January 7, 2026 Dataset Open Access

Data publication: Elemental data from transpired fluid from Norway spruce needles of the Horizon 2020 project NEXT

Pospiech, Solveig; Middleton, Maarit

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.

2. Column description

**Field Descriptions for Repository Metadata**

#### **Point Identification & 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").

#### **Geophysical & Electrical Properties**
9. **conductivity_ph-acid** – Electrical conductivity (EC) measured after acidification (mS/m).
10. **conductivity_ph-initial** – Initial EC of the soil sample (mS/m).
11. **conductivity_pit** – EC measured in the field pit (mS/m).
12. **conductivity** – Conductivity averaged or processed for analysis (units vary).
13. **dielectric permittivity_pit** – Dielectric constant measured in the pit (proxy for soil moisture).
14. **dielectric permittivity** – Processed or averaged dielectric permittivity value.
15. **pH_initial** – Initial pH of the soil sample.
16. **pH_with acid** – pH after acidification (indicates buffer capacity).
17. **pore water conductivity** – EC of extracted pore water (mS/m).

#### **Geospatial & Environmental Context**
18. **VTEM, TMI, APR** – Geophysical survey metrics (VTEM = Vertical Electromagnetic, TMI = Total Magnetic Intensity, APR = Airborne Radiometrics).
19. **Soilwetness** – Categorical soil wetness classification (e.g., `mesic`, `sub-xeric`).
20. **Soiltype** – Predominant soil type (e.g., `mineral soil`, `peat`).
21. **Naturetype** – Ecological classification (e.g., `Boreaaliset luonnonmetsät` = "Boreal natural forests").
22. **TMI_class** – Categorization of Total Magnetic Intensity (e.g., `low`, `middle`, `high`).
23. **Lithology** – Original rock type classification (e.g., `Calcsilicate rocks`, `Mafic rocks`).
24. **Lithology_updated** – Updated lithological classification (refining earlier interpretations).
25. **Lithology_updated_Sol** – Lithology-specific to soil horizons (e.g., `Mafic rocks + quartzite`).
26. **Mineralization** – Qualitative assessment of mineralized zones (e.g., `barren`, `potential`, `min`).
27. **Deposit** – Type of geological deposit (e.g., `Till`, `hardpan layer`).
28. **TMI_cat, VTEM_cat, APPRES_cat** – Categorized geophysical survey results (e.g., `high` intensity).
29. **vegetation_class_EFTAS** – Vegetation classification (e.g., `mesic heath forest`).
30. **i.ID_num** – Redundant numeric ID (same as `ID_num`).
31. **x, y** – Cartesian coordinates for the sampling point.
32. **Fotos** – Reference to associated field photos (e.g., `104-0905`).

#### **Site & Sampling Details**
33. **GeneralSiteDescription** – Textual description of terrain (e.g., "flat, paludified area starts 1m below").
34. **ForestType** – Dominant forest type (e.g., `VMT` = "Välimetsä" [forest type code]).
35. **Soil_paludification** – Degree of peatland/wetland influence on soil (e.g., `not paludified`).
36. **Soil_nutrient_status** – Nutrient availability assessment (e.g., `normal`).
37. **Observations2019** – Anomalies or notes from 2019 fieldwork (e.g., "eggs of gnomes in upper podsol layer").
38. **SedimentType** – Type of sediment observed (e.g., `Till`, `Sand`).
39. **SedimentGenesis** – Origin of sediment (e.g., `glacial`, `alluvial`).
40. **Pointtype** – Classification of sampling point (e.g., `replicate`).
41. **TMI_intensity, VTEM_intensity, APPRES_intensity** – Quantitative geophysical survey intensities.
42. **GPS-Easting, GPS-Northing** – Precise GPS coordinates for the point.
43. **SampleID** – Unique identifier for lab samples (e.g., `TF-NEXT-2019-193-NrS-tf-0A`).
44. **Date_full** – Timestamp of sample collection/analysis.

#### **Geochemical Data**
45. **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`.