Stand Delineation of Pinus sylvestris L. Plantations Suffering Decline Processes Based on Biophysical Tree Crown Variables: A Necessary Tool for Adaptive Silviculture

Many planted Pinus forests are severely affected by defoliation and mortality processes caused pests droughts. The mapping of forest tree crown variables (e.g., leaf area index pigments) is particularly useful in stand delineation for the management declining forests. This work explores potential integrating multispectral WorldView-2 (WV-2) Airborne Laser Scanning (ALS) data based on selected sylvestris plantations southern Spain. Needle pigments (chlorophyll carotenes) (LAI) were quantified. Eight vegetation indices ALS-derived metrics produced, seven predictors to estimate map using a Random Forest method Gini index. Chlorophylls b (Chla Chlb) significantly higher non-defoliated moderately defoliated trees than (F = 14.02, p < 0.001 Chla; F 13.09, Chlb). A similar response was observed carotenoids (Car) 14.13, 0.001). LAI also showed significant differences among levels 26.5, model chlorophyll pigment used two indices, Plant Senescence Reflectance Index (PSRI) Carotenoid (CRI); three WV-2 band metrics, ALS metrics. built describe Chlb content variables. classification established with single index, Green Normalized Difference Vegetation (GNDVI); blue band, contents models provided R2 values 0.87 (Chla, RMSE 12.98%), 0.74 (Chlb, 10.39%), 0.88 (Car, 10.05%). cross-validated confusion matrix achieved high overall accuracy (84.05%) Kappa (0.76). Defoliation Chla validation segmentations and, therefore, generation delineation. total 104 stands delineated, ranging from 6.96 54.62 ha (average 16.26 ha). distribution predicted severity P. mosaic patterns at individual scales. Overall, findings this underscore integration assessment health status. derived cartography relevant tool developing adaptive silvicultural practices reduce risk due climate change.