“…Spectral index values were estimated for each leaf using the mean of these 24 measurements. Spectral indices, including Water Band Index (WBI) for leaf water content (Peñuelas, Llusià, Piñol, & Filella, 1997), modified Normalized Difference Vegetation Index (mNDVI) for chlorophyll content (Fuentes, Gamon, Qiu, Sims, & Roberts, 2001), Photochemical Reflectance Index (PRI) for xanthophyll cycle pigments (Gamon, Peñuelas, & Field, 1992), red–green ratio (RGR) for anthocyanin content (Fuentes et al., 2001), Structure Intensive Pigment Index (SIPI) for carotenoid‐to‐chlorophyll a ratio (Peñuelas, Baret, & Filella, 1995), red–far‐red ratio (RFR) (Mascarini, Lorenzo, & Vilella, 2006), and Normalized Phaeophytinization Index (NPQI) for chlorophyll degradation (Barnes, Balaguer, Manrique, Elvira, & Davison, 1992), were calculated as follows,…”