Beech is one of the most important forest tree species in Europe, hence possible adverse factors affecting its physiology and productivity can have strong ecological and economic impacts. In this context, four beech forests along a latitudinal gradient from southern Apennines to middle European lowlands were selected for chronological determinations of carbon isotope composition (δ¹³C) in tree-ring cellulose. The main objectives of this study were to assess (i) the effect of climate on the carbon signature of tree-ring cellulose (δ¹³C); (ii) the physiological response to recent CO₂ concentration increment and to climatic variation; and (iii) the relationship between intrinsic water-use efficiency (iWUE, here the average long-term ratio of net photosynthesis to stomatal conductance) and growth of trees in different sites since 1950. Our results demonstrated that site climatic conditions peculiarly affect δ¹³C. In northern sites, a climatic control of summer precipitation and temperature on stomatal conductance was demonstrated by their opposite correlations with δ¹³C, negative and positive, respectively. Furthermore, an ‘earliness effect’ was suggested by a significant relationship between spring temperature and δ¹³C in the coldest sites and by a positive one between winter temperature and δ¹³C in the warmest ones. In all the study sites, during the maturity phase, a positive correlation between the increment of CO₂ and iWUE was observed, due to an active response of trees to CO₂ increment. This increment of CO₂ was the main driver of the long term increasing trend of iWUE, resulting by an active response of trees to CO₂ fertilization. Moreover, precipitation mostly influences positively and negatively the inter-annual variations of iWUE of the southernmost and northernmost sites, respectively. Overall, we observed a mean increment of 40% of iWUE. Moreover, the sensitivity of iWUE to the increase of CO₂ was different between the northernmost and southernmost sites. Increasing iWUE was correlated to growth in the two sites during the release phase and we hypothesize a positive effect of silvicultural treatments.

Biomass occupies a very important place among renewable energy sources, and the residual biomass recovery chain represents a sector of fundamental importance. Our work focused on the production of pellets by pruning residues from two of the most important woody crops in Italy: hazelnut and olive groves. We found a higher value of bulk density for the hazelnut pellet (581.30 kg m⁻³ vs. 562.38 kg m⁻³) and a higher value of length for the olive pellet (16.66 mm vs. 10.47 mm). The percentages of durability were very similar (98%). The low heating value and ash content of hazelnut and olive were 17.21 MJ kg⁻¹ and 3.1%, and 16.83 MJ kg⁻¹ and 2.5%. A higher concentration of Cu, Pb, and Ni was observed in the hazelnut. The contrary was observed for the concentration of Zn. N content was 0.77% and 1.24% for the hazelnut and the olive, respectively. The concentration of S was 0.00% for both. The quality parameters that do not meet current standards could be improved by mixing these materials with different types of wood.

Current expectations on future climate derive from coordinated experiments, which compile many climate models for sampling the entire uncertainty related to emission scenarios, initial conditions, and modelling process. Quantifying this uncertainty is important for taking decisions that are robust under a wide range of possible future conditions. Nevertheless, if uncertainty is too large, it can prevent from planning specific and effective measures. For this reason, reducing the spectrum of the possible scenarios to a small number of one or a few models that actually represent the climate pathway influencing natural ecosystems would substantially increase our planning capacity. Here we adopt a multidisciplinary approach based on the comparison of observed and expected spatial patterns of response to climate change in order to identify which specific models, among those included in the CMIP5, catch the real climate variation driving the response of natural ecosystems. We used dendrochronological analyses for determining the geographic pattern of recent growth trends for three European species of trees. At the same time, we modelled the climatic niche for the same species and forecasted the suitability variation expected across Europe under each different GCM. Finally, we estimated how well each GCM explains the real response of ecosystems, by comparing the expected variation with the observed growth trends. Doing this, we identified four climatic models that are coherent with the observed trends. These models are close to the highest range limit of the climatic variations expected by the ensemble of the CMIP5 models, suggesting that current predictions of climate change impacts on ecosystems could be underestimated.

Maize and wheat are two of the most widespread crops worldwide because of their high yield and importance for food, chemical purposes and livestock feed. Some of the residues of these crops (i.e., maize cob and wheat chaff) remain in the field after grain harvesting. In Europe, just maize cob and grain chaff could provide an annual potential biomass of 9.6 Mt and 54.8 Mt, respectively. Collecting such a biomass could be of interest for bioenergy production and could increase farmers’ income. Progress in harvest technology plays a key role in turning untapped by-products into valuable feedstocks. This article presents a study of the performance and the quality of the work of Harcob, an innovative system developed for maize cob collection. Furthermore, the feasibility of using the Harcob system to also harvest wheat chaff during wheat harvesting was also verified. The results showed that it was possible to harvest 1.72 t ha⁻¹ and 0.67 t ha⁻¹ of cob and chaff, respectively, without affecting the harvesting performance of the combine. The profit achievable from harvesting the corn cob was around 4%, while no significant economic benefits were observed during the harvesting of wheat chaff with the Harcob system. The use of cereal by-products for energy purposes may allow the reduction of CO₂ from fossil fuel between 0.7 to 2.2 t CO₂ ha⁻¹. The Harcob system resulted suitable to harvest such different and high potential crop by-products and may represent a solution for farmers investing in the bioenergy production chain.