Water Sorption and Desorption of Isolated Cuticles From Three Woody Species With Focus on .

The cuticle is a lipid-rich layer that protects aerial plant organs against multiple stress factors such as dehydration. In this study, cuticle composition and structure in relation to water loss are examined in a broad ecophysiological context, taking into consideration leaf age and side from (holly) in comparison with (eucalypt) and (cherry laurel). Enzymatically isolated cuticular membranes from holly leaves were studied under three treatment conditions: natural (no chemical treatment), after dewaxing, and after methanolysis, and the rate of water loss was assessed.

Climate Change Synchronizes Growth and iWUE Across Species in a Temperate-Submediterranean Mixed Oak Forest.

Tree species have good tolerance to a range of environmental conditions, though their ability to respond and persist to environmental changes is dramatically reduced at the rear-edge distribution limits. At those edges, gene flow conferring adaptation is impaired due to lack of populations at lower latitudes. Thus, trees mainly rely on phenotypic changes to buffer against long-term environmental changes.

Effect of irradiation and canopy position on anatomical and physiological features of Fagus sylvatica and Quercus petraea leaves.

Growing conditions at different tree canopy positions may significantly vary and lead to foliar changes even within the same tree. An assessment of foliar anatomy, including also epidermal features, can help us understand how plants respond to environmental factors. Working with two model tree species (i.

Unprecedented herbivory threatens rear-edge populations of Betula in southwestern Eurasia.

Mediterranean rear-edge populations of Betula, located at the southwestern Eurasian margin of the distribution range, represent unique reservoirs of genetic diversity. However, increasing densities of wild ungulates, enhanced dryness, and wildfires threaten their future persistence. A historical perspective on the past responses of these relict populations to changing herbivory, fire occurrence and climatic conditions may contribute to assessing their future responses under comparable scenarios.

Daytime depression in temperature-normalised stem CO efflux in young poplar trees is dominated by low turgor pressure rather than by internal transport of respired CO.

Daytime decreases in temperature-normalised stem CO efflux (E ) are commonly ascribed to internal transport of respired CO (F ) or to an attenuated respiratory activity due to lowered turgor pressure. The two are difficult to separate as they are simultaneously driven by sap flow dynamics. To achieve combined gradients in turgor pressure and F , sap flow rates in poplar trees were manipulated through severe defoliation, severe drought, moderate defoliation and moderate drought.

Temporal and spatial patterns of internal and external stem CO2 fluxes in a sub-Mediterranean oak.

To accurately estimate stem respiration (R), measurements of both carbon dioxide (CO) efflux to the atmosphere (E) and internal CO flux through xylem (F) are needed because xylem sap transports respired CO upward. However, reports of seasonal dynamics of F and E are scarce and no studies exist in Mediterranean species under drought stress conditions. Internal and external CO fluxes at three stem heights, together with radial stem growth, temperature, sap flow and shoot water potential, were measured in Quercus pyrenaica Willd.

Seasonal and diel variation in xylem CO2 concentration and sap pH in sub-Mediterranean oak stems.

Since a substantial portion of respired CO2 remains within the stem, diel and seasonal trends in stem CO2 concentration ([CO2]) are of major interest in plant respiration and carbon budget research. However, continuous long-term stem [CO2] studies are scarce, and generally absent in Mediterranean climates. In this study, stem [CO2] was monitored every 15min together with stem and air temperature, sap flow, and soil water storage during a growing season in 16 stems of Quercus pyrenaica to elucidate the main drivers of stem [CO2] at different temporal scales.

Stem CO2 efflux in six co-occurring tree species: underlying factors and ecological implications.

Stem respiration plays a role in species coexistence and forest dynamics. Here we examined the intra- and inter-specific variability of stem CO2 efflux (E) in dominant and suppressed trees of six deciduous species in a mixed forest stand: Fagus sylvatica L., Quercus petraea [Matt.