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LandClim Exports

LandClim exports provide Nordic pollen-sequence locations and REVEALS vegetation-reconstruction coverage. They are environmental context with their own observation units and time windows, not background decoration for an aDNA map.

Current Governed Surface

The checked-in normalized state contains:

Surface Count Observation unit
pollen site-sequence rows 490 dataset-specific site sequence
rows with supported numeric time bounds 368 site sequence with canonical numeric BP posture
rows with refused time bounds 122 112 negative-BP and 10 partial source intervals retained without canonical numeric bounds
aggregate REVEALS grid cells 77 discovery summary of reconstructed vegetation coverage
temporal REVEALS grid features 2,515 one dataset, cell, and published window
distinct modeled windows 25 explicit BP intervals available to the time filter

The normalized artifacts are:

  • data/landclim/normalized/nordic_pollen_site_sequences.csv for tabular reuse;
  • data/landclim/normalized/nordic_pollen_site_sequences.geojson for site locations;
  • data/landclim/normalized/nordic_reveals_grid_cells.geojson for aggregate reconstruction discovery;
  • data/landclim/normalized/nordic_reveals_temporal_grid_cells.geojson for time-filterable, dataset-specific reconstruction values and uncertainty;
  • data/landclim/normalized/landclim_bibliography.json for dataset citations and linked publications;
  • data/landclim/review/spatiotemporal_review.json for coverage and linkage verification; and
  • data/landclim/normalized/landclim_summary.json for layer identities and counts.

These paths identify the normalized family authority. Scope-specific copies in report bundles remain product members whose lineage leads back to these records; copying a feature into a map directory does not transfer ownership of its sequence identity or temporal posture.

flowchart LR
    Datasets["3 cited PANGAEA datasets"] --> Sites["490 site-sequence rows"]
    Datasets --> Grids["2,515 dataset-cell-window features"]
    Sites --> Time["368 rows with canonical numeric BP bounds"]
    Sites --> Refused["122 rows with explicit temporal refusals"]
    Sites --> Context["pollen-site context layer"]
    Grids --> Filter["atlas time filter"]
    Filter --> Context
    Time --> Compare["qualified temporal comparison"]

Site Rows And Grid Cells Are Not Interchangeable

A site row identifies one dataset-specific pollen sequence at a location and can carry its own time window, source URL, and sequence metadata. A grid cell summarizes published REVEALS coverage and can combine variables, datasets, and multiple time windows. One site can contribute to broader reconstruction context; that relationship does not make the site and cell the same record.

Names can recur across LandClim datasets. Stable record_id values retain the dataset and location identity needed to avoid merging similarly named site sequences by display label alone.

Temporal Reading

Numeric time_start_bp and time_end_bp values support interval-aware filtering for the 368 qualified rows. They do not guarantee equal dating resolution, identical sampling intervals, or event-level contemporaneity with an aDNA sample. The remaining 122 rows are not zero-dated: their source values remain inspectable while the canonical projection explicitly refuses 112 negative-BP intervals and 10 partial intervals.

REVEALS values are published as separate window features. The atlas selects them by their numeric BP bounds instead of filtering one aggregate cell that claims the whole Holocene. A selected window is still a modeled vegetation estimate, not a sample-owned chronology or evidence of a continuous value between adjacent windows.

The Marquer reconstruction contributes 309 grid-window features across 13 Nordic cells and 25 windows. LandClim I contributes 331 features across five windows. LandClim II contributes 1,875 across 25 windows and retains standard errors and cell quality where supplied. All 2,515 features have numeric bounds and bibliography links. Missing source estimates remain absent rather than becoming zero cover. The ten LandClim II site sequences without upstream numeric bounds remain explicitly unresolved rather than receiving synthetic dates.

Worked Record: Aal Præstesø

The normalized LandClim feature for Aal Præstesø demonstrates the minimum portable site-sequence claim:

Field Governed value Interpretation
record_id 897303:Aal Præstesø:55.637778:8.257222 dataset, label, and reported position form the retained record identity
country Denmark publication grouping, not the scientific identity
geometry 8.257222, 55.637778 GeoJSON longitude then latitude
source https://doi.org/10.1594/PANGAEA.897303 LandClim dataset lineage
interval 100-350 BP coverage attached to this site-sequence row
observation unit one site sequence not one pollen grain, sample event, or REVEALS cell

The interval permits interval-aware filtering at the site-sequence level. It does not state that every observation within the sequence has that date or that another record overlapping 100-350 BP represents the same event. If the feature is exported without its record_id, source DOI, and observation unit, the remaining name and point are insufficient to reconstruct that meaning.

flowchart LR
    Dataset["PANGAEA 897303"] --> Sequence["Aal Præstesø site sequence"]
    Sequence --> Place["reported point in Denmark"]
    Sequence --> Window["100-350 BP coverage"]
    Sequence --> Layer["LandClim pollen context"]
    Window -. "not an event date" .-> Layer

Reuse Contract

Keep record identity, source DOI, geometry type, observation unit, dataset, time bounds and label, record count, and popup/source details with each row. When aggregating, keep site sequences, aggregate discovery cells, and temporal grid features separate. State whether the denominator is 490 site rows, 368 numerically qualified site rows, 77 aggregate cells, or 2,515 dataset-cell-window features. Preserve dataset_id, parent_grid_record_id, numeric BP bounds, reconstruction values, uncertainty, and bibliography keys when extracting temporal features.

Continue to LandClim source guidance for acquisition and normalization, maps for layer interpretation, and chronology guidance for cross-family time claims.