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Closer-to-Nature Forest Management is a new concept proposed both in the EU Forest Strategy for 2030 and in the EU Biodiversity strategy for 2030. Closerto-Nature Forest Management aims to improve the conservation values and climate resilience of multifunctional, managed forests in Europe. We present the concept based on a set of seven guiding principles and discuss main problems and opportunities of its application at continental scale and in Italy. [ABSTRACT FROM AUTHOR]

In Europe, forest management has controlled forest dynamics to sustain commodity production over multiple centuries. Yet over‐regulation for growth and yield diminishes resilience to environmental stress as well as threatens biodiversity, leading to increasing forest susceptibility to an array of disturbances. These trends have stimulated interest in alternative management systems, including natural dynamics silviculture (NDS). NDS aims to emulate natural disturbance dynamics at stand and landscape scales through silvicultural manipulations of forest structure and landscape patterns. We adapted a "Comparability Index" (CI) to assess convergence/divergence between natural disturbances and forest management effects. We extended the original CI concept based on disturbance size and frequency by adding the residual structure of canopy trees after a disturbance as a third dimension. We populated the model by compiling data on natural disturbance dynamics and management from 13 countries in Europe, covering four major forest types (i.e., spruce, beech, oak, and pine‐dominated forests). We found that natural disturbances are highly variable in size, frequency, and residual structure, but European forest management fails to encompass this complexity. Silviculture in Europe is skewed toward even‐aged systems, used predominately (72.9% of management) across the countries assessed. The residual structure proved crucial in the comparison of natural disturbances and silvicultural systems. CI indicated the highest congruence between uneven‐aged silvicultural systems and key natural disturbance attributes. Even so, uneven‐aged practices emulated only a portion of the complexity associated with natural disturbance effects. The remaining silvicultural systems perform poorly in terms of retention compared to tree survivorship after natural disturbances. We suggest that NDS can enrich Europe's portfolio of management systems, for example where wood production is not the primary objective. NDS is especially relevant to forests managed for habitat quality, risk reduction, and a variety of ecosystem services. We suggest a holistic approach integrating NDS with more conventional practices. [ABSTRACT FROM AUTHOR]

Forest biomass is a renewable energy source, more climate-friendly than fossil fuels and widely available in Europe. The wood energy chain has been suggested as a means to re-activate forest management and improve the value of forest stands in marginalized rural areas. However, wall-to-wall estimates of forest biomass, needed to design the location and size of power and heat biomass plants in any given territory, are notoriously difficult to obtain. This paper tests an algorithm to predict forest biomass using publicly available Landsat satellite imagery in the Liguria region, northern Italy. We used regional forest inventory data to train and validate an artificial neural network (ANN) classifier that uses remotely-sensed information such as three principal components of Landsat-5 TM spectral bands, the Enhanced Vegetation Index (EVI), and topography, to retrieve aboveground live tree volume. Percent root mean square error was -9% and -23% for conifers and broadleaves respectively in the calibration dataset, and -27% and -24% in the validation dataset. The reconstructed volume map was updated to present day using current volume increment rates reported by the Italian National Forest Inventory. A wall-to-wall map of forest biomass from harvest residues was finally produced based on species-specific wood density, biomass expansion factors, volume logged for timber assortments, forest accessibility, and topography. Predicted aboveground forest volume ranged from 81 to 391 m³ ha-1. In forests available for wood supply (70% of the total), planned volume removals averaged 25.4 m³ ha-1, or 18.7% of the average standing stock across. Biomass available for bioenergy supply was 1.295.921 million Mg dry matter or 8.95 Mg ha-1. This analysis workflow can be replicated in all mountain regions with a predominant broadleaved coppice component. [ABSTRACT FROM AUTHOR]

A sever flood event hit Mt. Amiata region in July 2019. We know that trees can help to reduce or prevent flooding, but we also know that there are thresholds in this mitigation/prevention role and when these limits are exceeded we have to expect damages that cannot be avoided. Frequencies of extreme weather events such as floods, droughts and heat waves are increasing and expected to increase in the future. Researchers and managers have to dedicate time and effort to communicate better with stakeholders about the role of the forest and the forest management regarding these events and address the discussion on facts instead that on opinions. Facts are accurate statements while opinions are expressed statements that are believed to be true but may or may not be facts. The Amiata flood event is an example where the discussion spread in many media has been mainly based on opinions rather than facts. [ABSTRACT FROM AUTHOR]

Human activities have the potential to enhance carbon sequestration by the world's forests and contribute to climate change mitigation. Voluntary carbon trading is currently the only option to pursue and reward carbon sequestration by forestry activities. Carbon credits for enhanced sequestration can be sold to partners wishing to offset their own emissions. Here we illustrate the steps taken to design guidelines for the generation of voluntary carbon credits by improved forest management in Piemonte, Italy. The guidelines have been developed in a joint effort by academia, regional administrations, forest owners and professional consultants. In particular, we show how to compute the baseline and the additionality of credit-generating forest management activities, and how to reconcile the generation of forest carbon credits with law requirements, technical limitations, and the provision of other ecosystem services. To illustrate the profitability of carbon credit generation, we simulated the application of carbon credit guidelines to two forest-rich mountain watersheds in the southern part of the Piemonte region. The two dominating tree species are beech (Fagus sylvatica L.) and chestnut (Castanea sativa Mill.). We computed current forest carbon stock and carbon credits generated in 20 years under business as usual and an alternative biomass retention scenario. The IFM resulted in an avoided harvest of 39,362 m³ for a net total of 64,014 MgCO2e after subtracting harvest emissions, or 38 Mg ha-1 throughout the permanence period of 20 years. These steps can be replicated in other mountain regions where there is interest in promoting this ecosystem service as an alternative or an addition to production-oriented forest management. [ABSTRACT FROM AUTHOR]

Alluvial forests with black alder are a priority conservation habitat in Europe. In the Po plain, black alder is traditionally managed by coppicing with frequent rotations. This study aims to ascertain whether such management is compatible with habitat conservation, by measuring the effect of time since coppicing on forest structure and plant species composition across different layers. We compared the effects of three treatments, each thrice replicated: recent (10–20 years), medium (20–30 years) and old coppice (>40 years). In all nine stands we measured basal area, tree and regeneration density, mean tree diameter and height, dominance by alder, species richness, Shannon diversity, and the number of ruderal and non-native species. Significant differences in dendrometric variables, species richness, diversity, and percent cover by chorotype were assessed for treatment effects by two-way ANOVA. Frequently coppiced stands had a lower basal area, mean tree size, and volume, a more simplified vertical structure, a lower cover of the herbaceous layer and higher bare soil cover due to harvesting disturbance, a significantly lower cover by typical woodland Fraxinetalia species, and a significantly higher frequency and cover of non-native species. Our study showed that frequent coppicing worsened the conservation status of black alder forests in the study area, simplified stand structure, deteriorated species composition, and increased the spread of non-native and ruderal plant species. Such negative effects persisted even 20–30 years after cutting. We recommend amending the current legislation and introducing mandatory Implications Assessment procedures everywhere alder forests are susceptible to be impacted in a similarly negative way. [ABSTRACT FROM AUTHOR]

• Roe deer browsing impact was investigated in temperate hardwood coppice forests. • Browsing effects were monitored for 11 years in an exclusion experiment. • High browsing impact in the early years after coppicing on more palatable species. • Coppice forests showed significant post-browsing recovery in the medium term. • Long-term monitoring is key to assess browsing impact and management implications. In southern European temperate forests, coppicing is a traditional form of forest management that shaped the present cultural landscape, providing multiple ecosystem services. Roe deer densities have been growing notably during the last decades mainly due to the abandonment of rural areas, changes in human land use and restocking. The impact of roe deer on coppice forests can affect the resprouting and, in turn, compromise the products and ecosystem services provided by these forests. During coppicing, stems are cut down close to the ground, where the growing shoots are exposed to deer browsing, especially during the early years following cutting. In this study, using a browsing exclusion experiment, we investigated the impact of browsing on temperate mountain hardwood coppice forests in the western Italian Alps over a period of eleven years following coppicing. We found that the impact of browsing was highest in the first two years following coppicing, with Quercus pubescens and Castanea sativa being the most affected tree species. The height of shoots was the variable that showed the biggest difference between fenced and unfenced areas. A significant negative effect of browsing on shoot height was found at the beginning of the experiment, with shoots growing in unfenced area showing the lowest height increments. After the third year, when the browsing intensity diminished, we observed the opposite trend, with shoots growing in unfenced areas showing higher height increments compared with fenced areas. A similar trend was observed also for the diameter of shoots over the course of the experiment. Eleven years after coppicing, however, the structural characteristics of the natural regeneration converged at all sites and in both fenced and unfenced areas. This study shows that coppice forests are resilient to browsing and are capable to recover growth loss within a few years after browsing has naturally diminished and stopped. The research conducted also points out the importance of medium- to long-term monitoring to assess post-disturbance dynamics and evaluate implications for management. [ABSTRACT FROM AUTHOR]

For decades ecologists and natural resource managers have operated on the assumption that the normal condition of nature, if not disturbed by humans, is a state of equilibrium called homeostasis. This paradigm led to the doctrine, popular especially among conservationists, that nature knows best and that human intervention is bad by definition. In the last decades new evidences have led ecologists and natural resource managers to abandon such concept or consider it as irrelevant. The new paradigm is that ecosystems are constantly changing and the main engine of this change are natural disturbances (e.g., fire, wind, insect outbreaks, etc.). The biological diversity is dependent on natural disturbance, thus natural resource conservation and management must take into account the fundamental role of these events. [ABSTRACT FROM AUTHOR]

During the last millennia, all forests of the Italian Alps have been heavily affected by human land-use. Consequently, forest structures have been modified, and there are no old growth remains. In the last decades, however, many forests have been withdrawn from regular management, because wood production was unprofitable, and left to develop naturally. At the same time, in currently managed forests, silvicultural systems able to develop or maintain old-growth characteristics are being required. The aim of this paper was to assess the status and developmental dynamics of old-growth characteristics in mixed beech, silver fir, and Norway spruce montane forests of the eastern Italian Alps. We selected along a naturalness gradient (a) three old-growth forests in Bosnia and Montenegro (due to the lack of old-growth forests in the Italian Alps), (b) two forests withdrawn from regular management for at least 50 years, and (c) three currently managed forests. In each forest, we analysed 17 structural attributes, in order to assess their value as indicators of old-growth condition. Old-growth forests were characterized by significantly higher amounts of live and dead biomass, share of beech in the dominant and regeneration layers, and number of large trees. The diameter distribution was best described as a rotated sigmoid, differently from currently and formerly managed forest. We discuss the differences in old-growth characteristics across the management gradient and use our results to evaluate the effectiveness of retention prescriptions currently applied in the studied regions in maintaining or promoting old-growth structural attributes in managed forests. [ABSTRACT FROM AUTHOR]

European beech forests are of particular importance for biodiversity, although relatively little is known about how beech forest management impacts on invertebrate communities. In this paper we investigated the influence of beech forest management history [i.e. over-mature coppices (OC) and coppices in conversion to high forests (CCHF)], climatic, topographic and microhabitat characteristics on ground beetle diversity (measured as total relative abundance, species richness, Shannon diversity and abundance of the endangered endemic species Carabus olympiae) in northern Italy. The diversity of forest specialist carabids was higher in OC and in forest stands characterized by a higher mean temperature and lower relative humidity. Moreover, we detected a positive response of several diversity variables to coarse wood debris cover or volume, herb cover, and the standard deviation of tree diameter. Currently, OC seems to be a more favorable habitat for forest carabids, including C.olympiae, although succession over time can lead to a progressive homogenization of the vegetation structure, with negative consequences for the conservation of the forest carabid assemblage. Based on our results, we suggest that the traditional management of beech coppice and its conversion to high forest be modified by including practices aimed at promoting structural and microhabitat diversity such as retention of large trees, creation of canopy gaps, retention of coarse wood debris and the preservation of 'islands' of older trees in the managed stands. [ABSTRACT FROM AUTHOR]

Abstract: Forest structure is the result of past disturbances, regeneration establishment, competition, and mortality dynamics. Natural disturbances can create single dead tree to larger canopy gaps creating both small and large scale patterns and processes. The analysis of forest spatial pattern can provide information on these dynamics shaping forest ecosystems. Knowledge about primeval forest dynamics is relevant for their conservation and is an important reference for delineating sustainable forest management.The main aim of this research was to assess forest structure and understand spatial patterns and related disturbance processes in a mixed silver fir-Norway spruce-beech old-growth forest. The study site is the forest reserve of Lom, an old-growth forest located in Bosnia and Erzegovina. We analysed forest structure at different scales and with different approaches : a) landscape, b) forest, and c) single tree. A Kompsat-2 satellite image was used for forest canopy gaps delineation (a). The classification was based on an artificial neural network and allowed the identification of 297 canopy gaps (50-1776 m2). The size and spatial pattern of the gaps were found to be different between core area and buffer zone. Forest structure (b) in the core area was analysed applying a 120 m grid sampling design (40 plots). From this preliminary analysis we identified a stand with typical old-growth characteristics in the central part of the core area and a 1 ha intensive sampling plot was established (c). Inside the plot all trees were mapped, measured, and a core extracted to assess tree age. Spatial structure was investigated by means of Point Pattern Analysis and LISA (Local Indices of Spatial Autocorrelation). The three scales and approaches produced consistent results. The landscape approach confirmed the hypothesis that small-scale processes predominate at Lom especially within the core area of the reserve. At the forest stand level the presence of small scale disturbance/mortality processes was confirmed. [Copyright &y& Elsevier]

Abstract: The role of deadwood on biodiversity conservation of forest ecosystems is widely recognised. Interest on deadwood has increased in the last years, and forest management policy regards deadwood as indicator of sustainable forest management. This study took place in mixed montane forests in Eastern Italian Alps. The objective was to determine how past forest management, topography and forest structure influenced coarse woody debris (CWD) accumulation. 124 sampling points were established in four forest reserves, where time since active management activities ranges from 12 to more than 50 years. A multivariate analysis was performed to investigate the connections among site, stand characteristics, and CWD. Coarse woody debris volume in the reserves was similar to other forests withdrawn from regular management in last decades in central Europe. However, CWD stocking was much lower than in old-growth montane mixed forest. Both site and stand characteristics determined CWD accumulation. Elevation, basal area of living trees and human impact emerged as the most important factors. These aspects are connected with the accretion (density-dependent mortality) and the depletion (harvesting, decay) of deadwood in the stand. In the next decades we expect an increase of deadwood stocking, due to density-dependent mortality and disturbances. [ABSTRACT FROM AUTHOR]

Abstract: Rapid glacier retreat often results in extensive areas of deglaciated terrain where primary successional processes occur. We studied biotic and abiotic factors underlying the invasion of larch (Larix decidua Mill.) on a glacier foreland and tested the hypothesis that the pattern of its establishment was controlled primarily by terrain age. The time span between deglaciation and establishment of larch and the importance of the position and shape of the glacier on the forest structure were studied over ∼150 years of glacial retreat. We related three data sets (forest structure, topography and spatial position) using ordination methods. Simple and partial Mantel tests and kriging interpolation were used to map and identify the key factors underlying the spatial patterns of larch establishment. The elapsed time between deglaciation and the germination of the larch trees was estimated between 14 and 34 years, with lower values found closer to the glacier terminus. Sparse and young stands developed near the glacier terminus and Mantel tests indicated significant correlations between spatial distance and ecological distance. The kriging interpolation showed strong agreement between tree age and the spatial pattern of the retreating glacier. The most influential factors in determining stand density and age were proximity to the glacier terminus and seed sources, as well as litter cover and elevation. The age of trees was strongly influenced by terrain age or time since deglaciation, but as succession progressed forest structure became more complex. [Copyright &y& Elsevier]

Abstract: Density management diagrams (DMD) are graphical tools used in the design of silvicultural regimes in even-aged forests. They depict the relationship between stand density, average tree size, stand yield and dominant height, based upon relevant ecological and allometric relationships such as the self-thinning rule, the yield-density effect, and site index curves. DMD effectively summarize stand structural descriptors, and are therefore helpful in determining stand characteristics needed to achieve a range of management goals. We constructed a DMD for Scots pine (Pinus sylvestris L.) forests in the western Italian Alps. We used 210 sample plots from a region-wide forest inventory to determine the maximum density line and volume and top height isolines. Site index curves were used to assess the time taken by stands to progress along their development trajectories. The protection provided by Scots pine stands is most effective against rockfall, due to the frequent occurrence of such forests in active source or transition areas. We used the DMD to identify combinations of size and density representing optimal and sub-optimal protection from rockfall. An actual pine stand was used as a case study to illustrate how the diagram can be used to assess current functionality of the forest, forecast its likely development and compare alternative management strategies. [Copyright &y& Elsevier]

The tandem analysis of dendrochronological and genetic data is piquing forest ecologists' interest and represents a promising approach for studying the temporal development of genetic structure in forest tree populations. Such multidisciplinary approach can help elucidate to what extent different management practices have impacted the fine-scale spatial genetic structure of forest stands through time. In this study, we jointly analysed spatial, age and genetic data from three differently managed Norway spruce permanent plots to assess: (1) possible differences among plots in the spatial distribution of individuals and their genetic structure due to different management practices, and (2) whether modifications in the age structure influenced the fine-scale spatial genetic structure within each permanent plot. With these aims, we genetically characterized at five nuclear microsatellite markers a large subset (328) of all the trees for which spatial and age data were collected (1472). We found that different management practices determined a similar spatial structure in terms of trees' ages (r < 25 m in all plots) and neutral genetic diversity (Sp ranging from 0.002 to 0.004). Hot spots and cold spots of trees' age were not statistically different in terms of genetic diversity, and trees' age was not statistically different among the genetic clusters detected. On the other hand, the spatial distribution of individuals was significantly clustered up to 22 m only in the wooded pasture plot. Our main findings show that forest land use and management can indeed determine markedly different spatial layouts of Norway spruce individuals but do not produce strong distortions in the spatial structure of age and genetic parameters. [ABSTRACT FROM AUTHOR]

In the southern part of the Alps the intensive use of forests for domestic animals has declined this century and particularly during the last few decades. After the Second World War wild ungulates, rare or absent at the beginning of this century, increased in number and expanded their range. Mountain forests are very vulnerable to ungulate damage owing to the long periods needed for regeneration processes. In this study, the impact of ungulate browsing on forest regeneration was investigated in 10 areas of the Italian Alps. The incidence of browsing damage on forest regeneration (10-150 cm height) was found to vary between 52.8% in the most severely damaged area and 6.9%, in the least affected area. The lethality of browsing damage (used as index of browsing intensity) was found to he nil in 4 areas out of ten and up to 17.2170 in the areas with the highest ungulate density. Ungulate density is not the only factor influencing degree of browsing damage; winter tourism and land and road settlements in potential ungulatewinter ranges also play an important role. Naturalistic silvicultureis the most profitable system for the conservation and the sustainability of the whole forest ecosystem but high ungulate densities prevent its application. [ABSTRACT FROM AUTHOR]

Interest in coppices is growing due to the need to replace fossil fuels with renewable energy sources. In Italy, beech covers one million hectares, half of which originated by coppicing. This study tested which factors drive the presence and growth of beech resprouts, with a focus on fertility, cutting intensity, age, and size at time of coppicing. We analyzed 509 stools in 24 stands coppiced between 1 and 26 years before sampling. We fitted Generalized Linear Mixed Models of the probability of sprouting and height of the tallest resprout for each stool as a function of elevation, slope, aspect, bedrock, precipitation, temperature, age at coppicing, time since coppicing, residual shoot density, the sum, average and coefficient of variation of the diameter of cut shoots, and type of stool treatment. Of all harvested stools, 249 (49%) had sprouted with an average of 7.6 resprouts per stool. Height of the tallest resprout on each stool ranged from 3 to 800 cm, mainly as a function of time since coppicing. Resprout mortality was on average 1.4% per plot. Sprouting decreased with decreasing site fertility, increasing precipitation, and increasing size of cut stems. Leaving one or more shoots on the stool after felling produced a high proportion of sprouting stools (82%). Although based on a limited sample, our quantitative analysis of the driving factors of sprouting in beech can be used to support silvicultural decisions in over-mature beech coppices, and to optimize trade-offs between ecosystem services such as biomass production, biodiversity, and hydro-geologic protection. [ABSTRACT FROM AUTHOR]