biogeochemical processes in boreal wetlands need to be accounted for. Thus, a model of peat accumulation and decay was developed and included in the land surface model JSBACH of the Max Planck Institute Earth System Model (MPI-ESM). Here we present the evaluation of model results from 6000 yr BP to the pre-industrial period. Over this period of time, 240 Pg of peat carbon accumulated in the model in the areas north of 40° N. Simulated peat accumulation rates agree well with those reported for boreal wetlands. The model simulates CH4 emissions of 49.3 Tg CH4 yr−1 for 6000 yr BP and 51.5 Tg CH4 yr−1 for pre-industrial times. This is within the range of estimates in the literature, which range from 32 to 112 Tg CH4 yr−1 for boreal wetlands. The modelled methane emission for the West Siberian Lowlands and Hudson Bay Lowlands agree well with observations. The rising trend of methane emissions over the last 6000 yr is in agreement with measurements of Antarctic and Greenland ice cores.

Potential contribution from bioenergy with CCS to SDG13: an Earth system modelling perspective

2020 ◽  
Author(s):  
Helene Muri ◽  
Jan Sandstad Næss ◽  
Cristina Maria Iordan
Keyword(s):  
Renewable Energy ◽  
Carbon Cycle ◽  
Land Surface ◽  
Carbon Capture ◽  
Large Scale ◽  
Carbon Capture And Storage ◽  
System Modelling ◽  
Potential Contribution ◽  
Earth System ◽  
And Storage

<p>Renewable energy will play a key role in tranformation of the energy sector to reduce CO<sub>2</sub> emissions. Integrated Assessment Modelling scenarios reaching the temperature targets of the Paris Agreement rely on large scale deployment of Bioenergy with Carbon Capture and Storage (BECCS). BECCS are a key contributor to reducing emissions and acheiving net negative emissions in such scenarios. The potentials of large scale BECCS deployment in reaching the 1.5°C target is evaluated using Earth system model simulations in the work presented here. Fully coupled carbon cycle and interactive biogeochemistry is used to assess different rates of BECCS deployment, alongside assuming strong mitigation. BECCS at large scale influence not only the global carbon cycle, but also the feedbacks between the atmosphere and land surface. Changing the land cover to biocrops affects the terrestrial store of carbon, and also the physical properties of the land surface, i.e. biogeophysical forcing, which leads to important feedbacks in the climate system. Renewable energy from BECCS may have implications on several of the SDGs, in particular #13 Climate, #7 Energy, #15 Life on land, as well as #2 Hunger. It is found that it remains a challenge to achieve the 1.5°C target, relying strongly on bioenergy with CCS, and the mitigation potential depends on geografical location, and availability of suitable land areas.</p>

A Farmer’s Experience of Conservation Agriculture in the UK

2018 ◽  
pp. 708-724
Author(s):  
Anthony J. Reynolds
Keyword(s):  
Crop Yields ◽  
Organic Matter Content ◽  
Agricultural Practices ◽  
Conservation Agriculture ◽  
Matter Content ◽  
Sustainable Food ◽  
Cover Cropping ◽  
Farming Community ◽  
Beneficial Impact ◽  
The Uk

Conservation agricultural practices have been widely adopted across the world in the past 30 years. Farmers recognized that their soils had been degraded by deep ploughing and by dependence on chemical fertilizers, pesticides, and herbicides. Conservation agriculture, involving the agronomic and technological practices of no-till, cover cropping, and rotation, can be a sustainable alternative to conventional farming both economically and environmentally. While improving soil and crop health, it also has a dramatic and beneficial impact on the soil structure and on organic matter content that in turn can improve drainage and the availability of water. Costs are greatly reduced and crop yields—after an initial decline—return to former levels. Increasing interest and uptake by the global farming community shows that the system can be adapted in a variety of farming situations and significantly aid both the environment and sustainable food production.

scholarly journals Comparison of the HadGEM2 climate-chemistry model against in-situ and SCIAMACHY atmospheric methane data

2014 ◽  
Vol 14 (9) ◽  
pp. 12967-13020 ◽  
Author(s):  
G. D. Hayman ◽  
F. M. O'Connor ◽  
M. Dalvi ◽  
D. B. Clark ◽  
N. Gedney ◽  
...  
Keyword(s):  
Atmospheric Chemistry ◽  
Land Surface ◽  
Earth System Model ◽  
System Model ◽  
High Latitudes ◽  
Earth System ◽  
Atmospheric Methane ◽  
Surface Sites ◽  
Atmospheric Observations ◽  
The Uk

Abstract. Wetlands are a major emission source of methane (CH4) globally. In this study, we have evaluated wetland emission estimates derived using the UK community land surface model (JULES, the Joint UK Land Earth Simulator) against atmospheric observations of methane, including, for the first time, total methane columns derived from the SCIAMACHY instrument on board the ENVISAT satellite. Two JULES wetland emission estimates were investigated: (a) from an offline run driven with CRU-NCEP meteorological data and (b) from the same offline run in which the modelled wetland fractions were replaced with those derived from the Global Inundation Extent from Multi-Satellites (GIEMS) remote sensing product. The mean annual emission assumed for each inventory (181 Tg CH4 per annum over the period 1999–2007) is in line with other recently-published estimates. There are regional differences as the unconstrained JULES inventory gave significantly higher emissions in the Amazon and lower emissions in other regions compared to the JULES estimates constrained with the GIEMS product. Using the UK Hadley Centre's Earth System model with atmospheric chemistry (HadGEM2), we have evaluated these JULES wetland emissions against atmospheric observations of methane. We obtained improved agreement with the surface concentration measurements, especially at northern high latitudes, compared to previous HadGEM2 runs using the wetland emission dataset of Fung (1991). Although the modelled monthly atmospheric methane columns reproduced the large–scale patterns in the SCIAMACHY observations, they were biased low by 50 part per billion by volume (ppb). Replacing the HadGEM2 modelled concentrations above 300 hPa with HALOE–ACE assimilated TOMCAT output resulted in a significantly better agreement with the SCIAMACHY observations. The use of the GIEMS product to constrain JULES-derived wetland fraction improved the description of the wetland emissions in JULES and gave a good description of the seasonality observed at surface sites influenced by wetlands, especially at high latitudes. We found that the annual cycles observed in the SCIAMACHY measurements and at many of the surface sites influenced by non-wetland sources could not be reproduced in these HadGEM2 runs. This suggests that the emissions over certain regions (e.g., India and China) are possibly too high and/or the monthly emission patterns for specific sectors are incorrect. The comparisons presented in this paper have shown that the performance of the JULES wetland scheme is comparable to that of other process-based land surface models. We have identified areas for improvement in this and the atmospheric chemistry components of the HadGEM Earth System model. The Earth Observation datasets used here will be of continued value in future evaluations of JULES and the HadGEM family of models.

scholarly journals A new approach to simulate peat accumulation, degradation and stability in a global land surface scheme (JULES vn5.8_accumulate_soil)

2021 ◽  
Author(s):  
Sarah E. Chadburn ◽  
Eleanor J. Burke ◽  
Angela V. Gallego-Sala ◽  
Noah D. Smith ◽  
M. Syndonia Bret-Harte ◽  
...  
Keyword(s):  
Soil Carbon ◽  
Land Surface ◽  
Organic Material ◽  
Mineral Soil ◽  
Organic Soil ◽  
Organic Layer ◽  
New Approach ◽  
Land Surface Scheme ◽  
Mineral Soils ◽  
Surface Scheme

Abstract. Peatlands have often been neglected in Earth System Models (ESMs). Where they are included, they are usually represented via a separate, prescribed grid cell fraction that is given the physical characteristics of a peat (highly organic) soil. However, in reality soils vary on a spectrum between purely mineral soil (no organic material), and purely organic soil, typically with an organic layer of variable thickness overlying mineral soil below. They are also dynamic, with organic layer thickness and its properties changing over time. Neither the spectrum of soil types nor their dynamic nature can be captured by current ESMs. Here we present a new version of an ESM land surface scheme (Joint UK Land Environment Simulator, JULES) where soil organic matter accumulation - and thus peatland formation, degradation and stability – is integrated in the vertically-resolved soil carbon scheme. We also introduce the capacity to track soil carbon age as a function of depth in JULES, and compare this to measured peat age-depth profiles. This scheme simulates dynamic feedbacks between the soil organic material and its thermal and hydraulic characteristics. We show that draining the peatlands can lead to significant carbon loss along with soil compaction and changes in peat properties. However, negative feedbacks can lead to the potential for peatlands to rewet themselves following drainage. These ecohydrological feedbacks can also lead to peatlands maintaining themselves in climates where peat formation would not otherwise initiate in the model, i.e. displaying some degree of resilience. The new model produces similar results to the original model for mineral soils, and realistic profiles of soil organic carbon for peatlands. In particular the best performing configurations had root mean squared error (RMSE) in carbon density for peat sites of 7.7–16.7 kgC m−3 depending on climate zone, when compared against typical peat profiles based on 216 sites from a global dataset of peat cores. This error is considerably smaller than the soil carbon itself (around 30–60 kgC m−3) and reduced by 35–80 % compared with standard JULES. The RMSE at mineral soil sites is also smaller in JULES-Peat than JULES itself (reduced by ~30–50 %). Thus JULES-Peat can be used as a complete scheme that simulates both organic and mineral soils. It does not require any additional input data and introduces minimal additional variables to the model. This provides a new approach for improving the simulation of organic and peatland soils, and associated carbon-cycle feedbacks in ESMs, which other land surface models could follow.

scholarly journals Last-decade progress in understanding and modeling the land surface processes on the Tibetan Plateau

2020 ◽  
Vol 24 (12) ◽  
pp. 5745-5758
Author(s):  
Hui Lu ◽  
Donghai Zheng ◽  
Kun Yang ◽  
Fan Yang
Keyword(s):  
Heat Transfer ◽  
Tibetan Plateau ◽  
Land Surface ◽  
Organic Matter Content ◽  
Matter Content ◽  
Surface Processes ◽  
Soil Parameters ◽  
The Tibetan Plateau ◽  
Land Surface Processes ◽  
Near Surface

Abstract. Land surface models (LSMs) that simulate water and energy exchanges at the land–atmosphere interface are a key component of Earth system models. The Tibetan Plateau (TP) drives the Asian monsoon through surface heating and thus plays a key role in regulating the climate system in the Northern Hemisphere. Therefore, it is vital to understand and represent well the land surface processes on the TP. After an early review that identified key issues in the understanding and modeling of land surface processes on the TP in 2009, much progress has been made in the last decade in developing new land surface schemes and supporting datasets. This review summarizes the major advances. (i) An enthalpy-based approach was adopted to enhance the description of cryosphere processes such as glacier and snow mass balance and soil freeze–thaw transition. (ii) Parameterization of the vertical mixing process was improved in lake models to ensure reasonable heat transfer to the deep water and to the near-surface atmosphere. (iii) New schemes were proposed for modeling water flow and heat transfer in soils accounting for the effects of vertical soil heterogeneity due to the presence of high soil organic matter content and dense vegetation roots in surface soils or gravel in soil columns. (iv) Supporting datasets of meteorological forcing and soil parameters were developed by integrating multi-source datasets including ground-based observations. Perspectives on the further improvement of land surface modeling on the TP are provided, including the continuous updating of supporting datasets, parameter estimation through assimilation of satellite observations, improvement of snow and lake processes, adoption of data-driven and artificial intelligence methods, and the development of an integrated LSM for the TP.

scholarly journals Comparison of the HadGEM2 climate-chemistry model against in situ and SCIAMACHY atmospheric methane data

2014 ◽  
Vol 14 (23) ◽  
pp. 13257-13280 ◽  
Author(s):  
G. D. Hayman ◽  
F. M. O'Connor ◽  
M. Dalvi ◽  
D. B. Clark ◽  
N. Gedney ◽  
...  
Keyword(s):  
Atmospheric Chemistry ◽  
Land Surface ◽  
Earth System Model ◽  
System Model ◽  
Climatic Research Unit ◽  
Earth System ◽  
Atmospheric Methane ◽  
Surface Sites ◽  
Atmospheric Observations ◽  
The Uk

Abstract. Wetlands are a major emission source of methane (CH4) globally. In this study, we evaluate wetland emission estimates derived using the UK community land surface model (JULES, the Joint UK Land Earth Simulator) against atmospheric observations of methane, including, for the first time, total methane columns derived from the SCIAMACHY instrument on board the ENVISAT satellite. Two JULES wetland emission estimates are investigated: (a) from an offline run driven with Climatic Research Unit–National Centers for Environmental Prediction (CRU-NCEP) meteorological data and (b) from the same offline run in which the modelled wetland fractions are replaced with those derived from the Global Inundation Extent from Multi-Satellites (GIEMS) remote sensing product. The mean annual emission assumed for each inventory (181 Tg CH4 per annum over the period 1999–2007) is in line with other recently published estimates. There are regional differences as the unconstrained JULES inventory gives significantly higher emissions in the Amazon (by ~36 Tg CH4 yr−1) and lower emissions in other regions (by up to 10 Tg CH4 yr−1) compared to the JULES estimates constrained with the GIEMS product. Using the UK Hadley Centre's Earth System model with atmospheric chemistry (HadGEM2), we evaluate these JULES wetland emissions against atmospheric observations of methane. We obtain improved agreement with the surface concentration measurements, especially at high northern latitudes, compared to previous HadGEM2 runs using the wetland emission data set of Fung et al. (1991). Although the modelled monthly atmospheric methane columns reproduce the large-scale patterns in the SCIAMACHY observations, they are biased low by 50 part per billion by volume (ppb). Replacing the HadGEM2 modelled concentrations above 300 hPa with HALOE–ACE assimilated TOMCAT output results in a significantly better agreement with the SCIAMACHY observations. The use of the GIEMS product to constrain the JULES-derived wetland fraction improves the representation of the wetland emissions in JULES and gives a good description of the seasonality observed at surface sites influenced by wetlands, especially at high latitudes. We find that the annual cycles observed in the SCIAMACHY measurements and at many of the surface sites influenced by non-wetland sources cannot be reproduced in these HadGEM2 runs. This suggests that the emissions over certain regions (e.g. India and China) are possibly too high and/or the monthly emission patterns for specific sectors are incorrect. The comparisons presented in this paper show that the performance of the JULES wetland scheme is comparable to that of other process-based land surface models. We identify areas for improvement in this and the atmospheric chemistry components of the HadGEM Earth System model. The Earth Observation data sets used here will be of continued value in future evaluations of JULES and the HadGEM family of models.

INFLUENCE OF THE MAIN TREATMENT METHOD ON AGROCHEMICAL PROPERTIES OF MIGRATORY-MYCELIAL CLAY AGROCHERNOSEM SOIL OF SOUTH- EAST PART OF THE CENTRAL BLACK EARTH RESERVE

1970 ◽  
pp. 23-26 ◽  
Author(s):  
A. M. Grebennikov ◽  
V. A. Isaev ◽  
Yu. I. Cheverdin ◽  
V. M. Garmashov ◽  
N. А. Nuzhnaya ◽  
...  
Keyword(s):  
Organic Matter ◽  
Soil Properties ◽  
Humus Content ◽  
Soil Column ◽  
Organic Matter Content ◽  
Treatment Method ◽  
Matter Content ◽  
Processing Method ◽  
Mobile Phosphorus ◽  
Agrochemical Properties

In a field experiment on legalistic migration mizelialnah agrofermotech the South-East of CCZ considers the influence of processing method on agrochemical soil properties in a year and four years after laying the experience. To take into account the effect of tillage on the agrochemical properties of the soils in the corresponding experimental variants the humus content were determined by Tyurin and carbonates by Kozlovsky and mobile phosphorus and exchange potassium – according to Chirikov in depths of 0–10, 10–20, 20–30, 30–40, 40–50 cm in the selected samples. A study of the change in stocks of soil properties important for plant nutrition along the profile to a depth commensurate with the extent of the root system of crops was made. In assessing the heterogeneity of agro-chernozems on plots with different main tillage methods the coefficient of variation of the organic matter content, mobile phosphorus, and metabolic potassium in soil samples taken from depths of 0 - 10, 10 - 20, and 20 - 30 cm were calculated. It is shown that for the three years that passed between the agrochemical properties of some trends in the distribution of nutrients and organic matter on variations of the experience have remained virtually unchanged, whereas were marked and significant changes of these parameters in the upper layer of the soil column, depending on the applied processing method. The increase in the reserves of organic matter and plant nutrients in the variant with zero treatment compared to other methods, observed after four years of experiments, is apparently associated with the manifestation of the fertilizing effect of soil with mulch rotting, applied at zero treatment on the surface of agrochernozems.

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