Pan-European Phenological Data Analysis // Provides a framework for quality-aware analysis of ground-based phenological data from the PEP725 Pan-European Phenology Database (Templ et al. (2018) doi:10.1007/s00484-018-1512-8; Templ et al. (2026) doi:10.1111/nph.70869) and similar observation networks. Implements station-level data quality grading, outlier detection, phenological normals (climate baselines), anomaly detection, elevation and latitude gradient estimation with robust regression, spatial synchrony quantification, partial least squares (PLS) regression for identifying temperature- sensitive periods, and sequential Mann-Kendall trend analysis. Supports data import from PEP725 files, conversion of user- supplied data, and downloadable synthetic datasets for teaching without barriers of registration. All analysis outputs provide 'print', 'summary', and 'plot' methods. Interactive spatial visualization is available via 'leaflet'.