scholarly journals Soil Methanotrophy Model (MeMo v1.0): a process-based model to quantify global uptake of atmospheric methane by soil

2017 ◽  
Author(s):  
Fabiola Murguia-Flores ◽  
Sandra Arndt ◽  
Anita L. Ganesan ◽  
Guillermo N. Murray-Tortarolo ◽  
Edward R. C. Hornibrook
Keyword(s):  
Soil Moisture ◽  
Radiative Forcing ◽  
Deciduous Forest ◽  
Global Scale ◽  
Diffusion Reaction ◽  
Tropical Deciduous Forest ◽  
Seasonal Temperature ◽  
Atmospheric Methane ◽  
Oxidation Rates ◽  
The One

Abstract. Soil bacteria known as methanotrophs are the sole biological sink for atmospheric methane (CH4), a powerful greenhouse gas that is responsible for ~ 20 % of the human-driven increase in radiative forcing since pre-industrial times. Soil methanotrophy is controlled by a plethora of different factors, including temperature, soil texture and moisture or nitrogen content, resulting in spatially and temporally heterogeneous rates of soil methanotrophy. As a consequence, the exact magnitude of the global soil sink, as well as its temporal and spatial variability remains poorly constrained. We developed a process-based model (Methanotrophy Model; MeMo v1.0) to simulate and quantify the uptake of atmospheric CH4 by soils on the global scale. MeMo builds on previous models by Ridgwell et al. (1999) and Curry (2007) by introducing several advances, including: (1) a general analytical solution of the one-dimensional diffusion-reaction equation in porous media, (2) a refined representation of nitrogen inhibition on soil methanotrophy, and (3) updated factors governing the influence of soil moisture and temperature on CH4 oxidation rates. We show that the improved representation of these key drivers of soil methanotrophy resulted in a better fit to observational data. A global simulation of soil methanotrophy for the period 1990–2009 using MeMo yielded an average annual sink of 34.3 ± 4.3 Tg CH4 yr−1. Warm and semiarid regions (tropical deciduous forest, dense and open shrubland) had the highest CH4 uptake rates of 630 and 580 mg CH4 m−2 y−1, respectively. In these regions, favorable annual soil moisture content (~ 20 % saturation) and low seasonal temperature variations (variations

scholarly journals The consumption of atmospheric methane by soil in a simulated future climate

2009 ◽  
Vol 6 (11) ◽  
pp. 2355-2367 ◽  
Author(s):  
C. L. Curry
Keyword(s):  
Soil Moisture ◽  
Moisture Stress ◽  
Future Climate ◽  
Diffusion Reaction ◽  
Atmospheric Methane ◽  
Local Climate ◽  
Northern Latitudes ◽  
Methane Uptake ◽  
Soil Temperatures ◽  
The One

Abstract. A recently developed model for the consumption of atmospheric methane by soil (Curry, 2007) is used to investigate the global magnitude and distribution of methane uptake in a simulated future climate. In addition to solving the one-dimensional diffusion-reaction equation, the model includes a parameterization of biological CH4 oxidation that is sensitive to soil temperature and moisture content, along with specified reduction factors for land cultivation and wetland fractional coverage. Under the SRES emission scenario A1B, the model projects an 8% increase in the global annual mean CH4 soil sink by 2100, over and above the 15% increase expected from increased CH4 concentration alone. While the largest absolute increases occur in cool temperate and subtropical forest ecosystems, the largest relative increases in consumption (>40%) are seen in the boreal forest, tundra and polar desert environments of the high northern latitudes. Methane uptake at mid- to high northern latitudes increases year-round in 2100, with a 68% increase over present-day values in June. This increase is primarily due to enhanced soil diffusivity resulting from lower soil moisture produced by increased evaporation and reduced snow cover. At lower latitudes, uptake is enhanced mainly by elevated soil temperatures and/or reduced soil moisture stress, with the dominant influence determined by the local climate.

scholarly journals Soil Methanotrophy Model (MeMo v1.0): a process-based model to quantify global uptake of atmospheric methane by soil

2018 ◽  
Vol 11 (6) ◽  
pp. 2009-2032 ◽  
Author(s):  
Fabiola Murguia-Flores ◽  
Sandra Arndt ◽  
Anita L. Ganesan ◽  
Guillermo Murray-Tortarolo ◽  
Edward R. C. Hornibrook
Keyword(s):  
Soil Moisture ◽  
Observational Data ◽  
Diffusion Reaction ◽  
Tropical Deciduous Forest ◽  
Atmospheric Methane ◽  
Uptake Rates ◽  
Nitrogen Inputs ◽  
Soil Uptake ◽  
Global Soil ◽  
Ch4 Uptake

Abstract. Soil bacteria known as methanotrophs are the sole biological sink for atmospheric methane (CH4), a potent greenhouse gas that is responsible for ∼ 20 % of the human-driven increase in radiative forcing since pre-industrial times. Soil methanotrophy is controlled by a plethora of factors, including temperature, soil texture, moisture and nitrogen content, resulting in spatially and temporally heterogeneous rates of soil methanotrophy. As a consequence, the exact magnitude of the global soil sink, as well as its temporal and spatial variability, remains poorly constrained. We developed a process-based model (Methanotrophy Model; MeMo v1.0) to simulate and quantify the uptake of atmospheric CH4 by soils at the global scale. MeMo builds on previous models by Ridgwell et al. (1999) and Curry (2007) by introducing several advances, including (1) a general analytical solution of the one-dimensional diffusion–reaction equation in porous media, (2) a refined representation of nitrogen inhibition on soil methanotrophy, (3) updated factors governing the influence of soil moisture and temperature on CH4 oxidation rates and (4) the ability to evaluate the impact of autochthonous soil CH4 sources on uptake of atmospheric CH4. We show that the improved structural and parametric representation of key drivers of soil methanotrophy in MeMo results in a better fit to observational data. A global simulation of soil methanotrophy for the period 1990–2009 using MeMo yielded an average annual sink of 33.5 ± 0.6 Tg CH4 yr−1. Warm and semi-arid regions (tropical deciduous forest and open shrubland) had the highest CH4 uptake rates of 602 and 518 mg CH4 m−2 yr−1, respectively. In these regions, favourable annual soil moisture content (∼ 20 % saturation) and low seasonal temperature variations (variations < ∼ 6 ∘C) provided optimal conditions for soil methanotrophy and soil–atmosphere gas exchange. In contrast to previous model analyses, but in agreement with recent observational data, MeMo predicted low fluxes in wet tropical regions because of refinements in formulation of the influence of excess soil moisture on methanotrophy. Tundra and mixed forest had the lowest simulated CH4 uptake rates of 176 and 182 mg CH4 m−2 yr−1, respectively, due to their marked seasonality driven by temperature. Global soil uptake of atmospheric CH4 was decreased by 4 % by the effect of nitrogen inputs to the system; however, the direct addition of fertilizers attenuated the flux by 72 % in regions with high agricultural intensity (i.e. China, India and Europe) and by 4–10 % in agriculture areas receiving low rates of N input (e.g. South America). Globally, nitrogen inputs reduced soil uptake of atmospheric CH4 by 1.38 Tg yr−1, which is 2–5 times smaller than reported previously. In addition to improved characterization of the contemporary soil sink for atmospheric CH4, MeMo provides an opportunity to quantify more accurately the relative importance of soil methanotrophy in the global CH4 cycle in the past and its capacity to contribute to reduction of atmospheric CH4 levels under future global change scenarios.

scholarly journals Vascular Plants and Vegetation of the Sayula sub-basin, Jalisco, Mexico

2018 ◽  
Vol 96 (1) ◽  
pp. 103
Author(s):  
Miguel Ángel Macías-Rodríguez ◽  
Héctor Gerardo Frías-Ureña ◽  
Sergio Honorio Contreras-Rodríguez ◽  
Alfredo Frías-Castro
Keyword(s):  
Vascular Plants ◽  
Deciduous Forest ◽  
Field Work ◽  
Tropical Deciduous Forest ◽  
Floristic Diversity ◽  
Vegetation Types ◽  
Timely Manner ◽  
Complex Landscape ◽  
The One ◽  
Total Species

<p><strong>Background:</strong> The Sayula sub-basin presents a complex landscape composed of plants communities that to date have not been studied in a timely manner, so this study contributes to the knowledge of the flora and vegetation of the area and the State.</p><p><strong>Question:</strong> i) How many and which families, genera and species are in the Sayula sub-basin? ii) What are the main biological forms of the species? iii) Are there species under any category of protection? iv) How many vegetation types are present within the region?<br /> <strong>Studied species:</strong> Ferns, Gymnosperms and Angiosperms.<br /> <strong>Study site and years of study:</strong> The Sayula sub-basin, Jalisco, Mexico; from February 2012 to October 2015.<br /> <strong>Methods:</strong> Through the literature review and field work the floristic checklist was elaborated. In addition, with the use of geographic information systems, a map of land use and vegetation was made.<br /> <strong>Results:</strong> A total of 687 species were recorded, including 415 genera and 113 families. The five main families were Poaceae, Asteraceae, Fabaceae Solanaceae and Euphorbiaceae representing 42.6 % of the total species and 36.6 % of the genera. It should be noted that the predominant biological forms were herbs with 409, 105 shrubs and 74 trees. On the other hand, 47 species registered under some protection category of which, only one species <em>Cleomella jaliscensis</em> is endemic to the region. Finally, eight vegetation types were determined, being the tropical deciduous forest the one that occupies greater surface and presents greater floristic diversity.<br /> <strong>Conclusions:</strong> It is important to emphasize that during the realization of the work, agricultural activities were detected affecting the flora and vegetation, threatening the biodiversity and the natural balance of the region.</p>

scholarly journals Relationships between photosynthesis and formaldehyde as a probe of isoprene emission

2015 ◽  
Vol 15 (8) ◽  
pp. 11763-11797 ◽  
Author(s):  
Y. Zheng ◽  
N. Unger ◽  
M. P. Barkley ◽  
X. Yue
Keyword(s):  
Soil Moisture ◽  
Radiative Forcing ◽  
Global Climate ◽  
Global Scale ◽  
Emission Model ◽  
Earth System ◽  
Isoprene Emission ◽  
Moisture Dependence ◽  
Southeast Us

Abstract. Atmospheric oxidation of isoprene emission from land plants affects radiative forcing of global climate change. There is an urgent need to understand the factors that control isoprene emission variability on large spatiotemporal scales but such direct observations of isoprene emission do not exist. Two readily available global-scale long-term observations hold information about surface isoprene activity: gross primary productivity (GPP) and tropospheric formaldehyde column variability (HCHOv). We analyze multi-year seasonal linear correlations between observed GPP and HCHOv. The observed GPP-HCHOv correlation patterns are used to evaluate a global Earth system model that embeds three alternative leaf-level isoprene emission algorithms. GPP and HCHOv are decoupled in the summertime southeast US (r = −0.03). In the Amazon, GPP-HCHOv are weakly correlated in March-April-May (MAM), correlated in June-July-August (JJA) and weakly anti-correlated in September-October-November (SON). Isoprene emission algorithms that include soil moisture dependence demonstrate greater skill in reproducing the observed interannual seasonal GPP-HCHOv correlations in the southeast US and the Amazon. In isoprene emission models that include soil moisture dependence, isoprene emission is correlated with photosynthesis and anti-correlated with HCHOv. In an isoprene emission model without soil moisture dependence, isoprene emission is anti-correlated with photosynthesis and correlated with HCHOv. Long-term monitoring of isoprene emission, soil moisture and meteorology is required in water-limited ecosystems to improve understanding of the factors controlling isoprene emission and its representation in global Earth system models.

scholarly journals The consumption of atmospheric methane by soil in a simulated future climate

2009 ◽  
Vol 6 (3) ◽  
pp. 6077-6110 ◽  
Author(s):  
C. L. Curry
Keyword(s):  
Moisture Stress ◽  
Future Climate ◽  
Diffusion Reaction ◽  
Atmospheric Methane ◽  
Local Climate ◽  
Northern Latitudes ◽  
Methane Uptake ◽  
Soil Temperatures ◽  
Land Cultivation ◽  
The One

Abstract. A recently developed model for the consumption of atmospheric methane by soil (Curry, 2007) is used to investigate the global magnitude and distribution of methane uptake in a simulated future climate. In addition to solving the one-dimensional diffusion-reaction equation, the model includes a parameterization of biological CH4 oxidation that is sensitive to soil temperature and moisture content, along with simple scalings for land cultivation and wetland fractional coverage. Under the SRES emission scenario A1B, the model projects an 8% increase in the global annual mean CH4 soil sink by 2100, over and above the 15% increase expected from increased CH4 concentration alone. While the largest absolute increases occur in cool temperate and subtropical forest ecosystems, the largest relative increases in consumption (>40%) are seen in the boreal forest, tundra and polar desert environments of the high northern latitudes. Methane uptake at mid- to high northern latitudes increases year-round in 2100, with a 68% increase over present-day values in June. This increase is primarily due to enhanced soil diffusivity resulting from increased evaporation and reduced snow cover. At lower latitudes, uptake is enhanced mainly by elevated soil temperatures and/or reduced soil moisture stress, with the dominant influence determined by the local climate.

scholarly journals Relationships between photosynthesis and formaldehyde as a probe of isoprene emission

2015 ◽  
Vol 15 (15) ◽  
pp. 8559-8576 ◽  
Author(s):  
Y. Zheng ◽  
N. Unger ◽  
M. P. Barkley ◽  
X. Yue
Keyword(s):  
Soil Moisture ◽  
Radiative Forcing ◽  
Global Climate ◽  
Global Scale ◽  
Emission Model ◽  
Earth System ◽  
Isoprene Emission ◽  
Moisture Dependence ◽  
Southeast Us

Abstract. Atmospheric oxidation of isoprene emission from land plants affects radiative forcing of global climate change. There is an urgent need to understand the factors that control isoprene emission variability on large spatiotemporal scales but such direct observations of isoprene emission do not exist. Two readily available global-scale long-term observation-based data sets hold information about surface isoprene activity: gross primary productivity (GPP) and tropospheric formaldehyde column variability (HCHOv). We analyze multi-year seasonal linear correlations between observed GPP and HCHOv. The observed GPP–HCHOv correlation patterns are used to evaluate a global Earth system model that embeds three alternative leaf-level isoprene emission algorithms. GPP and HCHOv are decoupled in the summertime in the southeast US (r=−0.03). In the Amazon, GPP and HCHOv are weakly correlated in March-April-May (MAM), correlated in June-July-August (JJA) and weakly anticorrelated in September-October-November (SON). Isoprene emission algorithms that include soil moisture dependence demonstrate greater skill in reproducing the observed interannual seasonal GPP–HCHOv correlations in the southeast US and the Amazon. In isoprene emission models that include soil moisture dependence, isoprene emission is correlated with photosynthesis and anticorrelated with HCHOv. In an isoprene emission model without soil moisture dependence, isoprene emission is anticorrelated with photosynthesis and correlated with HCHOv. Long-term monitoring of isoprene emission, soil moisture and meteorology is required in water-limited ecosystems to improve understanding of the factors controlling isoprene emission and its representation in global Earth system models.

Differentiation of new coenomorph in context of the Belgard’s ecomorph system development

2017 ◽  
Vol 28 (1-2) ◽  
pp. 28-35 ◽  
Author(s):  
B. A. Baranovski
Keyword(s):  
Environmental Factors ◽  
Plant Species ◽  
Vascular Plants ◽  
Deciduous Forest ◽  
System Development ◽  
Vascular Plant ◽  
Tabular Form ◽  
Ecological Scales ◽  
The One ◽  
Different Levels

Nowadays, bioecological characteristics of species are the basis for flora and vegetation studying on the different levels. Bioecological characteristics of species is required in process of flora studying on the different levels such as biotopes or phytocenoses, floras of particular areas (floras of ecologically homogeneous habitats), and floras of certain territories. Ramensky scale is the one of first detailed ecological scales on plant species ordination in relation to various environmental factors; it developed in 1938 (Ramensky, 1971). A little later (1941), Pogrebnyak’s scale of forest stands was proposed. Ellenberg’s system developed in 1950 (Ellenberg, 1979) and Tsyganov’s system (Tsyganov, 1975) are best known as the systems of ecological scales on vascular plant species; these systems represent of habitat detection by ecotopic ecomorphs of plant species (phytoindication). Basically, the system proposed by Alexander Lyutsianovich Belgard was the one of first system of plant species that identiified ectomorphs in relation to environmental factors. As early as 1950, Belgard developed the tabulated system of ecomorphs using the Latin ecomorphs abbreviation; he also used the terminology proposed in the late 19th century by Dekandol (1956) and Warming (1903), as well as terminology of other authors. The article analyzes the features of Belgard’s system of ecomorphs on vascular plants. It has certain significance and advantages over other systems of ecomorphs. The use of abbreviated Latin names of ecomorphs in tabular form enables the use shortened form of ones. In the working scheme of Belgard’s system of ecomorphs relation of species to environmental factors are represented in the abbreviated Latin alphabetic version (Belgard, 1950). Combined into table, the ecomorphic analysis of plant species within association (ecological certification of species), biotope or area site (water area) gives an explicit pattern on ecological structure of flora within surveyed community, biotope or landscape, and on environmental conditions. Development and application by Belgrard the cenomorphs as «species’ adaptation to phytocenosis as a whole» were completely new in the development of systems of ecomorphs and, in this connection, different coenomorphs were distinguished. Like any concept, the system of ecomorphs by Belgard has the possibility and necessity to be developed and added. Long-time researches and analysis of literature sources allow to propose a new coenomorph in the context of Belgard’s system of ecomorphs development: silvomargoant (species of forest margin, from the Latin words margo – edge, boundary (Dvoretsky, 1976), margo – margin, ad margins silvarum – along the deciduous forest margins). As an example of ecomorphic characterization of species according to the system of ecomorphs by Belgard (when the abbreviated Latin ecomorph names are used in tabular form and the proposed cenomorph is used), it was given the part of the table on vascular plants ecomorphs in the National Nature Park «Orelsky» (Baranovsky et al). The Belgard’s system of ecomorphs is particularly convenient and can be successfully applied to data processing in the ecological analysis of the flora on wide areas with significant species richness, and the proposed ecomorph will be another necessary element in the Belgard’s system of ecomorphs. 

scholarly journals Large contribution to secondary organic aerosol from isoprene cloud chemistry

2021 ◽  
Vol 7 (13) ◽  
pp. eabe2952
Author(s):  
Houssni Lamkaddam ◽  
Josef Dommen ◽  
Ananth Ranjithkumar ◽  
Hamish Gordon ◽  
Günther Wehrle ◽  
...  
Keyword(s):  
Radiative Forcing ◽  
Flow Reactor ◽  
Secondary Organic Aerosol ◽  
Cloud Droplet ◽  
Organic Aerosol ◽  
Global Scale ◽  
Oxidation Products ◽  
Oh Radicals ◽  
Large Contribution ◽  
Cloud Processing

Aerosols still present the largest uncertainty in estimating anthropogenic radiative forcing. Cloud processing is potentially important for secondary organic aerosol (SOA) formation, a major aerosol component: however, laboratory experiments fail to mimic this process under atmospherically relevant conditions. We developed a wetted-wall flow reactor to simulate aqueous-phase processing of isoprene oxidation products (iOP) in cloud droplets. We find that 50 to 70% (in moles) of iOP partition into the aqueous cloud phase, where they rapidly react with OH radicals, producing SOA with a molar yield of 0.45 after cloud droplet evaporation. Integrating our experimental results into a global model, we show that clouds effectively boost the amount of SOA. We conclude that, on a global scale, cloud processing of iOP produces 6.9 Tg of SOA per year or approximately 20% of the total biogenic SOA burden and is the main source of SOA in the mid-troposphere (4 to 6 km).

scholarly journals Admixing Chaff with Straw Increased the Residues Collected without Compromising Machinery Efficiencies

Energies ◽  
2020 ◽  
Vol 13 (7) ◽  
pp. 1766 ◽  
Author(s):  
Alessandro Suardi ◽  
Sergio Saia ◽  
Walter Stefanoni ◽  
Carina Gunnarsson ◽  
Martin Sundberg ◽  
...  
Keyword(s):  
Energy Production ◽  
Dry Weight ◽  
Global Scale ◽  
Unit Weight ◽  
Residual Biomass ◽  
Energy Needs ◽  
The Mean ◽  
Field Efficiency ◽  
The One ◽  
Staple Crop

The collection of residues from staple crop may contribute to meet EU regulations in renewable energy production without harming soil quality. At a global scale, chaff may have great potential to be used as a bioenergy source. However, chaff is not usually collected, and its loss can consist of up to one-fifth of the residual biomass harvestable. In the present work, a spreader able to manage the chaff (either spreading [SPR] on the soil aside to the straw swath or admixed [ADM] with the straw) at varying threshing conditions (with either 1 or 2 threshing rotors [1R and 2R, respectively] in the combine, which affects the mean length of the straw pieces). The fractions of the biomass available in field (grain, chaff, straw, and stubble) were measured, along with the performances of both grain harvesting and baling operations. Admixing chaff allowed for a slightly higher amount of straw fresh weight baled compared to SPR (+336 kg straw ha−1), but such result was not evident on a dry weight basis. At the one time, admixing chaff reduced the material capacity of the combine by 12.9%. Using 2R compared to 1R strongly reduced the length of the straw pieces, and increased the bale unit weight; however, it reduced the field efficiency of the grain harvesting operations by 11.9%. On average, the straw loss did not vary by the treatments applied and was 44% of the total residues available (computed excluding the stubble). In conclusion, admixing of chaff with straw is an option to increase the residues collected without compromising grain harvesting and straw baling efficiencies; in addition, it can reduce the energy needs for the bale logistics. According to the present data, improving the chaff collection can allow halving the loss of residues. However, further studies are needed to optimise both the chaff and the straw recoveries.

Sign in / Sign up

Export Citation Format

Share Document