Latitudinal and Elevational Shifts in South Korean Plant Occurrence Records: Sensitivity to Sampling Heterogeneity

National occurrence databases combine sources with different objectives and spatiotemporal coverage, complicating the interpretation of changes in recorded locations. We evaluated the sensitivity of species-level shifts in mean recorded latitude and DEM-derived elevation to analytical specifications in an integrated South Korean vascular-plant database of 1,351,189 records, using 1980–2023 records for period-specific analyses. Empirical sensitivity comparisons were combined with controlled simulations of known centroid displacement. The primary analysis retained 1281 species and yielded across-species median shifts of +0.171° latitude and −102.7 m elevation. Aggregate estimates were similar before and after spatial thinning and record-count balancing. Positive latitude medians persisted under most specifications, but not under every spatial-support definition. Elevation estimates were more sensitive to temporal weighting and source composition: annual equal weighting reduced the median shift to −17.1 m, and omitting National Park records reversed its sign. In simulations, subtracting an assemblage-derived footprint markedly reduced recovery of imposed displacement. The empirical analyses characterize directional occurrence-centroid patterns and their sensitivity, rather than establish biological movement. Footprint subtraction cannot be assumed to recover unbiased change, and consistency across specifications does not demonstrate the absence of residual sampling bias.