37 results on '"Carey, Joanna C."'
Search Results
2. Emotional competency in the interdisciplinary classroom: A systems thinking perspective
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Carey, Joanna C., primary and Hunt, James, additional
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- 2022
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3. Climate, Hydrology, and Nutrients Control the Seasonality of Si Concentrations in Rivers.
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Johnson, Keira, Jankowski, Kathi Jo, Carey, Joanna C., Sethna, Lienne R., Bush, Sidney A., McKnight, Diane, McDowell, William H., Wymore, Adam S., Kortelainen, Pirkko, Jones, Jeremy B., Lyon, Nicholas J., Laudon, Hjalmar, Poste, Amanda E., and Sullivan, Pamela L.
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BIOAVAILABILITY ,CARBON sequestration ,RANDOM forest algorithms ,LAND cover ,POLITICAL systems - Abstract
The seasonal behavior of fluvial dissolved silica (DSi) concentrations, termed DSi regime, mediates the timing of DSi delivery to downstream waters and thus governs river biogeochemical function and aquatic community condition. Previous work identified five distinct DSi regimes across rivers spanning the Northern Hemisphere, with many rivers exhibiting multiple DSi regimes over time. Several potential drivers of DSi regime behavior have been identified at small scales, including climate, land cover, and lithology, and yet the large‐scale spatiotemporal controls on DSi regimes have not been identified. We evaluate the role of environmental variables on the behavior of DSi regimes in nearly 200 rivers across the Northern Hemisphere using random forest models. Our models aim to elucidate the controls that give rise to (a) average DSi regime behavior, (b) interannual variability in DSi regime behavior (i.e., Annual DSi regime), and (c) controls on DSi regime shape (i.e., minimum and maximum DSi concentrations). Average DSi regime behavior across the period of record was classified accurately 59% of the time, whereas Annual DSi regime behavior was classified accurately 80% of the time. Climate and primary productivity variables were important in predicting Average DSi regime behavior, whereas climate and hydrologic variables were important in predicting Annual DSi regime behavior. Median nitrogen and phosphorus concentrations were important drivers of minimum and maximum DSi concentrations, indicating that these macronutrients may be important for seasonal DSi drawdown and rebound. Our findings demonstrate that fluctuations in climate, hydrology, and nutrient availability of rivers shape the temporal availability of fluvial DSi. Plain Language Summary: The amount of dissolved silicon (DSi) in rivers is an important control on numerous ecological and biogeochemical processes, such as types of algae that bloom and rates of carbon sequestration. Compared to our knowledge of other nutrients, such as nitrogen and phosphorus, we have limited understanding of what controls the timing and concentration of DSi in rivers. Previous work identified five distinct seasonal patterns of DSi concentrations in rivers across the Northern Hemisphere; here we look at the environmental variables that control these seasonal patterns. We found that rivers often have one to five seasonal patterns over time due to interannual shifts in temperature, evapotranspiration, and streamflow. In addition, we found that the average shape of the seasonal pattern for a given river, specifically minimum and maximum DSi concentrations, was related to nitrogen (N) and phosphorus (P) concentrations, highlighting linkages between N, P, and DSi cycling in rivers. This work identifies why river DSi concentrations exhibit both within and between year variability, highlighting that temperature, streamflow, and nutrient availability control the timing of river DSi availability for biological uptake. Key Points: Seasonal variations in annual riverine dissolved silica concentrations (DSi regime) were correctly classified 80% of the timeClimate and primary productivity emerge as the most important drivers in differentiating among average DSi regimesMedian nitrogen and phosphorus concentrations strongly predicted minimum and maximum DSi concentration, regardless of regime type [ABSTRACT FROM AUTHOR]
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- 2024
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4. Temperature response of soil respiration largely unaltered with experimental warming
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Carey, Joanna C, Tang, Jianwu, Templer, Pamela H, Kroeger, Kevin D, Crowther, Thomas W, Burton, Andrew J, Dukes, Jeffrey S, Emmett, Bridget, Frey, Serita D, Heskel, Mary A, Jiang, Lifen, Machmuller, Megan B, Mohan, Jacqueline, Panetta, Anne Marie, Reich, Peter B, Reinsch, Sabine, Wang, Xin, Allison, Steven D, Bamminger, Chris, Bridgham, Scott, Collins, Scott L, de Dato, Giovanbattista, Eddy, William C, Enquist, Brian J, Estiarte, Marc, Harte, John, Henderson, Amanda, Johnson, Bart R, Larsen, Klaus Steenberg, Luo, Yiqi, Marhan, Sven, Melillo, Jerry M, Peuelas, Josep, Pfeifer-Meister, Laurel, Poll, Christian, Rastetter, Edward, Reinmann, Andrew B, Reynolds, Lorien L, Schmidt, Inger K, Shaver, Gaius R, Strong, Aaron L, Suseela, Vidya, and Tietema, Albert
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soil respiration ,climate change ,experimental warming ,temperature sensitivity ,biome - Published
- 2016
5. Stress alters the role of silicon in controlling plant water movement
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Cooke, Julia, primary and Carey, Joanna C., additional
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- 2023
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6. Long‐Term Changes in Concentration and Yield of Riverine Dissolved Silicon From the Poles to the Tropics
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Jankowski, Kathi Jo, primary, Johnson, Keira, additional, Sethna, Lienne, additional, Julian, Paul, additional, Wymore, Adam S., additional, Shogren, Arial J., additional, Thomas, Patrick K., additional, Sullivan, Pamela L., additional, McKnight, Diane M., additional, McDowell, William H., additional, Heindel, Ruth, additional, Jones, Jeremy B., additional, Wollheim, Wilfred, additional, Abbott, Benjamin, additional, Deegan, Linda, additional, and Carey, Joanna C., additional
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- 2023
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7. Biogenic silica accumulation varies across tussock tundra plant functional type
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Carey, Joanna C., Parker, Thomas C., Fetcher, Ned, and Tang, Jianwu
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- 2017
8. Human appropriation of biogenic silicon — the increasing role of agriculture
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Carey, Joanna C. and Fulweiler, Robinson W.
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- 2016
9. Higher Temperature Sensitivity of Ecosystem Respiration in Low Marsh Compared to High Elevation Marsh Ecosystems
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Carey, Joanna C., primary, Kroeger, Kevin D., additional, and Tang, Jianwu, additional
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- 2022
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10. We Must Stop Fossil Fuel Emissions to Protect Permafrost Ecosystems
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Abbott, Benjamin W., primary, Brown, Michael, additional, Carey, Joanna C., additional, Ernakovich, Jessica, additional, Frederick, Jennifer M., additional, Guo, Laodong, additional, Hugelius, Gustaf, additional, Lee, Raymond M., additional, Loranty, Michael M., additional, Macdonald, Robie, additional, Mann, Paul J., additional, Natali, Susan M., additional, Olefeldt, David, additional, Pearson, Pam, additional, Rec, Abigail, additional, Robards, Martin, additional, Salmon, Verity G., additional, Sayedi, Sayedeh Sara, additional, Schädel, Christina, additional, Schuur, Edward A. G., additional, Shakil, Sarah, additional, Shogren, Arial J., additional, Strauss, Jens, additional, Tank, Suzanne E., additional, Thornton, Brett F., additional, Treharne, Rachael, additional, Turetsky, Merritt, additional, Voigt, Carolina, additional, Wright, Nancy, additional, Yang, Yuanhe, additional, Zarnetske, Jay P., additional, Zhang, Qiwen, additional, and Zolkos, Scott, additional
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- 2022
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11. We Must Stop Fossil Fuel Emissions to Protect Permafrost Ecosystems
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Abbott, Benjamin W., Brown, Michael, Carey, Joanna C., Ernakovich, Jessica, Frederick, Jennifer, Guo, Laodong, Hugelius, Gustaf, Lee, Raymond M., Loranty, Michael M., Macdonald, Robie W, Mann, Paul James, Natali, Sue M., Olefeldt, David, Pearson, Pam, Rec, Abigail, Robards, Martin, Salmon, Verity G., Sayedi, Sayedeh Sara, Schädel, Christina, Schuur, Edward. A. G., Shakil, Sarah, Shogren, Arial J., Strauss, Jens, Tank, Suzanne E, Thornton, Brett F., Treharne, Rachael, Turetsky, Merritt, Voigt, Carolina, Wright, Nancy, Yang, Yuanhe, Zarnetske, Jay P., Zhang, Qiwen, Zolkos, Scott, Abbott, Benjamin W., Brown, Michael, Carey, Joanna C., Ernakovich, Jessica, Frederick, Jennifer, Guo, Laodong, Hugelius, Gustaf, Lee, Raymond M., Loranty, Michael M., Macdonald, Robie W, Mann, Paul James, Natali, Sue M., Olefeldt, David, Pearson, Pam, Rec, Abigail, Robards, Martin, Salmon, Verity G., Sayedi, Sayedeh Sara, Schädel, Christina, Schuur, Edward. A. G., Shakil, Sarah, Shogren, Arial J., Strauss, Jens, Tank, Suzanne E, Thornton, Brett F., Treharne, Rachael, Turetsky, Merritt, Voigt, Carolina, Wright, Nancy, Yang, Yuanhe, Zarnetske, Jay P., Zhang, Qiwen, and Zolkos, Scott
- Abstract
Climate change is an existential threat to the vast global permafrost domain. The diverse human cultures, ecological communities, and biogeochemical cycles of this tenth of the planet depend on the persistence of frozen conditions. The complexity, immensity, and remoteness of permafrost ecosystems make it difficult to grasp how quickly things are changing and what can be done about it. Here, we summarize terrestrial and marine changes in the permafrost domain with an eye toward global policy. While many questions remain, we know that continued fossil fuel burning is incompatible with the continued existence of the permafrost domain as we know it. If we fail to protect permafrost ecosystems, the consequences for human rights, biosphere integrity, and global climate will be severe. The policy implications are clear: the faster we reduce human emissions and draw down atmospheric CO2, the more of the permafrost domain we can save. Emissions reduction targets must be strengthened and accompanied by support for local peoples to protect intact ecological communities and natural carbon sinks within the permafrost domain. Some proposed geoengineering interventions such as solar shading, surface albedo modification, and vegetation manipulations are unproven and may exacerbate environmental injustice without providing lasting protection. Conversely, astounding advances in renewable energy have reopened viable pathways to halve human greenhouse gas emissions by 2030 and effectively stop them well before 2050. We call on leaders, corporations, researchers, and citizens everywhere to acknowledge the global importance of the permafrost domain and work towards climate restoration and empowerment of Indigenous and immigrant communities in these regions.
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- 2022
12. The ebb and flood of Silica: Quantifying dissolved and biogenic silica fluxes from a temperate salt marsh
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Vieillard, Amanda M., Fulweiler, Robinson W., Hughes, Zoe J., and Carey, Joanna C.
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- 2011
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13. Controls on Riverine Dissolved Organic Matter Composition Across an Arctic‐Boreal Latitudinal Gradient
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Johnston, Sarah Ellen, primary, Carey, Joanna C., additional, Kellerman, Anne, additional, Podgorski, David C., additional, Gewirtzman, Jonathan, additional, and Spencer, Robert G. M., additional
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- 2021
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14. High Productivity Makes Mangroves Potentially Important Players in the Tropical Silicon Cycle
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Elizondo, Elani B., primary, Carey, Joanna C., additional, Al-Haj, Alia N., additional, Lugo, Ariel E., additional, and Fulweiler, Robinson W., additional
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- 2021
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15. Plant uptake offsets silica release from a large arctic tundra wildfire
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Carey, Joanna C., Abbott, Benjamin W., Rocha, Adrian V., Carey, Joanna C., Abbott, Benjamin W., and Rocha, Adrian V.
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© The Author(s), 2019. This article is distributed under the terms of the Creative Commons Attribution License. The definitive version was published in Carey, J. C., Abbott, B. W., & Rocha, A. V. Plant uptake offsets silica release from a large arctic tundra wildfire. Earth’s Future, 7(9), (2019): 1044-1057, doi:10.1029/2019EF001149., Rapid climate change at high latitudes is projected to increase wildfire extent in tundra ecosystems by up to fivefold by the end of the century. Tundra wildfire could alter terrestrial silica (SiO2) cycling by restructuring surface vegetation and by deepening the seasonally thawed active layer. These changes could influence the availability of silica in terrestrial permafrost ecosystems and alter lateral exports to downstream marine waters, where silica is often a limiting nutrient. In this context, we investigated the effects of the largest Arctic tundra fire in recent times on plant and peat amorphous silica content and dissolved silica concentration in streams. Ten years after the fire, vegetation in burned areas had 73% more silica in aboveground biomass compared to adjacent, unburned areas. This increase in plant silica was attributable to significantly higher plant silica concentration in bryophytes and increased prevalence of silica‐rich gramminoids in burned areas. Tundra fire redistributed peat silica, with burned areas containing significantly higher amorphous silica concentrations in the O‐layer, but 29% less silica in peat overall due to shallower peat depth post burn. Despite these dramatic differences in terrestrial silica dynamics, dissolved silica concentration in tributaries draining burned catchments did not differ from unburned catchments, potentially due to the increased uptake by terrestrial vegetation. Together, these results suggest that tundra wildfire enhances terrestrial availability of silica via permafrost degradation and associated weathering, but that changes in lateral silica export may depend on vegetation uptake during the first decade of postwildfire succession., This research was supported by NSF EAR PD Fellowship 1451527 to J. C. Carey, NSF grants 1065587 and 1026843 to the Marine Biological Laboratory, and NSF grant 1556772 to the University of Notre Dame. B. W. Abbott was supported by the Plant and Wildlife Department and College of Life Sciences at Brigham Young University. Data are available from the Dryad Digital Repository (doi:10.5061/dryad.79q74n7). We thank Ian Klupar for field assistance. R. Fulweber at the Toolik Field Station GIS & Remote Sensing Office performed watershed delineations and other spatial analysis. We thank the NSF Arctic LTER and the UAF Toolik Field Station for logistical support. We declare no conflicts of interest.
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- 2020
16. Evaluation of simulated soil carbon dynamics in Arctic-Boreal ecosystems
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Huntzinger, Deborah N., Schaefer, Kevin, Schwalm, Christopher R., Fisher, Joshua B., Hayes, Daniel, Stofferahn, Eric, Carey, Joanna C., Michalak, Anna M., Wei, Yaxing, Jain, Atul K., Kolus, Hannah, Mao, Jiafu, Poulter, Benjamin, Shi, Xiaoying, Tang, Jianwu, Tian, Hanqin, Huntzinger, Deborah N., Schaefer, Kevin, Schwalm, Christopher R., Fisher, Joshua B., Hayes, Daniel, Stofferahn, Eric, Carey, Joanna C., Michalak, Anna M., Wei, Yaxing, Jain, Atul K., Kolus, Hannah, Mao, Jiafu, Poulter, Benjamin, Shi, Xiaoying, Tang, Jianwu, and Tian, Hanqin
- Abstract
© The Author(s), 2020. This article is distributed under the terms of the Creative Commons Attribution License. The definitive version was published in Huntzinger, D. N., Schaefer, K., Schwalm, C., Fisher, J. B., Hayes, D., Stofferahn, E., Carey, J., Michalak, A. M., Wei, Y., Jain, A. K., Kolus, H., Mao, J., Poulter, B., Shi, X., Tang, J., & Tian, H. Evaluation of simulated soil carbon dynamics in Arctic-Boreal ecosystems. Environmental Research Letters, 15(2), (2020): 025005, doi:10.1088/1748-9326/ab6784., Given the magnitude of soil carbon stocks in northern ecosystems, and the vulnerability of these stocks to climate warming, land surface models must accurately represent soil carbon dynamics in these regions. We evaluate soil carbon stocks and turnover rates, and the relationship between soil carbon loss with soil temperature and moisture, from an ensemble of eleven global land surface models. We focus on the region of NASA's Arctic-Boreal vulnerability experiment (ABoVE) in North America to inform data collection and model development efforts. Models exhibit an order of magnitude difference in estimates of current total soil carbon stocks, generally under- or overestimating the size of current soil carbon stocks by greater than 50 PgC. We find that a model's soil carbon stock at steady-state in 1901 is the prime driver of its soil carbon stock a hundred years later—overwhelming the effect of environmental forcing factors like climate. The greatest divergence between modeled and observed soil carbon stocks is in regions dominated by peat and permafrost soils, suggesting that models are failing to capture the frozen soil carbon dynamics of permafrost regions. Using a set of functional benchmarks to test the simulated relationship of soil respiration to both soil temperature and moisture, we find that although models capture the observed shape of the soil moisture response of respiration, almost half of the models examined show temperature sensitivities, or Q10 values, that are half of observed. Significantly, models that perform better against observational constraints of respiration or carbon stock size do not necessarily perform well in terms of their functional response to key climatic factors like changing temperature. This suggests that models may be arriving at the right result, but for the wrong reason. The results of this work can help to bridge the gap between data and models by both pointing to the need to constrain initial carbon pool sizes, as well as hig, This work was supported by NASA'S Arctic Boreal Vulnerability Experiment (ABoVE; https://above.nasa.gov); NNN13D504T. Funding for the Multi-scale synthesis and Terrestrial Model Intercomparison Project (MsTMIP; https://nacp.ornl.gov/MsTMIP.shtml) activity was provided through NASA ROSES Grant #NNX10AG01A. Data management support for preparing, documenting, and distributing model driver and output data was performed by the Modeling and Synthesis Thematic Data Center at Oak Ridge National Laboratory (MAST-DC; https://nacp.ornl.gov), with funding through NASA ROSES Grant #NNH10AN681. Finalized MsTMIP data products are archived at the ORNL DAAC (https://daac.ornl.gov). We also acknowledge the modeling groups that provided results to MsTMIP. The synthesis of site-level soil respiration, temperature, and moisture data reported in Carey et al 2016a, 2016b) was funded by the US Geological Survey (USGS) John Wesley Powell Center for Analysis and Synthesis Award G13AC00193. Additional support for that work was also provided by the USGS Land Carbon Program. JBF carried out the research at the Jet Propulsion Laboratory, California Institute of Technology, under a contract with the National Aeronautics and Space Administration. California Institute of Technology. Government sponsorship acknowledged.
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- 2020
17. A Resource-Efficient Modular Course Design for Co-Teaching Integrated Sustainability in Higher Education: Developing the Next Generation of Entrepreneurial Leaders
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Carey, Joanna C., primary, Beitelspacher, Lauren S., additional, Tosti-Kharas, Jennifer, additional, and Swanson, Elizabeth, additional
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- 2020
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18. Arctic River Dissolved and Biogenic Silicon Exports—Current Conditions and Future Changes With Warming
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Carey, Joanna C., primary, Gewirtzman, Jonathan, additional, Johnston, Sarah Ellen, additional, Kurtz, Andrew, additional, Tang, Jianwu, additional, Vieillard, Amanda M., additional, and Spencer, Robert G. M., additional
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- 2020
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19. Soil warming accelerates biogeochemical silica cycling in a temperate forest.
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Gewirtzman, Jonathan, Tang, Jianwu, Melillo, Jerry M., Werner, William J., Kurtz, Andrew C., Fulweiler, Robinson W., Carey, Joanna C., Gewirtzman, Jonathan, Tang, Jianwu, Melillo, Jerry M., Werner, William J., Kurtz, Andrew C., Fulweiler, Robinson W., and Carey, Joanna C.
- Abstract
© The Author(s), 2019. This article is distributed under the terms of the Creative Commons Attribution License. The definitive version was published in Gewirtzman, J., Tang, J., Melillo, J. M., Werner, W. J., Kurtz, A. C., Fulweiler, R. W., & Carey, J. C. Soil warming accelerates biogeochemical silica cycling in a temperate forest. Frontiers in Plant Science, 10, (2019): 1097, doi:10.3389/fpls.2019.01097., Biological cycling of silica plays an important role in terrestrial primary production. Soil warming stemming from climate change can alter the cycling of elements, such as carbon and nitrogen, in forested ecosystems. However, the effects of soil warming on the biogeochemical cycle of silica in forested ecosystems remain unexplored. Here we examine long-term forest silica cycling under ambient and warmed conditions over a 15-year period of experimental soil warming at Harvard Forest (Petersham, MA). Specifically, we measured silica concentrations in organic and mineral soils, and in the foliage and litter of two dominant species (Acer rubrum and Quercus rubra), in a large (30 × 30 m) heated plot and an adjacent control plot (30 × 30 m). In 2016, we also examined effects of heating on dissolved silica in the soil solution, and conducted a litter decomposition experiment using four tree species (Acer rubrum, Quercus rubra, Betula lenta, Tsuga canadensis) to examine effects of warming on the release of biogenic silica (BSi) from plants to soils. We find that tree foliage maintained constant silica concentrations in the control and warmed plots, which, coupled with productivity enhancements under warming, led to an increase in total plant silica uptake. We also find that warming drove an acceleration in the release of silica from decaying litter in three of the four species we examined, and a substantial increase in the silica dissolved in soil solution. However, we observe no changes in soil BSi stocks with warming. Together, our data indicate that warming increases the magnitude of silica uptake by vegetation and accelerates the internal cycling of silica in in temperate forests, with possible, and yet unresolved, effects on the delivery of silica from terrestrial to marine systems., This research was supported by the National Science Foundation (NSF PLR-1417763 to JT), the Geological Society of America (Stephen G. Pollock Undergraduate Research Grant to JG), the Institute at Brown for Environment and Society, and the Marine Biological Laboratory. Sample analysis and Fulweiler’s involvement were supported by Boston University and a Bullard Fellowship from Harvard University. The soil warming experiment was supported by the National Science Foundation (DEB-0620443) and Department of Energy (DE-FC02-06-ER641577 and DE-SC0005421).
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- 2019
20. Exploring Silica Stoichiometry on a Large Floodplain Riverscape
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Carey, Joanna C., primary, Jankowski, KathiJo, additional, Julian, Paul, additional, Sethna, Lienne R., additional, Thomas, Patrick K., additional, and Rohweder, Jason, additional
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- 2019
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21. Soil Warming Accelerates Biogeochemical Silica Cycling in a Temperate Forest
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Gewirtzman, Jonathan, primary, Tang, Jianwu, additional, Melillo, Jerry M., additional, Werner, William J., additional, Kurtz, Andrew C., additional, Fulweiler, Robinson W., additional, and Carey, Joanna C., additional
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- 2019
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22. Plant Uptake Offsets Silica Release From a Large Arctic Tundra Wildfire
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Carey, Joanna C., primary, Abbott, Benjamin W., additional, and Rocha, Adrian V., additional
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- 2019
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23. A Resource-Efficient Modular Course Design for Co-Teaching Integrated Sustainability in Higher Education: Developing the Next Generation of Entrepreneurial Leaders.
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Carey, Joanna C., Beitelspacher, Lauren S., Tosti-Kharas, Jennifer, and Swanson, Elizabeth
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- 2021
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24. Passive experimental warming decouples air and sediment temperatures in a salt marsh
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Carey, Joanna C., primary, Kroeger, Kevin D., additional, Zafari, Babak, additional, and Tang, Jianwu, additional
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- 2018
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25. Temperature response of soil respiration largely unaltered with experimental warming
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Carey, Joanna C., Tang, Jianwu, Templer, Pamela H., Kroeger, Kevin D., Crowther, Thomas W., Burton, Andrew J., Dukes, Jeffrey S., Emmett, Bridget, Frey, Serita D., Heskel, Mary A., Jiang, Lifen, Machmuller, Megan B., Mohan, Jacqueline, Panetta, Anne Marie, Reich, Peter B., Reinsch, Sabine, Wang, Xin, Allison, Steven D., Bamminger, Chris, Bridgham, Scott, Collins, Scott L., de Dato, Giovanbattista, Eddy, William C., Enquist, Brian J., Estiarte, Marc, Harte, John, Henderson, Amanda, Johnson, Bart R., Larsen, Klaus Steenberg, Luo, Yiqi, Marhan, Sven, Melillo, Jerry M., Peñuelas, Josep, Pfeifer-Meister, Laurel, Poll, Christian, Rastetter, Edward, Reinmann, Andrew B., Reynolds, Lorien L., Schmidt, Inger K., Shaver, Gaius R., Strong, Aaron L., Suseela, Vidya, Tietema, Albert, Carey, Joanna C., Tang, Jianwu, Templer, Pamela H., Kroeger, Kevin D., Crowther, Thomas W., Burton, Andrew J., Dukes, Jeffrey S., Emmett, Bridget, Frey, Serita D., Heskel, Mary A., Jiang, Lifen, Machmuller, Megan B., Mohan, Jacqueline, Panetta, Anne Marie, Reich, Peter B., Reinsch, Sabine, Wang, Xin, Allison, Steven D., Bamminger, Chris, Bridgham, Scott, Collins, Scott L., de Dato, Giovanbattista, Eddy, William C., Enquist, Brian J., Estiarte, Marc, Harte, John, Henderson, Amanda, Johnson, Bart R., Larsen, Klaus Steenberg, Luo, Yiqi, Marhan, Sven, Melillo, Jerry M., Peñuelas, Josep, Pfeifer-Meister, Laurel, Poll, Christian, Rastetter, Edward, Reinmann, Andrew B., Reynolds, Lorien L., Schmidt, Inger K., Shaver, Gaius R., Strong, Aaron L., Suseela, Vidya, and Tietema, Albert
- Abstract
The respiratory release of carbon dioxide (CO2) from soil is a major yet poorly understood flux in the global carbon cycle. Climatic warming is hypothesized to increase rates of soil respiration, potentially fueling further increases in global temperatures. However, despite considerable scientific attention in recent decades, the overall response of soil respiration to anticipated climatic warming remains unclear. We synthesize the largest global dataset to date of soil respiration, moisture, and temperature measurements, totaling >3,800 observations representing 27 temperature manipulation studies, spanning nine biomes and over 2 decades of warming. Our analysis reveals no significant differences in the temperature sensitivity of soil respiration between control and warmed plots in all biomes, with the exception of deserts and boreal forests. Thus, our data provide limited evidence of acclimation of soil respiration to experimental warming in several major biome types, contrary to the results from multiple single-site studies. Moreover, across all nondesert biomes, respiration rates with and without experimental warming follow a Gaussian response, increasing with soil temperature up to a threshold of ∼25 °C, above which respiration rates decrease with further increases in temperature. This consistent decrease in temperature sensitivity at higher temperatures demonstrates that rising global temperatures may result in regionally variable responses in soil respiration, with colder climates being considerably more responsive to increased ambient temperatures compared with warmer regions. Our analysis adds a unique cross-biome perspective on the temperature response of soil respiration, information critical to improving our mechanistic understanding of how soil carbon dynamics change with climatic warming.
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- 2016
26. Directly Measured Denitrification Reveals Oyster Aquaculture and Restored Oyster Reefs Remove Nitrogen at Comparable High Rates
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Humphries, Austin T., primary, Ayvazian, Suzanne G., additional, Carey, Joanna C., additional, Hancock, Boze T., additional, Grabbert, Sinead, additional, Cobb, Donald, additional, Strobel, Charles J., additional, and Fulweiler, Robinson W., additional
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- 2016
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27. Does elevated CO2 alter silica uptake in trees?
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Fulweiler, Robinson W., Maguire, Timothy J., Carey, Joanna C., Finzi, Adrien C., Fulweiler, Robinson W., Maguire, Timothy J., Carey, Joanna C., and Finzi, Adrien C.
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© The Author(s), 2015. This article is distributed under the terms of the Creative Commons Attribution License. The definitive version was published in Frontiers in Plant Science 5 (2015): 793, doi:10.3389/fpls.2014.00793., Human activities have greatly altered global carbon (C) and Nitrogen (N) cycling. In fact, atmospheric concentrations of carbon dioxide (CO2) have increased 40% over the last century and the amount of N cycling in the biosphere has more than doubled. In an effort to understand how plants will respond to continued global CO2 fertilization, long-term free-air CO2 enrichment experiments have been conducted at sites around the globe. Here we examine how atmospheric CO2 enrichment and N fertilization affects the uptake of silicon (Si) in the Duke Forest, North Carolina, a stand dominated by Pinus taeda (loblolly pine), and five hardwood species. Specifically, we measured foliar biogenic silica concentrations in five deciduous and one coniferous species across three treatments: CO2 enrichment, N enrichment, and N and CO2 enrichment. We found no consistent trends in foliar Si concentration under elevated CO2, N fertilization, or combined elevated CO2 and N fertilization. However, two-thirds of the tree species studied here have Si foliar concentrations greater than well-known Si accumulators, such as grasses. Based on net primary production values and aboveground Si concentrations in these trees, we calculated forest Si uptake rates under control and elevated CO2 concentrations. Due largely to increased primary production, elevated CO2 enhanced the magnitude of Si uptake between 20 and 26%, likely intensifying the terrestrial silica pump. This uptake of Si by forests has important implications for Si export from terrestrial systems, with the potential to impact C sequestration and higher trophic levels in downstream ecosystems., This research was supported in part by the Sloan Foundation in a fellowship to Robinson W. Fulweiler. The Duke Forest FACE was supported by his study was supported by the US Department of Energy (Grant No. DE-FG02-95ER62083) through the Office of Biological and Environmental Research (BER) and its National Institute for Global Environmental Change (NIGEC), Southeast Regional Center (SERC) at the University of Alabama, and by the US Forest Service through both the Southern Global Climate Change Program and the Southern Research Station. Adrien C. Finzi acknowledges ancillary support from the US NSF (DEB0236356).
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- 2015
28. Human appropriation of biogenic silicon – the increasing role of agriculture
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Carey, Joanna C., primary and Fulweiler, Robinson W., additional
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- 2015
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29. Silica cycling over geologic time
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Conley, Daniel J., primary and Carey, Joanna C., additional
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- 2015
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30. Does elevated CO2 alter silica uptake in trees?
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Fulweiler, Robinson W., primary, Maguire, Timothy J., additional, Carey, Joanna C., additional, and Finzi, Adrien C., additional
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- 2015
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31. Silica uptake by Spartina—evidence of multiple modes of accumulation from salt marshes around the world
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Carey, Joanna C., primary and Fulweiler, Robinson W., additional
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- 2014
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32. The Terrestrial Silica Pump
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Carey, Joanna C., primary and Fulweiler, Robinson W., additional
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- 2012
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33. Does elevated CO2 alter silica uptake in trees?
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Fulweiler, Robinson W., Maguire, Timothy J., Finzi, Adrien C., and Carey, Joanna C.
- Subjects
ATMOSPHERIC carbon dioxide ,SILICON ,SILICA content in soils ,SILICIC acid ,HARDWOOD forests - Abstract
Human activities have greatly altered global carbon (C) and Nitrogen (N) cycling. In fact, atmospheric concentrations of carbon dioxide (CO
2 ) have increased 40% over the last century and the amount of N cycling in the biosphere has more than doubled. In an effort to understand how plants will respond to continued global CO2 fertilization, long-term free-air CO2 enrichment experiments have been conducted at sites around the globe. Here we examine how atmospheric CO2 enrichment and N fertilization affects the uptake of silicon (Si) in the Duke Forest, North Carolina, a stand dominated by Pinus taeda (loblolly pine), and five hardwood species. Specifically, we measured foliar biogenic silica concentrations in five deciduous and one coniferous species across three treatments: CO2 enrichment, N enrichment, and N and CO2 enrichment. We found no consistent trends in foliar Si concentration under elevated CO2 , N fertilization, or combined elevated CO2 and N fertilization. However, two-thirds of the tree species studied here have Si foliar concentrations greater than well-known Si accumulators, such as grasses. Based on net primary production values and aboveground Si concentrations in these trees, we calculated forest Si uptake rates under control and elevated CO2 concentrations. Due largely to increased primary production, elevated CO2 enhanced themagnitude of Si uptake between 20 and 26%, likely intensifying the terrestrial silica pump. This uptake of Si by forests has important implications for Si export from terrestrial systems, with the potential to impact C sequestration and higher trophic levels in downstream ecosystems. [ABSTRACT FROM AUTHOR]- Published
- 2015
- Full Text
- View/download PDF
34. Silica uptake by Spartina—evidence of multiple modes of accumulation from salt marshes around the world.
- Author
-
Carey, Joanna C. and Fulweiler, Robinson W.
- Subjects
SPARTINA ,PLANT ecology ,PLANTS & the environment ,SALT marshes ,SILICON content of plants - Abstract
Silicon (Si) plays a critical role in plant functional ecology, protecting plants from multiple environmental stressors. While all terrestrial plants contain some Si, wetland grasses are frequently found to have the highest concentrations, although the mechanisms driving Si accumulation in wetland grasses remain in large part uncertain. For example, active Si accumulation is often assumed to be responsible for elevated Si concentrations found in wetland grasses. However, life stage and differences in Si availability in the surrounding environment also appear to be important variables controlling the Si concentrations of wetland grasses. Here we used original data from five North American salt marshes, as well as all known published literature values, to examine the primary drivers of Si accumulation in Spartina, a genus of prolific salt marsh grasses found worldwide. We found evidence of multiple modes of Si accumulation in Spartina, with passive accumulation observed in non-degraded marshes where Spartina was native, while rejective accumulation was found in regions where Spartina was invasive. Evidence of active accumulation was found in only one marsh where Spartina was native, but was also subjected to nutrient over-enrichment. We developed a conceptual model which hypothesizes that the mode of Si uptake by Spartina is dependent on local environmental factors and genetic origin, supporting the idea that plant species should be placed along a spectrum of Si accumulation. We hypothesize that Spartina exhibits previously unrecognized phenotypic plasticity with regard to Si accumulation, allowing these plants to respond to changes in marsh condition. These results provide new insight regarding how salt marsh ecosystems regulate Si exchange at the land-sea interface. [ABSTRACT FROM AUTHOR]
- Published
- 2014
- Full Text
- View/download PDF
35. Stress alters the role of silicon in controlling plant water movement
- Author
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Cooke, Julia, Carey, Joanna C., Cooke, Julia, and Carey, Joanna C.
- Abstract
1. One function of plant Si is ameliorating stress, including drought and salinity stress, which can induce active Si uptake in addition to passive uptake via transpiration. However, the interactions and feedbacks between stress, water movement and Si uptake remain unknown. 2. To examine this gap, we compiled papers reporting transpiration and/or stomatal conductance of plants exposed to stresses while varying Si availability. 3. Our meta‐analysis (34 studies, excluding rice) showed that stress alters the role of Si in controlling water movement across diverse plant groups. Increased Si availability significantly increased water movement in stressed plants, particularly stomatal conductance (p < 0.001, k = 84) in plants exposed to salinity (p < 0.05, k = 20) and drought (p < 0.05, k = 45) stress. 4. This signal of increased conductance was most apparent in C4 plants (p < 0.001, k = 41) and Poales (p < 0.001, k = 47). These findings have implications for plants under increasing water and salinity stress, particularly for Poales, where survival in affected ecosystems could be mediated by soil Si availability, and in agricultural systems, supplying Si to water‐stressed plants could increase productivity. 5. Intriguingly, Si addition to unstressed plants had no consistent impact on water movement, with reduction of water movement with Si addition to unstressed plants in 50% of studies, mostly those involving non‐Poales species. This is an important first broad‐scale Si cost quantification, as the costs of Si for plants have remained stubbornly mysterious, hampering evolutionary and functional understanding of plant Si use.
36. Biogeochemistry: Silica cycling over geologic time.
- Author
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Conley, Daniel J. and Carey, Joanna C.
- Subjects
- *
SILICA , *GEOLOGICAL time scales , *WEATHERING , *BIOGENIC landforms , *MARINE organisms , *SILICON content of plants , *DIATOMS - Abstract
The article focuses on the studies conducted by E. Trembath-Reichert and colleagues and P. Cermeño and colleagues which examine silica cycling over geological time and its association with weathering rates and biogenic uptake. Topics include the relationship of the evolution of silica-accumulating organisms in marine and terrestrial systems, the effect of early plants on silica cycling, and the role of continental silicate weathering in the ecological success of marine diatoms over time.
- Published
- 2015
- Full Text
- View/download PDF
37. Silicon cyling along the land-ocean continuum
- Author
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Carey, Joanna C.
- Subjects
- Biogeochemistry, New England, Land use, Rivers, Salt marshes, Sea level rise, Silicon
- Abstract
The alteration of the global environment by human activities is so widespread that scientists argue we've entered a new geologic epoch known as the Anthropocene. This dissertation examines the impact of human activities on biogeochemical cycling at the land-sea interface. I focus primarily on the role of land use/land cover (LULC) and coastal nutrient enrichment on silicon (Si) cycling in New England rivers and salt marshes. On land, Si is taken up by vegetation, improving plant fitness and protecting plants from a variety of environmental stressors. In aquatic systems, diatoms, the dominant type of phytoplankton in coastal temperate waters, require Si to survive. My research demonstrates that LULC is an important driver of Si export to coastal systems, accounting for 40-70% of the variability of riverine fluxes. Developed watersheds export significantly (p=0.03) more Si than their forested counterparts, which I hypothesize is due to less vegetated cover, a known Si sink, in developed watersheds. Building on this, I calculated the amount of Si fixed by land plants globally (84 Tmol yr-1) and the percent (55%) of global terrestrial net primary production that can be attributed to active Si-accumulating organisms. Next, I created the first complete salt marsh Si budget by quantifying tidal creek fluxes and net Si accumulation in a relatively undisturbed low-nutrient salt marsh. Further, comparing this Si accumulation to that of a high-nutrient marsh revealed that the high-nutrient marsh contained significantly (p
- Published
- 2013
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