## 5 Impacts and Recovery in Mediterranean Vegetation  
The maintenance of the community structure and plant species composition of the Mediterranean ecosystems is connected to their ability to recover after the impacts of repeated environmental stress and disturbances (i.e., drought, fire). Evergreen sclerophyllous species have a strong capacity of vegetative regeneration (resprouting) and can restore the stand before the disturbance in relatively short time. Evidences suggest that plant communities dominated by resprouter species (RS) recover from disturbance more quickly than those composed by non-resprouters (NRS). The ability of resprouter species to resist drought and avoid mortality, combined with their ability to restore, totally or partially, defoliated crowns, prompts that the impact of increased drought stress in communities dominated by these species may be smaller [72] than in those of non-resprouters. It is necessary, however, in RS to preserve the vitality of the cambium tissue, to allow the production of adventitious buds. Extraordinarily strong drought events may lead to the shrinkage of cambium [73], thus reducing the recovery ability of woody species. In addition, the ability to produce adventitious buds declines with the age of trees and stem size [74; 75]. Although resprouting capacity is advantageous in stressful conditions, there are some metabolic costs to sustain, as lower seed production, higher allocation of biomass to roots than to stem and crown, and longer time to reach sexual maturity [72]. Resprouting species, moreover, need greater allocation resources to roots than shoots and greater non-structural carbohydrate (NSC) stores to support the growth of shoots [72]. Drought, as well many other stress factors, implies the consumption of NSC reserves [76]. In a meta-analysis study, [77] compare responses of woody species to drought intensity and duration, in terms of soluble sugars, starch, and total non-structural carbohydrates (TNSC), in leaf, stem, and root. Starch decreased in all organs, while soluble sugars increased in leaf with prolonged experiment time. The changes in soluble sugars in all organs were stronger under severe drought than under slight-to-moderate drought. Under slight-to-moderate drought, trees increased carbon storage, by means of physiological regulation processes, in order to reduce the risks of carbon starvation. In contrast, long-term severe drought could lead to NSC depletion in the whole plant, so reducing the ability to recover after stress. [PERSON] and [PERSON] [78] found this process in _Q.__ilex_, which can vigorously resprout after drought episodes, but its resilience (i.e., the ability to cope with further stressful events) may be reduced. In the future, the higher frequency of recurrence of extreme droughts will be a challenge for plant communities, and thus, the capacity of these forests to recover. The time occurring for a (more or less) complete recovery of NSC reserves is therefore crucial for the resilience of Mediterranean vegetation subjected to dry spell events. Research focused on evaluating the development of crown conditions and NSC stored in lignotubers 7 years after a drought event [79] showed that crown dieback was associated with a depletion of the carbon reserves in lignotubers. [PERSON] et al. [80] found that, 10 years after a drought event, starch stocks in the lignotubers have recovered to half the former amount. In a study [80], it was pointed out that more frequent droughts may provoke a progressive depletion of carbon reserves and a loss of resilience in Mediterranean resprouter species. Concerning the recovery by sexual reproduction processes (i.e., by seeds), increased drought reduces acorn production in _Q.__ilex_[81]. The effects of drought on seed production and germinative ability may be different according to the sensitivity of each species to water stress [64]. Drought, moreover, can modify the local conditions of the soil by affecting the mycorrhizal status and thus the establishment of seedlings [82].