1. Overview

This repository contains the final, cleaned chemistry data that were produced from the 2019 Raja field campaign of the Horizon 2020 Project NEXT. The data combine:

Norway spruce needle transpired fluids concentrations for a set of selected elements.
Corresponding soil‑till depth, point location, lithology and basic tree information.
Element‑specific relative‑standard‑deviation (RSD) uncertainties that were calculated from laboratory‑derived uncertainty parameters.

All files are provided in CSV format (UTF‑8, , separator) and/or the R programming language binary format RData.

1. Column description

Field Descriptions for Repository Metadata

1. PointID – Unique identifier for each sampling point in the dataset (e.g., NEXT-2019-193).
2. till_depth – Depth of the till layer (in meters) at the sampling location.
3. ID_num – Numeric identifier for the point (e.g., 193).
4. grainsize_2mm_pct – Percentage of grain size >2mm in the soil sample (proxy for rock fragments or coarse material).
5. OM_thickness – Thickness of organic matter (cm) in the soil profile.
6. Soilwetness_by_photo – Soil wetness category inferred from field photos (e.g., mesic = moist, sub-xeric = moderately dry).
7. Soilwetness_cat – Numeric ranking of soil wetness (likely 1–7, with 1 = driest, 7 = wettest).
8. notes_by_photos – Qualitative observations from site photos (e.g., "paludified areas nearby," "boulders present").

1. conductivity_ph-acid – Electrical conductivity (EC) measured after acidification (mS/m).
2. conductivity_ph-initial – Initial EC of the soil sample (mS/m).
3. conductivity_pit – EC measured in the field pit (mS/m).
4. conductivity – Conductivity averaged or processed for analysis (units vary).
5. dielectric permittivity_pit – Dielectric constant measured in the pit (proxy for soil moisture).
6. dielectric permittivity – Processed or averaged dielectric permittivity value.
7. pH_initial – Initial pH of the soil sample.
8. pH_with acid – pH after acidification (indicates buffer capacity).
9. pore water conductivity – EC of extracted pore water (mS/m).

1. VTEM, TMI, APR – Geophysical survey metrics (VTEM = Vertical Electromagnetic, TMI = Total Magnetic Intensity, APR = Airborne Radiometrics).
2. Soilwetness – Categorical soil wetness classification (e.g., mesic, sub-xeric).
3. Soiltype – Predominant soil type (e.g., mineral soil, peat).
4. Naturetype – Ecological classification (e.g., Boreaaliset luonnonmetsät = "Boreal natural forests").
5. TMI_class – Categorization of Total Magnetic Intensity (e.g., low, middle, high).
6. Lithology – Original rock type classification (e.g., Calcsilicate rocks, Mafic rocks).
7. Lithology_updated – Updated lithological classification (refining earlier interpretations).
8. Lithology_updated_Sol – Lithology-specific to soil horizons (e.g., Mafic rocks + quartzite).
9. Mineralization – Qualitative assessment of mineralized zones (e.g., barren, potential, min).
10. Deposit – Type of geological deposit (e.g., Till, hardpan layer).
11. TMI_cat, VTEM_cat, APPRES_cat – Categorized geophysical survey results (e.g., high intensity).
12. vegetation_class_EFTAS – Vegetation classification (e.g., mesic heath forest).
13. i.ID_num – Redundant numeric ID (same as ID_num).
14. x, y – Cartesian coordinates for the sampling point.
15. Fotos – Reference to associated field photos (e.g., 104-0905).

1. GeneralSiteDescription – Textual description of terrain (e.g., "flat, paludified area starts 1m below").
2. ForestType – Dominant forest type (e.g., VMT = "Välimetsä" [forest type code]).
3. Soil_paludification – Degree of peatland/wetland influence on soil (e.g., not paludified).
4. Soil_nutrient_status – Nutrient availability assessment (e.g., normal).
5. Observations2019 – Anomalies or notes from 2019 fieldwork (e.g., "eggs of gnomes in upper podsol layer").
6. SedimentType – Type of sediment observed (e.g., Till, Sand).
7. SedimentGenesis – Origin of sediment (e.g., glacial, alluvial).
8. Pointtype – Classification of sampling point (e.g., replicate).
9. TMI_intensity, VTEM_intensity, APPRES_intensity – Quantitative geophysical survey intensities.
10. GPS-Easting, GPS-Northing – Precise GPS coordinates for the point.
11. SampleID – Unique identifier for lab samples (e.g., TF-NEXT-2019-193-NrS-tf-0A).
12. Date_full – Timestamp of sample collection/analysis.

1. Al, B, Ba, Bi, ... Zn – Concentrations of elements (likely in ppm/mg/g) measured via lab analysis (e.g., ICP-MS).    Note: These columns represent a full suite of geochemical elements (e.g., Aluminum, Barium, Lead, Zinc) critical for mineral exploration, environmental studies, or soil health assessments.

Key Notes for Repository Users

• Units: Conductivity (mS/m), pH (unitless), dielectric permittivity (dimensionless), GPS coordinates (meters, local system).
• Categorical Fields: Wetness, lithology, and mineralization use standardized codes (e.g., mesic vs. xeric).
• Geophysical Data: VTEM/TMI/APR are airborne survey metrics linked to subsurface mineralization.
• Geochemical Data: Elemental concentrations are essential for understanding soil fertility, contamination, or ore potential.

Suggested Use Cases

• Mineral Exploration: Cross-reference Mineralization + TMI_cat with elemental data (e.g., high Fe, Cr for mafic rocks).
• Soil Science: Analyze Soilwetness vs. dielectric permittivity to model moisture regimes.
• Ecological Studies: Correlate vegetation_class_EFTAS with Soil_nutrient_status.