# Vegetation Productivity Losses Linked to Mediterranean Hot and Dry Events
## 3 Results
### Land Cover Response  
The three study areas show distinct vegetation compositions. Low tree cover regions are the most abundant biome across IB and EM, representing, respectively, about 55% and 40% of the vegetation in the territories (Table 2). Conversely, in WE, croplands represent the main land cover type (Table 2) and had large reductions in GPP in 2003 and 2006. We analysed the relationships between the anomalies in GPP, SM and LST in the spring and summer as well as the relationships between the anomalies of SM and LST for each land cover type (Tables S1, S2 and S3). In general, [SM-GPP] and [LST-GPP] showed opposite correlations in the spring (positive for SM-GPP and negative for LST-GPP), with few exceptions. In summer, the relationship between SM and GPP anomalies was generally positive, while LST and GPP anomalies were negatively correlated. During summer, correlation values were stronger for LST-GPP than for SM-GPP. Regarding the SM and LST anomalies relationship, a negative correlation was generally found. Results in Figure 5 indicate that in IB, croplands and low tree cover areas, which are mainly characterized by herbaceous vegetation, showed rapid reductions in productivity in the spring, with prolonged negative GPP anomalies which were further amplified in the summer months. On the other hand, high tree cover areas showed later reductions in productivity, with negative GPP anomalies occurring mainly in summer. This pattern is found in 2005 and 2012 in IB and 2003 in EM, where low tree cover areas represented the major contribution to the annual productivity balance of ecologically stressed vegetation (Table 4). In contrast, the episodes of 2007 in EM (Figure 6) and 2003 (Figure 7) and 2006 in WE showed distinct responses of the different land cover types to temperature and SM anomalies in the spring and summer. The increase of hot and dry conditions in the summer months resulted in a strong reduction of productivity of all land covers, as represented in the shift to lower values of GPP anomalies. Figure 5: Impacts of 2005 on vegetation in IB: (**a**) Land cover types affected by the ecological event; (**b**) Distribution of GPP anomalies frequency for the three land cover classes during the spring (MAM) (bold lines and black bars) and summer (JJA) (dashed lines and dashed grey bars). Bars represent the sum of the normalized frequency of all land cover classes. It is worth mentioning that, despite their higher abundance across EM and WE, high tree cover areas seemed to have a higher reduction in GPP compared with the study cases in the literature. \begin{table}
\begin{tabular}{c c c c c c c c c c} \hline \hline \multirow{2}{*}{**Study** **Areas**} & \multirow{2}{*}{**Year**} & \multicolumn{2}{c}{**High Tree Cover**} & \multicolumn{2}{c}{**Low Tree Cover**} & \multicolumn{2}{c}{**Cropland**} & \multicolumn{2}{c}{**Others**} \\ \cline{3-10}  & & **TgC/year** & \% & **TgC/year** & \% & **TgC/year** & \% & **TgC/year** & \% \\ \hline \multirow{3}{*}{IB} & 2005 & \(-4.09\) & 16.78 & \(-30.84\) & 50.17 & \(-11.95\) & 44.95 & \(-0.09\) & _6.79_ \\  & 2012 & \(-1.24\) & 5.73 & \(-5.82\) & 14.40 & \(-3.11\) & 15.16 & \(-0.02\) & _2.00_ \\ \hline \multirow{3}{*}{EM} & 2003 & \(-4.63\) & 20.72 & \(-10.09\) & _30.73_ & \(-6.28\) & _31.42_ & \(-0.12\) & _4.59_ \\  & 2007 & \(-2.35\) & 14.37 & \(-4.40\) & 19.27 & \(-2.51\) & _18.80_ & \(-0.06\) & _2.60_ \\ \hline \multirow{3}{*}{WE} & 2003 & \(-2.57\) & _6.06_ & \(-1.89\) & _5.30_ & \(-3.22\) & _8.55_ & \(-0.04\) & _0.82_ \\  & 2006 & \(-6.14\) & 15.55 & \(-3.17\) & _9.91_ & \(-4.19\) & _10.98_ & \(-0.07\) & _1.63_ \\ \hline \hline \end{tabular}
\end{table} 
Table 4: Annual productivity balance of each land cover class, in TgC/year. The percentage of each affected land cover type of the region is also represented on italic values. Figure 6: As in Figure 5, but over EM for 2007.