Impacts of T_max, T_min, PA, and Photo on accuracy of the AGSI model, which were assessed using satellite phenological data at (a–b) all alpine grassland sites, (c–d) alpine meadow sites, and (e–f) alpine steppe sites, respectively. The box plots give the 25^th (Q1) and 75^th (Q3) quantile, and middle of each box is the 50^th quantile. The black dots inside boxes indicate mean values. The lower and upper whiskers are Q3 + 1.5IQR and Q1–1.5IQR, respectively, with IQR = Q3–Q1.