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Carbon cycle

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Full-Text Articles in Life Sciences

Deconstructing The Mangrove Carbon Cycle: Gains, Transformation, And Losses, M. F. Adame, N. Cormier, P. Taillardat, N. Iram, A. Rovai, T. M. Sloey, E. S. Yando, J. F. Blanco-Libreros, M. Arnaud, T. Jennerjahn, C. E. Lovelock, D. Friess, G. M. S. Reithmaier, C. A. Buelow, S. M. Muhammad-Nor, R. R. Twilley, R. A. Ribeiro Jan 2024

Deconstructing The Mangrove Carbon Cycle: Gains, Transformation, And Losses, M. F. Adame, N. Cormier, P. Taillardat, N. Iram, A. Rovai, T. M. Sloey, E. S. Yando, J. F. Blanco-Libreros, M. Arnaud, T. Jennerjahn, C. E. Lovelock, D. Friess, G. M. S. Reithmaier, C. A. Buelow, S. M. Muhammad-Nor, R. R. Twilley, R. A. Ribeiro

Biological Sciences Faculty Publications

Mangroves are one of the most carbon-dense forests on the Earth and have been highlighted as key ecosystems for climate change mitigation and adaptation. Hundreds of studies have investigated how mangroves fix, transform, store, and export carbon. Here, we review and synthesize the previously known and emerging carbon pathways in mangroves, including gains (woody biomass accumulation, deadwood accumulation, soil carbon sequestration, root and litterfall production), transformations (food web transfer through herbivory, decomposition), and losses (respiration as CO2 and CH4, litterfall export, particulate and dissolved carbon export). We then review the technologies available to measure carbon fluxes in …


Assessing Changing Carbon Pool Dynamics And Species Composition In A Pennsylvania Broadleaf Forest Fragment, Kyleigh Levinsky, Jessica L. Schedlbauer Jan 2024

Assessing Changing Carbon Pool Dynamics And Species Composition In A Pennsylvania Broadleaf Forest Fragment, Kyleigh Levinsky, Jessica L. Schedlbauer

Sustainability Research & Creative Activities Grants Reports

Temperate broadleaf forests are pivotal to the global carbon cycle, Representing 37% of the global forest carbon pool (Pan et al 2011). • Maintaining compositional diversity in temperate broadleaf forests, such as the Gordon Natural Area (GNA) is critical to maintaining ecosystem services, such as carbon sequestration. • Pressures from native and non-native herbivores threaten the biodiversity of temperate broadleaf forests in the United States (Ghandi et al. 2010). The introduction of non-native insects such as the emerald ash borer (Argrilus planipennis), as well as the overpopulation of white-tailed deer (Odocoileus virginianus) has led to declines in some tree species. …


The Carbon Balance Of Long Term And Newly Established Temperate Grasslands, J. Clifton-Brown, G. Lanigan, R. B. Taylor, J. I. Burke, M. B. Jones Jun 2023

The Carbon Balance Of Long Term And Newly Established Temperate Grasslands, J. Clifton-Brown, G. Lanigan, R. B. Taylor, J. I. Burke, M. B. Jones

IGC Proceedings (1997-2023)

Carbon (C) sequestration is the process of removing CO2 from the atmosphere and storing it in C pools of varying lifetime. Storage can be in the form of above-ground biomass, below-ground biomass or recalcitrant organic and inorganic C in the soil. While the processes of C sequestration are ultimately regulated at the molecular level, management practices and climate can greatly affect the way in which terrestrial ecosystems sequester C (Soussana et al., 2004). Because temperate grasslands account for a significant portion of the agricultural and semi-natural land-cover in N-W Europe any increase in the potential of temperate grasslands …


Inorganic Carbon Outwelling From A Mediterranean Seagrass Meadow Using Radium Isotopes, Claudia Majtényi-Hill, Gloria Reithmaier, Yvonne Y. Y. Yau, Oscar Serrano, Nerea Piñeiro-Juncal, Isaac R. Santos Apr 2023

Inorganic Carbon Outwelling From A Mediterranean Seagrass Meadow Using Radium Isotopes, Claudia Majtényi-Hill, Gloria Reithmaier, Yvonne Y. Y. Yau, Oscar Serrano, Nerea Piñeiro-Juncal, Isaac R. Santos

Research outputs 2022 to 2026

Seagrass meadows are ‘blue carbon’ ecosystems widely recognised for their potential role in climate change mitigation. Previous studies have focused mainly on carbon storage within meadows and sediments. However, little is known about contribution of outwelling (i.e., lateral transport) to seagrass carbon budgets. Here, radium isotopes (223Ra and 224Ra) were used to assess dissolved inorganic carbon (DIC) and total alkalinity (TA) outwelling from a Mediterranean Posidonia oceanica meadow during early autumn. DIC outwelling was 114 ± 61 mmol m − 2 day − 1 and exceeded above-meadow CO2 outgassing (3 ± 1 mmol m − 2 day …


Under Ice Photosynthetic Primary Production And Dark Carbon Fixation In A Temperate Freshwater System, Vanessa Cubillos Tellez Jan 2023

Under Ice Photosynthetic Primary Production And Dark Carbon Fixation In A Temperate Freshwater System, Vanessa Cubillos Tellez

Dissertations, Master's Theses and Master's Reports

Ice-covered lakes are vulnerable to environmental change, especially those in the Northern Hemisphere where ice cover is rapidly declining due to global warming. These changes can alter metabolic processes and disrupt carbon cycling driven by primary producers who form the base of the food chain and are key to sustaining ecosystem function. Photosynthetic primary production and dark carbon fixation under the ice in the Keweenaw Waterway, a temperate freshwater system that is ice-covered for ~3 months out of the year, were studied using a carbon isotopic labeling (14C-bicarbonate) technique. Water samples were collected weekly during ice cover and monthly during …


Changes In Ecosystem Processes And Functional Traits Over An Elevational Gradient, Tiana Issa Jan 2023

Changes In Ecosystem Processes And Functional Traits Over An Elevational Gradient, Tiana Issa

Honors Theses

Elevation gradients have been used to understand how climate change impacts various ecosystems processes by substituting distance across elevation with time, reflecting a previous, colder climate. To monitor the changes in soil organic carbon (SOC), plant community, and functional traits across time in the face of climate change, this study used space-for-time substitution to emulate a long-term study with elevational gradients and revisited the same gradient for nearly two decades to monitor elevational effects across time. With this research, I aim to answer the following questions: (1) How does elevation impact ecosystem processes and alpine plant traits? (2) How does …


Fire History And Long-Term Carbon Accumulation In Hemi-Boreal Peatlands Companion Dataset, Dominic Uhelski, Evan Kane, Katherine Heckman, Rodney Chimner Nov 2022

Fire History And Long-Term Carbon Accumulation In Hemi-Boreal Peatlands Companion Dataset, Dominic Uhelski, Evan Kane, Katherine Heckman, Rodney Chimner

Michigan Tech Research Data

This dataset contains peat property data including location, depth, bulk density, organic matter content, and carbon content, infrared spectra, and radiocarbon dates. Peat cores were collected between 2011 and 2019. Analyses were performed between 2018 and 2021. Samples were collected from peatlands in Michigan, Wisconsin, and Minnesota for the purposes of reconstruction of fire history. The data is associated with a yet-to-be-published manuscript to be submitted to Ecosystems.

A README file is included describing the contents of the dataset and all major spreadsheet files contain a Meta worksheet which describes each column of
data.


Contrasting Particle Fluxes And Composition In A Submarine Canyon Affected By Natural Sediment Transport Events And Bottom Trawling, Sarah Paradis, Marta Arjona-Camas, Miguel Goñi, Albert Palanques, Pere Masqué, Pere Puig Oct 2022

Contrasting Particle Fluxes And Composition In A Submarine Canyon Affected By Natural Sediment Transport Events And Bottom Trawling, Sarah Paradis, Marta Arjona-Camas, Miguel Goñi, Albert Palanques, Pere Masqué, Pere Puig

Research outputs 2022 to 2026

Submarine canyons are important conduits of sediment and organic matter to deep-sea environments, mainly during high-energy natural events such as storms, river floods, or dense shelf water cascading, but also due to human activities such as bottom trawling. The contributions of natural and trawling-induced sediment and organic matter inputs into Palamós Canyon (NW Mediterranean) were assessed from three instrumented moorings deployed in the axis and northern flank of the canyon covering the trawling closure (February) and the trawling season (March-December) of 2017. During the trawling closure, large sediment fluxes with high contents of labile marine organic matter content were registered …


Fresh Air For The Mire-Breathing Hypothesis: Sphagnum Moss And Peat Structure Regulate The Response Of Co2 Exchange To Altered Hydrology In A Northern Peatland Ecosystem, Ally O’Neill, Colin Tucker, Evan S. Kane Oct 2022

Fresh Air For The Mire-Breathing Hypothesis: Sphagnum Moss And Peat Structure Regulate The Response Of Co2 Exchange To Altered Hydrology In A Northern Peatland Ecosystem, Ally O’Neill, Colin Tucker, Evan S. Kane

Michigan Tech Publications

Sphagnum-dominated peatlands store more carbon than all of Earth’s forests, playing a large role in the balance of carbon dioxide. However, these carbon sinks face an uncertain future as the changing climate is likely to cause water stress, potentially reducing Sphagnum productivity and transitioning peatlands to carbon sources. A mesocosm experiment was performed on thirty-two peat cores collected from two peatland landforms: elevated mounds (hummocks) and lower, flat areas of the peatland (hollows). Both rainfall treatments and water tables were manipulated, and CO2 fluxes were measured. Other studies have observed peat subsiding and tracking the water table downward when experiencing …


Optimizing Process-Based Models To Predict Current And Future Soil Organic Carbon Stocks At High-Resolution, Marie-Anne De Graaff, Ryan Will Jun 2022

Optimizing Process-Based Models To Predict Current And Future Soil Organic Carbon Stocks At High-Resolution, Marie-Anne De Graaff, Ryan Will

Biology Faculty Publications and Presentations

From hillslope to small catchment scales (< 50 km2), soil carbon management and mitigation policies rely on estimates and projections of soil organic carbon (SOC) stocks. Here we apply a process-based modeling approach that parameterizes the MIcrobial-MIneral Carbon Stabilization (MIMICS) model with SOC measurements and remotely sensed environmental data from the Reynolds Creek Experimental Watershed in SW Idaho, USA. Calibrating model parameters reduced error between simulated and observed SOC stocks by 25%, relative to the initial parameter estimates and better captured local gradients in climate and productivity. The calibrated parameter ensemble was used to produce spatially continuous, high-resolution (10 m …


Geomorphic Gradients In Shallow Seagrass Carbon Stocks, Jahson Berhane Alemu, Siti Maryam Yaakub, Erik S. Yando, Rachel Yu San Lau, Cheng Chang Lim, Jun Yu Puah, Daniel A. Friess Jan 2022

Geomorphic Gradients In Shallow Seagrass Carbon Stocks, Jahson Berhane Alemu, Siti Maryam Yaakub, Erik S. Yando, Rachel Yu San Lau, Cheng Chang Lim, Jun Yu Puah, Daniel A. Friess

Biological Sciences Faculty Publications

Seagrass meadows are important sinks of organic carbon (Corg), in particular the near-surface Corg pool (≤ 15 cm) compared to deeper sediments. Near-surface carbon is highly susceptible to disturbance and loss to the atmosphere, however, inadequate accounting for variability in this pool of carbon limits their uptake into carbon accounting frameworks. We therefore investigated the spatial variability in seagrass near-surface Corg and biomass Corg across different geomorphic (estuary, lagoonal and reef-associated) and community typologies (pioneer and persistent). Near-surface Corg stock in vegetated areas (25.78 Mg Corg ha−1 ± 26.64) was twice that …


Tropicalization Of Seagrass Macrophytodetritus Accumulations And Associated Food Webs, Gilles Lepoint, Glenn A. Hyndes Jan 2022

Tropicalization Of Seagrass Macrophytodetritus Accumulations And Associated Food Webs, Gilles Lepoint, Glenn A. Hyndes

Research outputs 2022 to 2026

Seagrass, systems export significant amounts of their primary production as large detritus (i.e. macrophytodetritus). Accumulations of exported macrophytodetritus (AEM) are found in many areas in coastal environment. Dead seagrass leaves are often a dominant component of these accumulations, offering shelter and/or food to numerous organisms. AEM are particular habitats, different from donor habitats (i.e. seagrass meadow, kelp or macroalgae habitats) and with their own characteristics and dynamics. They have received less attention than donor habitats despite the fact they often connect different coastal habitats, are the place of intense remineralization processes and shelter associated detritus food web. As for seagrass …


Editorial: Advances In Understanding Lateral Blue Carbon Export From Coastal Ecosystems, Kai Xiao, Nengwang Chen, Zhaohui Aleck Wang, Joseph James Tamborski, Damien Troy Maher, Xuan Yu Jan 2022

Editorial: Advances In Understanding Lateral Blue Carbon Export From Coastal Ecosystems, Kai Xiao, Nengwang Chen, Zhaohui Aleck Wang, Joseph James Tamborski, Damien Troy Maher, Xuan Yu

OES Faculty Publications

No abstract provided.


What Is Refractory Organic Matter In The Ocean?, Federico Baltar, Xosé A. Alvarez-Salgado, Javier Arístegui, Ronald Benner, Dennis A. Hansell, Gerhard J. Herndl, Christian Lønborg Apr 2021

What Is Refractory Organic Matter In The Ocean?, Federico Baltar, Xosé A. Alvarez-Salgado, Javier Arístegui, Ronald Benner, Dennis A. Hansell, Gerhard J. Herndl, Christian Lønborg

Faculty Publications

About 20% of the organic carbon produced in the sunlit surface ocean is transported into the ocean’s interior as dissolved, suspended and sinking particles to be mineralized and sequestered as dissolved inorganic carbon (DIC), sedimentary particulate organic carbon (POC) or “refractory” dissolved organic carbon (rDOC). Recently, the physical and biological mechanisms associated with the particle pumps have been revisited, suggesting that accepted fluxes might be severely underestimated (Boyd et al., 2019; Buesseler et al., 2020). Perhaps even more poorly understood are the mechanisms driving rDOC production and its potential accumulation in the ocean. On the basis of …


What Is Refractory Organic Matter In The Ocean?, Federico Baltar, Xosé A. Alvarez-Salgado, Javier Arístegui, Ronald Benner, Dennis A. Hansell, Gerhard J. Herndl, Christian Lønborg Apr 2021

What Is Refractory Organic Matter In The Ocean?, Federico Baltar, Xosé A. Alvarez-Salgado, Javier Arístegui, Ronald Benner, Dennis A. Hansell, Gerhard J. Herndl, Christian Lønborg

Faculty Publications

About 20% of the organic carbon produced in the sunlit surface ocean is transported into the ocean’s interior as dissolved, suspended and sinking particles to be mineralized and sequestered as dissolved inorganic carbon (DIC), sedimentary particulate organic carbon (POC) or “refractory” dissolved organic carbon (rDOC). Recently, the physical and biological mechanisms associated with the particle pumps have been revisited, suggesting that accepted fluxes might be severely underestimated (Boyd et al., 2019; Buesseler et al., 2020). Perhaps even more poorly understood are the mechanisms driving rDOC production and its potential accumulation in the ocean. On the basis of …


What Is Refractory Organic Matter In The Ocean?, Federico Baltar, Xosé A. Alvarez-Salgado, Javier Arístegui, Ronald Benner, Dennis A. Hansell, Gerhard J. Herndl, Christian Lønborg Apr 2021

What Is Refractory Organic Matter In The Ocean?, Federico Baltar, Xosé A. Alvarez-Salgado, Javier Arístegui, Ronald Benner, Dennis A. Hansell, Gerhard J. Herndl, Christian Lønborg

Faculty Publications

About 20% of the organic carbon produced in the sunlit surface ocean is transported into the ocean’s interior as dissolved, suspended and sinking particles to be mineralized and sequestered as dissolved inorganic carbon (DIC), sedimentary particulate organic carbon (POC) or “refractory” dissolved organic carbon (rDOC). Recently, the physical and biological mechanisms associated with the particle pumps have been revisited, suggesting that accepted fluxes might be severely underestimated (Boyd et al., 2019; Buesseler et al., 2020). Perhaps even more poorly understood are the mechanisms driving rDOC production and its potential accumulation in the ocean. On the basis of …


An Operational Overview Of The Export Processes In The Ocean From Remote Sensing (Exports) Northeast Pacific Field Deployment, David A. Siegel, Ivona Cetinic, (...), Deborah K. Steinberg, Et Al Jan 2021

An Operational Overview Of The Export Processes In The Ocean From Remote Sensing (Exports) Northeast Pacific Field Deployment, David A. Siegel, Ivona Cetinic, (...), Deborah K. Steinberg, Et Al

VIMS Articles

The goal of the EXport Processes in the Ocean from RemoTe Sensing (EXPORTS) field campaign is to develop a predictive understanding of the export, fate, and carbon cycle impacts of global ocean net primary production. To accomplish this goal, observations of export flux pathways, plankton community composition, food web processes, and optical, physical, and biogeochemical (BGC) properties are needed over a range of ecosystem states. Here we introduce the first EXPORTS field deployment to Ocean Station Papa in the Northeast Pacific Ocean during summer of 2018, providing context for other papers in this special collection. The experiment was conducted with …


Biolability Of Fresh And Photodegraded Pyrogenic Dissolved Organic Matter From Laboratory-Prepared Chars, K. W. Bostick, A. R. Zimmerman, A. I. Goranov, S. Mitra, P. G. Hatcher, A. S. Wozniak Jan 2021

Biolability Of Fresh And Photodegraded Pyrogenic Dissolved Organic Matter From Laboratory-Prepared Chars, K. W. Bostick, A. R. Zimmerman, A. I. Goranov, S. Mitra, P. G. Hatcher, A. S. Wozniak

Chemistry & Biochemistry Faculty Publications

Pyrogenic dissolved organic matter (pyDOM) is known to be an important biogeochemical constituent of aquatic ecosystems and the carbon cycle. While recent studies have examined how pyDOM production, composition, and photolability varies with parent pyrogenic solid material type, we lack an understanding of potential microbial mineralization and transformation of pyDOM in the biogeosphere. Thus, leachates of oak, charred at 400 °C and 650 °C, as well as their photodegraded counterparts were incubated with a soil‐extracted microbial consortium over 96 days. During the incubation, significantly more carbon was biomineralized from the lower versus higher temperature char leachate (45% vs. 37% lost, …


Successional Changes In Carbon Storage Are Sustained In A Temperate Forest Across Different Initiating Disturbances, Cameron Clay Jan 2021

Successional Changes In Carbon Storage Are Sustained In A Temperate Forest Across Different Initiating Disturbances, Cameron Clay

Theses and Dissertations

Managing forests for carbon (C) sequestration requires an understanding of how disturbance history shapes C pools and fluxes over successional time. At the University of Michigan Biological Station, we examined how two stand establishing disturbances influenced C pools and fluxes over 100+ years of succession, comparing these secondary forests with “legacy” late-successional stands encompassing ages and compositions that would be present in the absence of region-wide stand-replacing disturbance. Our work utilized measurements taken between 2014 and 2020 from separate experimental forest chronosequences initiated following clear-cut harvesting only or clear-cut harvesting and fire, along with three >130-yr-old late successional stands comprising …


Global Co2 Emissions From Dry Inland Waters Share Common Drivers Across Ecosystems, P. S. Keller, N. Catalán, D. Von Schiller, H. -P. Grossart, M. Koschorreck, B. Obrador, M. A. Frassl, N. Karakaya, N. Barros, J. A. Howitt, C. Mendoza-Lera, A. Pastor, G. Flaim, R. Aben, T. Riis, M. I. Arce, G. Onandia, J. R. Paranaíba, A. Linkhorst, R. Del Campo, A. M. Amado, S. Cauvy-Fraunié, Soren Brothers, Et Al. May 2020

Global Co2 Emissions From Dry Inland Waters Share Common Drivers Across Ecosystems, P. S. Keller, N. Catalán, D. Von Schiller, H. -P. Grossart, M. Koschorreck, B. Obrador, M. A. Frassl, N. Karakaya, N. Barros, J. A. Howitt, C. Mendoza-Lera, A. Pastor, G. Flaim, R. Aben, T. Riis, M. I. Arce, G. Onandia, J. R. Paranaíba, A. Linkhorst, R. Del Campo, A. M. Amado, S. Cauvy-Fraunié, Soren Brothers, Et Al.

Ecology Center Publications

Many inland waters exhibit complete or partial desiccation, or have vanished due to global change, exposing sediments to the atmosphere. Yet, data on carbon dioxide (CO2) emissions from these sediments are too scarce to upscale emissions for global estimates or to understand their fundamental drivers. Here, we present the results of a global survey covering 196 dry inland waters across diverse ecosystem types and climate zones. We show that their CO2 emissions share fundamental drivers and constitute a substantial fraction of the carbon cycled by inland waters. CO2 emissions were consistent across ecosystem types and climate …


Global Patterns In Marine Sediment Carbon Stocks, Trisha B. Atwood, Andrew W. Witt, Juan Mayorga, Edd Hammill, Enric Sala Mar 2020

Global Patterns In Marine Sediment Carbon Stocks, Trisha B. Atwood, Andrew W. Witt, Juan Mayorga, Edd Hammill, Enric Sala

Ecology Center Publications

To develop more accurate global carbon (C) budgets and to better inform management of human activities in the ocean, we need high-resolution estimates of marine C stocks. Here we quantify global marine sedimentary C stocks at a 1-km resolution, and find that marine sediments store ∼ 3117 (3006–3209) Pg C in the top 1 m (more than twice that of terrestrial soils). Sediments in abyss/basin zones account for 75% of the global marine sediment C stock, and 52% of that stock is within the 200-mile Exclusive Economic Zones of countries. Currently, only ∼2% of sediment C stocks are located in …


Nitrogen Fertilization Restructured Spatial Patterns Of Soil Organic Carbon And Total Nitrogen In Switchgrass And Gamagrass Croplands In Tennessee Usa, Jianwei Li, Siyang Jian, Chad S. Lane, Chunlan Guo, Yuehan Lu, Qi Deng, Melanie A. Mayes, Kudjo E. Dzantor, Dafeng Hui Jan 2020

Nitrogen Fertilization Restructured Spatial Patterns Of Soil Organic Carbon And Total Nitrogen In Switchgrass And Gamagrass Croplands In Tennessee Usa, Jianwei Li, Siyang Jian, Chad S. Lane, Chunlan Guo, Yuehan Lu, Qi Deng, Melanie A. Mayes, Kudjo E. Dzantor, Dafeng Hui

Agricultural and Environmental Sciences Faculty Research

Nitrogen (N) fertilizers can potentially alter spatial distribution of soil organic carbon (SOC) and total nitrogen (TN) concentrations in croplands such as switchgrass (SG: Panicum virgatum L.) and gamagrass (GG: Tripsacum dactyloides L.), but it remains unclear whether these effects are the same between crops and under different rates of fertilization. 13C and 15N are two important proxy measures of soil biogeochemistry, but they were rarely examined as to their spatial distributions in soil. Based on a three-year long fertilization experiment in Middle Tennessee, USA, the top mineral horizon soils (0–15 cm) were collected using a spatially explicit design within …


Plant Species Determine Tidal Wetland Methane Response To Sea Level Rise, Peter Mueller, Thomas J. Mozdzer, J. Adam Langley, Lillian R. Aoki, Genevieve L. Noyce, J. Patrick Megonigal Jan 2020

Plant Species Determine Tidal Wetland Methane Response To Sea Level Rise, Peter Mueller, Thomas J. Mozdzer, J. Adam Langley, Lillian R. Aoki, Genevieve L. Noyce, J. Patrick Megonigal

Biology Faculty Research and Scholarship

Blue carbon (C) ecosystems are among the most effective C sinks of the biosphere, but methane (CH4) emissions can offset their climate cooling effect. Drivers of CH4 emissions from blue C ecosystems and effects of global change are poorly understood. Here we test for the effects of sea level rise (SLR) and its interactions with elevated atmospheric CO2, eutrophication, and plant community composition on CH4 emissions from an estuarine tidal wetland. Changes in CH4 emissions with SLR are primarily mediated by shifts in plant community composition and associated plant traits that determine both the direction and magnitude of SLR effects …


Senescent Trees Stabilize Aboveground Wood Net Primary Production Immediately After Disturbance, Maxim S. Grigri Jan 2020

Senescent Trees Stabilize Aboveground Wood Net Primary Production Immediately After Disturbance, Maxim S. Grigri

Theses and Dissertations

In the United States, forests sequester 17% of national carbon (C) emissions annually (UGCRP, 2018), however shifting forest disturbances threaten the stability of this essential C sink. Unlike the high severity, stand-replacing disturbances that were widespread a century ago, today’s eastern temperate forests experience frequent low-to-moderate severity disturbances from invasive pests and pathogens with mixed effects on net primary production (NPP). Carbon cycling stability after disturbance has been reported, however, the mechanisms underlying immediate NPP stability or decline are not well understood. Through weekly measurements of production in a landscape scale experiment, we show that the sustained growth of senescent …


Mountain Lakes: Eyes On Global Environmental Change, K. A. Moser, J. S. Baron, Janice Brahney, I. A. Oleksy, J. E. Saros, E. J. Hundey, S. A. Sadro, J. Kopáček, R. Sommaruga, M. J. Kainz, A. L. Strecker, S. Chandra, D. M. Walters, D. L. Preston, Et Al. Apr 2019

Mountain Lakes: Eyes On Global Environmental Change, K. A. Moser, J. S. Baron, Janice Brahney, I. A. Oleksy, J. E. Saros, E. J. Hundey, S. A. Sadro, J. Kopáček, R. Sommaruga, M. J. Kainz, A. L. Strecker, S. Chandra, D. M. Walters, D. L. Preston, Et Al.

Watershed Sciences Faculty Publications

Mountain lakes are often situated in protected natural areas, a feature that leads to their role as sentinels of global environmental change. Despite variations in latitude, mountain lakes share many features, including their location in catchments with steep topographic gradients, cold temperatures, high incident solar and ultraviolet radiation (UVR), and prolonged ice and snow cover. These characteristics, in turn, affect mountain lake ecosystem structure, diversity, and productivity. The lakes themselves are mostly small, and up until recently, have been characterized as oligotrophic. This paper provides a review and update of the growing body of research that shows that sediments in …


Coupling Metaproteomics With Taxonomy To Determine Responses Of Bacterioplankton To Organic Perturbations In The Western Arctic Ocean, Molly P. Mikan Apr 2019

Coupling Metaproteomics With Taxonomy To Determine Responses Of Bacterioplankton To Organic Perturbations In The Western Arctic Ocean, Molly P. Mikan

OES Theses and Dissertations

Understanding how the functionality of marine microbial communities change over time and space, and which taxonomic groups dominate distinct metabolic pathways, are essential to understanding the ecology of these microbiomes and the factors contributing to their regulation of elemental cycles in the oceans. The primary goal of this dissertation was to investigate the community metabolic and taxonomic responses and the degradation potential of two compositionally distinct marine microbiomes within the shallow shelf ecosystem of the Chukchi Sea after rapid fluctuations in algal organic matter availability. Novel bioinformatics tools were collaboratively developed and used together with community proteomics (metaproteomics) to characterize …


Individual-Based Modeling Of Amazon Forests Suggests That Climate Controls Productivity While Traits Control Demography, Sophie Fauset, Manuel Gloor, Nikolaos M. Fyllas, Oliver L. Phillips, Gregory P. Asner, Timothy R. Baker, Lisa Patrick Bentley, Roel J. W. Brienen, Bradley O. Christoffersen, John Del Aguila-Pasquel Apr 2019

Individual-Based Modeling Of Amazon Forests Suggests That Climate Controls Productivity While Traits Control Demography, Sophie Fauset, Manuel Gloor, Nikolaos M. Fyllas, Oliver L. Phillips, Gregory P. Asner, Timothy R. Baker, Lisa Patrick Bentley, Roel J. W. Brienen, Bradley O. Christoffersen, John Del Aguila-Pasquel

Biology Faculty Publications and Presentations

Climate, species composition, and soils are thought to control carbon cycling and forest structure in Amazonian forests. Here, we add a demographics scheme (tree recruitment, growth, and mortality) to a recently developed non-demographic model—the Trait-based Forest Simulator (TFS)—to explore the roles of climate and plant traits in controlling forest productivity and structure. We compared two sites with differing climates (seasonal vs. aseasonal precipitation) and plant traits. Through an initial validation simulation, we assessed whether the model converges on observed forest properties (productivity, demographic and structural variables) using datasets of functional traits, structure, and climate to model the carbon cycle at …


Southern Ocean Biogeochemical Float Deployment Strategy, With Example From The Greenwich Meridian Line (Go-Ship A12), L. D. Talley, I. Rosso, I. Kamenkovich, M. R. Mazloff, J. Wang, E. Boss, A. R. Gray, K. S. Johnson, R. M. Key, S. C. Riser, N. L. Williams, J. L. Sarmiento Jan 2019

Southern Ocean Biogeochemical Float Deployment Strategy, With Example From The Greenwich Meridian Line (Go-Ship A12), L. D. Talley, I. Rosso, I. Kamenkovich, M. R. Mazloff, J. Wang, E. Boss, A. R. Gray, K. S. Johnson, R. M. Key, S. C. Riser, N. L. Williams, J. L. Sarmiento

Marine Science Faculty Publications

Biogeochemical Argo floats, profiling to 2,000-m depth, are being deployed throughout the Southern Ocean by the Southern Ocean Carbon and Climate Observations and Modeling program (SOCCOM). The goal is 200 floats by 2020, to provide the first full set of annual cycles of carbon, oxygen, nitrate, and optical properties across multiple oceanographic regimes. Building from no prior coverage to a sparse array, deployments are based on prior knowledge of water mass properties, mean frontal locations, mean circulation and eddy variability, winds, air-sea heat/freshwater/carbon exchange, prior Argo trajectories, and float simulations in the Southern Ocean State Estimate and Hybrid Coordinate Ocean …


Nitrogen Fertilization Elevated Spatial Heterogeneity Of Soil Microbial Biomass Carbon And Nitrogen In Switchgrass And Gamagrass Croplands, Jianwei Li, Chunlan Guo, Siyang Jian, Qi Deng, Chih-Li Yu, Kudjo E. Dzantor, Dafeng Hui Jan 2018

Nitrogen Fertilization Elevated Spatial Heterogeneity Of Soil Microbial Biomass Carbon And Nitrogen In Switchgrass And Gamagrass Croplands, Jianwei Li, Chunlan Guo, Siyang Jian, Qi Deng, Chih-Li Yu, Kudjo E. Dzantor, Dafeng Hui

Agricultural and Environmental Sciences Faculty Research

The effects of intensive nitrogen (N) fertilizations on spatial distributions of soil microbes in bioenergy croplands remain unknown. To quantify N fertilization effect on spatial heterogeneity of soil microbial biomass carbon (MBC) and N (MBN), we sampled top mineral horizon soils (0-15 cm) using a spatially explicit design within two 15-m2 plots under three fertilization treatments in two bioenergy croplands in a three-year long fertilization experiment in Middle Tennessee, USA. The three fertilization treatments were no N input (NN), low N input (LN: 84 kg N ha−1 in urea) and high N input (HN: 168 kg N ha−1 in urea). …


Warming Deferentially Altered Multidimensional Soil Legacy Induced By Past Land Use History, Weiling Dong, Alin Song, Xueduan Liu, Bing Yu, Boren Wang, Yuqiu Lu, Yanling Li, Huaqun Yin, Jianwei Li, Fenliang Fan Jan 2018

Warming Deferentially Altered Multidimensional Soil Legacy Induced By Past Land Use History, Weiling Dong, Alin Song, Xueduan Liu, Bing Yu, Boren Wang, Yuqiu Lu, Yanling Li, Huaqun Yin, Jianwei Li, Fenliang Fan

Agricultural and Environmental Sciences Faculty Research

The legacy effects of previous land use and climate history may affect current soil function. However, the manner in which these legacy effects of land use are modulated by the subsequent climate remains unclear. For this reason, we investigated how the legacies of soil multiple functions left by conversion of grassland to agricultural management were mediated by climate warming with a reciprocal transplant approach. The overall legacy was further separated into the contributions by changes in the abiotic properties of the soil (abiotic process) and microbial community (biotic process). We here hypothesized that warming may mediate the legacy effects of …