The phenotypic responses of functional traits in natural populations are driven by genetic diversity and phenotypic plasticity. These two mechanisms enable trees to cope with rapid climate change. We studied two European temperate tree species (sessile oak and European beech), focusing on (i) in situ variations of leaf functional traits (morphological and physiological) along two altitudinal gr...

A four- to seven-fold enhancement of leaf hydraulic conductance by light has been reported in three temperate tree species. The enhancement occurs in the liquid-flow pathway between the petiole and the site of water evaporation. The enhancement occurs within 1 h, and dissipates in darkness over a period of 1 to 10 h depending on species. Here we report light-induced enhancement of leaf hydrauli...

Decomposition of three leaf species (Alnus glutinosa, Eucalyptus globulus and Quercus robur) were examined in a headstream. During two months decomposing leaves were periodically analysed for nutrient content, soluble sugars, phenols, protein precipitation capacity, total fiber, weight loss, microbial and macroinvertebrate colonisation. The leaves of the three species showed similar patterns in...

We conducted experiments to evaluate the effects of soluble components in senescent leaf material on the growth and development of the eastern tree hole mosquito, Aedes triseriatus (Say). Oak leaves that were either leached for three days to remove the labile nutrient fraction, or were not leached, served as basal nutrient inputs in each experiment.Mosquito performance in microcosms containing ...

H2O2 is an ubiquitous compound involved in signalling, metabolic control, stress responses and development. The compatibility of leaf tissue levels with these functions has, however, often been questioned. The objective here is to document H2O2 levels and variability under natural conditions, and their underlying causes. Using the FOX method, bulk H2O2 concentrations were analysed in leaf sampl...

Phytophthora ramorum, an invasive pathogen and the causal agent of Sudden Oak Death, has become established in mixed-evergreen and redwood forests in coastal northern California. While oak and tanoak mortality is the most visible indication of P. ramorum's presence, epidemics are largely driven by the presence of bay laurel (Umbellularia californica), a reservoir host that supports both prolifi...

Factors affecting the density and distribution of yellow-poplar regeneration after a single growing season prescribed fire were studied in mature upland oak stands in the southern Appalachian Mountains. In burned and unburned stands, density of one and two year old yellow-poplar seedlings was inventoried within 50 m from isolated yellow-poplar canopy seed trees in response to distance from seed...

Spring planting is standard operational practice in the Central Hardwood Region, though little is known about potential impacts of low root temperature (RT) common during spring on establishment success of temperate deciduous forest tree species. The effects of low RT on growth, gas exchange, and root respiration following winter dormancy were studied in 1-year-old northern red oak (Quercus rub...

Abiotic stresses have considerable negative impact on Mediterranean plant ecosystems and better comprehension of the genetic control of response and adaptation of trees to global changes is urgently needed. The single cell gel electrophoresis (SCGE) assay could be considered a good estimator of DNA damage in an individual eukaryotic cell. This method has been mainly employed in animal tissues, ...