ABSTRACT:

Measurements of precipitation depth, 5 minute resolution, in mm from a tipping bucket rain gauge (Campbell Scientific, TE525MM-L Metric Rain Gage with 9.6 in. Orifice , https://www.campbellsci.com/te525mm-l) at the Calhoun Critical Zone Observatory, manually downloaded every six weeks. The gauge is located in a clearing a short distance (~10 meters) from the Calhoun 70-m deep well. Time stamp is Eastern Standard Time, UTC-05:00.

ABSTRACT:

Capacitance rod installed in Weir 4 stilling pool, located in watershed 4, midway between USFS road 325 (top of hillslope) and Holcombe's Branch. Measuring Discharge/Runoff via stage (5 min resolution) in stilling pool of 90 degree v-notch weir and USFS rating curve: Q = 2.48*(h(ft))^2.49; Q = discharge in cfs, h = stage in feet. Discharge data converted to L/s. Runoff data, in mm/hr, calculated by normalizing discharge to watershed 4 area (6.9 ha). Capacitance water level meter is TruTrack, WT-HR 1000, manually donwloaded every six weeks.

ABSTRACT:

Well water depths in deep groundwater well in the Stone's pasture at the Calhoun Critical Zone Observatory. Groundwater well is situated in a mostly flat, broad interfluve and is cored to ~70m. Well casing ends at roughly 17m. Depths were measured continuously with a Solinst levellogger (3001 LTC) pressure transducer at a resolution of 20 minutes. Downloaded data is in positive depths above the sensor. These depths are corrected for barometric pressure by subtracting barometric pressure measured by a Solinst barologger (3001) which is co-located in the well and records barometric pressure at the same frequency. The data are then converted from depth above the sensor into depths below ground surface using manual measurements of depth below ground made at each download with a water level meter.

ABSTRACT:

Geochemical analysis summary table for samples collected during drilling of 70m deep borehole. On 17-18 November 2010 a 70-m deep borehole was drilled at the Calhoun Long Term Soil Experiment site to examine soil properties down to the bedrock. These results were published as Table 1 in Bacon et al. 2012.

We sampled a residual soil, classified as Oxyaquic Kanhapludult of the Cataula series, and underlying granite gneiss on a broad interfluve with
Date Range Comments: Samples collected during a single event, the drilling of 70m deep borehole.

We collected 3 continuous cores (10 m apart), each to a depth of 6.1 m, and collected deeper samples from a single point 30 m away. Saprolite from 6.1–18.3 m was sampled with a three-wing auger bit, and unweathered granite gneiss, contacted at 30.5 m, was sampled to 67.1 m with a roller-cone bit. We separated samples by horizon and depth, and air-dried all samples. We sieved soil and/or saprolite with a 2 mm screen, and found coarse fragments in only 8 of the 52 samples. By volume, these fragments composed 1%–11% (mean = 7%) of the 8 samples, and were removed from our analysis. We measured total elemental concentrations of all samples by inductively coupled plasma–atomic emission spectroscopy or flame atomic absorption spectroscopy (AAS) after LiBO2 fusion, and measured texture, pH in 0.01 M CaCl2, total carbon (C), exchangeable base cations (Ca, Mg, K, and Na), and exchangeable acidity on all soil and/or saprolite samples (Carter, 1993; Dane and Topp, 2002; Sparks, 2002).

We composited (by horizon) across the continuous cores, extracted the composited samples and samples from 6.1–18.3 m with hydroxylamine hydrochloride (1 M NH2OH·HCl in 1 M HCl; Wiederhold et al., 2007), and measured Be and Fe in solution by furnace and flame AAS, respectively. By complete dissolution of oxide minerals at low pH, hydroxylamine hydrochloride extractable (hhe) metals are an operationally defined pool that have been weathered from primary minerals and retained in the soil, and in our analyses are akin to the familiar dithionite citrate bicarbonate extractable metals (Fig. DR2) popularized by Mehra and Jackson (1958). We further composited these samples across horizons (Table 1), isolated meteoric 10Be with a method modified from Stone (1998), and measured 10Be/9Be isotopic ratios by accelerator mass spectrometry (AMS).

ABSTRACT:

Soil CO2 data manually collected from 8 locations at 7 different depths at the Calhoun Long-Term Soil Experiment site in Union County, SC.

ABSTRACT:

Summary data of hydraulic conductivity (Ksat, cm/hr) from a survey at the Calhoun LTSE site. Mean of 5 samples collected using an Amoozemeter by M. Lance Brewington and JDH. Calhoun LTSE Block 2, immediately east of 12x12 plot. Cataula series soil. Approximate coordinates: 34.60816, -81.72208 (WGS1984).

ABSTRACT:

Soil water chemistry, 0-600 cm depth, July 1991 - March 1994, 8 plots with 5 depths plus canopy throughfall, and open area precipitation (bulk and wet-only).

ABSTRACT:

Data measured every 2-3 weeks using Soil Moisture Corp 5201F1 gypsum blocks in 20 different locations/depths. Key to sample names: G is for gypsum block readings. B is for the LTSE's experimental blocks, 1 to 4. 015, 060, 100, 200, 300 are cm depth of measurement.

ABSTRACT:

The zip file contains a large tiff mosaic stitched together from a series of aerial photographs of the Calhoun CZO area taken in 1933, when the area was being acquired by the US Forest Service. USFS archaeologist Mike Harmon delivered the black-and-white photographs, known to him as the 'Sumter National Forest Purchase Aerials', to us in a box. The photographs include most of the Enoree District of the Sumter National Forest, including the entirety of the Calhoun CZO, not just the long-term plots and small watersheds. The photographs were scanned and georectified, then color-balanced and stitched together following 'seams' - high-contrast features such as rivers and roads ('seamlined'). In addition to the main tiff are four files that can be used to properly geolocate the composite image in ArcGIS.

The multilayer pdf file includes a smaller version of the seamlined 1933 aerial photography mosaic raster layer, as well as this aerial mosaic transparent over slope map (for a 3D-like 1933 image raster). Other layers include contours, roads, boundaries, sampling locations, 1.5 m DEM, 1.5m slope, 1m 2013 NAIP aerial imagery, and 2014 canopy height. The pdf file includes both 'interfluve order' and 'landshed order.' These two layers mean the same thing, but the landshed is the area unit around the interfluve that is used for statistics; this dataset has been QC'ed. The Interfluve Order network was used to delineate the landsheds and agrees with it >95% of the time, but has a few inaccuracies (it was automated by the computer) that were fixed manually. Use the network for viewing and considering the landscape at large, but for the specific interfluve order, check the color of the 'Landshed Order' dataset to verify its accuracy.

Date Range Comments: The exact date these photos were taken is unknown, but the year is thought to be 1933.The flight date is prior to the USFS land purchases for the Enoree District of the Sumter National Forest; the photos are thus known as the "pre-purchase photos").

ABSTRACT:

Dataset includes LiDAR features for 35 forest plots located at the Calhoun CZO. Both LiDAR data acquisition and field measurements using LAI-2000 (LI-COR, 1992) were performed during summer 2014. LAI-2000 is an optical device used to estimate Leaf Area Index (LAI, hemisurface area of foliage per unit horizontal ground surface area) and canopy gap fraction at five zenith angles. The LiDAR data were processed to match with the LAI-2000 measurements, and thus LiDAR returns arriving at angles more than 15 degrees were excluded before any calculations were performed.

Processing chain of LiDAR data included: 1) merging .las files which have forest plots near the edges, 2) calculating the ground surface, 3) removing noise, 4) removing duplicates, 5) extracting returns for the forest plots using a 15-m circle, 6) excluding returns arriving at an angle bigger than ±15 degrees, 7) calculation of return heights, 8) classifying returns to ground and vegetation based on return heights (limit set to 1.37-m), 9) calculation of LiDAR features for all forest plots.

The LiDAR features provided in this dataset are updated version of those presented earlier by Majasalmi et al. (2015).

References:

Majasalmi, T., Palmroth, S., Cook, W., Brecheisen, Z., Richter, D. (2015): Estimation of LAI, fPAR and AGB based on data from Landsat 8 and LiDAR at the Calhoun CZO. Calhoun CZO 2015 Summer Science Meeting. http://criticalzone.org/calhoun/publications/pub/majasalmi-et-al-2015-estimation-of-lai-fpar-and-agb-based-on-data-from-land/

LI-COR, 1992. LAI-2000 Plant Canopy Analyzer, Instruction manual. ftp://ftp.licor.com/perm/env/LAI-2000/Manual/LAI-2000_Manual.pdf

ABSTRACT:

Survey of trees within 62 15-m radius vegetation plots. Only trees with diameter at breast height (1.37m) of more than 15 cm are included in this survey. Approximately 37% of these trees were cored to estimate age of stands - those data are also included here.

ABSTRACT:

X-ray diffraction data collected for bulk sample collected by auger from 0 - 150 cm measured from the top of the mineral soil surface. Bulk sample < 2 mm was pulverized to < 10 microns using a McCrone Mill. The sample was mounted in a back-filled pressed powder mount and diffracation data was collected from 2 to 70 degrees 2 theta, stepsize: 0.01 steps/degree, scanspeen: 0.1 sec/step, using a Bruker D8 Advance X-ray diffractometer with Co radiation.
Date Range Comments: Date samples collected.

ABSTRACT:

Deep within soil profiles, organic matter (OM) inputs are derived from root growth and root exudates of deeply-rooted species, and organic compounds percolating through the profile from more shallow horizons. Severe disturbance “orphans” these deep roots, which eventually decay in place. When annual crops replace long-lived, deeply rooted vegetation, sustained organic inputs into deep soil volumes are limited to those that percolate down from the overlying horizons. Multiple studies suggest that even after forests are re-planted, it can take more than a century for deep roots to become re-established.

We thus ask if past disturbance and subsequent changes across depth in OM inputs (both content and form) have a contemporary influence on transformations and fate of deep, ancient soil OM and associated biogeochemical fluxes and microbial communities. If so, this phenomenon would suggest a far-reaching nature of the biogeochemical legacies of past disturbance, both in vertical space (down deep) and time (~60 y after forest re-establishment at the Calhoun experimental forest). Discerning and quantifying any such effect would add an additional dimension to existing disturbance-related literature, and helps address some of the questions raised in the Calhoun Critical Zone Observatory proposal.

Our objective was to quantify the influence of past land use history and current land cover on deep soil biogeochemical processes linked to OM transformations. For this, we collected soil samples from the Calhoun CZO, from three replicate sites of old-grown hardwood forests, from three replicate sites of old-field pine forests, and from one current crop field (“dovefield”), from depths of 40-50 cm and 400-500 cm by hand augering.

Once the shipped soil samples arrived at the University of Kansas, Lawrence, we incubated subsamples in mason jars and prepared them for gas sampling. Gas samples from the incubation jars were at time 0 and time 1, and CO2, CH4 and N2O concentrations in the sampled gas were analyzed with a gas chromatograph. This allowed us to compute rates of soil microbial CO2, CH4 and N2O production. Determining δ13C of the sampled gases with a 13CO2/12CO2 gas analyzer allowed us to assess the δ13C of the CO2 respired by the soil microbes. At the same sampling points during the soil incubations, we also took aliquots of the samples for flourometric enzyme assays. This aimed at quantifying the activities of the microbial extracellular enzymes β-glucosidase, β-N-acetyl glucosaminidase, acid phosphatase, and phenol oxidase.

All other soil parameters were analyzed on subsamples of the soils immediately after their arrival at the University of Kansas.
Date Range Comments: irregular collections

ABSTRACT:

Zachary Brecheisen, with help from Dan Richter, Will Cook, and others, augered and install 66 soil gas wells at various depths at 15 locations in the Calhoun CZO. Three of these locations are instrumented and continuously monitored, with data recorded every 30 minutes on a Campbell CR1000 datalogger, the rest sampled manually every 3 weeks. Installation occurred in the winter of 2015 through summer 2016. The continuously monitored gas wells target 3 different land use comparisons on flat upland topography. The land uses consist of a reference hardwood forest minimally degraded by human activity, an old-field secondary succession pine forest ~60 years old, and 1 plowed agricultural plot which has been, to the best of our knowledge, continually cultivated since at least the 1930s. The goal of this sampling is to identify anthropogenic biogeochemical signals in the soil profile of cultivated lands and to evaluate their persistence (or lack thereof) in old-field pine forests relative to reference hardwoods.

Methods:

Gasses measured include O2 (Apogee) and CO2 (Vaisala) probes located in soil gas wells at 25, 50, and 150 cm depths. Data are logged on a Campbell CR1000 datalogger every 30 minutes. Daily average values are computed.

Measurements (depths in cm):

Soil CO2: 50, 150 (all plots)

Soil O2: 50, 150 (all plots)

Soil temperature: 0 (soil surface temperature probe), 25 (all plots via TDR probe), 50 (all plots via TDR and apogee O2 probe), 150 (all plots via Apogee O2 probe)

Soil moisture (TDR probe): 25 (all plots), 50 (all plots)

Sites:

R1P1 - pine forest 34.60739,-81.72279

R1C1 - cultivated field 34.61014,-81.72699

R1H1 - hardwood forest 34.60643,-81.72332
Date Range Comments: data collection is ongoing, with data logged every 30 minutes

ABSTRACT:

Zachary Brecheisen, with help from Dan Richter, Will Cook, Alex Cherkinsky, Jay Austin, and others, have augered and installed soil gas wells at 4 depths at 15 locations in the Calhoun CZO. Most installation occurred in the summer of 2015 and completed in summer 2016. Gas sampling of existing wells commenced 7-31-15 and has proceeded approximately every 3 weeks since then. The gas wells target 3 different land forms: flat uplands, mid-slopes, and steeper slopes in 3 different land use comparisons. The land uses consist of 3 reference hardwood forests minimally degraded by human activity, 3 old-field secondary succession pine forests >60 years old, and 1 pseudo-replicated agricultural plot which has been, to the best of our knowledge, continually cultivated from the 1930s at the latest. The goal of this sampling is to identify anthropogenic biogeochemical signals in the deep soil profile of cultivated lands and to evaluate their persistence or lack thereof in old-field pine forests relative to reference hardwoods. Soil gas is analyzed in the field for O2 using an Apogee oxygen meter and CO2 with a Vaisala meter. Other (greenhouse) gasses are brought back to the lab, where they are analyzed on a Varian gas chromatograph with known concentration standards.
Date Range Comments: samples collected and analyzed approximately every 3 weeks; ongoing

ABSTRACT:

Zachary Brecheisen, Dan Richter, Mac Callaham, Will Cook, and Paul Heine have sampled and analyzed soils from 15 locations in the Calhoun CZO. Sampling is underway, though all soil texture samples have been collected and are in process. The first quarterly invertebrate sampling occurred in September 2015. Bulk density, Ksat, and water stable aggregate sampling and analyses will occur in 2016. This work targets 3 different land forms: flat uplands, mid-slopes, and steeper slopes in 3 different land use comparisons. The land uses consist of 3 reference hardwood forests minimally degraded by human activity, 3 old-field secondary succession pine forests >60 yo, and 1 pseudo-replicated agricultural plot which has been, to the best of our knowledge, continually cultivated from the 1930’s at the latest. The goal of this sampling is to identify physical anthropogenic signals in the upper meters in the soil profile of cultivated lands and to evaluate their persistence or lack thereof in old-field pine forests relative to reference hardwoods.

ABSTRACT:

This is a transcribed spreadsheet of the original US Census bureau data from the 1850 Agriculture Census of Union County, South Carolina.

Date Range Comments: Census was in 1850, not 1950. CZO CMS cannot handle pre-1900 dates so we're temporarily using 1950. Record to be fixed in HydroShare.

ABSTRACT:

The National Center for Airborne Laser Mapping (NCALM) conducted a leaf-on survey of the Calhoun CZO area on July 30, 2014 (hyperspectral imaging) and August 5-6, 2014 (LiDAR). Data is publicly available at the OpenTopography link below.

ABSTRACT:

Samples were collected from Steve Stone’s property which is adjacent to the Calhoun Long-term forest plots (see map below - click on 'Overview Maps' tab). Three continuous mineral soil cores were collected from 0-14 m with a Geoprobe in Steve Stone’s hardwood forest (“Core Locations” in map). These surficial samples were collected from this location because contemporary vegetation, aerial photography dating back to 1938, and soil profile morphology indicated that European agriculture had minimally affected soils in this hardwood forest. Samples deeper than 14 m were collected from Steve Stone’s pasture, approximately 30 m away from the “core locations”, during the installation of a groundwater well by a private contractor (Gill Drilling Services inc.). Samples from 14-18 m were collected with a three-wing bit auger while samples from 18-67 m were collected with a roller-cone bit. After collection all samples were air-dried, and samples from 0-18 m were sieved to 2 mm.

Texture was measured by the pipette method on 20 g of sample. Soil pH was measured with a continuous flow electrode in deionized water and in 0.01 M CaCl2 with a soil:solution ratio of 0.5 and a 15 minute extraction time. Exchangeable acidity was extracted with 1M KCl (soil:solution=0.002, 30 minute extraction) and titrated to 8.2 with 0.02 M NaOH. Exchangeable calcium, magnesium, potassium, and sodium were extracted with 1 M NH4OAc (soil:solution=0.05, 30 minute extraction) and measured by Atomic Absorption Spectrophotometry. Total aluminum, beryllium, calcium, manganese, silicon, titanium, and zirconium were measured by Inductively coupled plasma atomic emission spectroscopy while total iron, magnesium, phosphorus, potassium, and sodium were measured by Atomic Absorption Spectrophotometry following LiBO2 fusion of pulverized and oxidized (30 minutes at 800 C) subsamples (0.1 g sample, 0.4 g LiBO2, 13 minutes at 1000 C). “Free”-iron and “free”-beryllium (Mehra & Jackson, 1958, DOI: 10.1346/CCMN.1958.0070122) were measured by Atomic Absorption Spectrophotometry after extraction with 1 M NH2OH·HCl in 1 M HCl (soil:solution=0.05, 4 hours at 90 C). Meteoric Beryllium-10 was extracted by KHF and NaSO4 fusion and 10Be/9Be isotopic ratios were measured by accelerator mass spectrometry. Total carbon and nitrogen were measured by combustion on a CE Elantech Flash EA 1112 Elemental Analyzer.

ABSTRACT:

These are the output data from surveys of watersheds 2, 3, and 4 with a Dualem 2 electromagnetic induction (EMI) probe. The probe was carried along the contour of the slope and recorded georeferenced measurements of specific conductance every one to two seconds. These measurements were started in November of 2014 and continued to be made every two months for a year after (November 2014 – September 2015) by Caitlin Hodges. EMI provides information on soil specific conductance, which can then be used to infer soil moisture and texture conditions. When repeated measurements are made, soil moisture changes over time can be observed. This raw data is best utilized by importing into ArcMap and interpolating the specific conductivity measurements to generate a 2D map of soil conductivity. Hodges used the data to inform her installation of her rusted steel redox indicators in the watersheds to assess soil redox potential in the watersheds (first deployment, October 2015).
Date Range Comments: Measurements made every 2 months

ABSTRACT:

Soil Electrical Resistivity (SER) is being used to assist in subsurface modeling of hydrologic flows. In SER an artificially generated electric current is supplied to the soil and the resulting potential differences are measured. The patterns in potential differences provide information on the form of subsurface heterogeneities and these heterogeneities in electrical resistivity are considered as a proxy for the variability of soil physical and chemical properties. We have an Advance Geosciences (AGI Inc, Austin, TX) R8 SuperSting for resistivity measurement. Imaging is being done in 2D transects of 56 probes installed at the surface. Given that SER are images are be remeasured at the same location changes with time are inferred to reflect changes in moisture.
Date Range Comments: quarterly

ABSTRACT:

Soil samples analyzed via Mössbauer spectroscopy at three temperatures (295K, 77K and 4.2K). In each case the sample is loaded into the machine without prior modification (no grinding) to an ideal thickness based on the amount of iron in the sample. Transmission 57Fe Mössbauer spectroscopy was performed with a variable temperature He-cooled system with a 1024 channel detector. A 57Co source (~50 mCi) embedded in a Rh matrix was used at room temperature. Samples were mounted between two pieces of 0.127 mm thickness Kapton tape. In some cases, this was done inside an anoxic glovebox, and transferred immediately to the spectrometer cryostat to avoid sample oxidation prior to analysis. In other cases dried samples were used. The velocity (i.e., gamma-ray energy) was calibrated using α-Fe foil at 298 K. The transducer was operated in constant acceleration mode and folding was performed against the calibrated Fe foil to achieve a flat background. The raw sample files here are folded spectra using the most recent collected calibration standard. Data collection times are typically 24 h per sample per temperature, however can be longer/shorter in samples with less/more iron concentration.

ABSTRACT:

Leaf Area Index (LAI) was measured in July-August 2014 in 36 15-m diameter plots located throughout the Calhoun CZO LiDAR flight area on approximately the same dates as the 2014 leaf-on LiDar flight. In each plot, LAI was measured in six directions (W, E, NE, SW, SE, NE) relative to the plot center. The individual readings are presented here. LAI was measured using a LAI-2000 (LI-COR Inc., Lincoln, NE).

ABSTRACT:

This dataset is digitized from the stream flow and rainfall historic records from Calhoun Experimental Forest, Union County, South Carolina, from 1949 to 1962. The stream flow weirs are located at Stream #2, #3, and #4, and the rainfall data is from the rain gauge #9 and #11.

The Neurascanner/ Neuralog system was applied to scan and digitize the historic records. And currently, this is the digitization method is used in the USGS.

ABSTRACT:

To develop and calibrate a systematic approach for gullies identification from Digital Elevation Models we measured morphological characteristics of gullies at the Calhoun CZO. Gullies reference perimeters have been defined by a Georgia Tech team during a field survey (June 29-30 2015) through a visual identification of the change in slope at the top of the gully walls (i.e. the point where the relatively flat gully margins starts to slope into the gully). The perimeter coordinates have been acquired using a differential GPS total station (Topcon Hiper Lite +) in RTK (real Time Kinematic) mode with a horizontal accuracy of about 25 cm.

ABSTRACT:

This is soil texture data (% sand/silt/clay) for samples collected June-August, 2014, in References Areas 3 and 4. Samples were obtained by coring to depths of 100-200 cm (site dependent) with a bucket auger. Sampling occurred at fixed intervals, e.g. 0-20, 20-40, 40-60, 60-80, and 80-100 cm. Individual samples were uniquely identified by Reference Area, Transect Number, and Depth. Samples were transported to Duke in plastic bags where they were opened and allowed to air-dry for a minimum of 2 weeks. After air-drying, samples were passed multiple times through a #10 sieve (2-mm mesh) to separate soil from > 2-mm fraction. Obtaining pre-sieve bulk soil mass, and post-sieve >2-mm mass, allowed >2-mm mass fraction to be estimated. The < 2-mm fraction was transferred to paper bags for oven-drying at 40C for 48-72 hours. Texture was measured on the oven-dry sample using a standard method based on gravitational sedimentation. The lab SOP is available upon request.

ABSTRACT:

Discharge, stage, water temperature, and electrical conductivity/specific conductance (25° C) measured at 90° v-notch weir.
Date Range Comments: 5-minute resolution

ABSTRACT:

Water table measured in 3.84 m well. Well is screened below B-horizon and solid above.

ABSTRACT:

Well water depths in deep groundwater well in the Stone's pasture at the CCZO. Groundwater well is situated in a mostly flat, broad interfluve and is cored to ~70m. Well casing ends at roughly 17m. Depths were measured continuously with a Solinst levellogger (3001 LTC) pressure transducer at a resolution of 20 minutes. Downloaded data is in positive depths above the sensor. These depths are corrected for barometric pressure by subtracting barometric pressure measured by a Solinst barologger (3001) which is co-located in the well and records barometric pressure at the same frequency. The data are then converted from depth above the sensor into depths below ground surface using manual measurements of depth below ground made at each download with a water level meter.

ABSTRACT:

In 18 30-m diameter vegetation plots litter was collected once a month, twice a month in the fall (Jan-Oct: monthly, Nov-Dec: twice monthly). There were 4 litter baskets (laundry baskets) in each plot, located 10 m N, S, E, and W of the plot center. The litter from all 4 baskets was combined into one collection bag. Litter was dried, sorted by species (2014-2015 only), and weighed.
Date Range 10/21/2014 - 1/11/2019. Comments: collected once monthly Jan-Oct, twice monthly Nov-Dec.

ABSTRACT:

This is water chemistry data for stream samples collected monthly from July 2014-December 2018 within the Tyger River and Enoree River watersheds, including Holcombe’s Branch, Padgett’s Creek, Isaac Creek, Johns Creek, and Sparks Creek. These grab samples were obtained by dipping new 50mL polypropylene (PP) tubes into the stream channel. Care was taken to sample upstream of any disturbance caused by entering stream channel. Three tubes were filled at each sampling location and returned to the lab for filtration and analysis. Beginning in 2015, pH and conductivity were measured directly when collecting samples. In the lab, the 3 tubes from each sampling location were composited for vacuum filtration using Whatman Nuclepore 0.4 um polycarbonate membranes. The filtered sample was divided into 3 new PP tubes and stored at 4C prior to analysis. To analyze: 1) Dispense 20mLs of sample into glass tube; 2) Allow sample to reach equilibrium with room temp; 3) Calibrate temperature correction on YSI Model 32 Conductance Meter using 0.0001N, 0.0005N, and 0.001N KCl; 4) Immerse conductivity cell into sample, and swirl to eliminate air pockets; 5) Check range and temperature correction for each sample, adjust if necessary; 6) Allow reading to stabilize, record result in uS after stable for 30 sec; 7) Remove cell, place stir bar in tube, place tube on stir plate and mix for at least 15 minutes to allow sample to reach equilibrium with atmospheric CO2; 8) After calibrating pH meter (Brinkmann Model Phi 360) on pH 4 and 7 buffers, immerse pH electrode; 9) Reading may take several minutes to stabilize; 10) Record pH when change in value is less than 0.02 units on successive readings; 11) While continuously stirring, place titrator (Metrohm Model 665 Dosimat) dispensing tip in tube; 12) End of tip should align with bulb of electrode without touching; 13) Dispense titrant (0.005N HCl) until pH 5.00, 4.5, and 4.2 are reached; 14) Record volume when endpoint is stable for 15 sec; 15) Convert volume to meq/L alkalinity. 16) Measure Anions and cations of filtered samples by ion chromatography (IC) and inductively coupled mass spectrometry (ICP). 17) Measure TOC/TN by TOC-V CSH/CSN (Shimadzu).
Date Range Comments: monthly

ABSTRACT:

The National Center for Airborne Laser Mapping (NCALM) conducted a leaf-off LiDAR survey of the Calhoun CZO area in a single flight on February 26, 2016 (day of year 057). Data is publicly available at the OpenTopography link below.

Total lidar returns: 3,545,529,957 pts

Area: 78.30 km2

Point Density: 45.28 pts/m2

Raster Resolution: 1 meter

ABSTRACT:

Scanned photographs and slides and accompanying textual documentation from the Calhoun Experimental Forest, South Carolina 1932 – 1987. Photos and slides document the landscape at time of purchase by the United States Forest Service and later, landscape modifications, experimental plots, and researcher visits. We credit the Coweeta Hydrologic Laboratory for archiving the 35-mm slides and photos over the decades.

The scanned images have been processed, cropped, rotated and are stored in the .JPG format. The total size of the 866 photographs is 957 megabytes. Accompanying documentation for each photo is included in the CalhounCZO_photodatabase.xlsx file, which can be accessed by matching the image file name with its unique entry in the database.

Data Source: Calhoun Experimental Forest Archives, located at Coweeta Hydrological Laboratory, Otto, NC.

ABSTRACT:

Soil pits were dug to a depth of about 2 meters at ten locations in the Calhoun Critical Zone Observatory. The profiles were photographed by C. W. Cook on 19-20 October and 2 December 2016. These high-resolution photographs show the entire soil profile to the maximum depth of the pit in depth increments of approximately 45 cm. Three related files included here are a summary of the samples taken from the soil pits by many researchers and the soil pit profile descriptions by Lance Brewington and Gary Hankins of the USDA/NRCS in Laurens, SC and by Caitlin Hodges of the University of Georgia.

ABSTRACT:

These are soil texture data (% sand/silt/clay) for samples collected May-July 2015 and December 2016 in References Areas 1, 4, and 7 during the installation of gas wells. Samples were obtained by coring to depths of 500 cm with a bucket auger. From 50-500 cm, sampling occurred at fixed intervals: 50-100, 100-150, 150-200, 200-250, 250-300, 300-350, 350-400, 400-450, and 450-500 cm. In the upper 50 cm, samples were taken at the following depths: 0-7.5 cm, 7.5-15 cm, 15-30 cm, and 30-50 cm. Extracted soil was mixed on a tarp and sub-sampled in the field. Individual samples were uniquely identified by Reference Area, Gas Well Number, and Depth. Samples were transported to Duke in plastic bags where they were opened and allowed to air-dry for a minimum of 2 weeks. After air-drying, samples were passed multiple times through a #10 sieve (2-mm mesh) to separate soil from > 2-mm fraction. Obtaining pre-sieve bulk soil mass, and post-sieve >2-mm mass, allowed >2-mm mass fraction to be estimated. The < 2-mm fraction was transferred to paper bags for oven-drying at 40C for 48-72 hours. Texture was measured on the oven-dry sample using a standard method based on gravitational sedimentation. The lab SOP is available upon request.

ABSTRACT:

This tower is located in the young pine forest site of the Calhoun Critical Zone Observatory in South Carolina at 34.60811 N, -81.72247 E. Tower height is 9 m. CO2 concentration, water vapor concentration, and 3D wind speed are measured at 9 m at 10 Hz. Radiation including long wave and short wave is measured at 9 m. The air temperature and relative humidity are measured at five levels at 9m to 10 cm above the ground. Ground heat flux, soil temperature and soil moisture are measured from surface to 80 cm below ground. Additional measurements are made at 3 m height in the young pine forest and in a nearby cultivated field.

ABSTRACT:

Topic: The depth and persistence of land use effects on soil biogeochemistry at the Calhoun CZO

This file contains data of biogeochemical parameters of soils collected at the Calhoun CZO during 2015 and 2016 and analyzed at the University of Kansas. Please visit the “Read me” worksheet for a detailed explanation of the methods used to obtain the data.

Data in the worksheet “fixed depth sampling” originate from three Hardwood forest, three Pine forest and two cultivated sites. At each of these eight sites, we hand-augered and collected soil samples, integrating samples collected at depths between 40 and 50 cm, 100 and 150 cm, 150 and 200 cm, 250 and 300 cm, and 400 and 500 cm.

Data in the worksheet “Big Dig 2016” also originate from Hardwood forest, Pine forest and cultivated sites, ten sites in total. Instead of collecting soils from fixed depths, we sampled according to diagenetic soil horizons, as determined in joint group efforts during the “Big Dig” field trip in October 2016.

Contact:
Sharon.Billings@ku.edu
Department of Ecology and Evolutionary Biology, Kansas Biological Survey, University of Kansas, 2101 Constant Ave., Lawrence, KS 66047, USA

ABSTRACT:

Historic agricultural practices throughout the Piedmont region of the southeastern United States from ~1820 to 1940 led to accelerated erosion. Practices, such as tilling, degraded soil quality altering hydrologic processes on the landscape by limiting infiltration and leading to overland flow and erosion. Erosion due to these practices has substantially redistributed sediment from upper to lower landscape positions, causing a change in the depth-to-argillic horizon along hillslopes. By mapping the depth to argillic horizon within watersheds that have a history of farming and watersheds with little evidence of agricultural disturbance, a better understanding of the effects of farming practices on erosion and sediment redistribution can be made. This study uses extensive soil sampling within historically farmed and unfarmed watersheds to map spatial variations in the depth to argillic horizon. In addition to sampling, Electro-magnetic Induction (EMI) is being tested and calibrated to clay content and other topographic characteristic (i.e. landscape position, aspect, percent slope) from which the depth to argillic horizon can be predicted. Current hillslope and watershed hydrologic models use characteristics from soil classification maps for parameterization, however, these soil maps may lack sufficient spatial detail and may not accurately represent landscapes that have been eroded from historical farming. The results from this study will improve understanding of previous erosion on sediment redistribution and will characterize the potential use of electromagnetic induction as an accurate and efficient means to predict the depth to the argillic horizon. This information will improve parameterization of hillslope and watershed hydrologic models.

ABSTRACT:

Soil rock chemistry data set for 'Big Dig' 2016 soil pits and Rose Hill.

ABSTRACT:

Capacitance rod installed in Weir 4 stilling pool, located in watershed 4, midway between USFS road 325 (top of hillslope) and Holcombe's Branch. Measuring Discharge/Runoff via stage (5 min resolution) in stilling pool of 90 degree v-notch weir and USFS rating curve: Q = 2.48*(h(ft))^2.49; Q = discharge in cfs, h = stage in feet. Discharge data converted to L/s. Runoff data, in mm/hr, calculated by normalizing discharge to watershed 4 area (6.9 ha). Capacitance water level meter is TruTrack, WT-HR 1000 (http://www.trutrack.com/WT-HR.html), manually donwloaded every six weeks.

Date Range Comments: Water Years 2015-2016

ABSTRACT:

This 1m resolution 2014 CCZO canopy height (units in meters) raster GIS dataset was generated by subtracting the 2014 ground/bare earth DEM from the 2014 first return LiDAR default raster dataset. It was processed to fill gaps where water was exposed (0m canopy height) and is in UTM 17 map projection.

ABSTRACT:

Shapefiles showing the extent of the 9 research areas as well as all sampling locations at the Calhoun Critical Zone Observatory

ABSTRACT:

Soil moisture data collected using a CPN 503 Elite Hydroprobe (Instrotek, Inc., Raleigh, NC, USA) inserted into 5 m deep wells lined with PVC tubing. Measurements are taken in 30 cm intervals at depths between 30 and 480 cm, measured from the mineral soil surface. Standard count (R) is collected once per sampling date before data collection. Counts are collected for 30 sec per sample. These data are collected concurrently with soil gas sample collections at three locations in the Research Area 1 cultivated fields, and in References Hardwood and Old Field Pine pairs in Research Areas 1, 4 and 7. Hydroprobe and soil gas data are also collected in 6 locations in a pine forest in Research Area 1. Calibration relating count data to soil moisture is still in progress.

ABSTRACT:

Map data for the original land grants in the present Enoree District of the Sumter National Forest, with dates and names of grantees. This data set consists of a GIS shapefile mosaic of the original survey plats for land grants from the king of England and the state of South Carolina for the years 1749-1851 for the Enoree District of the Sumter National Forest.

Dataset DOI: http://dx.doi.org/10.3886/ICPSR37078.v1

ABSTRACT:

Radiocarbon measurements of samples from soil pits excavated in October 2016 were analyzed by Alex Cherkinsky at the University of Georgia Center for Applied Isotope Studies. The site is a field that has been cultivated since at least 1933, perhaps much longer.

ABSTRACT:

Mineralogical and chemical data from the weathered portion of the 70m deep well located in the CCZO. Seven samples ranging from the surface to a depth of approximately 13 meters are the subject of varied analytics. This data set includes results from thin section petrography, X-ray powder diffraction (UGA Bruker D8 Advance, Co-radiation), energy dispersive spectroscopy (UGA JOEL Superprobe), and bulk sample elemental analysis (Actlabs: Canada, FUS-ICP and GRAV methods).

Data

Thin sections photos (representative) 7 samples (0 to 13.7 m) using 5X, 10x, 20X and 50x objective magnifications (photos are paired in plane polarized and cross polarized light). Summary of observations for thin sections.

X-ray diffraction patterns of size fractions of the 7 samples (0 to 13.7 m) in waterfall display. Comments and annotations are made on each figure to note mineralogical trends. Quantitative analysis of size fractions using Rietveld refinement method. Include mineral tau plots (after Brimhall et al, 1988), assuming quartz is conservative.

Bulk elemental data for 7 samples (0 to 13.7 m). Includes plot of chemical alteration index (CAI).

Elemental data for micas/hydrous phyllosilicates/clay minerals in 7 samples (0 to 13.7 m) from energy dispersive spectroscopy with selected backscatter electron images. Plots of selected paired element concentrations are includes with annotations to the figures.

ABSTRACT:

US Forest Service survey and land use maps for purchase tracts in the Enoree District, Sumter National Forest. These maps have some information on the land use history of the Calhoun Critical Zone Observatory.

ABSTRACT:

Site: Locations within the Calhoun where measurements were taken, based on naming conventions used within the CCZO. LTSE II-10 Long Term Soil Experiment Rx Reference Site x WSx Watershed 1 Landscape Position: Position on hillslope within the site where measurements were taken (and some samples collected). Upslope, Midslope, and Toeslope. Note: All LTSE II-10 samples were collected on upland soil with no slope. UniqueID Created for sample transfer to Allan Bacon, including date of collection, collectors initials, area, landscape position & depth Depth (cm) The depth at the bottom of the augered hole. Soil samples were collected right above this depth. As the protocol developed, some soil samples in the LTSE site were taken above, at, and/or below the KSAT measurement depth, as noted by "AB","AT"or "B" next to the depth. This collection method will no longer take place Ksat & Ksat Class Ksat calculated with spreadsheet provided by xxxxx Ksat Class Class Limits (Range)     According to https://www.nrcs.usda.gov/wps/portal/nrcs/detail/soils/ref/?cid=nrcs142p2_053573 (cm/hr)   NRCS Ksat classification outlined in National Soil Survey Handbook Very High ≥ 36 High 3.6-36 Moderately High 0.36-3.6 Moderately Low 0.036-.36 Low 0.0036-0.036 Very Low <.0036 Latitude and Longitude: Geoid: GCS_WGS_1984 Datum: D_WGS_1984 Projection: No Projection Angular Unit: decimal degrees

Variables: Ksat (cm/hr)

Standard Variables: Hydraulic Conductivity

Date Range: (2017-06-13 to 2017-07-28)

Dataset Creators/Authors: Ryland, Rachel; Markewitz, Daniel; Sutter, Lori

Contact: Lori Sutter, Warnell School of Forestry and Natural Resources, University of Georgia, lsutter@uga.edu

Field Area: Calhoun CZO Research Area 2 | Calhoun CZO Research Area 3

ABSTRACT:

A Campbell weather station (ET107 Evapotranspiration Monitoring Station) was installed in Research Area 3 of the Calhoun Critical Zone Observatory (34.60945, -81.69092) by John Mallard and Will Cook on 21 August 2018.