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openOpenJan 2016View details →

Biogeochemistry data set for soil waters, streams, and lakes near Toolik on the North Slope of Alaska, 2011.

Data file describing the biogeochemistry of samples collected at various sites near Toolik Lake, North Slope of Alaska. Sample site descriptors include a unique assigned number (sortchem), site, date, time, depth, distance (downstream), elevation, treatment, date-time, category, and water type (lake, surface, soil). Physical measures collected in the field include temperature (water, soil, well water), conductivity, pH, average thaw depth, well height, discharge, stage height, and light (lakes). Chemical analysis for the sample include alkalinity; dissolved inorganic and organic carbon (DIC and DOC); inorganic and total dissolved nutrients (NH4, PO4, NO3, TDN, TDP); particulate carbon, nitrogen, and phosphorus (PC, PN, and PP); cations (Ca, Mg, Na, K, and Si); anions (SO4 and Cl); and oxygen.

openOpenDec 2015View details →

Biogeochemistry data set for NSF Arctic Photochemistry project on the North Slope of Alaska.

Data file describing the biogeochemistry of samples collected at various sites near Toolik Lake on the North Slope of Alaska. Sample site descriptors include a unique assigned number (sortchem), site, date, time, depth, and category (level of thermokarst disturbance). Physical measures collected in the field include temperature, electrical conductivity, and pH. Chemical analyses include alkalinity; dissolved organic carbon (DOC); inorganic and total dissolved nutrients (NH4, PO4, NO3, TDN, TDP); particulate carbon, nitrogen, and phosphorus (PC, PN, and PP); cations (Ca, Mg, Na, K); anions (Cl, SO4); and silica. A synthesis of much of the data presented here is published in Cory et al. 2013, PNAS 110:3429-3434; Cory et al. 2014, Science 345:925-928; and Page et al. 2013, Environment, Science, &amp;amp; Technology 47:12860âˆ’12867.

openOpenJul 1997View details →

Biogeochemistry of Permafrosted/NonPermafrosted Watersheds in CPCRW: Summer 1995

Chemical measurements of groundwater, soil water and stream water were made in watersheds C2 and C3 in CPCRW (DOC, DON, NO3-N, NH4-N, Al, Mg, Ca, Mn, Si, K, Na, SO4 and conductivity). One watershed C3 had extensive permafrost and the other C2 had limited permafrost. Stream discharge data was collected from permanently installed flumes. Soil water retained within the rooting zone (0.3 - 0.5 m) was high in DOC, DON and DIN but low in dissolved minerals (dominantly Ca, Mg and Na) and conductivity. The reverse was true for groundwater from springs and wells. Permafrost in C3 prevented deep percolation of water and generated stormflows rich in DOC. Stormflow accounted for 24% of total streamflow in C3 but only 3% of total streamflow in C2. The presence of permafrost appears to result in higher fluxes of DOC, DON and DIN into stream water from upland soils.

openOpenNov 2014View details →

McMurdo Dry Valleys Polygon Study: Variability in soil biogeochemistry and biodiversity

In the Antarctic Dry Valleys, soil polygons are prominent features of the landscape and may be key units for scaling local ecological information to the greater region. We examined polygon soils in each of the 3 basins of Taylor Valley, Antarctica. Our objectives were to characterize variability in soil biogeochemistry and biodiversity at local to regional scales, and to test the influence of soil properties upon invertebrate communities. We found that soil biogeochemical properties and biodiversity vary over multiple spatial scales from fine (less than 10 m) to broad (greater than 10 km) scales. Differences in biogeochemistry were most pronounced at broad scales among the major lake basins of Taylor Valley corresponding to differences in geology and microclimate, while variation in invertebrate biodiversity and abundance occurred at landscape scales of 10-500 m, and within individual soil polygons. Variation in biogeochemistry and invertebrate communities across these scales reflects the influence of physical processes and landscape development over ecosystem structure in the dry valleys. The development of soil polygons influences the spatial patterning of soil properties such as soil organic matter, salinity, moisture, and invertebrate habitat suitability. Nematode abundance and life history data indicate that polygon interiors are more suitable habitats than soils in the troughs at the edges of polygons. These data suggest that physical processes (i.e. polygon development) and biogeochemistry are an important influence on the spatial variability of biotic communities in dry valley soil ecosystems.

openCC (other)Jan 2022View details →

MCR LTER: Coral Reefs: KM14-16 Cruise BioGeoChemistry

Data products from biogeochemical analyses of bottle sample data collected during the July 2014 UNOLS cruise on the Kilo-Moana around Moorea.We sought to resolve the extent, variability, and magnitude of productivity enrichment around a high tropical island consistent with the phenomenon of an Island Mass Effect (IME). Key biogeochemical constituents and physical oceanographic parameters were measured offshore over the upper 500 m from July 27 to August 7, 2014 around the Society Island of Moorea in French Polynesia in association with the nearshore measurements of the Moorea Coral Reef Long Term Ecological Research program. High-resolution synoptic sampling in a rectangular grid around the island revealed vertical and horizontal patterns in hydrographic conditions, inorganic nutrients, rates of productivity, and concentrations of organic matter that are characteristic of oligotrophic gyre ecosystems. This study was supported in part by the National Science Foundation grants OCE-1236905 to MCR-LTER, OCE-1538428 to CC, OCE-1538393 to CN and OCE-1535203 to JL, and NASA grant NNX11AE87G (The Science of Terra and Aqua) to SM. Data products biogeochemical analyses of bottle sample data during the July 2014 UNOLS cruise on the Kilo-Moana around Moorea.

opencc-by-4.0Dec 2019View details →

Biogeochemistry of Cromwell and Connelly streams, Laurentians region, Quebec, Canada

These data combine nitrogen, phosphorus and carbon content in water samples as well as discharge obtained from >20 sampling sites along two streams in Saint-Hippolyte during a summer sampling campaign in 2017. These were obtained as part of a master’s student graduate research project in the biological science department of the University of Montreal. Sampling occurred in July and August during baseflow, and computation allowed calculation of loadings and mass balances over multiple reaches along the streams, using sampling location as upstream and downstream references points.

opencc-by-4.0Jul 2020View details →

Changing biogeochemistry of the Southern Ocean and its ecosystem implications

The datasets published here apply only to unpublished nutrient data from the wintertime trans-Southern Ocean sections WOCE line IO6 (2017) and A12 (2019) and one summertime surface ocean A12 ammonium dataset. Nutrient concentrations are in units micromole per liter. Variables measured from the CTD (pressure, temperature and salinity) for the two wintertime datasets are provided at 1 m resolution. Winter nutrient sampling was conducted aboard the R/V SA Agulhas II in 2017 (WC-17; 28 June – 13 July 2017) along WOCE line IO6 (Indian sector) and in 2019 (SCALE; 18 July – 12 August 2019) along WOCE line A12 (the GoodHope repeat hydrographic line; Atlantic sector). Seawater was collected at regular depth intervals in 12-L Niskin bottles attached to a CTD rosette. Samples for the analysis of nitrate, nitrite, dissolved silicon and phosphate concentrations were decanted into replicate 50 mL HDPE tubes that were copiously rinsed prior to filling. Duplicate tubes were immediately frozen at -20°C for later measurement of nitrate and dissolved silicon, whilst nitrite and phosphate samples that were to be measured shipboard within a few hours were stored in the fridge. Duplicate samples of unfiltered seawater (~40 mL) were also collected at each depth between the surface and 500 m for the analysis of ammonium concentrations in 50 mL HDPE Nalgene bottles that had been stored (“aged”) with orthophthaldialdehyde working reagent (OPA-WR) prior to sample collection. The OPA-WR was decanted just prior to sample collection and bottles were rinsed three times with sample seawater prior to filling. Phosphate and nitrite concentrations were analysed manually according to the methods described by Grasshoff et al. (1983), with absorbance measured using a Thermo Scientific Genesis 30 Visible spectrophotometer. Aliquots of a certified reference material (CRM; JAMSTEC) were analysed with each sample run to ensure data quality. Nitrate+nitrite and dissolved silicon were measured in the Marine Biogeochemistry Lab at the University of Cape Town (MBL-UCT) using a Lachat Quick-Chem flow injection autoanalyser (Wolters, 2002;Egan, 2008). Standards of varying concentration were run after every ten samples to monitor instrument performance and allow for correction of any drift, and a CRM was measured at the beginning and end of each run to ensure measurement accuracy. The precision of the nitrate+nitrite, dissolved silicon, phosphate, and nitrite measurements was ± 0.4 µmol L-1, ± 0.2 µmol L-1, ± 0.06 µmol L-1, and ± 0.05 µmol L-1, respectively, and the detection limit was 0.1 µmol L-1, 0.2 µmol L-1, 0.05 µmol L-1, and 0.05 µmol L-1, respectively. Ammonium concentrations were measured shipboard via the fluorometric method of Holmes et al. (1999) using a UV module in a Turner Designs Trilogy Fluorometer 7500-000. Standards were made daily using Type-1 ultrapure Milli-Q water, and samples and standards were measured in duplicate. Precision was ± 0.01 µmol L-1 and the detection limit was <0.02 µmol L-1. The matrix effect resulting from the calibration of seawater samples to Milli-Q standards was calculated according to the standard addition method (Saxberg and Kowalski, 1979). All samples were corrected for the matrix effect (Holmes et al., 1999), which was always <10% and typically <5%. No ammonium concentration data are available for the summer in the WOCE database. However, we collected triplicate samples of unfiltered seawater (~40 mL) from the underway system (~7 m intake depth) of the R/V SA Agulhas II every ~0.25 degrees of latitude during the 2018/2019 resupply voyage along WOCE line A12 between Cape Town and Antarctica (SANAE 58; 7 – 17 December 2018). These samples were measured shipboard as described above. Although not collected at the same time as the other summertime nutrient data from WOCE line A12, the SANAE 58 ammonium concentrations provide an indication of typical summertime conditions.  N* is a quasi-conservative tracer used to track the changes in dissolved inorganic nitrogen (DIN) relative to phosphate, thereby providing information as to whether fixed nitrogen is being added to or lost from an ecosystem relative to phosphorus (Gruber and Sarmiento, 1997). N* was originally defined as N* (µmol L-1) = [NO3-] – 16 x [PO43-]. Here, we further derive N*DIN = [NO3-+NO2-+NH4+] – 16 x [PO43-] where DIN is the sum of nitrate, nitrite and ammonium, and 16 is the average stoichiometric N:P ratio observed during the autotrophic production and heterotrophic remineralisation of organic matter (Redfield et al., 1963;Anderson and Sarmiento, 1994). The tracer Si* was initially developed to track SAMW from its formation region into the lower latitude ocean (Sarmiento et al., 2004). It is also an indicator of the nutrient status of diatoms. Si* leverages the general observation that under favourable conditions, diatoms consume dissolved silicon and nitrate in a ratio of ~1:1 (Hutchins and Bruland, 1998;Takeda, 1998;Ragueneau et al., 2000), but that under conditions of limitation (e.g. of low iron), the ratio of dissolved silicon-to-nitrate uptake changes (e.g. Franck et al., 2000;Brzezinski et al., 2003). Si* was computed from measurements of nitrate and dissolved silicon concentrations following Sarmiento et al. (2004) as Si* (µmol L-1) = [Si(OH)4] – [NO3-].

opencc-zeroAug 2019View details →

Data from: Resilience of lake biogeochemistry to boreal-forest wildfires during the late Holocene

Novel fire regimes are expected in many boreal regions, and it is unclear how biogeochemical cycles will respond. We leverage fire and vegetation records from a highly flammable ecoregion in Alaska and present new lake-sediment analyses to examine biogeochemical responses to fire over the past 5300 years. No significant difference exists in δ13C, %C, %N, C:N, or magnetic susceptibility between pre-fire, post-fire, and fire samples. However, δ15N is related to the timing relative to fire (Χ2=19.73, p<0.0001), with higher values for fire-decade samples (3.2±0.3‰) than pre-fire (2.4±0.2‰) and post-fire (2.2±0.1‰) samples. Sediment δ15N increased gradually from 1.8±0.6‰ to 3.2±0.2‰ over the late Holocene, probably as a result of terrestrial-ecosystem development. Elevated δ15N in fire decades likely reflects enhanced terrestrial nitrification and/or deeper permafrost-thaw depths immediately following fire. Similar δ15N values before and after fire decades suggest that N cycling in this lowland-boreal watershed was resilient to fire disturbance. However, this resilience may diminish as boreal ecosystems approach climate-driven thresholds of vegetation structure, permafrost thaw, and fire.

opencc-by-4.0Jan 2022View details →

Surface Ocean Biogeochemistry Regulates the Impact of Anthropogenic Aerosol Fe Deposition on the Cycling of Iron and Iron Isotopes in the North Pacific

Monthly-average (year 2014) netcdf output files of NEMO/PISCES Fe isotope model experiments on the ORCA2 grid for experiments with updated iron deposition fields; "ptrc" files contain model outputs for heavy and light iron tracers, "diad" files contain diagnostic model outputs for iron uptake (of light and heavy iron), primary production (for diatoms and nanophytoplankton), and iron deposition fluxes (from dust, anthropogenic, and fire sources).

opencc-by-nc-1.0Jun 2024View details →

Assessing the ocean carbon sink: Assimilation of temperature and salinity into a global ocean biogeochemistry model

Data underlying figures in manuscript draft.

opencc-by-4.0Sep 2024View details →

Biogeochemistry of Svalbard Glacial and Periglacial Groundwater Springs

Biogeochemical data collected from water samples of periglacial and glacial groundwater springs on Svalbard between 2018 and 2023.

opencc-zeroNov 2022View details →

Anticipating fluctuations of bigeye tuna in the Pacific Ocean from three-dimensional ocean biogeochemistry

1. Subseasonal to decadal ocean forecasting can make significant contributions to achieving effective management of living marine resources in a changing ocean. Most applications rely on indirect proxies, however, often measured at the ocean surface and lacking a direct mechanistic link to the dynamics of marine populations. 2. Here we take advantage of three-dimensional, dynamical reconstructions and forecasts of ocean biogeochemistry based on a global Earth System Model to hindcast and assess the capacity to anticipate fluctuations in the dynamics of bigeye tuna (Thunnus obesus Lowe) in the Pacific Ocean during the last six decades. We reconstructed spatial patterns in catch per unit effort (CPUE) through the combination of physiological indices capturing both habitat preferences and physiological tolerance limits in bigeye tuna. 3. Our analyses revealed a sequence of four distinct regimes characterized by changes in the zonal distribution and average CPUE of bigeye tuna in the Pacific Ocean. Habitat models accounting for basin-wide fluctuations in the thermal structure and oxygen concentration throughout the water column captured interannual fluctuations in CPUE and regime switches that models based solely on surface information were unable to reproduce. Decade-long forecast experiments further suggested that forecasts of three-dimensional biogeochemical information might enable anticipation of fluctuations in bigeye tuna several years ahead. 4. Synthesis and applications. Together, our results reveal the impact of variability of biogeochemical conditions in the ocean interior on the dynamics of bigeye tuna in the Pacific Ocean, raising concerns about the future impact of ocean warming and deoxygenation. The results also lend support to incorporating subsurface biogeochemical information into ecological forecasts to implement efficient dynamic management strategies and promote the sustainable use of marine living resources.

publicAug 2019View details →

Data from: Resilience of lake biogeochemistry to boreal-forest wildfires during the late Holocene

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publicDec 2025View details →

Data from: Repeated high severity fire effects on soil biogeochemistry in the Sierra Nevada, California

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publicFeb 2021View details →

Soil biogeochemistry across Central and South American tropical dry forests

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