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Integrating the conservation of biodiversity into silvicultural practices is one of the main challenges facing forest owners in the promotion of an emergent approach to sustainable forest management across European forests. The Mediterranean forests are among the richest biodiverse forest ecosystems due to their environmental heterogeneity, but climate change is threatening their integrity, with critical implications for the availability of ecosystem services. Forests managed for commercial purposes are under increasing pressure to provide timber while supporting biodiversity. This study aims to analyse the relationship between tree-related microhabitats (TreMs), which are structures occurring on living or standing dead trees that constitute an essential substrate for several living species, and beetles, an important indicator species group for forest biodiversity monitoring. Four generalized linear models were fitted to assess the influence of environmental factors, forest structure, and biodiversity-related parameters on the abundance and richness of beetles, mainly on saproxylic beetles. The study highlights significant associations between the abundance and richness of individual groups and types of TreMs and the Italian Red List of saproxylic species. Therefore, TreMs can serve as a tool to map, monitor, and enhance forest biodiversity in managed forests. [ABSTRACT FROM AUTHOR]

The possible differential response to the climatic fluctuations of co-occurring trees of different ages is still poorly known and rather controversial. Moreover, in managed forests, such a picture is further complicated by the impact of silvicultural practices. With this concern, in a multi-aged umbrella pine stand in the Maremma Regional Park (Tuscany, Italy), the spatial patterns and tree-ring response to the climate were investigated by differentiating trees into three classes, i.e., young, mature, and old. The aim was to assess the role of past management in shaping the current stand structure and affecting the growth dynamics at different ages, as well as to evaluate the possible shifting of tree adaptation to the climatic variables throughout plant aging. Our outcomes proved that the current mosaic of even-aged small patches results from a multifaceted forest management history. Until the 1960s, silvicultural treatments seemed more suitable in promoting tree growth and regeneration. Later on, inappropriate and/or untimely thinning probably triggered excessive competition from the top canopy trees, involving reduced stem and root system development in the younger plants living in the understory. Also, the intra-annual growth response to the climate showed some dependence on age. Younger trees are assumed not to be able to efficiently exploit water resources from the deep aquifer during the dry season, probably due to an insufficiently developed taproot, differently than older trees. Accordingly, appropriate and timely thinning, simulating frequent natural disturbances on small areas, could be a suitable management approach to promote sustained growth rates and regeneration processes, as well as healthy and vital trees at all life stages. [ABSTRACT FROM AUTHOR]

Interactions between tree species determine the dynamics of forest communities. Spatial and temporal changes in resource availability, variation in species composition and spatial distribution of trees may alter competitive interactions between species and, therefore, affect tree growth and forest productivity. In this study, we analyzed the intra and inter-specific interactions between European beech (Fagus sylvatica L.) and silver fir (Abies alba Mill.) in southern Italy (Molise and Calabria regions), and how these interactions affect basal area increments in mixed-species and pure stands. Results showed that intraspecific interactions have a negative effect on the basal area increment, both in pure and mixed-species stands of Molise and Calabria. Basal area increment was higher influenced by intra-specific interactions in pure stands than in mixed-species stands. Silver fir in Molise showed higher basal area increment in mixed-species stand, probably in relation with stand structure and space occupation that resulted in less competition between individual trees. European beech showed high values of intra-specific interactions in pure stands, likely related to the low self-tolerance of this species and to the spatial arrangement of trees, due to canopy closure. The absence of inter-specific interactions in mixed-species stands could be explained by the sub-dominant position of European beech, which may have limited the benefit derived from niche separation and complementarity for silver fir. [ABSTRACT FROM AUTHOR]

Surface biomass characterization plays a key role in wildfire management. It allows classifying vegetation fuels flammability for fire risk analysis, to define silvicultural prescriptions for fire hazard reduction, to plan prescribed burning, or to model fire behavior and its effects, such as greenhouse gas and pollutant emissions. To facilitate fuel classification and analysis of potential fire behavior and effects in Italy, we harmonized 634 measurements of surface wildland fuels from Alpine, temperate and Mediterranean environments. The dataset provides quantitative data for duff, fine dead fuels and downed woody material, live grasses and shrubs fuel components. Surface fuel data were harmonized by subdividing loads (Mg ha-1) to standard size classes for dead (0-6, 6-25 and 25-75 mm) and live (0-6, 6-25 mm) fuels, collecting percent cover and depth/height (cm) of the various fuel components, and classifying observations into 19 fuelbed categories. To ensure comparability with existing vegetation classification systems, we classified each observation according to the European Fuel Map, the Corine Land Cover classes (level IV), the European Forest Types, and the forest categories of the Italian National Forest Inventory. The dataset and a photo description of each fuelbed category are available as Supplementary material. This dataset is the first step to develop several products at the national scale such as: (i) fuel type classification and mapping; (ii) carbon stock and wildfire emission estimates; (iii) calibration of fuel models for the simulation of fire behavior and effects. [ABSTRACT FROM AUTHOR]

We present an innovative method based on the application of inverse yield models for producing spatially explicit estimations of forest age. Firstly, a raster growing stock volume map was produced using the non-parametric k- Nearest Neighbors estimation method on the basis of IRS LISS-III remotely sensed imagery and field data collected in the framework of a local forest inventory. Secondly, species-specific inverted yield equations were applied to estimate forest age as a function of growing stock volume. The method was tested in 128 000 ha of even-aged forests in central Italy (Molise region). The accuracy of the method was assessed using an independent dataset of 305 units from a local standwise forest inventory. The results demonstrated that the forest age map was accurate, with a root mean square error of 15.8 years (30% of the mean of field values), and useful for supporting forest management purposes, such as the assessment of harvesting potential and ecosystem services. Thanks to the use of remotely sensed data and spatial modeling, the proposed approach is cost-effective and easily replicable for vast regions. [ABSTRACT FROM AUTHOR]

The availability of common standardized geospatial information on composition, structure and distribution of forests is essential to support environmental actions, sustainable forest management and planning policies. Forest types maps are suitable tools for supporting both silvicultural and forest planning choices from local to global scale levels. For this reason local authorities may develop forest types maps independently, in which case a standardized/harmonized framework for their comparison and aggregation is essential. At the same time local forest types maps may not be directly related to pan-European forest resources assessments and classification systems. This paper presents results of the harmonization of four forest types maps available for central Italy. The process is based on a bottom-up approach aimed at maintaining the most detailed common nomenclature system across the different Regions. The final results, in terms of forest types area, are compared with several independent sources of information: (i) two forest maps, one developed at national level on the basis of the Corine Land Cover 2006, and one for high resolution forest / non forest classification developed at pan-European level; and (ii) two sample based inventories: the Italian National Forest Inventory (INFC) and the Italian Land Use Inventory (IUTI). The results show that the proposed bottomup harmonization approach is a suitable tool to guarantee the integrity and homogeneity of local forest types nomenclature systems, and to integrate such local data with European standards. [ABSTRACT FROM AUTHOR]

Competitive interactions are important predictors of tree growth. Spatial and temporal changes in resource availability, and variation in species and spatial patterning of trees alter competitive interactions, thus affecting tree growth and, hence, biomass. Competition indices are used to quantify the level of competition among trees. As these indices are normally computed only over small areas, where field measurements are done, it would be useful to have a tool to predict them over large areas. On this regard, remote sensing, and in particular light detection and ranging (lidar) data, could be the perfect tool. The objective of this study was to use lidar metrics to predict competition (on the basis of distance-dependent competition indices) of individual trees and to relate them with tree aboveground biomass (AGB). The selected study area was a mountain forest area located in the Italian Alps. The analyses focused on the two dominant species of the area: Silver fir (Abies alba Mill.) and Norway spruce (Picea abies (L.) H. Karst). The results showed that lidar metrics could be used to predict competition indices of individual trees (R2 above 0.66). Moreover, AGB decreased as competition increased, suggesting that variations in the availability of resources in the soil, and the ability of plants to withstand competition for light may influence the partitioning of biomass. [ABSTRACT FROM AUTHOR]