c7.5.6 – Morphological and functional adaptations in Cistus monspeliensis L. leaves facing a natural and a prolonged summer aridity

De Dato G*, Micali M, De Angelis P

Department of Forest Environment and Resources (DISAFRI), University of Tuscia, via S. Camillo De Lellis snc – 01100 Viterbo VT Italy
Collocazione: c7.5.6 – Tipo Comunicazione: Presentazione orale
7° Congresso SISEF *
Sessione 5: “Risposte ai disturbi ambientali” *

Contatto: Giovanbattista De Dato (gdd@unitus.it)

Abstract: The semi-deciduous summer habit is a common trait of different Mediterranean shrubs. The timing of leaf fall is related to the drought occurrence, exposing these plants to the direct effect of climate changes. The main objective of this research was to verify the dependence of leaf senescence on water shortage in Cistus monspeliensis plants subjected to natural (control) and prolonged (drought) water stress. We studied leaf production and leaf shedding, the parameters related to photosynthesis (assimilation, stomatal conductance, Vcmax, Jmax, dark respiration) and nutrient concentrations (N, C) in green leaves and in fresh leaf litter, in a Mediterranean gariga characterized by severe summer drought. With increasing drought conditions, Cistus replaced its spring leaves (high leaf area, thin leaves and low photosynthetic efficiency) with summer leaves, characterized by low leaf area, increased thickness, high photosynthetic rate and water use efficiency. Leaf senescence in Cistus is controlled by water availability, given that drier conditions (drought treatment) induced changes in photosynthetic parameters and in leaf morphology (earlier onset of summer leaves). The more efficient summer leaves allow Cistus to better utilize water availability during rain events in dry summer, and to start new phenophases with the onset of autumnal wetter climate conditions.

Citazione: De Dato G, Micali M, De Angelis P (2009). Morphological and functional adaptations in Cistus monspeliensis L. leaves facing a natural and a prolonged summer aridity . 7° Congresso Nazionale SISEF, Isernia – Pesche (IS), 29 Set – 03 Ott 2009, Contributo no. #c7.5.6