Development of new drainage factor in ECOSSE model to improve water dynamics and prediction of CO2 fluxes from drained peatlands

2021 ◽  
Author(s):  
Alina Premrov ◽  
David Wilson ◽  
Matthew Saunders ◽  
Jagadeesh Yeluripati ◽  
Florence Renou-Wilson
Keyword(s):  
Water Table ◽  
Empirical Data ◽  
Seasonal Variability ◽  
Model Simulation ◽  
Water Dynamics ◽  
Water Model ◽  
Biogeochemical Model ◽  
Water Table Level ◽  
Biogeochemical Models ◽  
Model Water

<p>ABSTRACT</p><p>Drained peatlands often act as carbon source and their drainage characteristics can be challenging to accommodate in biogeochemical models. This study uses the ECOSSE process-based  biogeochemical model [to simulate water-table level and CO<sub>2</sub> fluxes (heterotrophic respiration) <sub>[1]</sub>], and empirical data from two Irish drained peatlands: Blackwater and Moyarwood, which were partly rewetted (both sites are extensively described in earlier studies <sub>[2]</sub>). Here we explain details on the development of a new drainage factor with seasonal variability Dfa(i) for drained peatlands, based on our recently published work <sub>[3] </sub> that we hope can contribute towards the potential future development of IPCC Tier 3 emissions reporting. The Dfa(i) was developed using empirical data from Blackwater drained bare-peat site (BWdr) and its application was further tested at the Moyarwood site under drained (MOdr) and rewetted conditions (MOrw) <sub>[3]</sub>. The development of the Dfa(i) was carried out in three main steps <sub>[3]</sub>: 1 - identification of the ‘wt-discrepancy event’; 2 - development of Dfa without seasonal variability, and 3 - accounting for seasonal variability and development of Dfa(i). Dfa(i) was then applied to the rainfall inputs for the periods of active drainage in conjunction with the measured water-table inputs <sub>[3]</sub>. As explained in our published work <sub>[3]</sub>, the results indicate that the application of Dfa(i) could improve the model performance to predict water-table level (BWdr: r<sup>2 </sup>= 0.89 MOdr: r<sup>2 </sup>=  0.94); and CO<sub>2</sub> fluxes [BWdr: r<sup>2</sup> = 0.66 and MOdr: r<sup>2 </sup>= 0.78) under drained conditions, along with ability of the model to capture seasonal trends <sub>[2]</sub>. The model simulation of CO<sub>2</sub> fluxes at MOrw site was also satisfactory (r<sup>2</sup>=0.75); however, the MOrw water-table simulation results suggest that additional work on the water model component under rewetted conditions is still needed <sub>[3]</sub>. We further discuss our insights into potential opportunities for future additional improvements and upgrading of the ECOSSE model water module.</p><p><strong> </strong></p><p><strong>Acknowledgements</strong></p><p>The authors are grateful to the Irish Environmental Protection Agency (EPA) for funding the AUGER: Project (2015-CCRP-MS.30) under EPA Research Programme 2014–2020. Full acknowledgements are provided in Premrov et. al (2020) <sub>[3]</sub>.</p><p> </p><p><strong>Literature</strong></p><p>[1] Smith, J., et al. 2010. ECOSSE. User Manual.</p><p>[2] Renou-Wilson, F., et. al. 2019. Rewetting degraded peatlands for climate and biodiversity benefits: Results from two raised bogs. Ecol. Eng. 127:547-560.</p><p>[3] Premrov, A., D. Wilson, M. Saunders, J. Yeluripati and F. Renou-Wilson (2020). CO<sub>2 </sub>fluxes from drained and rewetted peatlands using a new ECOSSE model water table simulation approach. Sci. Total Environ. (https://doi.org/10.1016/j.scitotenv.2020.142433; on-line 2020; in print Vol. 754, 2021; under CC BY 4.0).</p>

scholarly journals Hysteretic temperature sensitivity of wetland CH<sub>4</sub> fluxes explained by substrate availability and microbial activity

2020 ◽  
Vol 17 (22) ◽  
pp. 5849-5860
Author(s):  
Kuang-Yu Chang ◽  
William J. Riley ◽  
Patrick M. Crill ◽  
Robert F. Grant ◽  
Scott R. Saleska
Keyword(s):  
Temperature Sensitivity ◽  
Seasonal Variability ◽  
Global Climate ◽  
Biogeochemical Model ◽  
Ch4 Emission ◽  
Substrate Availability ◽  
Ch4 Emissions ◽  
Ch4 Production ◽  
Biogeochemical Models ◽  
Abiotic Interactions

Abstract. Methane (CH4) emissions from wetlands are likely increasing and important in global climate change assessments. However, contemporary terrestrial biogeochemical model predictions of CH4 emissions are very uncertain, at least in part due to prescribed temperature sensitivity of CH4 production and emission. While statistically consistent apparent CH4 emission temperature dependencies have been inferred from meta-analyses across microbial to ecosystem scales, year-round ecosystem-scale observations have contradicted that finding. Here, we show that apparent CH4 emission temperature dependencies inferred from year-round chamber measurements exhibit substantial intra-seasonal variability, suggesting that using static temperature relations to predict CH4 emissions is mechanistically flawed. Our model results indicate that such intra-seasonal variability is driven by substrate-mediated microbial and abiotic interactions: seasonal cycles in substrate availability favors CH4 production later in the season, leading to hysteretic temperature sensitivity of CH4 production and emission. Our findings demonstrate the uncertainty of inferring CH4 emission or production rates from temperature alone and highlight the need to represent microbial and abiotic interactions in wetland biogeochemical models.

Effects of light and phosphorus on summer DMS dynamics in subtropical waters using a global ocean biogeochemical model

2016 ◽  
Vol 13 (2) ◽  
pp. 379 ◽  
Author(s):  
Italo Masotti ◽  
Sauveur Belviso ◽  
Laurent Bopp ◽  
Alessandro Tagliabue ◽  
Eva Bucciarelli
Keyword(s):  
General Circulation ◽  
North Atlantic Ocean ◽  
Model Simulation ◽  
Global Ocean ◽  
Longitudinal Distribution ◽  
Biogeochemical Model ◽  
Relative Role ◽  
Sargasso Sea ◽  
Ecological Processes ◽  
Climatological Data

Environmental context Models are needed to predict the importance of the changes in marine emissions of dimethylsulfide (DMS) in response to ocean warming, increased stratification and acidification, and to evaluate the potential effects on the Earth’s climate. We use complementary simulations to further our understanding of the marine cycle of DMS in subtropical waters, and show that a lack of phosphorus may exert a more important control on surface DMS concentrations than an excess of light. Abstract The occurrence of a summer DMS paradox in the vast subtropical gyres is a strong matter of debate because approaches using discrete measurements, climatological data and model simulations yielded contradictory results. The major conclusion of the first appraisal of prognostic ocean DMS models was that such models need to give more weight to the direct effect of environmental forcings (e.g. irradiance) on DMS dynamics to decouple them from ecological processes. Here, the relative role of light and phosphorus on summer DMS dynamics in subtropical waters is assessed using the ocean general circulation and biogeochemistry model NEMO-PISCES in which macronutrient concentrations were restored to monthly climatological data values to improve the representation of phosphate concentrations. Results show that the vertical and temporal decoupling between chlorophyll and DMS concentrations observed in the Sargasso Sea during the summer months is captured by the model. Additional sensitivity tests show that the simulated control of phosphorus on surface DMS concentrations in the Sargasso Sea is much more important than that of light. By extending the analysis to the whole North Atlantic Ocean, we show that the longitudinal distribution of DMS during summer is asymmetrical and that a correlation between the solar radiation dose and DMS concentrations only occurs in the Sargasso Sea. The lack of a widespread summer DMS paradox in our model simulation as well as in the comparison of discrete and climatological data could be due to the limited occurrence of phosphorus limitation in the global ocean.

scholarly journals Substantial hysteresis in emergent temperature sensitivity of global wetland CH4 emissions

2021 ◽  
Vol 12 (1) ◽  
Author(s):  
Kuang-Yu Chang ◽  
William J. Riley ◽  
Sara H. Knox ◽  
Robert B. Jackson ◽  
Gavin McNicol ◽  
...  
Keyword(s):  
Temperature Sensitivity ◽  
Spatial Scales ◽  
Biogeochemical Model ◽  
Spatial And Temporal Variability ◽  
Biogeochemical Models ◽  
Model Parameterization ◽  
Machine Learning Model ◽  
Meta Analyses ◽  
The Relationship ◽  
Global Carbon

AbstractWetland methane (CH4) emissions ($${F}_{{{CH}}_{4}}$$ F C H 4 ) are important in global carbon budgets and climate change assessments. Currently, $${F}_{{{CH}}_{4}}$$ F C H 4 projections rely on prescribed static temperature sensitivity that varies among biogeochemical models. Meta-analyses have proposed a consistent $${F}_{{{CH}}_{4}}$$ F C H 4 temperature dependence across spatial scales for use in models; however, site-level studies demonstrate that $${F}_{{{CH}}_{4}}$$ F C H 4 are often controlled by factors beyond temperature. Here, we evaluate the relationship between $${F}_{{{CH}}_{4}}$$ F C H 4 and temperature using observations from the FLUXNET-CH4 database. Measurements collected across the globe show substantial seasonal hysteresis between $${F}_{{{CH}}_{4}}$$ F C H 4 and temperature, suggesting larger $${F}_{{{CH}}_{4}}$$ F C H 4 sensitivity to temperature later in the frost-free season (about 77% of site-years). Results derived from a machine-learning model and several regression models highlight the importance of representing the large spatial and temporal variability within site-years and ecosystem types. Mechanistic advancements in biogeochemical model parameterization and detailed measurements in factors modulating CH4 production are thus needed to improve global CH4 budget assessments.

The biology of two species of Engaeus (Decapoda : Parastacidae) in Tasmania. III. Habitat, food, associated fauna and distribution

1977 ◽  
Vol 28 (1) ◽  
pp. 95 ◽  
Author(s):  
PJ Suter ◽  
AMM Richardson
Keyword(s):  
Dissolved Oxygen ◽  
Geographical Distribution ◽  
Water Table ◽  
Freshwater Crayfish ◽  
Associated Fauna ◽  
Water Table Level ◽  
Burrow Structure ◽  
Study Sites ◽  
North Western ◽  
Temperature Water

The habitats of two apparently sympatric freshwater crayfish, Engaeus cisternarius and E. fossor, in north-western Tasmania were compared. At two study sites data on rainfall, temperature, water table level, dissolved oxygen and pH were collected. E. fossor occupies regions below the water table, whilst E. cisternarius occupies drier areas above the water table. The burrow structure, burrow fauna, ectofauna and food were compared. The geographical distribution of each species is discussed.

scholarly journals Spatial scale-dependent land–atmospheric methane exchanges in the northern high latitudes from 1993 to 2004

2014 ◽  
Vol 11 (7) ◽  
pp. 1693-1704 ◽  
Author(s):  
X. Zhu ◽  
Q. Zhuang ◽  
X. Lu ◽  
L. Song
Keyword(s):  
Spatial Heterogeneity ◽  
Spatial Scale ◽  
Water Table ◽  
Spatial Scales ◽  
Grid Cell ◽  
High Latitudes ◽  
Atmospheric Methane ◽  
Ch4 Emissions ◽  
Biogeochemical Models ◽  
Macro Scale

Abstract. Effects of various spatial scales of water table dynamics on land–atmospheric methane (CH4) exchanges have not yet been assessed for large regions. Here we used a coupled hydrology–biogeochemistry model to quantify daily CH4 exchanges over the pan-Arctic from 1993 to 2004 at two spatial scales of 100 km and 5 km. The effects of sub-grid spatial variability of the water table depth (WTD) on CH4 emissions were examined with a TOPMODEL-based parameterization scheme for the northern high latitudes. We found that both WTD and CH4 emissions are better simulated at a 5 km spatial resolution. By considering the spatial heterogeneity of WTD, net regional CH4 emissions at a 5 km resolution are 38.1–55.4 Tg CH4 yr−1 from 1993 to 2004, which are on average 42% larger than those simulated at a 100 km resolution using a grid-cell-mean WTD scheme. The difference in annual CH4 emissions is attributed to the increased emitting area and enhanced flux density with finer resolution for WTD. Further, the inclusion of sub-grid WTD spatial heterogeneity also influences the inter-annual variability of CH4 emissions. Soil temperature plays an important role in the 100 km estimates, while the 5 km estimates are mainly influenced by WTD. This study suggests that previous macro-scale biogeochemical models using a grid-cell-mean WTD scheme might have underestimated the regional CH4 emissions. The spatial scale-dependent effects of WTD should be considered in future quantification of regional CH4 emissions.

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