Spatiotemporal dynamics of land use and land cover in Ecuadorian Andes (1990–2020)

High-Andean ecosystems rank among the most biodiverse and environmentally sensitive landscapes on Earth, yet they remain highly vulnerable to land use and land cover (LULC) changes driven by agricultural expansion and demographic pressure. The objective of this study was to quantify and analyze LULC dynamics between 1990 and 2020 in three parishes of Chimborazo Province, Ecuador: Achupallas, Columbe, and Quimiag, representing contrasting environmental and socioeconomic settings. The study focused on the transformation of native ecosystems, particularly paramo ecosystems and Andean forests, into croplands, pastures, and exotic forest plantations. Multitemporal Landsat imagery from 1990, 2000, 2010, and 2020 was analyzed using remote sensing and Geographic Information Systems. Annual rates of change, land-cover transitions, land-use conflicts, and the influence of topographic and climatic factors were also evaluated. The results showed substantial reductions in paramo cover (4%–30% depending on the parish), while croplands expanded by 4%–18% and pastures by up to 22%, indicating a sustained expansion of the agricultural frontier. Forest cover followed a different trajectory: after an initial reduction between 1990 and 2010, a partial recovery was observed in the final decade, which may be associated with the implementation of the national "Socio Bosque" conservation incentive program. Land-use conflicts increased throughout the study area and were more pronounced in lower-elevation zones with gentler slopes and higher population pressure. These findings demonstrate that LULC dynamics in the Ecuadorian High-Andean region are strongly influenced by both environmental and socioeconomic factors. Strengthening land-use planning, ecological restoration, and conservation strategies is essential to reduce agricultural expansion and promote the sustainable management of native High-Andean ecosystems. By combining multitemporal remote sensing with topographic, climatic, and socioeconomic analysis at the parish level over three decades, this study provides the most comprehensive local-scale assessment of LULC dynamics in the central Ecuadorian High-Andes to date.