Relative Environmental Suitability Modeling of Almaciga (Agathis philippinensis) in Davao Region, Philippines Using Geospatial-Based MaxEnt Framework Reveals Targeted Areas for Field Verification Assessments

Almaciga (Agathis philippinensis Warb.) is an ecologically and economically important forest tree in the Philippines, yet regional information on its environmental suitability remains limited. This study modeled current relative environmental suitability in the Davao Region using MaxEnt and a multicollinearity-controlled predictor-selection framework. From 504 assembled occurrence records, 1 km spatial thinning retained 36 records for modeling. Predictor screening reduced 20 climatic and topographic variables to maximum temperature of the warmest month (BIO5) and elevation. The model achieved training and testing AUC values of 0.8955 and 0.8415, respectively, indicating useful occurrence-background discrimination within the regional modeling domain. Elevation dominated the model, accounting for 95.28% of the contribution and 94.46% of the permutation importance. The retained occurrence records spanned 240–2804 m a.s.l., reflecting a broad regional elevational distribution. Higher predicted suitability was concentrated mainly in mountainous areas. The resulting map should be interpreted as a regional environmental-similarity and reconnaissance tool for guiding field verification rather than as evidence of confirmed occupancy or management suitability. Future validation should incorporate broader occurrence coverage and additional habitat and disturbance variables.