The neotropical genus Inga (Fabaceae) is a fast-growing tree component of tropical forests which plays crucial ecological and functional roles. However, its diversity patterns and the specific environmental drivers that structure its distribution in Andean landscapes remain insufficiently documented. This study aimed to quantify the diversity and distribution of Inga species in the province of Imbabura (4785 km²), northern Ecuador, while evaluating the influence of key environmental determinants. By integrating 52 field records along 321 km of exploration and 22 herbarium records (QCNE, MO, AAU, F, HUTN), the study analyzes the role of topographic variables (12.5 m resolution) and climate data (1 km² resolution). Seventeen species were recorded, almost tripling previous regional findings. The results demonstrate that species richness and occurrence are strongly structured by altitude, temperature, and soil properties as primary environmental drivers. Ten species showed narrow altitudinal ranges and limited thermal tolerance (<2 °C), indicating high habitat specialization, while I. densiflora and I. insignis exhibited broader niches. Edaphically, most species were associated with sandy loam soils, particularly Mollisols and Inceptisols developed from volcanic material. These findings indicate that climatic gradients and edaphic conditions act as the main environmental filters shaping Inga assemblages in heterogeneous montane landscapes. The observed high level of specialization suggests significant vulnerability to land-use change and highlights the need for habitat-specific conservation strategies in Andean forests.

The genus Inga Mill. (Fabaceae: Mimosoideae) comprises approximately 300 species distributed across the American tropics, playing key ecological roles in Andean forest ecosystems. In this study, occurrence data for 17 Inga species in Imbabura Province, Ecuador, were compiled through the review of five national and international herbaria (HUTN, QCNE, MO, AAU, F) and field expeditions conducted during 2024–2026, yielding a total of 181 georeferenced records. Potential distribution models were generated using the Maximum Entropy algorithm (MaxEnt v.3.4.4) for 10 species with sufficient records (≥ 6 presence points), integrating bioclimatic (WorldClim 2.1), edaphic (SoilGrids 2.0), and land-cover variables, pre-selected after multicollinearity screening (Pearson |r| < 0.75). Model validation was performed using the Area Under the ROC Curve (AUC), True Skill Statistic (TSS), and Jackknife tests. Training AUC values ranged from 0.9519 (I. cocleensis) to 0.9968 (I. punctata); TSS values ranged from 0.72 (I. striata) to 0.98 (I. feuillei), confirming high discriminative capacity. Seven species were classified as habitat specialists restricted to altitudinal ranges ≤ 400 m, and three as generalists spanning > 600 m of elevation. Productive land-use systems, water vapor pressure, geopedological units, and bioclimatic temperature and precipitation variables were the most influential predictors. Areas of high suitability for multiple species simultaneously (≥ 40% overlap) were concentrated in the cantons of Cotacachi, Otavalo, and Ibarra, identifying priority zones for conservation and sustainable agroforestry management in the Ecuadorian Andes.

The Neotropical genus Inga (Fabaceae) is a dominant component of tropical forests and plays important ecological and functional roles; however, its diversity patterns and environmental controls across Andean landscapes remain poorly documented under increasing deforestation pressure. This study quantified the diversity, distribution, and environmental determinants of Inga species in the Imbabura Province, northern Ecuador, by integrating field surveys along five elevational transects, herbarium records, and Geographic Information Systems (GIS)-based analyses of climatic and edaphic variables. We recorded 17 species, nearly tripling previous regional findings. Species richness and occurrence were strongly structured by altitude, temperature, and soil properties. Ten species showed narrow altitudinal range and limited thermal tolerance (<2 °C), indicating habitat specialization, whereas I. densiflora and I. insignis exhibited broader niche breadths and generalist behavior. Edaphically, most species were associated with sandy loam soils, particularly Mollisols and Inceptisols. These results indicate that environmental gradients and soil conditions act as primary filters shaping Inga assemblages in heterogeneous montane landscapes. The high level of specialization observed suggests elevated vulnerability to land-use change and highlights the need for habitat-specific conservation strategies in Andean forests.