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The summer of 2003 was the warmest summer in Europe since the 16th century. Its consequences on the fauna of a transitional ecosystem were studied through biodiversity, functional and ecological indicators, from summer 2002 to winter 2005. The heatwave caused considerable changes in the benthic community structure and relative composition, persisting in 2005. Animal assemblages switched from mollusc- to annelida-dominated. Biodiversity and functional indicators captured changes in community structure and composition, proving to be powerful tools to detect responses related to global warming. Ecological indicators rendered a monotonic response oscillating between bad and poor ecological status across the study period. The resilience of mollusc biocoenosis resulted limited with respect to other taxa, posing concerns about their conservation if, as predicted, the frequency of summers as hot as that of 2003 will progressively increase to become the norm at the end of this century.

Advantages of various micrometeorological methods to estimate evapotranspiration are discussed in this paper with an emphasis on the 'new' surface renewal method. The surface renewal method for estimating sensible heat flux density in conjunction with net radiation and soil heat flux density measurements provides a relatively inexpensive technique to determine evapotranspiration from tree and vine crops. Fine-wire thermocouples are used to measure high-frequency temperature above and within canopies and structure functions are used to determine temperature ramp characteristics, which are used in a fundamental conservation of energy equation to estimate sensible heat flux density. Experiments were conducted during the summer of 1998 in a peach orchard near Atalaia, Portugal and in a grape vineyards in California and Italy. Surface renewal measurements taken at several heights in the canopies were compared with simultaneous sonic anemometer measurements of sensible heat flux density. The results indicate that the surface renewal technique provides good estimates of sensible heat flux density under most conditions. These results are encouraging because sonic anemometers are costly, they are damaged easily, and they give spurious results in some conditions. Using a thermocouple, the surface renewal technique offers an inexpensive alternative for estimating ET with good accuracy.

Climate change is inducing shifts in species ranges across the globe. These can affect the genetic pools of species, including loss of genetic variability and evolutionary potential. In particular, geographically enclosed ecosystems, like the Mediterranean Sea, have a higher risk of suffering species loss and genetic erosion due to barriers to further range shifts and to dispersal. In this study, we address these questions for three habitat-forming seaweed species, Cystoseira tamariscifolia, C. amentacea and C. compressa, throughout their entire ranges in the Atlantic and Mediterranean regions. We aim to 1) describe their population genetic structure and diversity, 2) model the present and predict the future distribution and 3) assess the consequences of predicted future range shifts for their population genetic structure, according to two contrasting future climate change scenarios. A net loss of suitable areas was predicted in both climatic scenarios across the range of distribution of the three species. This loss was particularly severe for C. amentacea in the Mediterranean Sea (less 90% in the most extreme climatic scenario), suggesting that the species could become potentially at extinction risk. For all species, genetic data showed very differentiated populations, indicating low inter-population connectivity, and high and distinct genetic diversity in areas that were predicted to become lost, causing erosion of unique evolutionary lineages. Our results indicated that the Mediterranean Sea is the most threatened region, where future suitable Cystoseira habitats will become more limited. This is likely to have wider ecosystem impacts as there is a lack of species with the same ecological niche and functional role in the Mediterranean. The projected accelerated loss of already fragmented and disturbed populations and the long-term genetic effects highlight the urge for local scale management strategies that sustain the capacity of these habitat-forming species to persist despite climatic impacts while waiting for global emission reductions.

AbstractWhile several studies on regeneration in Salicaceae have focused on seedling recruitment, little is known about factors controlling their vegetative reproduction. In two greenhouse experiments, we studied the response of floodplain willows (Salix fragilis, S. viminalis, S. triandra) to competition with Poa trivialis, and to shoot and root removal when planted as vegetative cuttings. In the first experiment, growth performance variables were analysed in relation to full competition, shoot competition, root competition and control, taking into account two different water levels. After 9 weeks, shoots were removed and the resprouting capacity of the bare cuttings was recorded. In the second experiment, the cutting performance of the three floodplain and an additional two fen willow species (S. cinerea, S. aurita) was compared when grown in three different soil compositions and with two different water levels. After 9 weeks, shoot and root biomass was removed and the bare cuttings were replanted to test their ability to resprout. Cutting performance and secondary resprouting were negatively affected by full and shoot competition while root competition had no or weak effects. The floodplain species performed better than the fen species in all soil types and water levels. Secondary resprouting capacity was also higher in the floodplain species, which showed an additional strong positive response to the previous waterlogging treatment. The results contribute to understanding of the vegetative regeneration ecology of floodplain willows, and suggest that the use of vegetative plantings in restoration plantings could be an effective strategy for recovering floodplain forests.

Abstract The Italian National Agency for New Technology, Energy and Environment (ENEA) conducts research, development and testing on innovative technologies and equipment and on technology transfer to industry and agriculture. The Agency has a staff of around 5000 Italy-wide. In 1987, ENEA began a research project on new processes and technologies concerning the conversion of ligno-cellulosic materials. In 1992, a continuous steam explosion pilot plant designed by Stake Technology Ltd., Ontario, Canada was installed at the ENEA Trisaia Centre in Southern Italy. This has a capacity of 175 Kg h−1 throughput of dry biomass. The plant is also equipped with two continuous extraction systems for the separation of hemicellulose, lignin and cellulose. This work presents the main characteristics of the continuous pilot plant, the strategies and/or products; finally, introduces new applications of the steam explosion process which ENEA is carrying out in collaboration with an Italian Firm, SADEPAN CHIMICA Spa, to produce fibreboards or chemicals from agro-industrial residues.

Abstract Zostera marina was investigated for ethanol production. The examined plant contained 30% of glucan. It was pretreated by steam explosion and the best conditions were assessed by a 23 full factorial design with repeated centre point. Temperature, time of pretreatment and oxalic acid load were selected as experimental factors. The experimental data of water-soluble sugar recovery and enzymatic saccharification of the insoluble residue were analysed by the response surface regression procedure, which provided significant models with R2=0.98. The best results (5.06 g of soluble sugars and 52.9 g of glucose, respectively, from 100 g of exploded material and 100 g of insoluble fibre) were attained at pretreatment of 180 °C, 300 s and 2 wt% of oxalic acid. Fermentation tests of the hydrolysed fibre were carried out and the ethanol production was optimised by varying the enzyme load, the amount of yeast and the solid concentration. In the best cases 243 g of ethanol was produced per kg of Zostera fibre and the concentration of 4.7 v% was attained in tests of high-solid load.

The river continuum concept represents the most general framework addressing the spatial variation of both structure and function in river ecosystems. In the Mediterranean ecoregion, summer drought events and dams constitute the main sources of local disturbance to the structure and functioning of river ecosystems occurring in the river basin. In this study, we analysed patterns of spatial variation of detritus processing in a 7th order river of the Mediterranean ecoregion (River Tirso, Sardinia-Italy) and in three 4th order sub-basins which were exposed to different summer drought pressures. The study was carried out on Phragmites australis and Alnus glutinosa leaf detritus at 31 field sites in seasonal field experiment. Detritus processing rates were higher for Alnus glutinosa than for Phragmites australis plant detritus. Processing rates of Alnus glutinosa leaves varied among seasons and study sites from 0.006 d(-1) to 0.189 d(-1) and those of Phragmites australis leaves ranged from 0.0008 d(-1) to 0.102 d(-1), with the lowest values occurring at sites exposed to summer drought. Seasons and sites accounted for a significant proportion of such variability. Alder detritus decay rates generally decreased with increasing stream order, while reed detritus decay rates generally increased on the same spatial gradient. Summer drought events affected these spatial patterns of variation by influencing significantly the decay rates of both plant detritus. The comparisons among and within sub-basins showed strong negative influence of summer drought on detritus processing rates. Similarly, in the entire River Tirso basin decay rates were always lower at disturbed than at undisturbed sites for each stream order; decay rates of reed detritus remained lower at those sites even after the end of the disturbance events, while alder decay rates recovered rapidly from the summer drought perturbations. The different recovery of the processing rates of the two leaves could also explain the different patterns of spatial variation observed between the two leaves.

In this paper, the reaction of enzymatic trans-esterification of glycerides with ethanol in a reaction medium containing hexane at a temperature of 37 degrees C has been studied. The enzyme was Lipase from Mucor miehei, immobilized on ionic exchange resin, aimed at achieving high catalytic specific surface and recovering, regenerating and reusing the biocatalyst. A kinetic analysis has been carried out to identify the reaction path; the rate equation and kinetic parameters have been also calculated. The kinetic model has been validated by comparison between predicted and experimental results. Mass transport resistances estimation was undertaken in order to verify that the kinetics found was intrinsic. Model potentialities in terms of reactors design and optimization are also shown.