Forest and agricultural biomass are important sources of renewable and sustainable fuel for energy production. Their increasing consumption is mainly related to the increase in global energy demand and fossil fuel prices but also to the limited availability of petroleum and the lower environmental impact of these biomass compared with other non-renewable fuels. In particular, the pellet sector has seen important developments in terms of both production and the number of installed transformation plants. In addition, pellet production from non-woody biomass is increasing in importance. One of the fundamental aspects for the correct and sustainable use of a biofuel is evaluation of its quality. This is even more important when dealing with pellet production, considering the broad spectrum of possible raw materials for pelletizing. Considering the significant number of papers dealing with pellet quality evaluation and improvement in the last decade, this review aims to give the reader an overall view of the most current knowledge about this large and interesting topic. We focused on pellets of agricultural and forestry origin and analyzed papers regarding the specific topic of pellet quality evaluation and improvement from the last five years (2016–2020). In particular, the review findings are presented in the following order: the influence of different agro-forest management systems on pellet quality; analysis of pellets from pure feedstocks (no blending or binders); the influence of blending and binders on pellet quality; and the influence of pre and post treatments. Finally, a brief discussion about actual research lacks in this topic and the possibilities for future research are presented. It is important to underline that the present review is focused on the influence of the biomass characteristics on pellet quality. The effects of the process parameters (die temperature, applied pressure, holding time) on pellet features are not considered in this review, because that is another very large topic deserving a dedicated paper.

A well-planned forest road network is essential for meeting the goal of sustainable forest management. Forest roads play a key role in commercial purposes, fire prevention, and recreational activities. The aim of this work was to apply precision forestry in the analysis of the forest network of two forest ownerships in Tuscany. A proposal was formulated based on the information obtained regarding future forest road construction. This proposal takes into consideration technical effectiveness and environmental sustainability, with particular attention paid to low-impact logging. Two systems were tested so as to gain a better comprehension of different technical approaches. One system was reported by other researchers and the other was developed by the authors of this paper. The aim was to provide a valid instrument and possible alternative for forest managers involved in decision making. This study highlights the importance of precision forestry, even on a small-scale technical application level in forest road planning, thus helping managers and owners during the decision-making process in forestry operations.

Purpose of Review: Biodiversity is one of the most important features of forest ecosystems. One of the goals of Sustainable Forest Management is to reduce biodiversity disturbance, which can occur as a consequence of timber harvesting. The aim of this review was to define which silvicultural systems and forest operations can have an influence on forest tree biodiversity by summarising the findings of nearly 60 papers published in the last ten years (2013–2022). Recent Findings: In natural forest ecosystems characterised by a high level of structural complexity, such as uneven-aged tropical forests, selective logging and retention forestry are, in general, suitable forms of intervention that have a limited impact on tree biodiversity. Forest operations, in particular, should be of low intensity and try to simulate as much as possible small-scale natural disturbances. Thinning has proved to be a valid treatment for managing tree biodiversity. However, it is important to shape the magnitude of thinnings according to the management aims. Limited removal is recommended in interventions for maintaining the current structure, and more extensive removal is appropriate in cases when a change in species composition is expected, e.g. in the conversion of planted coniferous stands to uneven-aged mixed or broadleaved stands. In addition, coppicing is suitable for maintaining tree biodiversity due to its effectiveness in fostering the presence of light-demanding tree species. Findings show that it is important to establish the right rotation age, considering that an excessively short period between coppicing interventions can be detrimental to functional biodiversity. Skid trails and landing sites represent suitable areas for the initial establishment of natural regeneration. However, generally, the level of biodiversity on these sites declines with time as a consequence of soil compaction, thus highlighting the importance of the forest infrastructure network planning. Summary: In uneven-aged tropical forests, selective logging and retention forestry are the most suitable options for maintaining tree biodiversity. Thinning and coppicing help to manage biodiversity, whilst intensive thinning helps to change species composition. Skid trails and landing sites can support natural regeneration. Recommendations and management options were developed, as well as possible future research directions. The authors recommend that future studies should investigate how much tree biodiversity depends on different levels of harvesting technology applied within the same silvicultural treatment.

In the last years, there has been a growing need to improve forest-wood chain concerning all three pillars of sustainability (economic, environmental, and social). Using electronic systems, in particular GIS, GNSS, and various kinds of sensors related to forest harvesting, is clearly one of the most powerful instruments to reach this aim. The contribution of these tools to forest operation is wide and various. One of the most important application was integrating ICT and GPS/GNSS on-board systems on modern forest machines. This allowed one to ensure multiple benefits to forest operation field. On the one hand, electronic systems, and particularly GIS, could be used to improve forest harvesting with a previous planning of the skid trails network, in order to minimize utilization impacts and risks for operators, ensuring at the same time high work productivity. Moreover, GIS developed files could also be implemented in modern forest machine GPS/GNSS systems, helping forest machines operators to move only along a designed skid trails network or making it possible to avoid restricted access areas. On the other hand, modern forest machines could be equipped with complex and accurate sensors that are able to determine, register, and share information about wood biomass quantity and quality and even undertake economic evaluation of stumpage value. Finally, the input and output of these systems and sensors could be implemented in a decision support system (DSS) ensuring the best silvicultural and operative alternative from a sustainable forest management point of view. A detailed review of the contribution of electronics in the development of forest operations is provided here.

Purpose of Review: As litter decomposition is a fundamental process in forest ecosystems, representing the link between aboveground and belowground biogeochemical processes, we developed an effect size summarisation of the implications of forest management on litter decomposition rate, by applying a multi-level meta-analysis and multivariate mixed-effects meta-analytic linear models. Our aim was to review the findings of the current literature and to understand how forest management, silvicultural treatment, and forest operations could affect litter decomposition rate. Furthermore, we investigated the effects of environmental variables that included stand type, climatic conditions, and the percentage of biomass removal on litter decomposition rate.Recent Findings: We found a statistically significant reduction in litter decomposition rate associated with clear-cutting, and no statistically significant differences for the overall effects of retention forestry and logging activities (disturbed forest soil in the form of skid trails or strip roads). Concerning the sub-group analysis and multivariate meta-regression, there were no significant effects for stand type (broadleaf, coniferous, or mixed) or climatic conditions (mean annual temperature and annual precipitation). The percentage of biomass removal showed a significant positive correlation with the effect size, thus indicating that higher biomass removal in the framework of retention forestry leads to an increase in litter decomposition rate. Also, the mesh size of the litterbag showed a positive correlation with the effect size, suggesting that there is a probability of a factor of stronger disturbance to large-body decomposer organisms such as microarthropods.Summary: Litter decomposition rate is related, among other factors, to soil microclimatic conditions and soil biota. Therefore, this process can be strongly influenced by active forest management, meant as a silvicultural treatment carried out by applying a given harvesting system. In the context of retention forestry, increased light availability seems to be the driving force in shaping increased litter decomposition rates with increasing biomass removal. On the other hand, when a clear-cut is applied, the stronger modification to the edaphic community leads to decreased litter decomposition rates. It is worth noting that the modification may also be related to soil manipulation to favour the establishment of artificial regeneration. The findings, however, showed very large variability, thus suggesting the need for further research on such a complex topic. Multidisciplinary studies that analyse the microclimate and the edaphic biological communities along with the litter decomposition are particularly recommended.

The sustainable production of renewable energy is a key topic on the European community’s agenda in the next decades. The use of residuals from agriculture could not be enough to meet the growing demand for energy, and the contribution of vegetable oil to biodiesel production may be important. Moreover, vegetable oil can surrogate petroleum products in many cases, as in cosmetics, biopolymers, or lubricants production. However, the cultivation of oil crops for the mere production of industrial oil would arise concerns on competition for land use between food and non-food crops. Additionally, the economic sustainability is not always guaranteed, since the mechanical harvesting, in some cases, is still far from acceptable. Therefore, it is difficult to plan the future strategy on bioproducts production from oil crops if the actual feasibility to harvest the seeds is still almost unknown. With the present review, the authors aim to provide a comprehensive overview on the state of the art of mechanical harvesting in seven herbaceous oil crops, namely: sunflower (Heliantus annuus L.), canola (Brassica napus L.), cardoon (Cynara cardunculus L.), camelina (Camelina sativa (L.) Crantz), safflower (Carthamus tinctorius L.), crambe (Crambe abyssinica R. E. Fr.), and castor bean (Ricinus communis L.). The review underlines that the mechanical harvesting of sunflower, canola and cardoon seeds is performed relying on specific devices that perform effectively with a minimum seed loss. Crambe and safflower seeds can be harvested through a combine harvester equipped with a header for cereals. On the other hand, camelina and castor crops still lack the reliable implementation on combine harvesters. Some attempts have been performed to harvest camelina and castor while using a cereal header and a maize header, respectively, but the actual effectiveness of both strategies is still unknown.