Forecasted stability of Mediterranean evergreen species considering global changes

Plant communities of the Mediterranean climate Regions are exposed tohigh temperatures, high radiation and water stress during summer, they
are dominated by evergreen sclerophyllous species and drought semi
deciduous species. To define the adaptive strategies, anatomical and
morphological leaf traits of Quercus ilex L., Phillyrea latifolia L.
(typical evergreen sclerophyllous species) and Cistus incanus L., (a
drought semi deciduous species), growing in the Mediterranean maquis
along Pome's coast line (Italy) were analysed. The typical evergreen
sclerophyllous species have long leaf life span (from 1 to 4 years),
steeper leaf inclination (average 56 degrees), higher specific leaf mass
(average 21.3 mg cm(-2)) and the highest leaf thickness (average 324
mum). The semi deciduous species have a lower leaf life span (from 4 to
8 months), a lower leaf inclination (44 degrees +/- 13 degrees), a lower
specific leaf mass (14.7 +/-1.5 mg cm(-2)) and a lower leaf thickness
(244 +/- 15 mum). The more xeromorphyc species (Q. ilex and P.
latifolia) may be at a competitive advantage considering the forecasted
air temperature increase in the Mediterranean basin. Increasing drought
stress may in fact determine a shortening of leaf life span that may
prove to be critical for C. incanus. Knowledge of plant response to
stress factors is important in the perspective of climatic changes.