Table 2. Average and maximum temperature differences between internal temperature of intact C. revoluta cones (Tcone) and ambient air temperature (Tair)

Averages ± sd are presented for Tcone, Tair, and ΔT (Tcone − Tair). Maximum temperature differences are shown as ΔTmax, and the times at which differences were measured are shown as tTmax.

Sex of ConesAverage Temperature (°C)Average Difference (°C)Maximum Difference (°C)Times
TconeTairΔTΔTmaxtTmax
Malea29.69 ± 2.2523.58 ± 3.406.19 ± 1.0911.52:18
Femalea31.48 ± 3.5228.28 ± 3.673.35 ± 0.58*8.319:01
Maleb27.72 ± 1.8921.39 ± 1.515.80 ± 1.469.52:32
Femaleb27.39 ± 0.8123.31 ± 0.684.055.419:46
  • a Temperature data for intact male cones (n = 3), intact female cones (n = 4), and ambient air were recorded over 10 successive days and used to calculate the average and maximum differences between Tcone and Tair. The asterisk indicates a significant difference (Student’s t test; P < 0.05) between male and female ΔT values.

  • b Data corresponding to the day that temperature did not exceed 25°C were extracted from the 10-day data and used to calculate the average and maximum differences between Tcone and Tair on that particular day. Since only one female cone experienced air temperature that did not exceed 25°C, as shown in Fig. 1B right (blue background), the statistical analysis between male ΔT and female ΔT could not be executed. Male cones bloom earlier than female cones, and therefore, it is more likely that male cones will be exposed to cooler weather conditions.