High severity stand-replacing wildfires can deeply affect forest ecosystems whose composition includes plant species lacking fire-related traits and specific adaptations. Land managers and policymakers need to be aware of the importance of properly managing these ecosystems, adopting post-disturbance interventions designed to reach management goals, and restoring the required ecosystem services. Recent research frequently found that post-fire salvage logging negatively affects natural regeneration dynamics, thereby altering successional pathways due to a detrimental interaction with the preceding disturbance. In this study, we compared the effects of salvage logging and other post-disturbance interventions (adopting different deadwood management strategies) to test their impact on microclimatic conditions, which potentially affect tree regeneration establishment and survival. After one of the largest and most severe wildfires in the Western Alps that affected stand-replacing behavior (100% tree mortality), a mountain forest dominated by Pinus sylvestris L., three post-fire interventions were adopted (SL-Salvage Logging, logging of all snags; CR-Cut and Release, cutting snags and releasing all deadwood on the ground; NI-No Intervention, all snags left standing). The differences among interventions concerning microclimatic conditions (albedo, surface roughness, solar radiation, soil moisture, soil temperature) were analyzed at different spatial scales (site, microsite). The management interventions influenced the presence and density of safe sites for regeneration. Salvage logging contributed to the harsh post-fire microsite environment by increasing soil temperature and reducing soil moisture. The presence of deadwood, instead, played a facilitative role in ameliorating microclimatic conditions for seedlings. The CR intervention had the highest soil moisture and the lowest soil temperature, which could be crucial for seedling survival in the first post-fire years. Due to its negative impact on microclimatic conditions affecting the availability of preferential microsites for regeneration recruitment, salvage logging should not be considered as the only intervention to be applied in post-fire environments. In the absence of threats or hazards requiring specific management actions (e.g., public safety, physical hazards for facilities), in the investigated ecosystems, no intervention, leaving all deadwood on site, could result in better microclimatic conditions for seedling establishment. A preferred strategy to speed-up natural processes and further increase safe sites for regeneration could be felling standing dead trees whilst releasing deadwood (at least partially) on the ground.

Flavescence dorée (FD) is a grapevine disease caused by ‘Candidatus Phytoplasma vitis’ (FDp), which is epidemically transmitted by the Nearctic leafhopper Scaphoideus titanus. In this study, we applied dendrochronological techniques to analyse the response to FDp infections in terms of wood ring widths and anatomical structures of the xylem and phloem tissues of the trunk of the susceptible grapevine cultivar ‘Chardonnay.’ As a rule, grapevines are susceptible to water shortage and reduce their growth in diameter in case of summer drought. In the season of the external expression of FD symptoms, however, the ring width reductions are extreme and supersede any drought-induced effects. In addition, the anatomy of the phloem tissue in the year of the FD symptom expression appears heavily disarranged. Moreover, in the most suffering individuals, the xylem formation remains incomplete and mostly limited to the early wood tissue. In conclusion, even though the FD phytoplasma does not inhabit and replicate inside the xylem tissue, our results confirm existing indirect inhibiting effects on the ring growth and the xylem tissue formation in FDp-infected grapevines.

Thinning trials in lowland plantations in the Veneto Region (North-eastern Italy). More than 234 hectares of new plantations of lowland mixed forest have been realized in the last 20 years in the Veneto Region (North-eastern Italy). In many of these is now needed to start thinning operations, but there is a lack of experience about this topic. Aim of this work was to undertake an experimentation on different types of thinnings. The thinning trial has been performed at Bosco San Marco forest, municipality of Cessalto (Venice), in a very dense hornbeam-oak plantation aged 16. In 2010, three different thinning types were implemented on 9 hectares according to the following layout: geometrical (34% of woody mass removed), selective (15%), mixed geometrical-selective (30%), control plot. Three years later no significant differences between thinning trials in term of diametric growth, geometrical thinning excepted, were observed. These results provide a suite of solutions to the forest manager for choosing the early thinning type in high tree density condition.

Over the last decades, the abandonment of the traditional management due to many adverse factors caused a general aging of chestnut coppices; this led to an increased mortality of the chestnut stools and a consequent replacement with the entry of other species. Preservation and improvement of the chestnut coppice emphasize the importance of natural regeneration for future forest management: seed regeneration contributes to provide new stools for future coppice generations and promotes a proper development of the stand in terms of specific and structural diversity. In this study, we propose a method for investigating the relationship between density, diversity, development of natural regeneration and possible driving forces in terms of site conditions and stand parameters. At this purpose, a survey based on mixed sampling plots was conducted in different coppice systems (simple coppice, coppice with standards), 4÷8 years after the coppicing: measurements on stools, shoots and standards, as well as seed regeneration were carried out. Chestnut seed regeneration was characterized by taller individuals in simple coppice plots, even though the seedlings were fewer than those in coppice with standards treatment. Canopy cover and amount of standards, density of stools and resprouting shoots negatively influenced the establishment of chestnut seed regeneration: likewise, within the same treatment, plots with greater site index promoted the development of chestnut regeneration. The proposed methods allowed a characterization of the dynamics related to the natural regeneration of classical chestnut coppice systems, identifying the main controlling factors. Among them, factors modifiable by management, such as stand structure and amount of standards, offer forest managers multiple silvicultural options to control seed regeneration processes.