## 3 Results
### Soil Temperature  
The average hourly air and substrate temperature variations in the three irrigation treatments of each of the three species during a typical day (17 August 2009; Figure 3a). Air temperatures underwent an oscillation of 18.7 \({}^{\circ}\)C over the course of one day; in the irrigated substrates temperatures oscillated between 6.8 and 9 \({}^{\circ}\)C, and in the non-irrigated substrate oscillation was between 8.6 and 11.7 \({}^{\circ}\)C. Maximum substrate temperature usually occurred 4/5 h after maximum air temperature. The hourly minimum temperatures throughout a typical winter's day (17 December 2009, Figure 3b), in the 40% ET\({}_{0}\) treatment varied between 5 and 10 \({}^{\circ}\)C, in the 20% ET\({}_{0}\) treatment they varied between 2.5 and 9 \({}^{\circ}\)C, and in the non-irrigated treatment they were between 4.2 and 10.8 \({}^{\circ}\)C. On the same day, air temperatures varied between 1.7 and 13 \({}^{\circ}\)C. \begin{table}
\begin{tabular}{c c c c c c c c} \hline \hline \multicolumn{2}{c}{**Rainfall**} & \multicolumn{4}{c}{**Variation after Each Rain (L/m\({}^{2}\))**} & \multicolumn{4}{c}{**Variation after 60 h of Rain (L/m\({}^{2}\))**} \\ \hline
**Events** & **Amount** & _D. margaretae_ & _F. laevis_ & _I. lutescens_ & _D. margaretae_ & _F. laevis_ & _I. lutescens_ \\ \hline
10 August 2009 & 27.3 mm & +7.03 & +10.56 & +4.04 & \(-\)2.93 & \(-\)4.81 & \(-\)1.97 \\
15 September 2009 & 48.3 mm & +5.94 & +9.96 & +5.33 & \(-\)2.70 & \(-\)4.20 & \(-\)2.21 \\
20 September 2009 & 23.3 mm & +2.39 & +2.58 & +2.50 & \(-\)2.56 & \(-\)2.89 & \(-\)1.92 \\
09 February 2010 & 33 mm & +1.57 & +2.18 & +1.42 & \(-\)2.75 & \(-\)3.66 & \(-\)2.12 \\
08 March 2010 & 30.4 mm & +0.85 & +1.63 & +1.38 & \(-\)1.63 & \(-\)2.53 & \(-\)1.45 \\ \hline \hline \end{tabular}
\end{table} 
Table 2: Variation of substrate water content after different rainfall events (volumetric water content (VWC) before–VWC after) and between field capacity and 60 h after the rainfall events in each species. Figure 2: Relative extractable water (REW) of the substrate from July to March for all irrigation treatments in each species. The average daily maximum temperature during the summer season resulted not significantly different from average air temperature for all species and irrigation treatments. In particular, the maximum substrate temperature, in the summer season (Figure 4a, Table A1), of the non-irrigated plot of \(D\). _margaretae_ and _F. laevis_ resulted significantly higher than irrigated substrates, and they were also higher than the air temperature respectively of 2.8 \({}^{\circ}\)C and 1.1 \({}^{\circ}\)C. By contrast, the substrate temperature of 20% ET\({}_{0}\) plots for both species were significantly lower than air temperature respectively of 1.9 \({}^{\circ}\)C and 1.2 \({}^{\circ}\)C. The two species displayed similar behaviour in the 40% ET\({}_{0}\) plot didn't presenting significant differences between air and substrate temperatures. The average maximum daily substrates' temperature of _Iris lutscens_ plots for all irrigation treatments was significantly lower than air temperature of 3.8 \({}^{\circ}\)C in 20% ET\({}_{0}\) plot; 1.7 \({}^{\circ}\)C in the 40% ET\({}_{0}\) plot, and 1.2 \({}^{\circ}\)C in the non-irrigated plot. The relationship between maximum air temperatures and substrate temperatures for all three species and each irrigation treatment resulted statistically significant (\(r>0.2540\) por \(n>100\)\(\alpha=0.01\)). The average daily minimum temperature during the winter season for all three species and all irrigation treatments (Figure 4b) resulted significantly different from average air temperature. For \(D\). _margaretae_, the substrate's temperature resulted higher than air temperature for all plots: 4.8 \({}^{\circ}\)C for 40% ET\({}_{0}\); 4.2 \({}^{\circ}\)C for 20% ET\({}_{0}\) plot, and 3.6 \({}^{\circ}\)C in the non-irrigated substrate. Moreover, there were significant differences between the 40% ET\({}_{0}\) treatment and the non-irrigated treatment. In this way, also _F.