scholarly journals Redox-informed models of global biogeochemical cycles

2020 ◽  
Vol 11 (1) ◽  
Author(s):  
Emily J. Zakem ◽  
Martin F. Polz ◽  
Michael J. Follows
Keyword(s):  
Climate Change ◽  
Microbial Activity ◽  
First Principles ◽  
Biogeochemical Cycles ◽  
Ecological Interactions ◽  
Climate Change Projections ◽  
Global Models ◽  
Biogeochemical Models ◽  
Georgia O'keefe ◽  
Global Biogeochemical Cycles

Abstract Microbial activity mediates the fluxes of greenhouse gases. However, in the global models of the marine and terrestrial biospheres used for climate change projections, typically only photosynthetic microbial activity is resolved mechanistically. To move forward, we argue that global biogeochemical models need a theoretically grounded framework with which to constrain parameterizations of diverse microbial metabolisms. Here, we explain how the key redox chemistry underlying metabolisms provides a path towards this goal. Using this first-principles approach, the presence or absence of metabolic functional types emerges dynamically from ecological interactions, expanding model applicability to unobserved environments. “Nothing is less real than realism. It is only by selection, by elimination, by emphasis, that we get at the real meaning of things.” –Georgia O’Keefe

scholarly journals Farmers’ Perspective on Agriculture and Environmental Change in the Circumpolar North of Europe and America

Land ◽  
2019 ◽  
Vol 8 (12) ◽  
pp. 190 ◽  
Author(s):  
Christopher Poeplau ◽  
Julia Schroeder ◽  
Ed Gregorich ◽  
Irina Kurganova
Keyword(s):  
Climate Change ◽  
Environmental Change ◽  
Online Survey ◽  
Environmental Changes ◽  
Biogeochemical Cycles ◽  
Small Scale ◽  
Local Market ◽  
Food Transport ◽  
Circumpolar North ◽  
Global Biogeochemical Cycles

Climate change may increase the importance of agriculture in the global Circumpolar North with potentially critical implications for pristine northern ecosystems and global biogeochemical cycles. With this in mind, a global online survey was conducted to understand northern agriculture and farmers’ perspective on environmental change north of 60° N. In the obtained dataset with 67 valid answers, Alaska and the Canadian territories were dominated by small-scale vegetable, herbs, hay, and flower farms; the Atlantic Islands were dominated by sheep farms; and Fennoscandia was dominated by cereal farming. In Alaska and Canada, farmers had mostly immigrated with hardly any background in farming, while farmers in Fennoscandia and on the Atlantic Islands mostly continued family traditions. Accordingly, the average time since conversion from native land was 28 ± 28 and 25 ± 12 years in Alaska and Canada, respectively, but 301 ± 291 and 255 ± 155 years on the Atlantic Islands and in Fennoscandia, respectively, revealing that American northern agriculture is expanding. Climate change was observed by 84% of all farmers, of which 67% have already started adapting their farming practices, by introducing new varieties or altering timings. Fourteen farmers reported permafrost on their land, with 50% observing more shallow permafrost on uncultivated land than on cultivated land. Cultivation might thus accelerate permafrost thawing, potentially with associated consequences for biogeochemical cycles and greenhouse gas emissions. About 87% of the surveyed farmers produced for the local market, reducing emissions of food transport. The dynamics of northern land-use change and agriculture with associated environmental changes should be closely monitored. The dataset is available for further investigations.

scholarly journals Carbon limitation leads to thermodynamic regulation of aerobic metabolism

2020 ◽  
Author(s):  
Vanessa A. Garayburu-Caruso ◽  
James C. Stegen ◽  
Hyun-Seob Song ◽  
Lupita Renteria ◽  
Jaqueline Wells ◽  
...  
Keyword(s):  
Nitrogen Content ◽  
Biogeochemical Cycles ◽  
Freshwater Ecosystems ◽  
Aerobic Respiration ◽  
Carbon Limitation ◽  
New Paradigm ◽  
Ultrahigh Resolution ◽  
Respiration Rates ◽  
Biogeochemical Models ◽  
Global Biogeochemical Cycles

AbstractOrganic matter (OM) metabolism in freshwater ecosystems is a critical source of uncertainty in global biogeochemical cycles, yet aquatic OM cycling remains poorly understood. Here, we present the first work to explicitly test OM thermodynamics as a key regulator of aerobic respiration, challenging long-held beliefs that organic carbon and oxygen concentrations are the primary determinants of respiration rates. We pair controlled microcosm experiments with ultrahigh-resolution OM characterization to demonstrate a clear relationship between OM thermodynamic favorability and aerobic respiration under carbon limitation. We also demonstrate a shift in the regulation of aerobic respiration from OM thermodynamics to nitrogen content when carbon is in excess, highlighting a central role for OM thermodynamics in aquatic biogeochemical cycling particularly in carbon-limited ecosystems. Our work therefore illuminates a structural gap in aquatic biogeochemical models and presents a new paradigm in which OM thermodynamics and nitrogen content interactively govern aerobic respiration.

scholarly journals Macroecological drivers of archaea and bacteria in benthic deep-sea ecosystems

2016 ◽  
Vol 2 (4) ◽  
pp. e1500961 ◽  
Author(s):  
Roberto Danovaro ◽  
Massimiliano Molari ◽  
Cinzia Corinaldesi ◽  
Antonio Dell’Anno
Keyword(s):  
Climate Change ◽  
Field Study ◽  
Food Supply ◽  
Deep Sea ◽  
Crucial Role ◽  
Biogeochemical Cycles ◽  
High Latitudes ◽  
Group I ◽  
Extensive Field ◽  
Global Biogeochemical Cycles

Bacteria and archaea dominate the biomass of benthic deep-sea ecosystems at all latitudes, playing a crucial role in global biogeochemical cycles, but their macroscale patterns and macroecological drivers are still largely unknown. We show the results of the most extensive field study conducted so far to investigate patterns and drivers of the distribution and structure of benthic prokaryote assemblages from 228 samples collected at latitudes comprising 34°N to 79°N, and from ca. 400- to 5570-m depth. We provide evidence that, in deep-sea ecosystems, benthic bacterial and archaeal abundances significantly increase from middle to high latitudes, with patterns more pronounced for archaea, and particularly for Marine Group I Thaumarchaeota. Our results also reveal that different microbial components show varying sensitivities to changes in temperature conditions and food supply. We conclude that climate change will primarily affect deep-sea benthic archaea, with important consequences on global biogeochemical cycles, particularly at high latitudes.

Uncertainty in CMIP6 climate change projections for the Australian monsoon is tied to hemispheric-scale changes

2020 ◽  
Author(s):  
Sugata Narsey ◽  
Josephine R. Brown ◽  
Robert A. Colman ◽  
Francois Delage ◽  
Scott Brendan Power ◽  
...  
Keyword(s):  
Climate Change ◽  
Climate Change Projections ◽  
Australian Monsoon

scholarly journals Special Issue “Anaerobes in Biogeochemical Cycles”

2020 ◽  
Vol 9 (1) ◽  
pp. 23
Author(s):  
Caroline M. Plugge ◽  
Diana Z. Sousa
Keyword(s):  
Essential Role ◽  
Biogeochemical Cycles ◽  
Special Issue ◽  
Anaerobic Microorganisms ◽  
Global Biogeochemical Cycles

Anaerobic microorganisms, Bacteria and Archaea, have an essential role in global biogeochemical cycles [...]

scholarly journals Heating and Cooling Degree-Days Climate Change Projections for Portugal

Atmosphere ◽  
2021 ◽  
Vol 12 (6) ◽  
pp. 715
Author(s):  
Cristina Andrade ◽  
Sandra Mourato ◽  
João Ramos
Keyword(s):  
Climate Change ◽  
High Resolution ◽  
Thermal Comfort ◽  
Energy Demand ◽  
Residential Buildings ◽  
Degree Days ◽  
Climate Change Projections ◽  
Heating And Cooling ◽  
Cooling Degree Days ◽  
Heating Energy Demand

Climate change is expected to influence cooling and heating energy demand of residential buildings and affect overall thermal comfort. Towards this end, the heating (HDD) and cooling (CDD) degree-days along with HDD + CDD were computed from an ensemble of seven high-resolution bias-corrected simulations attained from EURO-CORDEX under two Representative Concentration Pathways (RCP4.5 and RCP8.5). These three indicators were analyzed for 1971–2000 (from E-OBS) and 2011–2040, and 2041–2070, under both RCPs. Results predict a decrease in HDDs most significant under RCP8.5. Conversely, it is projected an increase of CDD values for both scenarios. The decrease in HDDs is projected to be higher than the increase in CDDs hinting to an increase in the energy demand to cool internal environments in Portugal. Statistically significant linear CDD trends were only found for 2041–2070 under RCP4.5. Towards 2070, higher(lower) CDD (HDD and HDD + CDD) anomaly amplitudes are depicted, mainly under RCP8.5. Within the five NUTS II

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