Ilex paraguariensis A. St. Hil. is a native plant of South America widely consumed as beverages for its ethno pharmacological properties, such as antioxidant, anti-inflammatory, hypocholesterolemic as well as its benefits on the cardiovascular system. Since these properties are related to its chemical composition, the identification and quantification of the major compounds of I. paraguariensis...

Numerous plant species are shifting their range polewards in response to ongoing climate change. Range shifts typically involve the repeated establishment and growth of leading-edge populations well ahead of the main species range. How these populations recover from founder events and associated diversity loss remains poorly understood. To help fill this gap, we exhaustively investigated a newl...

Responses of leaf water relations and photosynthesis to summer drought and autumn rewetting were studied in two evergreen Mediterranean oak species, Quercus ilex spp. rotundifolia and Quercus suber. The predawn leaf water potential (Ψ(lPD)), stomatal conductance (gs) and photosynthetic rate (A) at ambient conditions were measured seasonally over a 3-year period. We also measured the photosynthe...

BACKGROUND AND AIMS Several widespread tree species of temperate forests, such as species of the genus Quercus, produce recalcitrant (desiccation-sensitive) seeds. However, the ecological significance of seed desiccation sensitivity in temperate regions is largely unknown. Do seeds of such species suffer from drying during the period when they remain on the soil, between shedding in autumn and ...

The water permeability of the leaves of three deciduous plants (Acer campestre, Fagus sylvatica, Quercus petraea) and two evergreen plants (Hedera helix, Ilex aquifolium) was analysed in order to assess its role as a mechanism of drought resistance. Cuticular permeances were determined by measurement of the water loss through adaxial, astomatous leaf surfaces. Minimum conductances after complet...

The present study was undertaken to verify ancient data in the literature on ovipositional preference o f the cuttlefish Sepia officinalis for the terrestrial plant Pistacia lentiscus (mastic tree). Adult specimens o f Sepia were placed in basins together with aerial parts not only of P. lentiscus, but also o f Artemisia arborescens, Centaurea alba var. deusta, Quercus ilex and Laurus nobilis. ...

We analyzed 14C, 13C and 18O isotope variations over a 50-year period in tree rings of Quercus ilex L. trees growing at a natural CO2 spring in a Mediterranean ecosystem. We compared trees from two sites, one with high and one with low exposure to CO2 from the spring. The spring CO2 is free of 14C. Thus, this carbon can be traced in the wood, and the amount originating from the spring calculate...

Three hypotheses have been proposed to explain the functional relationship between seed mass and seedling performance: the reserve effect (larger seeds retain a larger proportion of reserves after germinating), the metabolic effect (seedlings from larger seeds have slower relative growth rates), and the seedling-size effect (larger seeds produce larger seedlings). We tested these hypotheses by ...

To advance understanding of the mechanisms underpinning the coexistence of Mediterranean oak species, we conducted a year-long analysis of the production, architecture, and mycorrhization status of the fine roots of a mixed evergreen (Quercus ilex) and winter deciduous (Quercus faginea) oak stand. We used the ingrowth bag technique to sample the fine roots produced by each species in spring, su...

We study the existence of minimizers for a constrained variational problems in H(R). These minimizers are stable waves solutions for the Generalized Camassa-Holm equation, and their derivative may have a singularity (in which case the travelling wave is called a peakon). The existence result is based on a method developed by the same author in a previous work. By giving examples, we show how ou...