Enriched Time-Series Dataset of Polish Forest Composition (2009-2019)

This dataset contains processed forest inventory data from Polish State Forests covering the period 2009-2019. The dataset includes both original inventory measurements and derived metrics calculated using established forestry and ecological methods.
Dataset Contents:
Data files:

Original data with standardized classifications (1,260 records)
Annual summary statistics (11 years)
Biodiversity indices (Shannon, Simpson, Pielou's evenness, species richness)
Forest structure metrics (age distribution, weighted mean age)
Composition analysis (coniferous/deciduous ratios, dominant species)
Growth and productivity metrics (MAI, CAI, volume density)
Temporal trends (year-over-year changes)
Species-specific annual metrics (110 records: 10 species × 11 years)

Data Provenance System
Each calculated variable includes a companion column indicating its source:

RAW: Original measurement from inventory
RAW_SUMMED: Aggregated raw values
CALCULATED: Formula-derived from raw data
COUNTED: Direct count from data
DETERMINED: Identified through analysis

Documentation:

Data dictionary: Definitions for 100+ variables
Methodology: Formulas and scientific references for all calculations
Metadata: Explanation of source type categories
README: Dataset overview and usage information

Limitations:

Species are taxonomically aggregated (e.g., "Oak" includes multiple Quercus species)
National-level data without regional breakdowns
Avg_Age field provided only for species-level totals (Total_Area), not for age class breakdowns (110/1,260 records)
Age class midpoints estimated where exact distributions unavailable