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Biology, Chemistry, and Environmental Sciences Faculty Articles and Research

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Full-Text Articles in Biogeochemistry

Lowland Tropical Forests Remain A Methane Sink Under Warming And Long-Term Hurricane Disturbance Recovery, Gabriele Larocca Conte, Lucia Zuvela, Rachel Cruz-Pérez, Tatiana Barreto-Vélez, Nibia Becerra-Santillan, Sophia F. Campbell, Hieu P. Chu, Trung Dam, Iana F. Grullón-Penkova, Miriam Kleit, Deyaneira A. Ortiz-Iglesias, Laura C. Rubio-Lebrón, Molly A. Cavaleri, Sasha C. Reed, Debjani Sihi, Tana E. Wood, Christine S. O'Connell May 2026

Lowland Tropical Forests Remain A Methane Sink Under Warming And Long-Term Hurricane Disturbance Recovery, Gabriele Larocca Conte, Lucia Zuvela, Rachel Cruz-Pérez, Tatiana Barreto-Vélez, Nibia Becerra-Santillan, Sophia F. Campbell, Hieu P. Chu, Trung Dam, Iana F. Grullón-Penkova, Miriam Kleit, Deyaneira A. Ortiz-Iglesias, Laura C. Rubio-Lebrón, Molly A. Cavaleri, Sasha C. Reed, Debjani Sihi, Tana E. Wood, Christine S. O'Connell

Biology, Chemistry, and Environmental Sciences Faculty Articles and Research

Methane (CH4) is a potent greenhouse gas, and tropical forests account for roughly one–third of global atmospheric CH4 uptake by soils. Projected warming and more frequent hurricanes in these ecosystems may alter soil CH4 sink strength, as warmer and wetter soils enhance methanogenesis activity. We measured soil CH4 and CO2 efflux during the calendar summer months of 2023 and 2024 alongside continuous records of soil moisture, soil and air temperature, and precipitation in an in–situ warming experiment (TRACE) located in a lowland tropical forest in Puerto Rico, six to seven years after Hurricanes Irma …


Global Estimates Of The Storage And Transit Time Of Water Through Vegetation, Andrew Felton, Joshua B. Fisher, Koen Hufkens, Adam J. Purdy, Seth A. Spawn-Lee, Lou F. Duloisy, Gregory R. Goldsmith Jan 2025

Global Estimates Of The Storage And Transit Time Of Water Through Vegetation, Andrew Felton, Joshua B. Fisher, Koen Hufkens, Adam J. Purdy, Seth A. Spawn-Lee, Lou F. Duloisy, Gregory R. Goldsmith

Biology, Chemistry, and Environmental Sciences Faculty Articles and Research

The time it takes for water to transit from the ground back to the atmosphere affects weather, climate, biogeochemistry and ecosystem function. The transit time of water through vegetation, defined as the age of water transpiring from vegetation since time of entry, is a particularly understudied aspect of the terrestrial hydrologic cycle. Here we use a synergy of satellite remote sensing measurements over a five-year period to estimate global aboveground vegetation water storage to be on average 484 km3, roughly half of which is stored in Earth’s water-limited savannah, grassland and shrubland ecosystems. We then combine these storage …


Permafrost Carbon: Progress On Understanding Stocks And Fluxes Across Northern Terrestrial Ecosystems, Claire C. Treat, Anna-Maria Virkkala, Eleanor Burke, Lori Bruhwiler, Abhishek Chatterjee, Joshua B. Fisher, Josh Hashemi, Frans-Jan W. Parmentier, Brendan M. Rogers, Sebastian Westermann, Jennifer D. Watts, Elena Blanc-Betes, Matthias Fuchs, Stefan Kruse, Avni Malhotra, Kimberley Miner, Jens Strauss, Amanda Armstrong, Howard E. Epstein, Bradley Gay, Mathias Goeckede, Aram Kalhori, Dan Kou, Charles E. Miller, Susan M. Natali, Youmi Oh, Sarah Shakil, Oliver Sonnentag, Ruth K. Varner, Scott Zolkos, Edward A.G. Schuur, Gustaf Hugelius Jan 2024

Permafrost Carbon: Progress On Understanding Stocks And Fluxes Across Northern Terrestrial Ecosystems, Claire C. Treat, Anna-Maria Virkkala, Eleanor Burke, Lori Bruhwiler, Abhishek Chatterjee, Joshua B. Fisher, Josh Hashemi, Frans-Jan W. Parmentier, Brendan M. Rogers, Sebastian Westermann, Jennifer D. Watts, Elena Blanc-Betes, Matthias Fuchs, Stefan Kruse, Avni Malhotra, Kimberley Miner, Jens Strauss, Amanda Armstrong, Howard E. Epstein, Bradley Gay, Mathias Goeckede, Aram Kalhori, Dan Kou, Charles E. Miller, Susan M. Natali, Youmi Oh, Sarah Shakil, Oliver Sonnentag, Ruth K. Varner, Scott Zolkos, Edward A.G. Schuur, Gustaf Hugelius

Biology, Chemistry, and Environmental Sciences Faculty Articles and Research

Significant progress in permafrost carbon science made over the past decades include the identification of vast permafrost carbon stocks, the development of new pan-Arctic permafrost maps, an increase in terrestrial measurement sites for CO2 and methane fluxes, and important factors affecting carbon cycling, including vegetation changes, periods of soil freezing and thawing, wildfire, and other disturbance events. Process-based modeling studies now include key elements of permafrost carbon cycling and advances in statistical modeling and inverse modeling enhance understanding of permafrost region C budgets. By combining existing data syntheses and model outputs, the permafrost region is likely a wetland methane …


Volcanic Diffuse Volatile Emissions Tracked By Plant Responses Detectable From Space, Robert R. Bogue, Peter M. J. Douglas, Joshua B. Fisher, John Stix Nov 2023

Volcanic Diffuse Volatile Emissions Tracked By Plant Responses Detectable From Space, Robert R. Bogue, Peter M. J. Douglas, Joshua B. Fisher, John Stix

Biology, Chemistry, and Environmental Sciences Faculty Articles and Research

Volcanic volatile emissions provide information about volcanic unrest but are difficult to detect with satellites. Volcanic degassing affects plants by elevating local CO2 and H2O concentrations, which may increase photosynthesis. Satellites can detect plant health, or a reaction to photosynthesis, through a Normalized Difference Vegetation Index (NDVI). This can act as a potential proxy for detecting changes in volcanic volatile emissions from space. We tested this method by analyzing 185 Landsat 5 and 8 images of the Tern Lake thermal area (TLTA) in northeast Yellowstone caldera from 1984 to 2022. We compared the NDVI values of the thermal area with …


Small Community Water Systems Have The Highest Prevalence Of Mn In Drinking Water In California, Usa, Miranda Aiken, Samantha C. Ying May 2023

Small Community Water Systems Have The Highest Prevalence Of Mn In Drinking Water In California, Usa, Miranda Aiken, Samantha C. Ying

Biology, Chemistry, and Environmental Sciences Faculty Articles and Research

Manganese (Mn) is currently regulated as a secondary contaminant in California, USA; however, recent revisions of the World Health Organization drinking water guidelines have increased regulatory attention of Mn in drinking water due to increasing reports of neurotoxic effects in infants and children. In this study, Mn concentrations reported to California’s Safe Drinking Water Information System were used to estimate the potentially exposed population within California based on system size. We estimate that between 2011 and 2021, over 525,000 users in areas with reported Mn data are potentially exposed to Mn concentrations exceeding the WHO health-based guideline (80 μg L …


Rapid Bacterial And Fungal Successional Dynamics In First Year After Chaparral Wildfire, M. Fabiola Pulido-Chavez, James W. J. Randolph, Cassandra A. Zalman, Loralee Larios, Peter M. Homyak, Sydney I. Glassman Dec 2022

Rapid Bacterial And Fungal Successional Dynamics In First Year After Chaparral Wildfire, M. Fabiola Pulido-Chavez, James W. J. Randolph, Cassandra A. Zalman, Loralee Larios, Peter M. Homyak, Sydney I. Glassman

Biology, Chemistry, and Environmental Sciences Faculty Articles and Research

The rise in wildfire frequency and severity across the globe has increased interest in secondary succession. However, despite the role of soil microbial communities in controlling biogeochemical cycling and their role in the regeneration of post-fire vegetation, the lack of measurements immediately post-fire and at high temporal resolution has limited understanding of microbial secondary succession. To fill this knowledge gap, we sampled soils at 17, 25, 34, 67, 95, 131, 187, 286, and 376 days after a southern California wildfire in fire-adapted chaparral shrublands. We assessed bacterial and fungal biomass with qPCR of 16S and 18S and richness and composition …


Radiocarbon Analyses Quantify Peat Carbon Losses With Increasing Temperature In A Whole Ecosystem Warming Experiment, Rachel M. Wilson, Natalie A. Griffiths, Ate Visser, Karis J. Mcfarlane, Stephen D. Sebestyen, Keith C. Oleheiser, Samantha Bosman, Anya M. Hopple, Malak M. Tfaily, Randall K. Kolka, Paul J. Hanson, Joel E. Kostka, Scott D. Bridgham, Jason K. Keller, Jeffrey P. Chanton Oct 2021

Radiocarbon Analyses Quantify Peat Carbon Losses With Increasing Temperature In A Whole Ecosystem Warming Experiment, Rachel M. Wilson, Natalie A. Griffiths, Ate Visser, Karis J. Mcfarlane, Stephen D. Sebestyen, Keith C. Oleheiser, Samantha Bosman, Anya M. Hopple, Malak M. Tfaily, Randall K. Kolka, Paul J. Hanson, Joel E. Kostka, Scott D. Bridgham, Jason K. Keller, Jeffrey P. Chanton

Biology, Chemistry, and Environmental Sciences Faculty Articles and Research

Climate warming is expected to accelerate peatland degradation and release rates of carbon dioxide (CO2) and methane (CH4). Spruce and Peatlands Responses Under Changing Environments is an ecosystem-scale climate manipulation experiment, designed to examine peatland ecosystem response to climate forcings. We examined whether heating up to +9 °C to 3 m-deep in a peat bog over a 7-year period led to higher C turnover and CO2 and CH4 emissions, by measuring 14C of solid peat, dissolved organic carbon (DOC), CH4, and dissolved CO2 (DIC). DOC, a major substrate for heterotrophic respiration, increased significantly with warming. There was no 7-year trend …


An Integrative Model For Soil Biogeochemistry And Methane Processes: I. Model Structure And Sensitivity Analysis, Daniel M. Ricciuto, Xiaofeng Xu, Xiaoying Shi, Yihui Wang, Xia Song, Christopher W. Schadt, Natalie A. Griffiths, Jiafu Mao, Jeffrey M. Warren, Peter E. Thornton, Jeff Chanton, Jason K. Keller, Scott D. Bridgham, Jessica Gutknecht, Stephen D. Sebestyen, Adrien Finzi, Randall Kolka, Paul J. Hanson Jul 2021

An Integrative Model For Soil Biogeochemistry And Methane Processes: I. Model Structure And Sensitivity Analysis, Daniel M. Ricciuto, Xiaofeng Xu, Xiaoying Shi, Yihui Wang, Xia Song, Christopher W. Schadt, Natalie A. Griffiths, Jiafu Mao, Jeffrey M. Warren, Peter E. Thornton, Jeff Chanton, Jason K. Keller, Scott D. Bridgham, Jessica Gutknecht, Stephen D. Sebestyen, Adrien Finzi, Randall Kolka, Paul J. Hanson

Biology, Chemistry, and Environmental Sciences Faculty Articles and Research

Environmental changes are anticipated to generate substantial impacts on carbon cycling in peatlands, affecting terrestrial-climate feedbacks. Understanding how peatland methane (CH4) fluxes respond to these changing environments is critical for predicting the magnitude of feedbacks from peatlands to global climate change. To improve predictions of CH4 fluxes in response to changes such as elevated atmospheric CO2 concentrations and warming, it is essential for Earth system models to include increased realism to simulate CH4 processes in a more mechanistic way. To address this need, we incorporated a new microbial-functional group-based CH4 module into the Energy …


Carbon Fluxes And Microbial Activities From Boreal Peatlands Experiencing Permafrost Thaw, M. P. Waldrop, J. W. Mcfarland, K. L. Manies, M. C. Leewis, S. J. Blazewicz, M. C. Jones, R. B. Neumann, Jason K. Keller, L. Cohen, E. S. Euskirchen, C. Edgar, M. R. Turetsky, W. L. Cable Feb 2021

Carbon Fluxes And Microbial Activities From Boreal Peatlands Experiencing Permafrost Thaw, M. P. Waldrop, J. W. Mcfarland, K. L. Manies, M. C. Leewis, S. J. Blazewicz, M. C. Jones, R. B. Neumann, Jason K. Keller, L. Cohen, E. S. Euskirchen, C. Edgar, M. R. Turetsky, W. L. Cable

Biology, Chemistry, and Environmental Sciences Faculty Articles and Research

Permafrost thaw in northern ecosystems may cause large quantities of carbon (C) to move from soil to atmospheric pools. Because soil microbial communities play a critical role in regulating C fluxes from soils, we examined microbial activity and greenhouse gas production soon after permafrost thaw and ground collapse (into collapse‐scar bogs), relative to the permafrost plateau or older thaw features. Using multiple field and laboratory‐based assays at a field site in interior Alaska, we show that the youngest collapse‐scar bog had the highest CH4 production potential from soil incubations, and, based upon temporal changes in porewater concentrations and 13 …


Modeling Holocene Peatland Carbon Accumulation In North America, Qianlai Zhuang, Sirui Wang, Bailu Zhao, Filipe Aires, Catherine Prigent, Zicheng Yu, Jason K. Keller, Scott Bridgham Nov 2020

Modeling Holocene Peatland Carbon Accumulation In North America, Qianlai Zhuang, Sirui Wang, Bailu Zhao, Filipe Aires, Catherine Prigent, Zicheng Yu, Jason K. Keller, Scott Bridgham

Biology, Chemistry, and Environmental Sciences Faculty Articles and Research

Peatlands are a large carbon reservoir. Yet the quantification of their carbon stock still has a large uncertainty due to lacking observational data and well‐tested peatland biogeochemistry models. Here, a process‐based peatland model was calibrated using long‐term peat carbon accumulation data at multiple sites in North America. The model was then applied to quantify the peat carbon accumulation rates and stocks within North America over the last 12,000 years. We estimated that 85–174 Pg carbon was accumulated in North American peatlands over the study period including 0.37–0.76 Pg carbon in subtropical peatlands. During the period from 10,000 to 8,000 years …


Predicting Spatial Patterns In Precipitation Isotope (Δ2h And Δ18o) Seasonality Using Sinusoidal Isoscapes, Scott T. Allen, James W. Kirchner, Gregory R. Goldsmith May 2018

Predicting Spatial Patterns In Precipitation Isotope (Δ2h And Δ18o) Seasonality Using Sinusoidal Isoscapes, Scott T. Allen, James W. Kirchner, Gregory R. Goldsmith

Biology, Chemistry, and Environmental Sciences Faculty Articles and Research

Understanding how precipitation isotopes vary spatially and temporally is important for tracer applications. We tested how well month‐to‐month variations in precipitation δ18O and δ2H were captured by sinusoidal cycles, and how well spatial variations in these seasonal cycles could be predicted, across Switzerland. Sine functions representing seasonal cycles in precipitation isotopes explained between 47% and 94% of the variance in monthly δ18O and δ2H values at each monitoring site. A significant sinusoidal cycle was also observed in line‐conditioned excess. We interpolated the amplitudes, phases, and offsets of these sine functions across the landscape, using multiple linear …


Nutrient Addition Effects On Tropical Dry Forests: A Mini-Review From Microbial To Ecosystem Scales, Jennifer S. Powers, Kristen K. Becklund, Maria G. Gei, Siddharth B. Iyengar, Rebecca Meyer, Christine S. O'Connell, Erik M. Schilling, Christina M. Smith, Bonnie G. Waring, Leland K. Werden Jun 2015

Nutrient Addition Effects On Tropical Dry Forests: A Mini-Review From Microbial To Ecosystem Scales, Jennifer S. Powers, Kristen K. Becklund, Maria G. Gei, Siddharth B. Iyengar, Rebecca Meyer, Christine S. O'Connell, Erik M. Schilling, Christina M. Smith, Bonnie G. Waring, Leland K. Werden

Biology, Chemistry, and Environmental Sciences Faculty Articles and Research

Humans have more than doubled inputs of reactive nitrogen globally and greatly accelerated the biogeochemical cycles of phosphorus and metals. However, the impacts of increased element mobility on tropical ecosystems remain poorly quantified, particularly for the vast tropical dry forest biome. Tropical dry forests are characterized by marked seasonality, relatively little precipitation, and high heterogeneity in plant functional diversity and soil chemistry. For these reasons, increased nutrient deposition may affect tropical dry forests differently than wet tropical or temperate forests. Here, we review studies that investigated how nutrient availability affects ecosystem and community processes from the microsite to ecosystem scales …