Two Decades of Non-Monotonic Arboreal Canopy Change and Spatial Reconfiguration in an Urban Mangrove Remnant of Guayaquil, Ecuador

Small urban mangrove remnants may undergo substantial spatial reorganization that regional land-cover products or endpoint area change alone poorly represent. Arboreal canopy dynamics were reconstructed in an urban estuarine sector within a common 12.75 ha cartographic region of interest (ROI) of the Estero Salado in Guayaquil, Ecuador, using twelve historical images with visually interpretable canopy boundaries accessed through Google Earth Pro v7.3.6 between 2003 and 2023. The mapped class represents a visible woody canopy rather than validated species-specific mangrove cover and may therefore include non-mangrove woody vegetation along terrestrial margins. Canopy polygons were quality-controlled and analyzed for area change, patch configuration, endpoint overlap, gain and loss, Jaccard similarity, and repeated presence; a December 2025 UAV orthomosaic provided an independent contemporary spatial reference. Mapped canopy area increased from 1.75 to 2.44 ha (+39.7%), but the trajectory was strongly non-monotonic. Between 2003 and 2023, 1.28 ha was mapped at both endpoints; 1.16 ha represented gain, and 0.472 ha represented loss, yielding 1.64 ha of gross mapped spatial turnover. The 2022–2023 interval alone accounted for 76.6% of the total net gain while including 0.303 ha of mapped loss. Patch configuration also changed substantially, and only 0.27 ha (7.6% of the 3.58 ha union footprint) were mapped as canopy at all twelve sampled dates, without implying uninterrupted presence between dates. By integrating canopy-area change with spatial turnover, patch configuration, and repeated canopy presence, this study provides a fine-scale monitoring framework capable of detecting internal spatial reorganization that endpoint area estimates alone may overlook in small urban mangrove remnants.