@article{kiera l. o'donnell_bernhardt_yang_emanuel_ardon_lerdau_manda_braswell_bendor_edwards_et al._2024, title={Saltwater intrusion and sea level rise threatens U.S. rural coastal landscapes and communities}, volume={45}, ISSN={["2213-3054"]}, url={http://dx.doi.org/10.1016/j.ancene.2024.100427}, DOI={10.1016/j.ancene.2024.100427}, abstractNote={The United States (U.S.) coastal plain is subject to rising sea levels, land subsidence, more severe coastal storms, and more intense droughts. These changes lead to inputs of marine salts into freshwater-dependent coastal systems, creating saltwater intrusion. The penetration of salinity into the coastal interior is exacerbated by groundwater extraction and the high density of agricultural canals and ditches throughout much of the rural U.S. landscape. Together saltwater intrusion and sea level rise (SWISLR) create substantial changes to the social-ecological systems situated along the coastal plain. Many scholars and practitioners are engaged in studying and managing SWISLR impacts on social, economic, and ecological systems. However, most efforts are localized and disconnected, despite a widespread desire to understand this common threat. In addition to variable rates of sea level rise across the U.S. outer coastal plain, differences in geomorphic setting, water resources infrastructure and management, and climate extremes are resulting in different patterns of saltwater intrusion. Understanding both the absolute magnitude of this rapid environmental change, and the causes and consequences for its spatial and temporal variation presents an opportunity to build new mechanistic models to link directional climate change to temporally and spatially dynamic socio-environmental impacts. The diverse trajectories of change offer rich opportunities to test and refine modern theories of ecosystem state change in systems with exceptionally strong socioecological feedbacks.}, journal={ANTHROPOCENE}, author={Kiera L. O'Donnell and Bernhardt, Emily S. and Yang, Xi and Emanuel, Ryan E. and Ardon, Marcelo and Lerdau, Manuel T. and Manda, Alex K. and Braswell, Anna E. and BenDor, Todd K. and Edwards, Eric C. and et al.}, year={2024}, month={Mar} }
 @misc{helton_morse_sudduth_ardon_bier_voss_ross_blaszczak_brandt_simonin_et al._2023, title={At the interfaces of the hydrologic sciences: Connecting water, elements, ecosystems, and people through the major contributions of Dr. Emily Bernhardt}, volume={619}, ISSN={["1879-2707"]}, DOI={10.1016/j.jhydrol.2023.129251}, abstractNote={In this paper, we describe the major contributions of Professor Emily Bernhardt to the hydrologic sciences. Dr. Bernhardt’s work addresses how carbon, nutrient, and contaminant dynamics respond to a wide range of environmental perturbations that alter hydrologic dynamics within and connectivity among ecosystems. Her research leverages intensive and extensive field sampling, experimental manipulations, macroscale data harmonization and exploration, and continental to global-scale synthesis activities to uncover key drivers and patterns of the impacts human perturbations have on water and elemental cycles. Dr. Bernhardt’s research program is defined by her ability to ask questions and use approaches that explicitly consider connectivity and interfaces in a variety of ways. Here, we highlight significant contributions from Dr. Bernhardt’s work, organized by connectivity, interfaces, and interactions among and across (1) elemental cycles, (2) ecosystems, (3) watersheds, (4) scales, and (5) disciplines. We conclude with a section on Dr. Bernhardt’s impact on the hydrologic sciences and beyond through her exceptional dedication to mentorship, engagement, and service.}, journal={JOURNAL OF HYDROLOGY}, author={Helton, Ashley M. and Morse, Jennifer L. and Sudduth, Elizabeth B. and Ardon, Marcelo and Bier, Raven and Voss, Kristofor A. and Ross, Matthew R. V. and Blaszczak, Joanna R. and Brandt, Jessica E. and Simonin, Marie and et al.}, year={2023}, month={Apr} }
 @article{ardon_clark_marzolf_ramirez_pringle_2023, title={Can we see the nitrate from the trees? Long-term linkages between tropical forest productivity and stream nitrogen concentrations}, volume={2}, ISSN={["1573-515X"]}, DOI={10.1007/s10533-023-01030-1}, journal={BIOGEOCHEMISTRY}, author={Ardon, Marcelo and Clark, Deborah A. and Marzolf, Nicholas S. and Ramirez, Alonso and Pringle, Catherine M.}, year={2023}, month={Feb} }
 @article{neville_emanuel_ardon_pavelsky_2023, title={Location and Design of Flow Control Structures Differentially Influence Salinity Patterns in Small Artificial Drainage Systems}, volume={149}, ISSN={["1943-5452"]}, url={https://doi.org/10.1061/JWRMD5.WRENG-5840}, DOI={10.1061/JWRMD5.WRENG-5840}, abstractNote={Saltwater intrusion is a pervasive threat to coastal ecosystems. Common management strategies entail the installment of engineered flow control structures, though there is a dearth of work on their prevalence across the landscape and how different structures impact salinity under various hydrologic conditions. We manually classified more than 900 structures with most either being culvert pipes or riser structures. We then investigated how these structures impacted salinity in surface waters after the landfall of Hurricane Florence in 2018 and during the Summer of 2020. To accomplish this, we combined longitudinal and depth surveys, with long-term monitoring of salinity up and downstream of three flow control structures. Our results reveal that a flow control structure’s ability to exclude or trap saltwater from/in upstream environments depends on its position inland and design. Engineered structures were effective at excluding saltwater, while unintentional structures sometimes trapped saltwater in upstream environments. This work sheds light on important factors land managers should consider when putting in place new structures for freshwater management purposes.}, number={6}, journal={JOURNAL OF WATER RESOURCES PLANNING AND MANAGEMENT}, author={Neville, Justine A. and Emanuel, Ryan E. and Ardon, Marcelo and Pavelsky, Tamlin}, year={2023}, month={Jun} }
 @article{ury_ardon_wright_bernhardt_2023, title={Restored forested wetland surprisingly resistant to experimental salinization}, volume={18}, ISSN={["1932-6203"]}, DOI={10.1371/journal.pone.0296128}, abstractNote={Salinization of coastal freshwater wetlands is an increasingly common and widespread phenomenon resulting from climate change. The ecosystem consequences of added salinity are poorly constrained and highly variable across prior observational and experimental studies. We added 1.8 metric tons of marine salts to replicated 200 m2 plots within a restored forested wetland in Eastern North Carolina over the course of four years. Based on prior small-scale experiments at this site, we predicted that salinization would lead to slower tree growth and suppressed soil carbon cycling. Results from this large-scale field experiment were subtle and inconsistent over space and time. By the fourth year of the experiment, we observed the predicted suppression of soil respiration and a reduction of water extractable carbon from soils receiving salt treatments. However, we found no cumulative effects of four years of salinization on total soil carbon stocks, tree growth, or root biomass. We observed substantial variation in soil solution chemistry (notably, pH and base saturation) across replicated treatment blocks; the effective salt levels, ionic composition, and pH varied following treatment depending upon pre-existing differences in edaphic factors. Our multi-year monitoring also revealed an underlying trend of wetland acidification across the entire site, a suspected effect of ecosystem recovery following wetland restoration on former agricultural land. The overwhelming resistance to our salt treatments could be attributed to the vigor of a relatively young, healthy wetland ecosystem. The heterogeneous responses to salt that we observed over space and time merits further investigation into the environmental factors that control carbon cycling in wetlands. This work highlights the importance of multi-year, large-scale field experiments for investigating ecosystem responses to global environmental change.}, number={12}, journal={PLOS ONE}, author={Ury, Emily A. and Ardon, Marcelo and Wright, Justin P. and Bernhardt, Emily S.}, year={2023}, month={Dec} }
 @article{ulus_tsui_sakar_nyarko_aitmbarek_ardon_chow_2022, title={Declines of methylmercury along a salinity gradient in a low-lying coastal wetland ecosystem at South Carolina, USA}, volume={308}, ISSN={["1879-1298"]}, DOI={10.1016/j.chemosphere.2022.136310}, abstractNote={Wetlands are widely regarded as biogeochemical hotspots of highly toxic methylmercury (MeHg), mainly mediated by sulfate-reducing bacteria. In low-lying coastal wetlands, sea level rise, a phenomenon caused by global climate change, is slowly degrading numerous healthy freshwater forested wetlands into salt-degraded counterparts with a nickname "ghost forests", and eventually converting them to saltmarshes. However, little is known about the changes of mercury (Hg) methylation, bioaccumulation, and biomagnification along the forest-to-saltmarsh gradient. Here, we conducted extensive field sampling in three wetland states (healthy forested wetlands, salt-degraded forested wetlands, and saltmarsh) along a salinity gradient (from 0 to 9.4 ppt) in Winyah Bay, South Carolina, USA. We found that in our study wetland systems the saltmarshes had the lowest levels of both total Hg and MeHg in sediments and biota, as compared to healthy forested wetlands and saltwater-degraded ghost forests. Our results suggest that the slow conversion of forested wetland to saltmarsh could reduce net MeHg production in our study wetland systems, which we hypothesized that could be attributed to increased sulfate reduction and excessive buildup of sulfide in sediment that inhibits microbial Hg methylation, and/or reduced canopy density and increased photodegradation of MeHg. However, it should be noted that biogeochemical MeHg responses to salinity changes may be site-specific and we urge more similar studies in other wetland systems along a salinity gradient. Therefore, long-term salinization of coastal wetlands and the slow conversion of forests to marshes could decrease long-term exposure of toxic MeHg levels in coastal food webs that are similar to our system, and ultimately reduce human exposure to this neurotoxin.}, journal={CHEMOSPHERE}, author={Ulus, Yener and Tsui, Martin Tsz-Ki and Sakar, Aslihan and Nyarko, Paul and Aitmbarek, Nadia B. and Ardon, Marcelo and Chow, Alex T.}, year={2022}, month={Dec} }
 @article{marzolf_baca_bruce_vega-gomez_watson_ganong_ramirez_pringle_ardon_2022, title={Do experimental pH increases alter the structure and function of a lowland tropical stream?}, volume={13}, ISSN={["2150-8925"]}, url={https://doi.org/10.1002/ecs2.4097}, DOI={10.1002/ecs2.4097}, abstractNote={Abstract}, number={7}, journal={ECOSPHERE}, publisher={Wiley}, author={Marzolf, Nicholas S. and Baca, Dominic M. and Bruce, Terrius K. and Vega-Gomez, Mariely and Watson, Christopher D. and Ganong, Carissa N. and Ramirez, Alonso and Pringle, Catherine M. and Ardon, Marcelo}, year={2022}, month={Jul} }
 @article{armstrong_peralta_krauss_cormier_moss_soderholm_mccall_pickens_ardon_2022, title={Hydrologic Restoration Decreases Greenhouse Gas Emissions from Shrub Bog Peatlands in Southeastern US}, volume={42}, ISSN={["1943-6246"]}, url={https://doi.org/10.1007/s13157-022-01605-y}, DOI={10.1007/s13157-022-01605-y}, number={7}, journal={WETLANDS}, author={Armstrong, Luise and Peralta, Ariane and Krauss, Ken W. and Cormier, Nicole and Moss, Rebecca F. and Soderholm, Eric and McCall, Aaron and Pickens, Christine and Ardon, Marcelo}, year={2022}, month={Oct} }
 @article{martinez_ardon_carmichael_2022, title={Identifying Sources and Oxidation of Methane in Standing Dead Trees in Freshwater Forested Wetlands}, volume={9}, ISSN={["2296-665X"]}, DOI={10.3389/fenvs.2021.737379}, abstractNote={Wetlands are large sources of methane (CH4), therefore it is vital to understand the pathways, mechanisms, and sources to anticipate future positive feedbacks to climate change. Plant mediated transport of CH4 from sediment-borne gases is thought to be a major contributor in wetland ecosystems, though few studies have measured standing dead trees (snags). Snags are expected to become more common across the southeastern coast as marshes migrate into freshwater forested wetlands. In this study, our goal was to distinguish the main sources of CH4 being emitted from snags, that is, from soil or in situ origin. The δ2H and δ13C stable isotopic composition from various sources was sampled for source determination. We measured CH4 in various components: emissions from snag stem sides and the soil-atmosphere interface; and concentrations from snag trunk airspace at various heights from ground level (30, 60, and 120 cm), and soil porewater. Potential CH4 production and oxidation in tree cores from two heights (60 and 120 cm) was also measured to examine the potential for CH4 generation or oxidation in stems. We found that CH4 concentrations inside snags (∼10–200 ppm) were 2–50 times higher than atmospheric levels, and generally decreased with increasing stem height. The stable isotopes δ13C and δ2H showed an enrichment from porewater to soils and snag stems. δ13C enrichment of CH4 in snag stems suggests that CH4 is being oxidized as it moves through snags. The tree core vial incubations showed that very few cores produced small amounts of CH4 under anaerobic conditions (n = 5 out of 50), and very few cores oxidized CH4 under more aerobic conditions (n = 5 out of 50). It is possible that a small amount of CH4 is produced in-situ within the heartwood, but it is likely this depends on the density, porosity, and aeration of snags (degree of decay). Our results highlight that high concentrations of CH4 can persist within the heartwood of snags long after initial decay, and that CH4 emitted from snags is largely derived from deep wetland soils and oxidized during transport (via diffusion) throughout the stem of snags.}, journal={FRONTIERS IN ENVIRONMENTAL SCIENCE}, author={Martinez, Melinda and Ardon, Marcelo and Carmichael, Mary Jane}, year={2022}, month={Feb} }
 @article{marzolf_small_oviedo-vargas_ganong_duff_ramirez_pringle_genereux_ardon_2022, title={Partitioning inorganic carbon fluxes from paired O-2-CO2 gas measurements in a Neotropical headwater stream, Costa Rica}, volume={7}, ISSN={["1573-515X"]}, url={https://doi.org/10.1007/s10533-022-00954-4}, DOI={10.1007/s10533-022-00954-4}, abstractNote={The role of streams and rivers in the global carbon (C) cycle remains unconstrained, especially in headwater streams where CO2 evasion (FCO2) to the atmosphere is high. Stream C cycling is understudied in the tropics compared to temperate streams, and tropical streams may have among the highest FCO2 due to higher temperatures, continuous organic matter inputs, and high respiration rates both in-stream and in surrounding soils. In this paper, we present paired in-stream O2 and CO2 sensor data from a headwater stream in a lowland rainforest in Costa Rica to explore temporal variability in gas concentrations and ecosystem processes. Further, we estimate groundwater CO2 inputs (GWCO2) from riparian well CO2 measurements. Paired O2–CO2 data reveal stream CO2 supersaturation driven by groundwater CO2 inputs and large in-stream production of CO2. At short time scales, CO2 was diluted during storm events, but increased at longer seasonal scales. Areal fluxes in our study reach show that FCO2 is supported by greater in-stream metabolism compared to GWCO2. Our results underscore the importance of tropical headwater streams as large contributors of carbon dioxide to the atmosphere and show evaded C can be derived from both in-stream and terrestrial sources.}, journal={BIOGEOCHEMISTRY}, publisher={Springer Science and Business Media LLC}, author={Marzolf, Nicholas S. and Small, Gaston E. and Oviedo-Vargas, Diana and Ganong, Carissa N. and Duff, John H. and Ramirez, Alonso and Pringle, Catherine M. and Genereux, David P. and Ardon, Marcelo}, year={2022}, month={Jul} }
 @article{swails_ardon_krauss_peralta_emanuel_helton_morse_gutenberg_cormier_shoch_et al._2022, title={Response of soil respiration to changes in soil temperature and water table level in drained and restored peatlands of the southeastern United States}, volume={17}, ISSN={["1750-0680"]}, url={http://dx.doi.org/10.1186/s13021-022-00219-5}, DOI={10.1186/s13021-022-00219-5}, abstractNote={Abstract}, number={1}, journal={CARBON BALANCE AND MANAGEMENT}, publisher={Springer Science and Business Media LLC}, author={Swails, E. E. and Ardon, M. and Krauss, K. W. and Peralta, A. L. and Emanuel, R. E. and Helton, A. M. and Morse, J. L. and Gutenberg, L. and Cormier, N. and Shoch, D. and et al.}, year={2022}, month={Nov} }
 @article{zanne_flores-moreno_powell_cornwell_dalling_austin_classen_eggleton_okada_parr_et al._2022, title={Termite sensitivity to temperature affects global wood decay rates}, volume={377}, ISSN={["1095-9203"]}, url={http://dx.doi.org/10.1126/science.abo3856}, DOI={10.1126/science.abo3856}, abstractNote={Deadwood is a large global carbon store with its store size partially determined by biotic decay. Microbial wood decay rates are known to respond to changing temperature and precipitation. Termites are also important decomposers in the tropics but are less well studied. An understanding of their climate sensitivities is needed to estimate climate change effects on wood carbon pools. Using data from 133 sites spanning six continents, we found that termite wood discovery and consumption were highly sensitive to temperature (with decay increasing >6.8 times per 10°C increase in temperature)—even more so than microbes. Termite decay effects were greatest in tropical seasonal forests, tropical savannas, and subtropical deserts. With tropicalization (i.e., warming shifts to tropical climates), termite wood decay will likely increase as termites access more of Earth’s surface.}, number={6613}, journal={SCIENCE}, publisher={American Association for the Advancement of Science (AAAS)}, author={Zanne, Amy E. and Flores-Moreno, Habacuc and Powell, Jeff R. and Cornwell, William K. and Dalling, James W. and Austin, Amy T. and Classen, Aimee T. and Eggleton, Paul and Okada, Kei-Ichi and Parr, Catherine L. and et al.}, year={2022}, month={Sep}, pages={1440-+} }
 @article{gareis_larson_ardon_berges_brandt_busch_chraibi_gallagher_hondula_kincaid_et al._2022, title={Using Wikipedia Assignments to Teach Critical Thinking and Scientific Writing in STEM Courses}, volume={7}, ISSN={["2504-284X"]}, DOI={10.3389/feduc.2022.905777}, abstractNote={While many instructors have reservations against Wikipedia use in academic settings, editing Wikipedia teaches students valuable writing, editing, and critical thinking skills. Wikipedia assignments align with the community of inquiry framework, which focuses on the elements needed for a successful online learning experience. We report on a faculty mentoring network, created by WikiProject Limnology and Oceanography, which helped 14 instructors with little to no prior experience implement a Wikipedia assignment in their classes. We found that Wikipedia assignments increase students’ motivation to produce high quality work and enhance their awareness of reliable scientific sources. Wikipedia assignments can be comparable to other writing assignments in length and complexity, but have a far wider audience than a traditional research paper. Participants in our mentoring network reported challenges with implementing this new type of assignment, and here, we share resources and solutions to those reported barriers.}, journal={FRONTIERS IN EDUCATION}, author={Gareis, Jolie A. L. and Larson, Erin I. and Ardon, Marcelo and Berges, John A. and Brandt, Jessica E. and Busch, Kaitlyn M. and Chraibi, Victoria L. S. and Gallagher, Elizabeth N. and Hondula, Kelly L. and Kincaid, Dustin W. and et al.}, year={2022}, month={Jun} }
 @article{martinez_ardon_2021, title={Drivers of greenhouse gas emissions from standing dead trees in ghost forests}, volume={154}, ISSN={["1573-515X"]}, url={https://doi.org/10.1007/s10533-021-00797-5}, DOI={10.1007/s10533-021-00797-5}, abstractNote={Coastal freshwater forested wetlands are rapidly transitioning from forest to marsh, leaving behind many standing dead trees (snags) in areas often called ‘ghost forests’. Snags can act as conduits for soil produced greenhouse gases (GHG) and can also be sources as they decompose. Thus, snags have the potential to contribute GHGs to the atmosphere, but emissions are not well understood. We assessed GHG emissions (carbon dioxide—CO2, methane—CH4, and nitrous oxide—N2O) from snags and soils in five ghost forests along a salinity gradient on the coast of North Carolina, USA. Mean (± SE) soil GHG fluxes (416 ± 44 mg CO2 m−2 h−1, 5.9 ± 1.9 mg CH4 m−2 h−1, and 0.1 ± 0.06 mg N2O m−2 h−1) were ~ 4 times greater than mean snag GHGs (116 ± 15 mg CO2 m−2 h−1, 0.3 ± 0.09 mg CH4 m−2 h−1, and 0.04 ± 0.009 mg N2O m−2 h−1). Hydrological conditions and salinity influenced soil GHG fluxes between the two field campaigns, but snags were less predictable and more variable. Snag and soil CO2/N2O fluxes were influenced by similar environmental parameters. The drivers for soil and snag CH4 however, were often not the same and at times oppositely correlated. Our results illustrate the need to further research into the drivers and importance of GHG emissions from snags, and the need to include tree stems into ecosystem GHG research.}, number={3}, journal={BIOGEOCHEMISTRY}, publisher={Springer Science and Business Media LLC}, author={Martinez, Melinda and Ardon, Marcelo}, year={2021}, month={Jul}, pages={471–488} }
 @misc{marzolf_ardon_2021, title={Ecosystem metabolism in tropical streams and rivers: a review and synthesis}, volume={66}, ISSN={["1939-5590"]}, DOI={10.1002/lno.11707}, abstractNote={Abstract}, number={5}, journal={LIMNOLOGY AND OCEANOGRAPHY}, author={Marzolf, Nicholas S. and Ardon, Marcelo}, year={2021}, month={May}, pages={1627–1638} }
 @article{ardón_zeglin_utz_cooper_dodds_bixby_burdett_shah_griffiths_harms_et al._2021, title={Experimental nitrogen and phosphorus enrichment stimulates multiple trophic levels of algal and detrital‐based food webs: a global meta‐analysis from streams and rivers}, url={https://doi.org/10.1111/brv.12673}, DOI={10.1111/brv.12673}, abstractNote={ABSTRACT}, journal={Biological Reviews}, author={Ardón, Marcelo and Zeglin, Lydia H. and Utz, Ryan M. and Cooper, Scott D. and Dodds, Walter K. and Bixby, Rebecca J. and Burdett, Ayesha S. and Shah, Jennifer Follstad and Griffiths, Natalie A. and Harms, Tamara K. and et al.}, year={2021}, month={Apr} }
 @article{gundersen_corbett_long_martinez_ardon_2021, title={Long-Term Sediment, Carbon, and Nitrogen Accumulation Rates in Coastal Wetlands Impacted by Sea Level Rise}, volume={44}, ISSN={["1559-2731"]}, url={https://doi.org/10.1007/s12237-021-00928-z}, DOI={10.1007/s12237-021-00928-z}, number={8}, journal={ESTUARIES AND COASTS}, publisher={Springer Science and Business Media LLC}, author={Gundersen, Gillian and Corbett, D. Reide and Long, Austyn and Martinez, Melinda and Ardon, Marcelo}, year={2021}, month={Dec}, pages={2142–2158} }
 @article{anderson_ury_taillie_ungberg_moorman_poulter_ardon_bernhardt_wright_2021, title={Salinity thresholds for understory plants in coastal wetlands}, volume={11}, ISSN={["1573-5052"]}, DOI={10.1007/s11258-021-01209-2}, abstractNote={The effects of sea level rise and coastal saltwater intrusion on wetland plants can extend well above the high-tide line due to drought, hurricanes, and groundwater intrusion. Research has examined how coastal salt marsh plant communities respond to increased flooding and salinity, but more inland coastal systems have received less attention. The aim of this study was to identify whether ground layer plants exhibit threshold responses to salinity exposure. We used two vegetation surveys throughout the Albemarle-Pamlico Peninsula (APP) of North Carolina, USA to assess vegetation in a low elevation landscape (≤ 3.8 m) experiencing high rates of sea level rise (3–4 mm/year). We examined the primary drivers of community composition change using Non-metric Multidimensional Scaling (NMDS) and used Threshold Indicator Taxa Analysis (TITAN) to detect thresholds of compositional change based on indicator taxa, in response to potential indicators of exposure to saltwater (Na, and the Σ Ca + Mg) and elevation. Salinity and elevation explained 64% of the variation in community composition, and we found two salinity thresholds for both soil Na+ (265 and 3843 g Na+/g) and Ca+ + Mg+ (42 and 126 µeq/g) where major changes in community composition occur on the APP. Similar sets of species showed sensitivity to these different metrics of salt exposure. Overall, our results showed that ground layer plants can be used as reliable indicators of salinity thresholds in coastal wetlands. These results can be used for monitoring salt exposure of ecosystems and for identifying areas at risk for undergoing future community shifts.}, journal={PLANT ECOLOGY}, author={Anderson, Steven M. and Ury, Emily A. and Taillie, Paul J. and Ungberg, Eric A. and Moorman, Christopher E. and Poulter, Benjamin and Ardon, Marcelo and Bernhardt, Emily S. and Wright, Justin P.}, year={2021}, month={Nov} }
 @article{ury_wright_ardon_bernhardt_2021, title={Saltwater intrusion in context: soil factors regulate impacts of salinity on soil carbon cycling}, volume={11}, ISSN={["1573-515X"]}, url={https://doi.org/10.1007/s10533-021-00869-6}, DOI={10.1007/s10533-021-00869-6}, journal={BIOGEOCHEMISTRY}, publisher={Springer Science and Business Media LLC}, author={Ury, Emily A. and Wright, Justin P. and Ardon, Marcelo and Bernhardt, Emily S.}, year={2021}, month={Nov} }
 @article{taillie_moorman_poulter_ardón_emanuel_2019, title={Decadal-Scale Vegetation Change Driven by Salinity at Leading Edge of Rising Sea Level}, volume={22}, ISSN={1432-9840 1435-0629}, url={http://dx.doi.org/10.1007/s10021-019-00382-w}, DOI={10.1007/s10021-019-00382-w}, number={8}, journal={Ecosystems}, publisher={Springer Science and Business Media LLC}, author={Taillie, Paul J. and Moorman, Christopher E. and Poulter, Benjamin and Ardón, Marcelo and Emanuel, Ryan E.}, year={2019}, month={Apr}, pages={1918–1930} }
 @article{helton_ardón_bernhardt_2019, title={Hydrologic Context Alters Greenhouse Gas Feedbacks of Coastal Wetland Salinization}, volume={22}, ISSN={1432-9840 1435-0629}, url={http://dx.doi.org/10.1007/s10021-018-0325-2}, DOI={10.1007/s10021-018-0325-2}, number={5}, journal={Ecosystems}, publisher={Springer Science and Business Media LLC}, author={Helton, Ashley M. and Ardón, Marcelo and Bernhardt, Emily S.}, year={2019}, month={Jan}, pages={1108–1125} }
 @article{leroy_hipp_lueders_follstad shah_kominoski_ardón_dodds_gessner_griffiths_lecerf_et al._2019, title={Plant phylogenetic history explains in‐stream decomposition at a global scale}, volume={108}, ISSN={0022-0477 1365-2745}, url={http://dx.doi.org/10.1111/1365-2745.13262}, DOI={10.1111/1365-2745.13262}, abstractNote={Abstract}, number={1}, journal={Journal of Ecology}, publisher={Wiley}, author={LeRoy, Carri J. and Hipp, Andrew L. and Lueders, Kate and Follstad Shah, Jennifer J. and Kominoski, John S. and Ardón, Marcelo and Dodds, Walter K. and Gessner, Mark O. and Griffiths, Natalie A. and Lecerf, Antoine and et al.}, editor={Wardle, DavidEditor}, year={2019}, month={Aug}, pages={17–35} }
 @inbook{christian_blum_ardón_leorri_2019, place={Boca Raton, FL}, title={Sea-level change and its potential effects on coastal blue carbon}, booktitle={A Blue Carbon Primer}, publisher={CRC Press}, author={Christian, R.R. and Blum, L.K. and Ardón, M. and Leorri, E.}, editor={Windham-Myers, L. and Crooks, S. and Troxler, T.Editors}, year={2019} }
 @article{bhattachan_emanuel_ardon_bernhardt_anderson_stillwagon_ury_bendor_wright_2018, title={Evaluating the effects of and-use change and future climate change on vulnerability of coastal landscapes to saltwater intrusion}, volume={6}, ISSN={["2325-1026"]}, url={http://www.scopus.com/inward/record.url?eid=2-s2.0-85054817111&partnerID=MN8TOARS}, DOI={10.1525/elementa.316}, abstractNote={The exposure of freshwater-dependent coastal ecosystems to saltwater is a present-day impact of climate and land-use changes in many coastal regions, with the potential to harm freshwater and terrestrial biota, alter biogeochemical cycles and reduce agricultural yields. Land-use activities associated with artificial drainage infrastructure (canals, ditches, and drains) could exacerbate saltwater exposure. However, studies assessing the effects of artificial drainage on the vulnerability of coastal landscapes to saltwater exposure are lacking. We examined the extent to which artificial drainage infrastructure has altered the potential for saltwater intrusion in the coastal plain of eastern North Carolina. Regional spatial analyses demonstrate that artificial drainages not only lower the overall elevation in coastal landscapes, but they also alter the routing and concentration of hydrological flows. Together, these factors have the potential to increase the total proportion of the landscape vulnerable to saltwater intrusion, not only in areas adjacent to drainage infrastructure but also in places where no artificial drainages exist due to large scale effects of flow rerouting. Among all land cover types in eastern North Carolina, wetlands are most vulnerable to saltwater exposure. Droughts and coastal storms associated with climate change potentially exacerbate vulnerability to saltwater facilitated by artificial drainage.}, journal={ELEMENTA-SCIENCE OF THE ANTHROPOCENE}, author={Bhattachan, Abinash and Emanuel, Ryan E. and Ardon, Marcelo and Bernhardt, Emily S. and Anderson, Steven M. and Stillwagon, Matthew G. and Ury, Emily A. and BenDor, Todd K. and Wright, Justin P.}, year={2018}, month={Sep} }
 @article{ardón_helton_bernhardt_2018, title={Salinity effects on greenhouse gas emissions from wetland soils are contingent upon hydrologic setting: a microcosm experiment}, volume={140}, ISSN={0168-2563 1573-515X}, url={http://dx.doi.org/10.1007/s10533-018-0486-2}, DOI={10.1007/s10533-018-0486-2}, number={2}, journal={Biogeochemistry}, publisher={Springer Science and Business Media LLC}, author={Ardón, Marcelo and Helton, Ashley M. and Bernhardt, Emily S.}, year={2018}, month={Aug}, pages={217–232} }
 @article{ardón_helton_scheuerell_bernhardt_2017, title={Fertilizer legacies meet saltwater incursion: challenges and constraints
                        for coastal plain wetland restoration}, volume={5}, ISSN={2325-1026}, url={http://dx.doi.org/10.1525/elementa.236}, DOI={10.1525/elementa.236}, abstractNote={Coastal wetland restoration is an important tool for climate change adaptation and excess nutrient runoff mitigation. However, the capacity of restored coastal wetlands to provide multiple ecosystem services is limited by stressors, such as excess nutrients from upstream agricultural fields, high nutrient legacies on-site, and rising salinities downstream. The effects of these stressors are exacerbated by an accelerating hydrologic cycle, expected to cause longer droughts punctuated by more severe storms. We used seven years of surface water and six years of soil solution water chemistry from a large (440 ha) restored wetland to examine how fertilizer legacy, changes in hydrology, and drought-induced salinization affect dissolved nutrient and carbon concentrations. To better understand the recovery trajectory of the restored wetland, we also sampled an active agricultural field and two mature forested wetlands. Our results show that nitrogen (N) and phosphorus (P) concentrations in soil solution were 2–10 times higher in the restored wetland compared to two mature forested wetlands, presumably due to legacy fertilizer mobilized by reflooding. Despite elevated nutrient concentrations relative to reference wetlands, the restored wetland consistently attenuated N and P pulses delivered from an upstream farm. Even with continued loading, N and P concentrations in surface water throughout the restored wetland have decreased since the initial flooding. Our results suggest that high nutrient concentrations and export from wetlands restored on agricultural lands may be a severe but temporary problem. If field to wetland conversion is to become a more widespread method for ameliorating nutrient runoff and adapting coastal plain ecosystems to climate change, we should adopt new methods for minimizing the initial export phase of wetland restoration efforts.}, number={0}, journal={Elem Sci Anth}, publisher={University of California Press}, author={Ardón, Marcelo and Helton, Ashley M. and Scheuerell, Mark D. and Bernhardt, Emily S.}, editor={Zak, Donald R. and Peralta, Ariane L.Editors}, year={2017}, month={Jul}, pages={41} }
 @article{shah_kominoski_ardon_dodds_gessner_griffiths_hawkins_johnson_lecerf_leroy_et al._2017, title={Global synthesis of the temperature sensitivity of leaf litter breakdown in streams and rivers}, volume={23}, ISSN={["1365-2486"]}, url={http://www.scopus.com/inward/record.url?eid=2-s2.0-85013945742&partnerID=MN8TOARS}, DOI={10.1111/gcb.13609}, abstractNote={Abstract}, number={8}, journal={GLOBAL CHANGE BIOLOGY}, author={Shah, Jennifer J. Follstad and Kominoski, John S. and Ardon, Marcelo and Dodds, Walter K. and Gessner, Mark O. and Griffiths, Natalie A. and Hawkins, Charles P. and Johnson, Sherri L. and Lecerf, Antoine and Leroy, Carri J. and et al.}, year={2017}, month={Aug}, pages={3064–3075} }
 @article{powell_jackson_ardon_2016, title={Disentangling the effects of drought and salinity on growth of bald cypress trees at different life stages}, volume={24}, journal={Restoration Ecology}, author={Powell, A. M. and Jackson, L. and Ardon, M.}, year={2016}, pages={548–557} }
 @article{powell_jackson_ardón_2016, title={Disentangling the effects of drought, salinity, and sulfate on baldcypress growth in a coastal plain restored wetland}, url={http://www.scopus.com/inward/record.url?eid=2-s2.0-84961282442&partnerID=MN8TOARS}, DOI={10.1111/rec.12349}, abstractNote={Because of their dominance in swamps of the southeastern United States, baldcypress (Taxodium distichum) trees are commonly used in wetland restoration. Though baldcypress are known to tolerate moderate flooding and salinity, their growth has been shown to decrease when they experience drought and high salinity. This study examined the effects of drought and elevated salinity on the growth of baldcypress seedlings and saplings. In a restored wetland in North Carolina, we examined the growth of 8‐year‐old baldcypress by measuring height and diameter at breast height (DBH) along salinity, nutrient, and flooding gradients. In a greenhouse, we placed 1‐year‐old baldcypress seedlings in either drought or saturated conditions and applied different water treatments: fresh water, sulfate, and artificial salt water (5 ppt [parts per thousand]). Over 26 weeks, we measured diameter at root collar, height, and biomass. In the field, chloride concentrations in soil solution had a negative effect on DBH and height (51 and 36% decrease, respectively); high water levels had a negative effect on height (47% decrease) and DBH (46% decrease). In the greenhouse, both drought and salinity decreased diameter growth (43 and 61% decline, respectively) and height (64 and 43% decline, respectively). Sulfate did not have a significant effect on diameter growth, but caused a 14% decrease in height. Our results suggest that both drought and salinity (even as low as 1 ppt) can lead to a 20–60% decline in baldcypress growth. Restoration practitioners should consider the negative consequences of both drought and increased salinity on baldcypress growth when planning for wetland restoration.}, journal={Restoration Ecology}, author={Powell, A.S. and Jackson, L. and Ardón, M.}, year={2016} }
 @article{ardon_helton_bernhardt_2016, title={Drought and saltwater incursion synergistically reduce dissolved organic carbon export from coastal freshwater wetlands}, volume={127}, ISSN={["1573-515X"]}, url={http://www.scopus.com/inward/record.url?eid=2-s2.0-84959521459&partnerID=MN8TOARS}, DOI={10.1007/s10533-016-0189-5}, abstractNote={The hydrologic transport of dissolved organic carbon (DOC) represents both a primary energetic loss from and a critical energetic link between ecosystems. Coastal freshwater wetlands serve as a primary source of DOC to estuaries; historically the magnitude and timing of DOC transfers has been driven by water movement. Extensive agricultural development throughout the coastal plain of the southeastern US has hydrologically connected much of the landscape via canals to facilitate drainage. The resulting large-scale loss of topographic relief and reduced mean elevation is interacting with increasingly frequent and severe droughts to facilitate the landward movement of seawater through the highly connected artificial drainage networks. The resulting changes in hydrologic regime and salinity are each expected to reduce DOC export from coastal freshwater wetlands, yet their individual and combined impacts are not well understood. Here we show that repeated saltwater incursion during late summer droughts substantially decreased DOC concentrations in surface water (from ~40 to ~18 mg/L) from a mature and a restored forested wetland in the coastal plain of North Carolina, USA. These declines in DOC concentration reduced annual export of DOC to the estuary by 70 % and dampened storm fluxes by 76 %. We used a long-term experiment with intact soil columns to measure the independent and combined effects of drought, salinity, and sulfate loading as potential drivers of the large changes in DOC concentration. We found that soil drying and salinization each reduced DOC similarly (20 % reduction by drought alone, 29 % by salinization) and their combined effect was additive (49 % reduction in salinization + drought treatments). Our results demonstrate that, well in advance of significant sea-level rise, drought and relatively low levels of saltwater incursion (<6 ppt) are already significantly altering the timing and magnitude of dissolved organic carbon flux between coastal forested wetlands and downstream estuaries.}, number={2-3}, journal={BIOGEOCHEMISTRY}, author={Ardon, Marcelo and Helton, Ashley M. and Bernhardt, Emily S.}, year={2016}, month={Feb}, pages={411–426} }
 @article{small_ardón_duff_jackman_ramírez_triska_pringle_2016, title={Phosphorus retention in a lowland Neotropical stream following an eight-year enrichment experiment}, volume={35}, ISSN={2161-9549 2161-9565}, url={http://dx.doi.org/10.1086/684491}, DOI={10.1086/684491}, abstractNote={Human alteration of the global P cycle has led to widespread P loading in freshwater ecosystems. Much research has been devoted to the capacity of wetlands and lakes to serve as long-term sinks for P inputs from the watershed, but we know much less about the potential of headwater streams to serve in this role. We assessed storage and retention of P in biotic and abiotic compartments after an 8-y experimental P addition to a 1st-order stream in a Neotropical wet forest. Sediment P extractions indicated that nearly all P storage was in the form of Fe- and Al-bound P (∼700 μg P/g dry sediment), similar to nearby naturally high-P streams. At the end of the enrichment, ∼25% of the total P added over the 8-y study was still present in sediments within 200 m of the injection site, consistent with water-column measurements showing sustained levels of high net P uptake throughout the experiment. Sediment P declined to baseline levels (∼100 μg P/g dry sediment) over 4 y after the enrichment ended. Leaf-litter P content increased nearly 2× over background levels during P enrichment and was associated with a 3× increase in microbial respiration rates, although these biotic responses were low compared to nearby naturally high-P streams. Biotic storage accounted for <0.03% of retention of the added P. Our results suggest that the high sorption capacity of these sediments dampened the biotic effects of P loading and altered the timing and quantity of P exported downstream.}, number={1}, journal={Freshwater Science}, publisher={University of Chicago Press}, author={Small, Gaston E. and Ardón, Marcelo and Duff, John H. and Jackman, Alan P. and Ramírez, Alonso and Triska, Frank J. and Pringle, Catherine M.}, year={2016}, month={Mar}, pages={1–11} }
 @inbook{pringle_anderson_ardón_bixby_connelly_duff_jackman_paaby_ramírez_small_et al._2016, place={Chicago, IL}, title={Rivers of Costa Rica}, ISBN={9780226278933 9780226121505 9780226121642}, url={http://dx.doi.org/10.7208/chicago/9780226121642.003.0018}, DOI={10.7208/chicago/9780226121642.003.0018}, booktitle={Costa Rican Ecosystems}, publisher={University of Chicago Press}, author={Pringle, Catherine M. and Anderson, Elizabeth P. and Ardón, Marcelo and Bixby, Rebecca J. and Connelly, Scott and Duff, John H. and Jackman, Alan P. and Paaby, Pia and Ramírez, Alonso and Small, Gaston E. and et al.}, editor={Kappelle, M.Editor}, year={2016}, month={Feb}, pages={621–655} }
 @article{herbert_boon_burgin_neubauer_franklin_ardon_hopfensperger_lamers_gell_langley_2015, title={A global perspective on wetland salinization: ecological consequences of a growing threat to freshwater wetlands}, volume={6}, ISSN={2150-8925}, url={http://dx.doi.org/10.1890/ES14-00534.1}, DOI={10.1890/ES14-00534.1}, abstractNote={Salinization, a widespread threat to the structure and ecological functioning of inland and coastal wetlands, is currently occurring at an unprecedented rate and geographic scale. The causes of salinization are diverse and include alterations to freshwater flows, land‐clearance, irrigation, disposal of wastewater effluent, sea level rise, storm surges, and applications of de‐icing salts. Climate change and anthropogenic modifications to the hydrologic cycle are expected to further increase the extent and severity of wetland salinization. Salinization alters the fundamental physicochemical nature of the soil‐water environment, increasing ionic concentrations and altering chemical equilibria and mineral solubility. Increased concentrations of solutes, especially sulfate, alter the biogeochemical cycling of major elements including carbon, nitrogen, phosphorus, sulfur, iron, and silica. The effects of salinization on wetland biogeochemistry typically include decreased inorganic nitrogen removal (with implications for water quality and climate regulation), decreased carbon storage (with implications for climate regulation and wetland accretion), and increased generation of toxic sulfides (with implications for nutrient cycling and the health/functioning of wetland biota). Indeed, increased salt and sulfide concentrations induce physiological stress in wetland biota and ultimately can result in large shifts in wetland communities and their associated ecosystem functions. The productivity and composition of freshwater species assemblages will be highly altered, and there is a high potential for the disruption of existing interspecific interactions. Although there is a wealth of information on how salinization impacts individual ecosystem components, relatively few studies have addressed the complex and often non‐linear feedbacks that determine ecosystem‐scale responses or considered how wetland salinization will affect landscape‐level processes. Although the salinization of wetlands may be unavoidable in many cases, these systems may also prove to be a fertile testing ground for broader ecological theories including (but not limited to): investigations into alternative stable states and tipping points, trophic cascades, disturbance‐recovery processes, and the role of historical events and landscape context in driving community response to disturbance.}, number={10}, journal={Ecosphere}, publisher={Wiley}, author={Herbert, E.R. and Boon, P. and Burgin, A.J. and Neubauer, S.C. and Franklin, R.B. and Ardon, M. and Hopfensperger, K.N. and Lamers, L.P.M. and Gell, P. and Langley, J.A.}, year={2015}, month={Oct}, pages={art206} }
 @article{ganong_small_ardón_mcdowell_genereux_duff_pringle_2015, title={Interbasin flow of geothermally modified ground water stabilizes stream exports of biologically important solutes against variation in precipitation}, volume={34}, ISSN={2161-9549 2161-9565}, url={http://dx.doi.org/10.1086/679739}, DOI={10.1086/679739}, abstractNote={Geothermally modified ground water (GMG) in tectonically active areas can be an important source of stream nutrients, and the relative importance of GMG inflows is likely to change with shifts in precipitation that are predicted to occur in response to climate change. However, few studies have quantified the influence of GMG inflows on export of biologically important solutes from watersheds across years differing in precipitation. We quantified N, soluble reactive P (SRP), and dissolved organic C (DOC) export during a year with high precipitation (6550 mm rain) and a year with average precipitation (4033 mm rain) in 2 gauged tropical streams at La Selva Biological Station in lowland Costa Rica. One stream receives extensive inputs of regional GMG, whereas the other is fed entirely by local runoff. In the stream fed only by local runoff, a 62% increase in precipitation from the dry year to the wet year led to a 68% increase in stream discharge, a 67% increase in export of SRP, DOC, dissolved organic N (DON), and NH4+, and a 91% increase in NO3– export. In contrast, in an adjacent stream where >⅓ of discharge consists of GMG, the same increase in precipitation from dry year to wet year led to a 14% increase in discharge, a 14 to 31% increase in export of NO3–, NH4+, DON, and DOC, and only a 2% increase in SRP export. We are unaware of an SRP export rate from a natural system that is higher than the export from the stream receiving interbasin flow of GMG (19 kg ha–1 y–1). Our results illustrate that regional ground water, geothermally modified or not, can stabilize stream export of biologically relevant solutes and water across a varying precipitation regime.}, number={1}, journal={Freshwater Science}, publisher={University of Chicago Press}, author={Ganong, Carissa N. and Small, Gaston E. and Ardón, Marcelo and McDowell, William H. and Genereux, David P. and Duff, John H. and Pringle, Catherine M.}, year={2015}, month={Mar}, pages={276–286} }
 @article{helton_ardón_bernhardt_2015, title={Thermodynamic constraints on the utility of ecological stoichiometry for explaining global biogeochemical patterns}, volume={18}, url={http://www.scopus.com/inward/record.url?eid=2-s2.0-84941022537&partnerID=MN8TOARS}, DOI={10.1111/ele.12487}, abstractNote={Abstract}, number={10}, journal={Ecology Letters}, author={Helton, A.M. and Ardón, M. and Bernhardt, E.S.}, year={2015}, pages={1049–1056} }
 @article{ramírez_ardón_m. douglas_a. s. graça_2015, title={Tropical freshwater sciences: an overview of ongoing tropical research}, volume={34}, ISSN={2161-9549 2161-9565}, url={http://dx.doi.org/10.1086/681257}, DOI={10.1086/681257}, abstractNote={Alonso Ramirez, Marcelo Ardon, Michael Douglas, and Manuel Graca Department of Environmental Science, University of Puerto Rico, Rio Piedras campus, San Juan, Puerto Rico 00919 USA Department of Biology and North Carolina Center for Biodiversity, East Carolina University, Greenville, North Carolina 27858 USA Research Institute for the Environment and Livelihoods, Charles Darwin University, Darwin, Northern Territories 0909 Australia MARE – Marine and Environmental Sciences Centre, Department of Life Sciences, University of Coimbra, Largo Marques de Pombal, Coimbra, Portugal}, number={2}, journal={Freshwater Science}, publisher={University of Chicago Press}, author={Ramírez, Alonso and Ardón, Marcelo and M. Douglas, Michael and A. S. Graça, Manuel}, year={2015}, month={Jun}, pages={606–608} }
 @article{ardón_morse_colman_bernhardt_2013, title={Drought-induced saltwater incursion leads to increased wetland nitrogen export}, volume={19}, url={http://www.scopus.com/inward/record.url?eid=2-s2.0-84883556749&partnerID=MN8TOARS}, DOI={10.1111/gcb.12287}, abstractNote={Abstract}, number={10}, journal={Global Change Biology}, author={Ardón, M. and Morse, J.L. and Colman, B.P. and Bernhardt, E.S.}, year={2013}, pages={2976–2985} }
 @article{ardón_duff_ramírez_small_jackman_triska_pringle_2013, title={Experimental acidification of two biogeochemically-distinct neotropical streams: Buffering mechanisms and macroinvertebrate drift}, volume={443}, ISSN={0048-9697}, url={http://dx.doi.org/10.1016/j.scitotenv.2012.10.068}, DOI={10.1016/j.scitotenv.2012.10.068}, abstractNote={Research into the buffering mechanisms and ecological consequences of acidification in tropical streams is lacking. We have documented seasonal and episodic acidification events in streams draining La Selva Biological Station, Costa Rica. Across this forested landscape, the severity in seasonal and episodic acidification events varies due to interbasin groundwater flow (IGF). Streams that receive IGF have higher concentrations of solutes and more stable pH (~6) than streams that do not receive IGF (pH ~5). To examine the buffering capacity and vulnerability of macroinvertebrates to short-term acidification events, we added hydrochloric acid to acidify a low-solute, poorly buffered (without IGF) and a high-solute, well buffered stream (with IGF). We hypothesized that: 1) protonation of bicarbonate (HCO(3)(-)) would neutralize most of the acid added in the high-solute stream, while base cation release from the sediments would be the most important buffering mechanism in the low-solute stream; 2) pH declines would mobilize inorganic aluminum (Ali) from sediments in both streams; and 3) pH declines would increase macroinvertebrate drift in both streams. We found that the high-solute stream neutralized 745 μeq/L (96% of the acid added), while the solute poor stream only neutralized 27.4 μeq/L (40%). Protonation of HCO(3)(-) was an important buffering mechanism in both streams. Base cation, Fe(2+), and Ali release from sediments and protonation of organic acids also provided buffering in the low-solute stream. We measured low concentrations of Ali release in both streams (2-9 μeq/L) in response to acidification, but the low-solute stream released double the amount Ali per 100 μeq of acid added than the high solute stream. Macroinvertebrate drift increased in both streams in response to acidification and was dominated by Ephemeroptera and Chironomidae. Our results elucidate the different buffering mechanisms in tropical streams and suggest that low-solute poorly buffered streams might be particularly vulnerable to episodic acidification.}, journal={Science of The Total Environment}, publisher={Elsevier BV}, author={Ardón, Marcelo and Duff, John H. and Ramírez, Alonso and Small, Gaston E. and Jackman, Alan P. and Triska, Frank J. and Pringle, Catherine M.}, year={2013}, month={Jan}, pages={267–277} }
 @article{morse_ardón_bernhardt_2012, title={Greenhouse gas fluxes in southeastern U.S. coastal plain wetlands under contrasting land uses}, volume={22}, url={http://www.scopus.com/inward/record.url?eid=2-s2.0-84858669656&partnerID=MN8TOARS}, DOI={10.1890/11-0527.1}, abstractNote={Whether through sea level rise or wetland restoration, agricultural soils in coastal areas will be inundated at increasing rates, renewing connections to sensitive surface waters and raising critical questions about environmental trade‐offs. Wetland restoration is often implemented in agricultural catchments to improve water quality through nutrient removal. Yet flooding of soils can also increase production of the greenhouse gases nitrous oxide and methane, representing a potential environmental trade‐off. Our study aimed to quantify and compare greenhouse gas emissions from unmanaged and restored forested wetlands, as well as actively managed agricultural fields within the North Carolina coastal plain, USA. In sampling conducted once every two months over a two‐year comparative study, we found that soil carbon dioxide flux (range: 8000–64 800 kg CO2·ha−1·yr−1) comprised 66–100% of total greenhouse gas emissions from all sites and that methane emissions (range: −6.87 to 197 kg CH4·ha−1·yr−1) were highest from permanently inundated sites, while nitrous oxide fluxes (range: −1.07 to 139 kg N2O·ha−1·yr−1) were highest in sites with lower water tables. Contrary to predictions, greenhouse gas fluxes (as CO2 equivalents) from the restored wetland were lower than from either agricultural fields or unmanaged forested wetlands. In these acidic coastal freshwater ecosystems, the conversion of agricultural fields to flooded young forested wetlands did not result in increases in greenhouse gas emissions.}, number={1}, journal={Ecological Applications}, author={Morse, J.L. and Ardón, M. and Bernhardt, E.S.}, year={2012}, pages={264–280} }
 @article{ulloa_anderson_ardón_murcia_valenzuela_2012, title={Organic matter characterization and decomposition dynamics in sub-Antarctic streams impacted by invasive beavers,Caracterización de la materia orgánica y la dinámica de descomposición en arroyos subantárticos impactados por castores invasores}, volume={40}, url={http://www.scopus.com/inward/record.url?eid=2-s2.0-84876232214&partnerID=MN8TOARS}, DOI={10.3856/vol40-issue4-fulltext-6}, abstractNote={Despite being a relatively remote and well conserved area, the sub-Antarctic ecoregion faces pressing global threats from climate change, the ozone hole and introduced species. Its freshwater ecosystems are one of the least studied components of this biome, but they are known to confront a host of invasive taxa including trout and beavers. We set out to understand the basic characterization and dynamics of organic matter processing and decomposition in sub-Antarctic streams under natural forest (NF) conditions and in ponds constructed by North American beavers (Castor canadensis) (BP). We found these streams have a naturally stable benthic organic matter regime throughout the year with a peak in leaf input from Nothofagus pumilio in autumn. Beaver ponds significantly increased the retention of organic matter and caused significantly higher decomposition rates, probably associated with increased density and biomass of Hyalella spp. As expected, leaf decay rates for N. pumilio, a deciduous species, were higher (NF: -0.0028 day -1 ±}, number={4}, journal={Latin American Journal of Aquatic Research}, author={Ulloa, E. and Anderson, C.B. and Ardón, M. and Murcia, S. and Valenzuela, A.E.J.}, year={2012}, pages={881–892} }
 @article{small_ardón_jackman_duff_triska_ramírez_snyder_pringle_2012, title={Rainfall-Driven Amplification of Seasonal Acidification in Poorly Buffered Tropical Streams}, volume={15}, ISSN={1432-9840 1435-0629}, url={http://dx.doi.org/10.1007/s10021-012-9559-6}, DOI={10.1007/s10021-012-9559-6}, number={6}, journal={Ecosystems}, publisher={Springer Science and Business Media LLC}, author={Small, Gaston E. and Ardón, Marcelo and Jackman, Alan P. and Duff, John H. and Triska, Frank J. and Ramírez, Alonso and Snyder, Marcía and Pringle, Catherine M.}, year={2012}, month={Jun}, pages={974–985} }
 @article{morse_ardón_bernhardt_2012, title={Using environmental variables and soil processes to forecast denitrification potential and nitrous oxide fluxes in coastal plain wetlands across different land uses}, volume={117}, ISSN={0148-0227}, url={http://dx.doi.org/10.1029/2011JG001923}, DOI={10.1029/2011JG001923}, abstractNote={We examined relationships between denitrification (DNF) and nitrous oxide (N2O) fluxes and potentially important chemical and physical predictors to build a predictive understanding of gaseous N losses from coastal plain wetlands. We collected soil, gas, and pore water samples from 48 sampling locations across a large (440 ha) restored wetland, an adjacent drained agricultural field, and nearby forested wetlands every two months over two years. In summer and fall 2007, we measured soil DNF potential (21.6–3560 mg N m−3 d−1) and N2O efflux (−4.36–8.81 mg N m−2 d−1), along with 17 predictor variables. We developed statistical models for the most comprehensive subset of the data set (fall 2007) and used another subset (summer 2007) for cross‐validation. Soil pH and total soil nitrogen were the best predictors of DNF potential (Radj2 = 0.68). A regression using carbon dioxide flux and soil temperature together with soil extractable NH4+ and DNF potential explained 85% of the variation in fall N2O fluxes. The model for DNF performed reasonably well when cross‐validated with summer data (R2 = 0.40), while the N2O model did not predict summer N2O fluxes (R2 < 0.1). Poor model performance was likely due to nonlinear responses to high temperatures and/or higher and more variable root respiration by plants during the growing season, leading to overprediction of N2O flux. Our results suggest that soil DNF potential may be modeled fairly effectively from a small number of soil parameters, that DNF potential is uncorrelated with N2O effluxes, and that successful estimation of wetland N2O effluxes will require finer‐scale models that incorporate seasonal dynamics.}, number={G2}, journal={Journal of Geophysical Research: Biogeosciences}, publisher={American Geophysical Union (AGU)}, author={Morse, Jennifer L. and Ardón, Marcelo and Bernhardt, Emily S.}, year={2012}, month={Jun}, pages={n/a-n/a} }
 @article{ardón_montanari_morse_doyle_bernhardt_2010, title={Phosphorus export from a restored wetland ecosystem in response to natural and experimental hydrologic fluctuations}, volume={115}, ISSN={0148-0227}, url={http://dx.doi.org/10.1029/2009jg001169}, DOI={10.1029/2009JG001169}, abstractNote={Wetland restoration is a commonly used approach to reduce nutrient loading to freshwater and coastal ecosystems, with many wetland restoration efforts occurring in former agricultural fields. Restored wetlands are expected to be effective at retaining or removing both nitrogen and phosphorus (P), yet restoring wetland hydrology to former agricultural fields can lead to the release of legacy fertilizer P. Here, we examined P cycling and export following rewetting of the Timberlake Restoration Project, a 440 ha restored riverine wetland complex in the coastal plain of North Carolina. We also compared P cycling within the restored wetland to two minimally disturbed nearby wetlands and an adjacent active agricultural field. In the restored wetland we observed increased soluble reactive phosphorus (SRP) concentrations following initial flooding, consistent with our expectations that P bound to iron would be released under reducing conditions. SRP concentrations in spring were 2.5 times higher leaving the restored wetland than a forested wetland and an agricultural field. During two large‐scale drawdown and rewetting experiments we decreased the water depth by 1 m in ∼10 ha of inundated wetland for 2 weeks, followed by reflooding. Rewetting following experimental drainage had no effect on SRP concentrations in winter, but SRP concentrations did increase when the experiment was repeated during summer. Our best estimates suggest that this restored wetland could release legacy fertilizer P for up to a decade following hydrologic restoration. The time lag between restoration and biogeochemical recovery should be incorporated into management strategies of restored wetlands.}, number={G4}, journal={Journal of Geophysical Research}, publisher={American Geophysical Union (AGU)}, author={Ardón, Marcelo and Montanari, Shaena and Morse, Jennifer L. and Doyle, Martin W. and Bernhardt, Emily S.}, year={2010}, month={Dec} }
 @article{bernhardt_ardón_morse_2010, title={Research reveals negative consequences of flooding former agricultural fields for wetlands restoration}, url={http://www.scopus.com/inward/record.url?eid=2-s2.0-78650385395&partnerID=MN8TOARS}, number={372}, journal={Water Resources Research Institute News of the University of North Carolina}, author={Bernhardt, E.S. and Ardón, M. and Morse, J.}, year={2010} }
 @article{ardón_morse_doyle_bernhardt_2010, title={The Water Quality Consequences of Restoring Wetland Hydrology to a Large Agricultural Watershed in the Southeastern Coastal Plain}, volume={13}, url={http://www.scopus.com/inward/record.url?eid=2-s2.0-77957755741&partnerID=MN8TOARS}, DOI={10.1007/s10021-010-9374-x}, number={7}, journal={Ecosystems}, author={Ardón, M. and Morse, J.L. and Doyle, M.W. and Bernhardt, E.S.}, year={2010}, pages={1060–1078} }
 @article{ardón_pringle_eggert_2009, title={Does leaf chemistry differentially affect breakdown in tropical vs temperate streams? Importance of standardized analytical techniques to measure leaf chemistry}, volume={28}, url={http://www.scopus.com/inward/record.url?eid=2-s2.0-67650911687&partnerID=MN8TOARS}, DOI={10.1899/07-083.1}, abstractNote={Abstract Comparisons of the effects of leaf litter chemistry on leaf breakdown rates in tropical vs temperate streams are hindered by incompatibility among studies and across sites of analytical methods used to measure leaf chemistry. We used standardized analytical techniques to measure chemistry and breakdown rate of leaves from common riparian tree species at 2 sites, 1 tropical and 1 temperate, where a relatively large amount of information is available on litter chemistry and breakdown rates in streams (La Selva Biological Station, Costa Rica, and Coweeta Hydrologic Laboratory, North Carolina, USA). We selected 8 common riparian tree species from La Selva and 7 from Coweeta that spanned the range of chemistries of leaf litter naturally entering streams at each site. We predicted that concentrations of secondary compounds would be higher in the tropical species than in the temperate species and that high concentrations of condensed tannins would decrease breakdown rates in both sites. Contrary to our predictions, mean concentration of condensed tannins was significantly greater (2.6×, p < 0.001) for species at Coweeta than for species at La Selva. Concentration of condensed tannins was negatively correlated with breakdown rate among Coweeta species (r = −0.80), not among La Selva species, and negatively correlated when the 2 sites were combined (r = −0.53). Concentrations of structural compounds were strongly correlated with breakdown rate at both sites (Coweeta species, lignin r = −0.94, cellulose r = −0.77; La Selva species, cellulose r = −0.78, C r = −0.73). The chemistries of 8 riparian species from La Selva and 7 riparian species from Coweeta were not as different as expected. Our results underline the importance of standardized analytical techniques when making cross-site comparisons of leaf chemistry.}, number={2}, journal={Journal of the North American Benthological Society}, author={Ardón, M. and Pringle, C.M. and Eggert, S.L.}, year={2009}, pages={440–453} }
 @misc{ardón_bernhardt_2009, title={Restoring Rivers and Streams}, ISBN={0470016175 9780470016176 047001590X 9780470015902}, url={http://dx.doi.org/10.1002/9780470015902.a0020148}, DOI={10.1002/9780470015902.a0020148}, abstractNote={Abstract}, journal={Encyclopedia of Life Sciences}, publisher={John Wiley & Sons, Ltd}, author={Ardón, Marcelo and Bernhardt, Emily S}, year={2009}, month={Mar} }
 @article{ardón_pringle_2008, title={Do secondary compounds inhibit microbial- and insect-mediated leaf breakdown in a tropical rainforest stream, Costa Rica?}, volume={155}, url={http://www.scopus.com/inward/record.url?eid=2-s2.0-39249084360&partnerID=MN8TOARS}, DOI={10.1007/s00442-007-0913-x}, abstractNote={We examined the hypothesis that high concentrations of secondary compounds in leaf litter of some tropical riparian tree species decrease leaf breakdown by inhibiting microbial and insect colonization. We measured leaf breakdown rates, chemical changes, bacterial, fungal, and insect biomass on litterbags of eight species of common riparian trees incubated in a lowland stream in Costa Rica. The eight species spanned a wide range of litter quality due to varying concentrations of nutrients, structural and secondary compounds. Leaf breakdown rates were fast, ranging from 0.198 d(-1 )(Trema integerrima) to 0.011 d(-1) (Zygia longifolia). Processing of individual chemical constituents was also rapid: cellulose was processed threefold faster and hemicellulose was processed fourfold faster compared to similar studies in temperate streams. Leaf toughness (r = -0.86, P = 0.01) and cellulose (r = -0.78, P = 0.02) were the physicochemical parameters most strongly correlated with breakdown rate. Contrary to our initial hypothesis, secondary compounds were rapidly leached (threefold faster than in temperate studies), with all species losing all secondary compounds within the first week of incubation. Cellulose was more important than secondary compounds in inhibiting breakdown. Levels of fungal and bacterial biomass were strongly correlated with breakdown rate (fungi r = 0.64, P = 0.05; bacteria r = 0.93, P < 0.001) and changes in structural compounds (lignin r = -0.55, P = 0.01). Collector-gatherers were the dominant functional group of insects colonizing litterbags, in contrast to temperate studies where insect shredders dominate. Insect biomass was negatively correlated with breakdown rate (r = -0.70, P = 0.02), suggesting that insects did not play an important role in breakdown. Despite a wide range of initial concentrations of secondary compounds among the eight species used, we found that secondary compounds were rapidly leached and were less important than structural compounds in determining breakdown rates.}, number={2}, journal={Oecologia}, author={Ardón, M. and Pringle, C.M.}, year={2008}, pages={311–323} }
 @article{small_pringle_triska_duff_jackman_hidalgo_ramírez_ardón_2008, title={The dynamics of phosphorus retention during an eight-year P-addition in a Neotropical headwater stream}, volume={30}, ISSN={0368-0770}, url={http://dx.doi.org/10.1080/03680770.2008.11902187}, DOI={10.1080/03680770.2008.11902187}, abstractNote={Understanding the capacity of stream ecosystems to retain nutrients through physical-chemical processes and biotic assimilation has been a central goal of stream ecologists for decades. Currently, most of our understanding of nutrient saturation is based on short-term (<1 day) nutrient addition experiments, while predicting total stream ecosystem response to long-term anthropogenic nutrient loading requires considering the stream’s capacity to remove nutrients over extended periods. Dissolved phosphorus (P) retention results from a combination of biotic and abiotic mechanisms, which could follow different trajectories through time. Short-term biotic P uptake by algae and heterotrophic microbes typically involves direct assimilation from the water column and is saturated at low background soluble reactive phosphorus (SRP) levels (MULHOLLAND et al. 1990). However, during long-term P-loading, the biotic community could also respond by increasing biomass (PETERSON et al. 1985, SLAVIK et al. 2004, but see GREENWOOD & ROSEMOND 2005), temporarily increasing the community’s P-retention capacity. Abiotic P-sorption is an equilibrium process controlled by the relative concentrations of sorbed-P and dissolved-P, although it also depends on sediment size, iron, aluminum, organic content, and pH (MEYER 1979). During long-term P-loading, sediment should become increasingly P-saturated, decreasing abiotic retention. Because biotic and abiotic P-uptake mechanisms could have opposite responses to long-term Ploading, the relative importance of each mechanism will control a stream’s retention capacity over time. Specifically, where P-uptake is dominated by biotic pathways, streams could become temporarily more efficient at removing dissolved-P, whereas where P-uptake is primarily abiotic, streams potentially become less efficient. Here we present data from an 8-year experimental P-addition in a first-order stream, the Carapa, at La Selva Biological Station, Costa Rica. Previous experiments of P-dynamics in the Rio Salto at La Selva indicate that most uptake of P due to the input of naturally P-enriched regional groundwater is due to abiotic sorption (TRISKA et al. 2006). Biweekly measurements of dissolved P concentration upstream and at 3 downstream stations during the long-term P-injection in the Carapa allowed us to calculate P-uptake rates over the 8-year study. Assuming a dominance of abiotic control, we predicted that sediments would become saturated over time, decreasing Puptake efficiency.}, number={4}, journal={SIL Proceedings, 1922-2010}, publisher={Informa UK Limited}, author={Small, Gaston E. and Pringle, Catherine M. and Triska, Frank J. and Duff, John H. and Jackman, Alan P. and Hidalgo, Minor and Ramírez, Alonso and Ardón, Marcelo}, year={2008}, month={Jan}, pages={551–554} }
 @article{ardón_pringle_2007, title={The quality of organic matter mediates the response of heterotrophic biofilms to phosphorus enrichment of the water column and substratum}, volume={52}, url={http://www.scopus.com/inward/record.url?eid=2-s2.0-34547773582&partnerID=MN8TOARS}, DOI={10.1111/j.1365-2427.2007.01807.x}, abstractNote={Summary}, number={9}, journal={Freshwater Biology}, author={Ardón, M. and Pringle, C.M.}, year={2007}, pages={1762–1772} }
 @article{ardón_stallcup_pringle_2006, title={Does leaf quality mediate the stimulation of leaf breakdown by phosphorus in Neotropical streams?}, volume={51}, url={http://www.scopus.com/inward/record.url?eid=2-s2.0-33645109287&partnerID=MN8TOARS}, DOI={10.1111/j.1365-2427.2006.01515.x}, abstractNote={Summary}, number={4}, journal={Freshwater Biology}, author={Ardón, M. and Stallcup, L.A. and Pringle, C.M.}, year={2006}, pages={618–633} }
 @article{stallcup_ardón_pringle_2006, title={Does nitrogen become limiting under high-P conditions in detritus-based tropical streams?}, volume={51}, url={http://www.scopus.com/inward/record.url?eid=2-s2.0-33746265510&partnerID=MN8TOARS}, DOI={10.1111/j.1365-2427.2006.01588.x}, abstractNote={Summary}, number={8}, journal={Freshwater Biology}, author={Stallcup, L.A. and Ardón, M. and Pringle, C.M.}, year={2006}, pages={1515–1526} }
 @article{ardón_stallcup_pringle_2006, title={Erratum: Does leaf quality mediate the stimulation of leaf breakdown by phosphorus in Neotropical streams? (Freshwater Biology (2006) 51, (618-633))}, volume={51}, url={http://www.scopus.com/inward/record.url?eid=2-s2.0-33645862269&partnerID=MN8TOARS}, DOI={10.1111/j.1365-2427.2006.01553.x}, abstractNote={Freshwater BiologyVolume 51, Issue 5 p. 983-983 Free Access Erratum First published: 24 March 2006 https://doi.org/10.1111/j.1365-2427.2006.01553.xAboutSectionsPDF ToolsRequest permissionExport citationAdd to favoritesTrack citation ShareShare Give accessShare full text accessShare full-text accessPlease review our Terms and Conditions of Use and check box below to share full-text version of article.I have read and accept the Wiley Online Library Terms and Conditions of UseShareable LinkUse the link below to share a full-text version of this article with your friends and colleagues. Learn more.Copy URL Share a linkShare onFacebookTwitterLinked InRedditWechat Figure 6 published in Ardón et al. (2006) has been incorrectly laid out. The panels have been set in the wrong order. The correct figure is published below. The publisher would like to apologise for this error. Figure 6Open in figure viewerPowerPoint Leaf nutrient content during breakdown of three species of leaves incubated in six streams in La Selva Biological Station. Percent nitrogen in: (a) Trema, (b) Castilla and (c) Zygia over time. Percent phosphorus in: (d)Trema, (e) Castilla and (f) Zygia over time. Note the different scale on the X axis for (a) & (d) Trema. Reference Ardón M., Stallcup L.A. & Pringle, C.M. (2006) Does leaf quality mediate the stimulation of leaf breakdown by phosphorus in Neotropical streams? Freshwater Biology, 51, 618– 633. Wiley Online LibraryCASWeb of Science®Google Scholar Volume51, Issue5May 2006Pages 983-983 FiguresReferencesRelatedInformation}, number={5}, journal={Freshwater Biology}, author={Ardón, M. and Stallcup, L.A. and Pringle, C.M.}, year={2006} }
 @article{triska_pringle_duff_avanzino_ramirez_ardon_jackman_2006, title={Soluble Reactive Phosphorus Transport and Retention in Tropical, Rainforest Streams Draining a Volcanic and Geothermally Active Landscape in Costa Rica. : Long-Term Concentration Patterns, Pore Water Environment and Response to ENSO Events}, volume={81}, ISSN={0168-2563 1573-515X}, url={http://dx.doi.org/10.1007/s10533-006-9026-6}, DOI={10.1007/s10533-006-9026-6}, number={2}, journal={Biogeochemistry}, publisher={Springer Science and Business Media LLC}, author={Triska, Frank J. and Pringle, Catherine M. and Duff, John H. and Avanzino, Ronald J. and Ramirez, Alonso and Ardon, Marcelo and Jackman, Alan P.}, year={2006}, month={Jun}, pages={131–143} }
 @article{orians_ardón_mohammad_2002, title={Vascular architecture and patchy nutrient availability generate within-plant heterogeneity in plant traits important to herbivores}, volume={89}, url={http://www.scopus.com/inward/record.url?eid=2-s2.0-0036191885&partnerID=MN8TOARS}, number={2}, journal={American Journal of Botany}, author={Orians, C.M. and Ardón, M. and Mohammad, B.A.}, year={2002}, pages={270–278} }