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iForest -Biogeosciences and Forestry
IntroductionThe international discussion on the climate change and the hypothesis that it is determined also by the human activities fosters the renewable energy uses. Renewable energy uses play a key role to honor the commitments that Italy has signed with the European Commission in order to achieve by 2020 for the whole Europe: (i) a reduction of 20% in energy consumption; (ii) a reduction of 20% in CO2 emission compared to 1990; (iii) more than 20% of the total energy demand will come from renewable energy. The Short Rotation Forestry (SRF) is one of the measures indicated by the article 3.4 (additional activities) of the Kyoto Protocol (Schulze et al. 2002); they serve as feedstock for the pulp and paper industry but also can be established specifically to address the feedstock needs for energy or biofuel industry and to combat desertification processes. Among these, the woody biomass attracts great attention as a renewable energy and as alternative to fossil fuels (e.g., firewood, wood chips and pellets). The wood biomass production for energy has promising productive and environmental benefits, with a minor impact on food markets, and a significant potential to lower net CO2 emissions in the environment and improving the energy balance (Smith 1995, IPCC 2007, Muller 2009). SRF system is an intensive cultivation: the fast-growing hardwoods at high density are employed and the average period of rotation is less than 10 years (Rockwood et al. 2004). The Italian interest of SRF as a renewable energy began in the 1990s. Based on recent inventories (Bisoffi et al. 2008, Verani et al. 2009), the Italian surface of SRF was estimated around 7 000 hectares, mostly established in northern Italy, where the regional services of Lombardy, Veneto, Piedmont and Friuli released goods grants to establish and manage the SRF. Also European actions aimed to promote and extend the SRF since 2005 (Biomass Action Plan). Poplars (Populus spp.), especially modern hybrids, are well adapted to site conditions in Italy, and are the most common tree species used in SRF plantations (Paris et al. 2011) because they show great plasticity over a wide range of habitats. However, most regions in central Italy are affected by long summer dryness, resulting to be a suboptimal site for poplar cultivation, due to the very high water consumption of the woody crop in comparison with northern latitudes. For this reason some poplar clones were selected for growing in suboptimal sites of Italy.Other species for SRF, such as willow (Salix spp.), black locust (Robinia pseudoacacia L.) and eucalyptus (Eucalyptus spp.) are still under research assessment and are not commercially available yet (Scarascia-Mugnozza et al. 2007). This was because Robinia is strongly sensitive to water limiting; eucalypts are particularly sensitive to low winter temperatures; willows are also sensitive to water limitations. Indeed, they are currently used in others European country like Sweden (Mola-Yudegoa & Aronssonb 2008), Hungary (Ré...