Figure 4

Environmental temperature ranges, current monthly average temperature variation ranges, and monthly average temperature variation ranges after a temperature increase of 3 °C of the five populations.

(a) Enshi, (b) Xiuning, (c) Lechang, (d) Rongshui, and (e) Xinyin. The curves shown in the figure are quadratic RGR-temperature function regression curves (Enshi: y  = −0.0001x² + 0.005x − 0.0297 [R² = 0.40, P = 0.001]; Xiuning: y = −0.00008x² + 0.0038x − 0.0227 [R² = 0.16, P = 0.081]; Lechang: y = −0.00007x² + 0.0038x − 0.0198 [R² = 0.24, P = 0.017]; Rongshui: y = −0.00009x² + 0.0044x − 0.0235 [R² = 0.18, P = 0.051]; Xinyi: y = −0.0001x² + 0.0057x − 0.0438 [R² = 0.38, P = 0.001]). The blue areas indicate the current monthly average temperature variation ranges of the provenances of the populations. The red areas indicate the monthly average temperature variation ranges of the provenances of the populations after a temperature increase of 3 °C.