scholarly journals Evaluation of carbonyl sulfide biosphere exchange in the Simple Biosphere Model (SiB4)

2021 ◽  
Vol 18 (24) ◽  
pp. 6547-6565
Author(s):  
Linda M. J. Kooijmans ◽  
Ara Cho ◽  
Jin Ma ◽  
Aleya Kaushik ◽  
Katherine D. Haynes ◽  
...  
Keyword(s):  
Mole Fraction ◽  
Mechanistic Model ◽  
Carbonyl Sulfide ◽  
Growing Season ◽  
Global Scale ◽  
Terrestrial Plants ◽  
Large Variability ◽  
Accurate Representation ◽  
High Productivity ◽  
Biosphere Model

Abstract. The uptake of carbonyl sulfide (COS) by terrestrial plants is linked to photosynthetic uptake of CO2 as these gases partly share the same uptake pathway. Applying COS as a photosynthesis tracer in models requires an accurate representation of biosphere COS fluxes, but these models have not been extensively evaluated against field observations of COS fluxes. In this paper, the COS flux as simulated by the Simple Biosphere Model, version 4 (SiB4), is updated with the latest mechanistic insights and evaluated with site observations from different biomes: one evergreen needleleaf forest, two deciduous broadleaf forests, three grasslands, and two crop fields spread over Europe and North America. We improved SiB4 in several ways to improve its representation of COS. To account for the effect of atmospheric COS mole fractions on COS biosphere uptake, we replaced the fixed atmospheric COS mole fraction boundary condition originally used in SiB4 with spatially and temporally varying COS mole fraction fields. Seasonal amplitudes of COS mole fractions are ∼50–200 ppt at the investigated sites with a minimum mole fraction in the late growing season. Incorporating seasonal variability into the model reduces COS uptake rates in the late growing season, allowing better agreement with observations. We also replaced the empirical soil COS uptake model in SiB4 with a mechanistic model that represents both uptake and production of COS in soils, which improves the match with observations over agricultural fields and fertilized grassland soils. The improved version of SiB4 was capable of simulating the diurnal and seasonal variation in COS fluxes in the boreal, temperate, and Mediterranean region. Nonetheless, the daytime vegetation COS flux is underestimated on average by 8±27 %, albeit with large variability across sites. On a global scale, our model modifications decreased the modeled COS terrestrial biosphere sink from 922 Gg S yr−1 in the original SiB4 to 753 Gg S yr−1 in the updated version. The largest decrease in fluxes was driven by lower atmospheric COS mole fractions over regions with high productivity, which highlights the importance of accounting for variations in atmospheric COS mole fractions. The change to a different soil model, on the other hand, had a relatively small effect on the global biosphere COS sink. The secondary role of the modeled soil component in the global COS budget supports the use of COS as a global photosynthesis tracer. A more accurate representation of COS uptake in SiB4 should allow for improved application of atmospheric COS as a tracer of local- to global-scale terrestrial photosynthesis.

scholarly journals Evaluation of carbonyl sulfide biosphere exchange in the Simple Biosphere Model (SiB4)

2021 ◽  
Author(s):  
Linda M. J. Kooijmans ◽  
Ara Cho ◽  
Jin Ma ◽  
Aleya Kaushik ◽  
Katherine D. Haynes ◽  
...  
Keyword(s):  
Mole Fraction ◽  
Mechanistic Model ◽  
Carbonyl Sulfide ◽  
Global Scale ◽  
Terrestrial Plants ◽  
Large Variability ◽  
High Productivity ◽  
Crop Fields ◽  
Soil Component ◽  
Biosphere Model

Abstract. The uptake of carbonyl sulfide (COS) by terrestrial plants is linked to photosynthetic uptake of CO2 by a shared diffusion pathway. Applying COS as a photosynthesis tracer in models requires an accurate representation of biosphere COS fluxes, but these models have not been extensively evaluated against field observations of COS fluxes. In this paper, the COS flux as simulated by the Simple Biosphere Model, version 4 (SiB4) is updated with the latest mechanistic insights and evaluated with site observations from different biomes: one evergreen needleleaf forest, two deciduous broadleaf forests, three grasslands, and two crop fields spread over Europe and North America. To account for the effect of atmospheric COS mole fractions on COS biosphere uptake, we replaced the fixed COS mole fraction originally used in SiB4 with spatially and temporally varying COS mole fraction fields. The lower COS mole fractions in the late growing season reduces COS uptake rates in agreement with observations. We also replaced the empirical soil COS uptake model in SiB4 with a mechanistic model that represents both uptake and production of COS in soils, which improves the match with observations over agricultural fields and fertilized grassland soils. SiB4 was capable of simulating the diurnal and seasonal variation of COS fluxes in the boreal, temperate and Mediterranean region. The daytime vegetation COS flux is on average 8 ± 27 % underestimated, albeit with large variability across sites. On a global scale, our model modifications caused a drop in the COS biosphere sink from 922 Gg S yr−1 in the original SiB4 model to 753 Gg S yr−1 in the updated version. The largest drop in fluxes was driven by lower atmospheric COS mole fractions over regions with high productivity, which highlights the importance of accounting for variations in atmospheric COS mole fractions. The change to a different soil model, on the other hand, had a relatively small effect on the global biosphere COS sink. The small role of the modeled soil component in the COS budget supports the use of COS as a global photosynthesis tracer.

scholarly journals A new mechanistic framework to predict OCS fluxes from soils

2016 ◽  
Vol 13 (8) ◽  
pp. 2221-2240 ◽  
Author(s):  
Jérôme Ogée ◽  
Joana Sauze ◽  
Jürgen Kesselmeier ◽  
Bernard Genty ◽  
Heidi Van Diest ◽  
...  
Keyword(s):  
Large Scale ◽  
Soil Microorganisms ◽  
Soil Moisture Content ◽  
Mechanistic Model ◽  
Carbonyl Sulfide ◽  
Reaction Diffusion ◽  
Global Scale ◽  
First Order ◽  
Uptake Rates ◽  
Hydrolysis Of

Abstract. Estimates of photosynthetic and respiratory fluxes at large scales are needed to improve our predictions of the current and future global CO2 cycle. Carbonyl sulfide (OCS) is the most abundant sulfur gas in the atmosphere and has been proposed as a new tracer of photosynthetic gross primary productivity (GPP), as the uptake of OCS from the atmosphere is dominated by the activity of carbonic anhydrase (CA), an enzyme abundant in leaves that also catalyses CO2 hydration during photosynthesis. However soils also exchange OCS with the atmosphere, which complicates the retrieval of GPP from atmospheric budgets. Indeed soils can take up large amounts of OCS from the atmosphere as soil microorganisms also contain CA, and OCS emissions from soils have been reported in agricultural fields or anoxic soils. To date no mechanistic framework exists to describe this exchange of OCS between soils and the atmosphere, but empirical results, once upscaled to the global scale, indicate that OCS consumption by soils dominates OCS emission and its contribution to the atmospheric budget is large, at about one third of the OCS uptake by vegetation, also with a large uncertainty. Here, we propose a new mechanistic model of the exchange of OCS between soils and the atmosphere that builds on our knowledge of soil CA activity from CO2 oxygen isotopes. In this model the OCS soil budget is described by a first-order reaction–diffusion–production equation, assuming that the hydrolysis of OCS by CA is total and irreversible. Using this model we are able to explain the observed presence of an optimum temperature for soil OCS uptake and show how this optimum can shift to cooler temperatures in the presence of soil OCS emission. Our model can also explain the observed optimum with soil moisture content previously described in the literature as a result of diffusional constraints on OCS hydrolysis. These diffusional constraints are also responsible for the response of OCS uptake to soil weight and depth observed previously. In order to simulate the exact OCS uptake rates and patterns observed on several soils collected from a range of biomes, different CA activities had to be invoked in each soil type, coherent with expected physiological levels of CA in soil microbes and with CA activities derived from CO2 isotope exchange measurements, given the differences in affinity of CA for both trace gases. Our model can be used to help upscale laboratory measurements to the plot or the region. Several suggestions are given for future experiments in order to test the model further and allow a better constraint on the large-scale OCS fluxes from both oxic and anoxic soils.

scholarly journals Inverse modelling of carbonyl sulfide: implementation, evaluation and implications for the global budget

2021 ◽  
Vol 21 (5) ◽  
pp. 3507-3529
Author(s):  
Jin Ma ◽  
Linda M. J. Kooijmans ◽  
Ara Cho ◽  
Stephen A. Montzka ◽  
Norbert Glatthor ◽  
...  
Keyword(s):  
Mole Fraction ◽  
Satellite Data ◽  
Dimethyl Sulfide ◽  
Transport Model ◽  
Carbonyl Sulfide ◽  
Stratospheric Aerosol ◽  
Inverse Modelling ◽  
Model Framework ◽  
Tropical Ocean ◽  
Biosphere Model

Abstract. Carbonyl sulfide (COS) has the potential to be used as a climate diagnostic due to its close coupling to the biospheric uptake of CO2 and its role in the formation of stratospheric aerosol. The current understanding of the COS budget, however, lacks COS sources, which have previously been allocated to the tropical ocean. This paper presents a first attempt at global inverse modelling of COS within the 4-dimensional variational data-assimilation system of the TM5 chemistry transport model (TM5-4DVAR) and a comparison of the results with various COS observations. We focus on the global COS budget, including COS production from its precursors carbon disulfide (CS2) and dimethyl sulfide (DMS). To this end, we implemented COS uptake by soil and vegetation from an updated biosphere model (Simple Biosphere Model – SiB4). In the calculation of these fluxes, a fixed atmospheric mole fraction of 500 pmol mol−1 was assumed. We also used new inventories for anthropogenic and biomass burning emissions. The model framework is capable of closing the COS budget by optimizing for missing emissions using NOAA observations in the period 2000–2012. The addition of 432 Gg a−1 (as S equivalents) of COS is required to obtain a good fit with NOAA observations. This missing source shows few year-to-year variations but considerable seasonal variations. We found that the missing sources are likely located in the tropical regions, and an overestimated biospheric sink in the tropics cannot be ruled out due to missing observations in the tropical continental boundary layer. Moreover, high latitudes in the Northern Hemisphere require extra COS uptake or reduced emissions. HIPPO (HIAPER Pole-to-Pole Observations) aircraft observations, NOAA airborne profiles from an ongoing monitoring programme and several satellite data sources are used to evaluate the optimized model results. This evaluation indicates that COS mole fractions in the free troposphere remain underestimated after optimization. Assimilation of HIPPO observations slightly improves this model bias, which implies that additional observations are urgently required to constrain sources and sinks of COS. We finally find that the biosphere flux dependency on the surface COS mole fraction (which was not accounted for in this study) may substantially lower the fluxes of the SiB4 biosphere model over strong-uptake regions. Using COS mole fractions from our inversion, the prior biosphere flux reduces from 1053 to 851 Gg a−1, which is closer to 738 Gg a−1 as was found by Berry et al. (2013). In planned further studies we will implement this biosphere dependency and additionally assimilate satellite data with the aim of better separating the role of the oceans and the biosphere in the global COS budget.

Climate warming extends growing season but not reproductive phase of terrestrial plants

2021 ◽  
Vol 30 (5) ◽  
pp. 950-960
Author(s):  
Huiying Liu ◽  
Chunyan Lu ◽  
Songdan Wang ◽  
Fei Ren ◽  
Hao Wang
Keyword(s):  
Climate Warming ◽  
Growing Season ◽  
Terrestrial Plants ◽  
Reproductive Phase

Warming effects on biomass allocation are jointly regulated by precipitation and mycorrhizal association in terrestrial plants

2021 ◽  
Author(s):  
Xuhui Zhou ◽  
Lingyan Zhou ◽  
Yanghui He ◽  
Yuling Fu ◽  
Zhenggang Du ◽  
...  
Keyword(s):  
Biomass Allocation ◽  
Mycorrhizal Fungi ◽  
Global Scale ◽  
Mean Annual Precipitation ◽  
Shoot Biomass ◽  
Terrestrial Plants ◽  
Terrestrial Carbon ◽  
Shoot Ratio ◽  
Root Shoot Ratio ◽  
Mycorrhizal Association

Abstract Biomass allocation in plants is fundamental for understanding and predicting terrestrial carbon storage. Recent studies suggest that climate warming can differentially affect root and shoot biomass, and subsequently alter root: shoot ratio. However, warming effects on root: shoot ratio and their underlying drivers at a global scale remain unclear. Using a global synthesis of >300 studies, we here show that warming significantly increases biomass allocation to roots (by 13.1%), and two factors drive this response: mean annual precipitation of the site, and the type of mycorrhizal fungi associated with a plant. Warming-induced allocation to roots is greater in relatively drier habitats compared to shoots (by 15.1%), but lower in wetter sites (by 4.9%), especially for plants associated with arbuscular mycorrhizal fungi compared to ectomycorrhizal fungi. Root-biomass responses to warming predominantly determine the biomass allocation in terrestrial plants suggesting that warming can reinforce the importance of belowground resource uptake. Our study highlights that the wetness or dryness of a site and plants’ mycorrhizal associations strongly regulate terrestrial carbon cycle by altering biomass allocation strategies in a warmer world.

scholarly journals Relations among Valencia orange yields with soil and leaf nutrients in Northwestern Paraná, Brazil

2000 ◽  
Vol 43 (4) ◽  
pp. 387-391 ◽  
Author(s):  
Jonez Fidalski ◽  
Pedro Antonio Martins Auler ◽  
Valdomiro Tormem
Keyword(s):  
Growing Season ◽  
Fruit Weight ◽  
Soil Samples ◽  
Low Fertility ◽  
High Productivity ◽  
Leaf Nutrients ◽  
Valencia Orange ◽  
Northwest Region ◽  
The Relationship ◽  
K Fertilization

The Valencia orange orchards established on soils of low fertility in the Northwest region of Paraná State, Brazil, have showed symptoms of Mg deficiency and reduced fruit yields. The objective of this study was to verify the relationship between yield with soil and leaf nutrients during 1996/97 growing season. Two sites of low and high productivity were selected in seven orchards. Leaf and soil samples (fertilized rows and interrows) were collected in 1996. The results showed that the citrus yields were negatively related with soil Mg/K and Ca+Mg/K ratios in the fertilized rows, and fruit weight positively correlated with leaf Zn in the low productivity orchards. The fruit weight was positively related with leaf Ca and soil Ca in the fertilized rows of the high productivity orchards. The results suggested an adequate lime and K fertilization managements in the fertilized rows, as well as an adequate Zn supply.

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

2016 ◽  
Vol 9 (2) ◽  
pp. 841-855 ◽  
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.

scholarly journals ECOLOGICAL-GEOGRAPHIC APPROACHES TO THE STUDY OF GENETIC DIVERSITY OF BARLEY AND OAT FROM THE VIR COLLECTION

2020 ◽  
Author(s):  
Igor Loskutov ◽  
Lubov Novikova ◽  
Olga Kovaleva ◽  
Nadezhda Ivanova ◽  
Elena Blinova ◽  
...  
Keyword(s):  
Environmental Conditions ◽  
Growing Season ◽  
Regression Coefficients ◽  
Cultivation Conditions ◽  
High Productivity ◽  
Sum Of Effective Temperatures ◽  
Economically Valuable Traits ◽  
Effective Temperatures ◽  
The Stability ◽  
Selection Of

Under conditions of climate change, the assessment of the stability of genotypes is of particular importance. To conduct directed selection of genotypes with a narrow or broad reaction rate, it is necessary to assess their stability already in the early stages of breeding. The aim of the study was to study the stability of breeding significant traits of oat and barley samples in contrasting ecological and geographical conditions. 25 oat samples and 25 barley samples were studied over 3 years under contrasting conditions in St. Petersburg and the Tambov region. Varieties are characterized by average values of economically valuable traits and genotype regression coefficients on the influence of the bi environment according to Eberhart and Russell. The most sensitive to a change in the ecological and geographical situation were the durations of the germination-heading, germination-harvest periods and grain yield. These characters varied to a greater extent depending on the cultivation conditions than on the genotype. According to regression coefficients for environmental conditions, significant differences in genotypes were only in yield. Contrasting groups of varieties were distinguished by regression coefficients on environmental conditions, genotypes with high productivity. The durations of germination-heading, germination-harvest, the plant height reacted to the change in the environment the same in different varieties. The duration of the growing season was determined by the sum of effective temperatures above 15C. The reduction of the growing season in both crops was 3 days with an increase in the sum of effective temperatures above 15C by 100C.

scholarly journals Challenges to Reproduce Vegetation Structure and Dynamics in Amazonia Using a Coupled Climate–Biosphere Model

2009 ◽  
Vol 13 (11) ◽  
pp. 1-28 ◽  
Author(s):  
Mônica Carneiro Alves Senna ◽  
Marcos Heil Costa ◽  
Lucía Iracema Chipponelli Pinto ◽  
Hewlley Maria Acioli Imbuzeiro ◽  
Luciana Mara Freitas Diniz ◽  
...  
Keyword(s):  
Vegetation Structure ◽  
Carbon Allocation ◽  
Net Primary Production ◽  
Ecosystem Structure ◽  
Intergovernmental Panel ◽  
Area Index ◽  
Carbon Cycle Model ◽  
Accurate Representation ◽  
Structure And Dynamics ◽  
Biosphere Model

Abstract The Amazon rain forest constitutes one of the major global stocks of carbon. Recent studies, including the last Intergovernmental Panel on Climate Change report and the Coupled Climate Carbon Cycle Model Intercomparison Project, have suggested that it may reduce in size and lose biomass during the twenty-first century through a savannization process. A better understanding of how this ecosystem structure, dynamics, and carbon balance may respond to future climate changes is needed. This article investigates how well a fully coupled atmosphere–biosphere model can reproduce vegetation structure and dynamics in Amazonia to the extent permitted by available data. The accurate representation of the coupled climate–biosphere dynamics requires the accurate representation of climate, net primary production (NPP), and its partition among the several carbon pool components. The simulated climate is validated against precipitation (within 5% of four datasets) and incident solar radiation (within 7% of observations). The authors also validate (i) simulated land cover, which reproduces well the observed patterns; (ii) NPP, within 5% of observations; and (iii) respiration rates, within 15% of observations. The performance of simulated variables that depend on carbon allocation, like NPP partitioning, leaf area index, and aboveground live biomass, although good on a regional mean, is significantly low when spatial patterns are considered. These errors may be attributed to fixed carbon allocation and residence time parameters assumed by the model. Carbon allocation apparently varies spatially, and to simulate this spatial variability is quite a challenge.

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