Figure 1.
Fit of temperature time series with discrete Fourier transforms at the daily frequency Kd.
Air temperatures are in blue, crop canopy temperatures are in green and soil temperatures are in brown.
Figure 2.
Maps showing the differences between local air temperatures and the WorldClim interpolated minimum (A) and maximum (B) (Δ Air L − Air WC).
Blue colours indicate Δ Air L − Air WC <0, i.e. area where local air temperatures are cooler than those gave by WorldClim. Red colours indicate Δ Air L − Air WC >0, i.e. area where air local temperatures are warmer than the ones gave by the WorldClim. White colours Δ Air L − Air WC = 0 indicate areas where air WorldClim temperatures equate air local temperatures (±1°C). The extent and position of each square is equal to the spatial resolution of the WorldClim database: 30-arc sec that is the equivalent of 0.86 km2 for the study area. Temperatures in storages were obtained from [26].
Figure 3.
Maps showing the differences between local air canopy and soil temperatures with the air local for minimum (A) and maximum (B) (Δ Layer L − Air L).
Colour code is given in Figure 2.
Figure 4.
Mean thermal buffering from Fourier transforms at the daily frequency for canopy (A, B) and soil temperatures (C, D) as a function of elevation and leaf area index.
(A, C) show the daytime temperature excursion with respect to air, whereas (B, D) are the equivalent results for night-time temperatures. The 95% interval of confidence is given between brackets. Blue colours show colder temperatures than air. Red colours show warmer temperatures than air.
Table 1.
Results of the two-way ANOVA with a Bonferroni correction on the effects of habitat, elevation, LAI and elevation × LAI terms on daytime and nigh-time DFT amplitudes and thermal time lag on inside-canopy and soil temperature time series.
Figure 5.
Thermal time lag from Fourier transforms at the daily frequency for canopy (A) and soil temperatures (B) as a function of elevation and leaf area index.
The z-axis (log+1 transformed) is expressed in minutes (A) and in hours (B).
Figure 6.
Superimposed plot of the temperature-dependent growth rate curve of the potato moth Phthorimaea operculella (dashed line) and the frequency distribution (% of area) of average minimum (blue), maximum (red) and mean (striped) temperatures for canopy and soil layers at the three studied elevations.
Grey (shaded) bands in the background represent the WorldClim minimum and maximum temperature range.