Revista Chilena de Historia Natural 75 (3): 625-637, 2002
REVIEW ARTICLE
Ecophysiological responses of plants in ecosystems with Mediterranean-like climate and high
mountain environments
This review highlights the studies on plant physiological ecology of Mediterranean-like
climate zones, with interest in the photosynthesis and in the multiple stress characteristics of these environments. It incorporates an
eco-physiological approach to the study of the distribution of the life forms and species of Mediterranean ecosystems, particularly in the
Mediterranean zone of central Chile. It is emphasized the effect of drought (water), thermal (temperatures) and luminic stress
(radiation) on photosynthesis. Drought stress would be the determinant factor in the distribution in evergreen and deciduous trees at
low altitudes, whereas in shrubs and cushions at intermediate altitudes -at the treeline- or higher, it would be the temperatures and/or
the combination of both stresses, moreover the light stress. The photoinhibition of photosynthesis caused by the multiple stresses in
Mediterranean-climate zones is also discussed, explaining the theoretical basic concepts in chlorophyll “a” fluorescence and
photoprotection provided by the xanthophylls cycle. The hypotheses to explain how these multiple stresses modulate the distribution
and the seasonal and annual phonological patterns of plants are postulated. Finally, in order to avoid the clear ecological differences in
the ecophysiological responses of plants, comparisons are done among phylogenetically close species (i.e., congener) and
interspecific differences in phenotypic characters that are correlated with environmental parameters. These aspects are explained
through examing the adaptative processes and not throughout the independence of the characteristics resulting from the phylogenetic
inertia.
Key words:
ecophysiology,
photosynthesis, water, temperature and light stress
