• Energy Research

Coppice is one of the most important management system of Italian forests. An overall view of Italian coppices situation taken from National Forest Inventory is given in the present work. Moreover forest enterprises characteristics were analyzed and the overlay between these investigated parameters allowed to an evaluation of the improvement possibilities of coppice management in Italian context. The main results of this analysis showed that the main problems of Italian forest sector, with particular reference to coppice are: predominance of private properties, lacking of forest utilizations planning, lacking of technological innovation mostly linked to bunching-extraction operation, low economic value of fuel wood and lacking of products diversification. Proceedings of the 28th European Biomass Conference and Exhibition, 6-9 July 2020, Virtual, pp. 74-76

The increasing need in renewable energy production is fostering the utilization of Italian artificial coniferous stands for wood chips production. On the one hand, such interventions are crucial for the development of the forest stand, however, the low economic value of wood chips not often guarantees a positive stumpage value. According to this iussue, studies dedicated to analyze and improve working productivity in pine stands interventions are fundamental for the correct development of the value chain. The present work analyzed three different forest yards in Central Italy, in order to evaluate the differences in work productivity between motor manual and fully mechanized felling. In particular, two motor manual and one fully mechanized felling operations were analyzed. The work productivity in fully mechanized felling by Harvester TimberJack 1270 showed a very high value of 28.18 t h-1, which resulted substantially higher than motor manual felling productivity (1.84 and 4.18 t h-1). Obviously, the use of fully mechanized felling is linked to the improvement of forest operator skills, furthermore it can be positive not only concerning economic aspects but also for social purposes, through limiting the possibility of work accidents and increasing the comfort of forest operators. Proceedings of the 29th European Biomass Conference and Exhibition, 26-29 April 2021, Online, pp. 263-264

High-quality pellets are typically produced from coniferous sawdust. However, achieving comparable quality from alternative feedstocks, such as broadleaf wood, often necessitates pre-treatments or additives. Yet, within the framework of small-scale pellet production, local forest enterprises may lack the resources for such treatments and usually produce pellets from the whole trees, including branches, leaves and tops. This can have an impact on the quality of the pellets obtained in this manner. To be classified as high-quality pellets (A1 class), the specific features of the pellet must be higher or fall below the thresholds specified in the EN ISO 17225 standard. In this study, we developed an alternative statistical approach to evaluate pellet quality in comparison to the constant thresholds reported in the technical standard. We applied such an approach to evaluate the quality of pellets produced from the broadleaved species common in the Mediterranean forestry, including European beech (Fagus sylvatica L.), Turkey oak (Quercus cerris L.), Eucalyptus (clone Eucalyptus camaldulensis x C. bicostata), and Poplar clone AF6. In particular, we focused on three variables that are generally the most troublesome for the production of high-quality pellets from the broadleaved species, namely bulk density, ash content, and lower heating value. We found that the beech pellets showed satisfactory bulk density (average effect size of −1.2, with no statistical difference in comparison to the standard’s threshold) and ash content (average effect size of about −5 and significantly lower than the standard’s threshold), but the heating value was significantly lower than the threshold required by the standard (average effect size of about −3). Conversely, other investigated species exhibited notable deficiencies, with turkey oak pellets displaying acceptable heating values. We found a significant improvement in ash content and heating value with increasing stem age within the same species thus suggesting that material derived from thinning interventions might be preferable over coppice-derived biomass for high-quality pellet production. We suggest that future research on the topic should focus on investigating pellets produced from blends of beech and turkey oak biomass. We further recommend a wider application of the proposed statistical approach, considering that it is clear and easy to interpret, and allows for a statistical comparison of the obtained values against the requirements of the technical standard.

Reducing potential soil damage due to the passing of forest machinery is a key issue in sustainable forest management. Limiting soil compaction has a significant positive impact on forest soil. With this in mind, the aim of this work was the application of precision forestry tools, namely the Global Navigation Satellite System (GNSS) and Geographic Information System (GIS), to improve forwarding operations in hilly areas, thereby reducing the soil surface impacted. Three different forest study areas located on the slopes of Mount Amiata (Tuscany, Italy) were analyzed. Extraction operations were carried out using a John Deere 1410D forwarder. The study was conducted in chestnut (Castanea sativa Mill.) coppice, and two coniferous stands: black pine (Pinus nigra Arn.) and Monterey pine (Pinus radiata D. Don). The first stage of this work consisted of field surveys collecting data concerning new strip roads prepared by the forwarder operator to extract all the wood material from the forest areas. These new strip roads were detected using a GNSS system: specifically, a Trimble Juno Sb handheld data collector. The accumulated field data were recorded in GIS Software Quantum GIS 2.18, allowing the creation of strip road shapefiles followed by a calculation of the soil surface impacted during the extraction operation. In the second phase, various GIS tools were used to define a preliminary strip road network, developed to minimize impact on the surface, and, therefore, environmental disturbance. The results obtained showed the efficiency of precision forestry tools to improve forwarding operations. This electronic component, integrated with the on-board GNSS and GIS systems of the forwarder, could assure that the machine only followed the previously-planned strip roads, leading to a considerable reduction of the soil compaction and topsoil disturbances. The use of such tool can also minimize the risks of accidents in hilly areas operations, thus allowing more sustainable forest operations under all the three pillars of sustainability (economy, environment and society).

Traditional coppice management system is one of the most debated topics in the Mediterranean area, as it is a forest management system that accounts for over 23 million hectares. Coppicing is considered the oldest form of sustainable forest management. Its past and current widespread popularity is mainly due to its capacity to positively contribute to the rural economy and ecosystem services. This research aimed at assessing the effect of coppicing on soil characteristics, understanding a possible treatment return time, and evaluating the implementation of proper sustainable forest operations (SFOs) in order to have a better understanding of the disturbance caused by silvicultural treatment and forest operations with two different harvesting techniques. The results demonstrated that physical, chemical, and biological soil features were partially disturbed by the coppicing. Both silvicultural treatment and forest operations influenced soil disturbance. The least impactful technique was extraction by winch, while forwarding resulted in heavier alterations of soil characteristics. It took about five years for the soil to recover its original pre-harvest conditions when the disturbance was caused by the silvicultural treatment alone (non-trafficked areas) and about eight to nine years when the disturbance was the cumulated effect of silvicultural treatment and logging activity (trafficked areas).

European Union is strongly encouraging renewable energy production from biomass, and forests show a major role in this context. Italian Alps zone is one of the few that, in Italy, presents wide application of aerial extraction systems, like cable yarder. Proper analysis of work productivity and costs of such kind of harvesting system could be the starting point for their introduction even in central and south Italy. According to what previously stated, the main aim of the present study was the analysis of an harvesting system, consisting of motor manual felling with chainsaw, bunching and extraction by heavy gravity cable yarder and final processing by an excavator-based with processing head. This harvesting system allowed for the production of both timber and wood chips, these last from little branches and tops. Gross productivity of the overall harvesting systems resulted to be 6.217 m3 h-1 with net productivity of 6.486 m3 h-1. Harvesting cost was 35.18 ��� m-3. This system showed therefore high productivity and limited costs, even if there is a certain degree of possible improvement. The work was performed in the framework of SUSCACE project