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Porewater chemistry measurements from the GCE-LTER Seawater Addition Long-Term Experiment (SALTEx) from July 2017 through July 2019.
The Georgia Coastal Ecosystems LTER Seawater Addition Long-Term Experiment (SALTEx) is a large-scale field experiment designed to simulate saltwater intrusion in a tidal freshwater wetland to predict how chronic (Press) and acute (Pulse) salinization will affect this and other tidal freshwater ecosystems. The SALTEx experiment was initiated in 2012 and consists of 31 field plots, each 2.5 m on a side. There are three treatments (Press, Pulse, and Fresh) and two types of controls (with and without sides), each consisting of six replicates. The Press treatment plots receive regular (4 times each week) additions of a mixture of seawater and fresh river water. Pulse plots receive the same mixture of seawater and river water during September and October, which is historically a time of low flow in the river when natural saltwater intrusion occurs. The Fresh treatment plots receive regular additions of fresh river water. Treatment water is added during low tide to facilitate its infiltration into the soil, and all plots are inundated by astronomical tides at high tide. Response measurements include porewater chemistry, specifically concentrations of chloride, sulfate, sulfide, dissolved organic carbon (DOC), ammonium-N, nitrate/nitrite-N, dissolved reactive phosphorus, total phosphorus, total nitrogen, organic nitrogen, carbon:nitrogen (C:N) ratio, organic-carbon:organic-nitrogen ratio, and pH. Samples of source water were taken after collection (seawater, river water) or mixing (mixed seawater and river water in tanks) and analyzed for concentrations of dissolved reactive phosphorus, total phosphorus, ammonium-N, nitrate/nitrite-N, total nitrogen, organic nitrogen. Source water samples from 2016 and beyond also included measurements of dissolved organic carbon (DOC), carbon:nitrogen ratio, organic-carbon:organic-nitrogen ratio, chloride and sulfate.
Longitudinal Stream Chemistry at the Hubbard Brook Experimental Forest, Watershed 6, 1982 - ongoing
Longitudinal variation in streamwater chemistry has been measured in two watersheds (W1 and W6) at the Hubbard Brook Experimental Forest. This dataset includes samples that have been collected approximately monthly in Watershed 6 at six sampling locations (1982 - present) along an elevational gradient. Samples are analyzed for pH, ANC, anions, cations, nitrogen, dissolved inorganic and organic carbon. These data were gathered as part of the Hubbard Brook Ecosystem Study (HBES). The HBES is a collaborative effort at the Hubbard Brook Experimental Forest, which is operated and maintained by the USDA Forest Service, Northern Research Station.
Chemistry of freely-draining soil solutions at the Hubbard Brook Experimental Forest, Watershed 1, 1996 - present
Tension-free lysimeters were installed in three soil horizons at 13 locations within Hubbard Brook Experimental Forest Watershed 1, representing the variation in elevation and forest type of the watershed. At each location lysimeters were placed beneath the Oa horizon and within the upper and lower B horizon. Soil solution samples were collected approximately monthly and analyzed for pH, acid neutralizing capacity (ANC), base cations, soluble anions, trace metals, nitrogen and carbon. These data were gathered as part of the Hubbard Brook Ecosystem Study (HBES). The HBES is a collaborative effort at the Hubbard Brook Experimental Forest, which is operated and maintained by the USDA Forest Service, Northern Research Station.
Longitudinal Stream Chemistry at the Hubbard Brook Experimental Forest, Watershed 1, 1991 - ongoing
Longitudinal variation in streamwater chemistry has been measured in two watersheds (W1 and W6) at the Hubbard Brook Experimental Forest. This dataset includes samples that have been collected approximately monthly in Watershed 1 at five sampling locations (1991 - ongoing) along an elevational gradient. Samples are analyzed for pH, ANC, anions, cations, nitrogen, dissolved inorganic and organic carbon. These data were gathered as part of the Hubbard Brook Ecosystem Study (HBES). The HBES is a collaborative effort at the Hubbard Brook Experimental Forest, which is operated and maintained by the USDA Forest Service, Northern Research Station.
Mass and Chemistry of Organic Horizons and Surface Mineral Soils on Watershed 6 at the Hubbard Brook Experimental Forest, 1976 - present
The forest floor of Watershed 6 was first sampled in 1969-70. These data include forest floor thickness, soil mass, organic matter content, and major-element composition for samples collected since 1976. Watershed 6 has been resampled at intervals varying from one to ten years. Sampling at five to ten year intervals is expected to continue. These data were gathered as part of the Hubbard Brook Ecosystem Study (HBES). The HBES is a collaborative effort at the Hubbard Brook Experimental Forest, which is operated and maintained by the USDA Forest Service, Northern Research Station.
Mass and Chemistry of Organic Horizons and Surface Mineral Soils on Watershed 1 at the Hubbard Brook Experimental Forest 1996-present
This data set includes chemistry of O-horizons ("forest floor") and the 0-10 cm mineral soil layer in Watershed 1 at Hubbard Book. Calcium in the form of wollastonite (CaSiO3) was added to Watershed 1 in October 1999. The application rate was 1028 kg Ca per ha, and the application was relatively uniform across the watershed. Pre-treatment forest floor surveys were completed in 1996 and 1998. The first post-treatment forest floor survey was completed in 2000. This data set includes mass and thickness data for the sampled layers. Chemical data include concentrations and pools of organic matter, C, N, Ca, Mg, K, P, Mn, Fe, Al, Cu, Pb, and Zn. Soil pH and exchangeable Al, Ca, Mg, K, and H are also included. Sampling is intended to continue at 4 or 5 year intervals. These data were gathered as part of the Hubbard Brook Ecosystem Study (HBES). The HBES is a collaborative effort at the Hubbard Brook Experimental Forest, which is operated and maintained by the USDA Forest Service, Northern Research Station.
Continuous precipitation and stream chemistry data, Hubbard Brook Ecosystem Study, 1963 – ongoing.
The Hubbard Brook Watershed Stream and Precipitation Chemistry Record is a dataset of chemical concentration data for precipitation and streamwater samples that have been collected weekly since the summer of 1963 from streams and precipitation gauges throughout the Hubbard Brook Experimental Forest, a research forest in the White Mountains of New Hampshire. HBWatER currently collects weekly samples from nine gauged watersheds, the mainstem of the Hubbard Brook into which each small stream drains, and two long-term precipitation collection sites. HBWatER was begun in the 1960's by Gene E. Likens, F. Herbert Bormann, Robert S. Pierce, and Noye M. Johnson who began collecting and analyzing stream and precipitation (rain and snow). They had a simple idea, that by comparing watershed inputs in rain and snow to watershed outputs from streams, they could measure the behavior of entire ecosystems in response to atmospheric pollution or forestry practices. Stream and precipitation samples have been collected every week from 1963 to the present day. Insights gained from studying this long-term chemical record led to the discovery of acid rain in North America and have documented the effectiveness of federal clean air legislation in reducing coalfired power plant emissions. The collection and analysis of HBWatER samples is currently sustained by Tammy Wooster (Cary IES) and Jeff Merriam (USFS) and the dataset is curated and maintained by a team of researchers: Chris Solomon (Cary IES), Emily Bernhardt (Duke), Bill McDowell (UNH), Charley Driscoll (Syracuse U.), Keith Nislow (USFS), and Mark Green (Case Western). Current Financial Support for HBWatER is provided by NSF LTREB # 2401760 and the USDA Forest Service Northern Research Station. These data were gathered as part of the Hubbard Brook Ecosystem Study (HBES). The HBES is a collaborative effort at the Hubbard Brook Experimental Forest, which is operated and maintained by the USDA Forest Service, Northern Research Station.
Multiple Element Limitation in Northern Hardwood Ecosystems (MELNHE): Fresh Litter Chemistry
Freshly senesced leaf litter was collected during autumn in New Hampshire at the Bartlett Experimental Forest, Hubbard Brook Experimental Forest, and Jeffers Brook as part of the Multiple Elementation Limitation in Northern Hardwood Ecosystems (MELNHE) study. Leaf litter was collected in October of 2009, 2010, 2014, 2015, 2016, 2021, and 2022 at peak litterfall (i.e., mid-October) during a rain-free period. These leaf-litter samples were analyzed for nutrient concentrations for use in resorption analyses. Besides adding 2021 and 2022 to the previous version of this data package, this version includes updated values for some samples from 2009 and 2010. Some were re-run to check unusual values, and 8 samples from 2010 for which fresh litter was not collected were estimated by analyzing litter samples collected in litter traps in the same plots in that year. These additions and corrections are indicated in the comments section of the data. These leaf litter samples correspond with green foliage samples collected in late July and early August of the same years: the green foliage EDI package can be found at the following citation: Zukswert, J.M., S.D. Hong, K.E. Gonzales, C.R. See, and R.D. Yanai. 2025. Multiple Element Limitation in Northern Hardwood Ecosystems (MELNHE): Foliar Chemistry 2008-2022 in Bartlett, Hubbard Brook, and Jeffers Brook ver 4. Environmental Data Initiative. https://doi.org/10.6073/pasta/ef3696a753150d0a420fd9009f73b1e9 (Accessed 2025-01-13). These data were gathered as part of the Hubbard Brook Ecosystem Study (HBES). The HBES is a collaborative effort at the Hubbard Brook Experimental Forest, which is operated and maintained by the USDA Forest Service, Northern Research Station.
Federer Chronosequence: Litterfall Biomass and Chemistry; 1993-1997, 2003-2006
The project reports the flux of biomass and nutrients in leaf litterfall in 14 stands (the “Federer Chronosequence”) of northern hardwood forests. These 14 stands are located in the White Mountains of New Hampshire. Monitoring occurred from August 1993 through summer 1997 and again from August 2003 through summer 2006. The litterfall year is defined as starting in August (when we first set out baskets) and ending in August of the following year, years are named by the fall (in which most litter falls). In some years, we have litter mass by basket (3 per transect): 1993, 1994, 1995, 2003, 2005. In other years, we have only transect means: 1996, 2004. Seasonal masses are provided for 2005. Litterfall was sorted by species in all years except for 2005. Twig mass is reported only for 2005. Litter chemistry was measured in fresh litter samples collected in the same stands from 1994 through 2004. Raw, unedited data sorted by season can be found in “Other Entities”, though note the substantial changes that occurred between these values and the processed values published in this dataset. These data were gathered as part of the Hubbard Brook Ecosystem Study (HBES). The HBES is a collaborative effort at the Hubbard Brook Experimental Forest, which is operated and maintained by the USDA Forest Service, Northern Research Station. Related publications: Yanai, R. D., Arthur, M. A., Acker, M., Levine, C. R., & Park, B. B. (2012). Variation in mass and nutrient concentration of leaf litter across years and sites in a northern hardwood forest. Canadian Journal of Forest Research, 42(8), 1597-1610. Acker, M. 2006.Base cation concentration and content in litterfall and woody debris across a northern hardwood forest chronosequence. MS Thesis. Lexington, KY: University of Kentucky. Yang, Y., Yanai, R. D., See, C. R., & Arthur, M. A. (2017). Sampling effort and uncertainty in leaf litterfall mass and nutrient flux in northern hardwood forests. Ecosphere, 8(11), e01999.
Hubbard Brook Experimental Forest: Watershed 6 Temporal Canopy Leaf Chemistry, 1992 - ongoing
Overstory foliage is collected in late summer from a reference forest to the west of Watershed 6 (also referred to as Bear Brook Watershed). Concentrations of C, N, P, K, Ca, Mn, Mg, and the natural abundance of N and C isotopes (delta-15N and delta-13C) in foliage are measured. These measurements, in combination with litterfall estimates of foliar biomass, allow us to estimate the pool of nutrients in foliage. They also allow us to estimate nutrient retranslocation, using measurements of leaf litterfall chemistry. Long-term measurements continue with the aim of detecting disturbances in nutrient cycling and trends in foliar chemistry over long time scales. These data were gathered as part of the Hubbard Brook Ecosystem Study (HBES). The HBES is a collaborative effort at the Hubbard Brook Experimental Forest, which is operated and maintained by the USDA Forest Service, Northern Research Station.
Hubbard Brook Experimental Forest: Chemistry of freely-draining soil solutions in Watershed 6, 1984 - ongoing
Tension-free lysimeters were installed in three soil horizons at three locations adjacent to Hubbard Brook Experiment Forest Watershed 6. At each location lysimeters were placed beneath the Oa horizon and within the upper and lower B horizon. Soil solution samples were collected approximately monthly and analyzed for pH, acid neutralizing capacity (ANC), base cations, soluble anions, trace metals, nitrogen and carbon. These data were gathered as part of the Hubbard Brook Ecosystem Study (HBES). The HBES is a collaborative effort at the Hubbard Brook Experimental Forest, which is operated and maintained by the USDA Forest Service, Northern Research Station.
Hubbard Brook Experimental Forest: Chemistry of Mirror Lake outlet streamwater 1967 – 2021
Mirror Lake is located within the Hubbard Brook Valley, NH and has been the subject of numerous continuous limnological investigations since the early 1960s. The long-term Mirror Lake record is part of the Hubbard Brook Watershed Ecosystem Record (HBWatER), which is a long-term record of weekly sampling of nine gaged watersheds at Hubbard Brook and includes sampling of the Mirror Lake inlets, outlets and water column. This data set reports streamwater chemistry samples from the Mirror Lake outlet beginning in 1967 and continuing through 2014. The collection and management of the long-term record was initiated in 1963 by Gene E. Likens, F. Herbert Bormann, Robert S. Pierce, and Noye M. Johnson. HBWatER is currently sustained by Tammy Wooster (Cary IES) and Jeff Merriam (USFS) and the datasets are curated and maintained by a team of researchers: Chris Solomon (Cary IES), Emma Rosi (Cary IES), Emily Bernhardt (Duke), Lindsey Rustad (USFS), John Campbell (USFS), Bill McDowell (UNH), Charley Driscoll (Syracuse U.), Mark Green (Case Western), and Scott Bailey (USFS). Current financial Support for HBWatER is provided by NSF LTREB # 1907683 and the USDA Forest Service Northern Research Station. These data were gathered as part of the Hubbard Brook Ecosystem Study (HBES). The HBES is a collaborative effort at the Hubbard Brook Experimental Forest, which is operated and maintained by the USDA Forest Service, Northern Research Station.
Soil chemistry and nutrient distribution in long-term NPP plots at the Jornada Basin LTER site, 1989
This dataset contains soil nutrient and chemistry data from soils collected in 1989 at the 15 long-term NPP study sites at the Jornada Basin LTER site. The study sites were selected to represent the 5 major ecosystem types in the Chihuahuan Desert (upland grasslands, playa grasslands, mesquite-dominated shrublands, creosotebush-dominated shrublands, tarbush-dominated shrublands). For each ecosystem type, three sites were selected to represent the range in variability in production and plant diversity; thus the locations are not replicates. In 1989, replicate soil samples were collected at multiple depths from buffer zones surrounding the long-term vegetation monitoring plots. Nutrient and chemical analyses were subsequently performed on these soils, and the data here include inorganic nitrogen, phosphorus, pH, cation concentration, percent organic carbon, and other variables. This dataset is complete.
Soil chemistry and nutrient distribution in long-term NPP plots at the Jornada Basin LTER site, 1991
This dataset contains soil nutrient and chemistry data from soils collected in 1991 at the 15 long-term NPP study sites at the Jornada Basin LTER site. The study sites were selected to represent the 5 major ecosystem types in the Chihuahuan Desert (upland grasslands, playa grasslands, mesquite-dominated shrublands, creosotebush-dominated shrublands, tarbush-dominated shrublands). For each ecosystem type, three sites were selected to represent the range in variability in production and plant diversity; thus the locations are not replicates. In fall of 1991, replicate soil samples were collected at multiple spatial grid designs in the biomass plots of the long-term vegetation monitoring plots. Nutrient and chemical analyses were subsequently performed on these soils, and the data here include total nitrogen, pH, gravimetric water content, and other variables. This dataset is complete.
Saint Louis River Estuary Water Chemistry, Wisconsin, Minnesota, USA 2012 - 2013
These data pertain to water and sediments collected from the Saint Louis River Estuary (SLRE) and its nearby water sources by Luke Loken and collaborators for his Masters thesis and additional publications. In brief, we sampled SLRE surface waters and sediments for a variety of physical, chemical, and biological attributes. Ten estuary stations were sampled approximately monthly from April 2012 through September 2013. On four of the sampling campaigns, water was collected from an additional 20 sites. Sites were selected to represent a gradient from the Saint Louis River to Lake Superior and included several tributaries that drain directly into the estuary. This design aimed to understand the spatial and temporal mixing pattern of the estuary as it receives water from several rivers, 2 waste water treatment plant, and Lake Superior. We sampled the estuary to assess the magnitude and timing of source water contributions to the estuary and establish a baseline of chemical and physical measurements to aid in future limnological research. Additionally, we performed nitrogen and carbon cycling rate experiments to determine the estuary-wide influence on nitrate, ammonium, and dissolved organic carbon. This included 8 sediment denitrification, 1 nitrification, and 2 breakdown dissolved organic carbon (BDOD) surveys. This work was funded by the Minnesota and Wisconsin Sea Grant and in coordination with the establishment of the Lake Superior National Estuary Research Reserve (LSNERR).
SBC LTER: Ocean: Ocean Currents and Biogeochemistry: Nearshore water profiles (monthly CTD and chemistry), ongoing since 2000
This data package contains water chemistry measurements taken monthly at these reefs in the nearshore areas of the Santa Barbra Channel, CA, USA: Arroyo Quemado, Bullito, Naples, Arroyo Burro, Mohawk and Carpinteria. Measurements include standard CTD parameters, nutrients, pigments, particulate CN, total dissolved N and P, stable isotopes of C and N (not all parameters are measured at all stations). Sampling began in November 2000. Some stations are sampled only occasionally. During the first 2 years, CTD data were collected with a SBE19 Seacat Profiler and water samples with a pump. Starting in February 2003, a SBE19-Plus with a rosette sampler was used. There are 3 tables in this dataset. Water chemistry and profiles from "registered stations" (see geographic coverage) are in 2 tables with "registered" in their name. CTD profiles are often collected ad hoc, or as "stations of opportunity". These have been collected in a third table as "non-registered". The station codes for these may be reused, and are not recorded in metadata (but can be found in data).
SBC LTER: Ocean: Time-series: Mid-water SeaFET and CO2 system chemistry at Alegria (ALE), 2011-2014
Calibrated pH (Total scale, SeaFET sensor) data was collected from Alegria in the Santa Barbara Channel (site ID: ALE) along with in situ temperature and associated carbonate chemistry parameters. The SeaFET instrument is located about 4 meters from the surface, with other moored instruments. Associated carbonate chemistry parameters were calculated with the CO2calc programs from USGS, and include: partial pressure and fugosity of CO2, concentrations of bicarbonate, carbonate and hyrdroxide ion, Omega (saturation state) of calcite and aragonite. Data have been interpolated to a 20 minute time interval for compatibility with other SBC LTER moored instrument data. Data coverage is 2011-06-21 to 2014-01-07.The update of this dataset was terminated in 2019. All data from this site have been concatenated with the pH data from the other sites and merged into one data package: https://portal.edirepository.org/nis/mapbrowse?scope=knb-lter-sbc&identifier=6005
SBC LTER: pH time series: Water-sample pH and CO2 system chemistry, ongoing since 2011
Data are a time-series of pH and carbonate chemistry in manually-collected sea water samples from sixteen near-shore locations and 20 locations along the Santa Barbara Channel, California, USA, and intended to benchmark data from moored pH instruments. Data collection began in June 2011 and is ongoing. Time-series for pH sensors deployed in the field (e.g., SeaFET) are available elsewhere. Discrete seawater samples were collected by hand or using a Niskin bottle. In the laboratory, samples were analyzed for pH (total scale) and total alkalinity. Two parameters were used to calculate the full suite of carbonate chemistry parameters using the CO2calc algorithms. Program outputs are included for laboratory conditions as input, and adjusted for situ temperature. See Methods for more information, e.g., Lunden, et al. Data were collected by a consortium of research groups with the intent to leverage their collective assets and expertise. These groups (and sponsors) include Santa Barbara Coastal LTER (NSF), OMEGAS Project (NSF), Passow Lab (Calif. State Water Board), Hofmann Lab (NSF, CINMS, US NPS).
Dataset of "Liquid-Jet Photoemission Spectroscopy as a Structural Tool: Site-Specific Acid-Base Chemistry of Vitamin C"
<p>Liquid-jet photoemission spectroscopy (LJ-PES) directly probes the electronic structure of solutes<br>and solvents. It also emerges as a novel tool to explore chemical structure in aqueous solutions, yet<br>the scope of the approach has to be examined. Here, we present a pH-dependent liquid-jet photoelectron<br>spectroscopic investigation of ascorbic acid (vitamin C). We combine core-level photoelectron<br>spectroscopy and ab initio calculations, allowing us to site-specifically explore the acid-base chemistry<br>of the biomolecule. For the first time, we demonstrate the capability of the method to simultaneously<br>assign two deprotonation sites within the molecule. We show that a large change in chemical shift<br>appears even for atoms distant several bonds from the chemically modified group. Furthermore, we<br>present a highly efficient and accurate computational protocol based on a single structure using the<br>maximum overlap method for modeling core-level photoelectron spectra in aqueous environments.<br>This work poses a broader question: To what extent can LJ-PES complement established structural<br>techniques such as nuclear magnetic resonance? Answering this question is highly relevant in view<br>of the large number of incorrect molecular structures published.</p>
Dataset supporting the paper "Supramolecular chemistry based on 4-acetylbiphenyl on Au(111). Phys. Chem. Chem. Phys. 22: 15208 (2020)"
<p>Dataset corresponding to theoretical calculations in the paper "Supramolecular chemistry based on 4-acetylbiphenyl on Au(111)" Phys. Chem. Chem. Phys. 22: 15208 (2020), <a href="http://dx.doi.org/10.1039/d0cp01657h">http://dx.doi.org/10.1039/d0cp01657h</a></p> <p>List of files:</p> <p>Several folders corresponding to the figures of the paper. They contain:</p> <ul> <li>.siesta files: STM images in WsXM format (<a href="http://www.wsxm.eu/">http://www.wsxm.eu/</a>) simulated using STMpw (<a href="https://doi.org/10.5281/zenodo.3581159">https://doi.org/10.5281/zenodo.3581159</a>).</li> <li>CONTCAR and POSCAR files: relaxed structures in VASP format. They can be visualized with VESTA (<a href="https://jp-minerals.org/vesta/en/">https://jp-minerals.org/vesta/en/</a>)</li> <li>.agr: grace files (<a href="https://plasma-gate.weizmann.ac.il/Grace/">https://plasma-gate.weizmann.ac.il/Grace/</a>).</li> </ul>
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OpenNeuro
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