<p>Trail penetration within strictly designated protected areas is often treated as a conservation concern, yet its consequences for vegetation trends at national scales remain empirically unresolved. This study evaluated whether trail penetration was associated with detectable vegetation-trend differences across all 213 Special Protection Areas (SPAs) in Korean national parks using Sentinel-2 NDVI time series, equivalence testing (TOST), Markov-chain risk projections, and media discourse analysis. At the SPA polygon scale, trail-penetrated and non-penetrated SPAs showed no statistically detectable difference in NDVI trend slopes (Welch’s t = −0.2925, <i>p</i> = 0.7703). Practical equivalence was supported under the selected management-oriented margin of Δ = ±0.003 NDVI yr⁻¹ (TOST max <i>p</i> = 0.009), but not under stricter bounds (Δ ≤ ±0.002), indicating that equivalence is margin-dependent rather than absolute. Markov-chain projections showed that the 3-year horizon retained spatial differentiation between risk classes (Caution: 130; High Risk: 83), whereas 5-year and 10-year projections converged to a single Caution class under the stationarity assumption. Media discourse emphasized governance and regulatory concerns, suggesting a perception gap between public narratives and satellite-derived vegetation indicators. These findings suggest that trail penetration does not necessarily translate into detectable SPA-scale canopy-vitality decline under current monitoring conditions, but they do not rule out localized trail-edge impacts below the spatial and ecological sensitivity of polygon-level NDVI indicators.</p>