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Silvopastoral systems with grazing pigs are mainly concentrated in Mediterranean regions, for instance in Iberian dehesas and montados. Conversely, in European deciduous forests, outdoor pig farming has almost disappeared, despite it could provide several environmental and socioeconomic benefits. For instance, pig grazing could be used for habitat restoration and conservation, while providing high quality meat products and promoting local breeds. In this study, we investigated (i) the plant species selection and (ii) the impact on tree resprouts (after a silvicultural cut) by semi-free ranging pigs in a degraded oak temperate forest in Northwestern Italy. We monitored pigs foraging behavior by direct observations and discriminated the plant species into three groups: preferred, indifferently consumed and avoided plants. The impact on the resprouts of six tree species was assessed by modeling the percentage of damaged shoots and their height through time using Generalized Linear and Additive Mixed Models. Swine expressed a selective foraging behavior, which was likely influenced by the forage quality and toxicity of plant species. The leaves and resprouts of Corylus avellana and Castanea sativa were highly consumed, whereas Acer and Quercus species and Fraxinus ornus were avoided. Mature leaves of Robinia pseudoacacia were highly preferred while its young resprouts were only slightly impacted, suggesting that pig grazing may not be effective to control this alien invasive species. Contrarily, pigs consumed Rubus sp. abundantly, suggesting they could be used to clear the understory in degraded forests.

European beech (Fagus sylvatica L.) can regenerate successfully from seeds after mixed-severity fires with mid-to-long fire return intervals (>60 years). However, if fire return interval is lower than the age of sexual maturity, post-fire seeding will be limited, leaving vegetative resprouting as the only viable option for recovery. This means that the forecasted increase in fire frequency driven by climate change may erode beech forest resilience to fire. Here, we surveyed tree regeneration in a European beech forest affected by two consecutive fires, in 2003 and 2017, and applied experimental clipping of tree saplings to address the following questions: (1) What is the fire resistance and post-fire recovery via resprouting of tree saplings? (2) Which factors drive post-fire resprouting of beech saplings? (3) Does post-fire clipping of tree saplings increase the probability of survival and resprouting vigor? We monitored 2195 beech saplings and 953 saplings of other tree species during three consecutive years, from 2018 to 2020. Almost all beech saplings were top-killed by fire, and two-thirds of them died completely. However, 3 years after the second fire, 30 per cent of beech saplings survived by resprouting from the base. Post-fire resprouting was less likely in small-diameter saplings and in those more injured by fire. Overall, the second fire did not cause a major decline of beech regeneration and consequently did not alter the dominant species composition of post-fire recovery. Given the low specific resistance to fire, post-fire resprouting of saplings is therefore a key component of beech resilience to short-interval fires. The effects of clipping on post-fire survival and resprouting vigor were very limited, suggesting the unsuitability of actively clearing burned beech regeneration as a post-fire management prescription. In conclusion, basal resprouting from beech saplings after fire-induced top-kill led to a higher-than-expected resilience of beech to short-interval fires (i.e. circa 15 years).

Tree height (H) survey is a fundamental step in forest mensuration. The error affecting tree height measure, necessarily influences the correspondent tree estimates. The remotely survey of vegetation using PHODAR (PHOtogrammetric Detection And Ranging) or LiDAR (Light Detection And Ranging) techniques generates very high-density point clouds, that result into Canopy Height Models (CHMs) having GSD (Ground Sampling Distance) of few centimetres. This GSD value potentially allows to survey single crown apexes, which, from a forestry point of view, do not represent the actual tree height. Apex height value, in fact, does not represent the prevailing dendrometric height (PDH) but the maximum tree value. In this study we propose a new approach aimed at measuring dendrometric height by PHODAR derived CHM, taking care about this issue. The proposed method defines a correcting factor (found equal to 95% percentile of CHM values distribution within a given crown) for the tree height extraction from CHM based on the PDH concept. The method could be implemented to single crown approach in forest parameters extraction algorithms permitting more reliable results, especially in terms of tree volume and related estimations (e.g., carbon stock quantification, allometric models).

12 Pág., The relationships that control seed production in trees are fundamental to understanding the evolution of forest species and their capacity to recover from increasing losses to drought, fire, and harvest. A synthesis of fecundity data from 714 species worldwide allowed us to examine hypotheses that are central to quantifying reproduction, a foundation for assessing fitness in forest trees. Four major findings emerged. First, seed production is not constrained by a strict trade-off between seed size and numbers. Instead, seed numbers vary over ten orders of magnitude, with species that invest in large seeds producing more seeds than expected from the 1:1 trade-off. Second, gymnosperms have lower seed production than angiosperms, potentially due to their extra investments in protective woody cones. Third, nutrient-demanding species, indicated by high foliar phosphorus concentrations, have low seed production. Finally, sensitivity of individual species to soil fertility varies widely, limiting the response of community seed production to fertility gradients. In combination, these findings can inform models of forest response that need to incorporate reproductive potential., The project has been funded continuously since 1992 by National Science Foundation grants to J.S.C, most recently DEB-1754443, and by the Belmont Forum (1854976), NASA (AIST16-0052, AIST18-0063), and the Programme d’Investissement d’Avenir under project FORBIC (18-MPGA-0004)(Make Our Planet Great Again). Puerto Rico data were funded by NSF grants to M.U., most recently, DEB 0963447 and LTREB 11222325. Data from the Andes Biodiversity and Ecosystem Research Group were funded by the Gordon and Betty Moore Foundation and NSF LTREB 1754647 to M.S. Additional funding to M.Z. came from the W.Szafer Institute of Botany of the Polish Academy of Sciences and the Polish National Science Foundation (2019/33/B/NZ8/0134). M.B. was supported by the Polish National Science Centre grant no. 2019/35/D/NZ8/00050, and Polish National Agency for Academic Exchange Bekker programme PPN/BEK/2020/1/00009/U/00001. J.M.L. was supported by NSF grant DEB 1745496. Jerry Franklin’s data remain accessible through NSF LTER DEB-1440409. USDA Forest Service and USGS research was funded by those agencies.

12 páginas.- 5 figuras.- 67 referencias.- Additional supporting information may be found in the online version of the article at the publisher’s website .- The peer review history for this article is available at https://publons.com/publon/10.1111/ele.14012 .- All data and code supporting our results are archived on the Zenodo Repository at the following link: https://doi.org/10.5281/zenodo.6381799, Lack of tree fecundity data across climatic gradients precludes the analysis of how seed supply contributes to global variation in forest regeneration and biotic interactions responsible for biodiversity. A global synthesis of raw seedproduction data shows a 250-fold increase in seed abundance from cold-dry to warm-wet climates, driven primarily by a 100-fold increase in seed production for a given tree size. The modest (threefold) increase in forest productivity across the same climate gradient cannot explain the magnitudes of these trends. The increase in seeds per tree can arise from adaptive evolution driven by intense species interactions or from the direct effects of a warm, moist climate on tree fecundity. Either way, the massive differences in seed supply ramify through food webs potentially explaining a disproportionate role for species interactions in the wet tropics., The project has been funded by grants to JSC from the National Science Foundation, most recently DEB-1754443, and by the Belmont Forum (1854976), NASA (AIST16-0052, AIST18-0063) and the Programme d’Investissement d’Avenir under project FORBIC (18-MPGA-0004) (Make Our Planet Great Again). Jerry Franklin’s data remain accessible through NSF LTER DEB-1440409. Puerto Rico data were funded by NSF grants, most recently, DEB 0963447 and LTREB 11222325. Data from the Andes Biodiversity and Ecosystem Research Group were funded by the Gordon and Betty Moore Foundation and NSF LTREB 1754647. MB was supported by grant no. 2019/35/D/NZ8/00050 from the (Polish) National Science Centre, and Polish National Agency for Academic Exchange Bekker programme PPN/BEK/2020/1/00009/U/00001. Research by the USDA Forest Service and the USGS was funded by these agencies. Any use of trade, firm or product names does not imply endorsement by the US Government.

International audience; Despite its importance for forest regeneration, food webs, and human economies, changes in tree fecundity with tree size and age remain largely unknown. The allometric increase with tree diameter assumed in ecological models would substantially overestimate seed contributions from large trees if fecundity eventually declines with size. Current estimates are dominated by overrepresentation of small trees in regression models. We combined global fecundity data, including a substantial representation of large trees. We compared size–fecundity relationships against traditional allometric scaling with diameter and two models based on crown architecture. All allometric models fail to describe the declining rate of increase in fecundity with diameter found for 80% of 597 species in our analysis. The strong evidence of declining fecundity, beyond what can be explained by crown architectural change, is consistent with physiological decline. A downward revision of projected fecundity of large trees can improve the next generation of forest dynamic models.

Climate change is expected to alter disturbance regimes including fires in European beech (Fagus sylvatica L.) forests. Regarding the resilience of beech forests to fire it is questionable whether seeds of this non-serotinous obligate masting seeder find advantageous conditions in a post-fire environment. The probability of recruitment success has been shown to increase when fire coincides with a mast year. However, the fire-induced recruitment window is poorly defined, and it is unclear how other interacting factors influence its duration. We used a space-for-time approach to model the relationships between post-fire beech recruitment, timing of seed mast events, and interacting environmental conditions using a zero-inflated model. Our results show that recruitment peaks 5–12 years after a fire, and continues throughout three decades post-fire. Beech recruitment in the post-fire period is driven by mast intensity interacting with (i) canopy opening as a consequence of progressive post-fire tree mortality and (ii) coverages of competing ground vegetation. Spring-summer moisture showed a weak positive effect on beech recruitment. We conclude that fires increase light availability, which in coincidence with a mast event results in pulses of beech recruitment. The delayed post-fire mortality of beech creates a recruitment window lasting for up to three decades, resulting in a higher-than-expected resilience of beech to individual fire disturbances.

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.

Tree growth and reproduction are subject to trade-offs in resource allocation. At the same time, they are both influenced by climate. In this study, we combined long records of reproductive effort at the individual- (29 years), population- (41 years) and regional (up to 53 years) scale, and tree ring chronologies, to investigate the effects of climate and reproductive allocation on radial growth in an Alpine Norway spruce forest. Seed and cone production was highly variable between years (mean individual CV = 1.39, population CV = 1.19), but showed high reproductive synchrony between individuals (mean inter-tree correlation = 0.72). No long-term trend in reproductive effort was detected over four decades of observations. At the stand scale, cone production was dominated by a small number of individuals (“super-producers”), who remained dominant over three decades. Individual tree growth responded positively to summer temperature, but the response to cone production varied between individual trees. Consequently, we found some evidence that mast years were associated with a divergence in growth between high and low cone producing individuals, and a decline in within-population growth synchrony. At the population level we found limited evidence of a relationship between growth and reproduction. Radial growth was lower than average in some mast years, but not in others. This was partly explained by summer temperature during the year of growth, with growth reductions restricted to mast years that coincided with colder than average summers. Regional mast records and tree ring chronologies provided some support to indicate that our results were consistent in other spruce stands, although the effect of mast years on growth appeared to vary between sites. Tree ring variation at the individual and population level, and between-tree growth synchrony are influenced by masting, and consequently dendrochronologists should consider both the occurrence of masting and the individual differences in reproductive effort when interpreting tree ring datasets. Our results also indicate that tree ring chronologies contain information to facilitate reconstruction of mast events, which will help address outstanding questions regarding the future response of masting to climate change.

The tandem analysis of dendrochronological and genetic data is piquing forest ecologists&rsquo, 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&rsquo, ages (r &lt, 25 m in all plots) and neutral genetic diversity (Sp ranging from 0.002 to 0.004). Hot spots and cold spots of trees&rsquo, age were not statistically different in terms of genetic diversity, and trees&rsquo, 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.

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.

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.

Modeling and assessing the factors that drive forest fire ignitions is critical for fire prevention and sustainable ecosystem management. In southern Europe, the anthropogenic component of wildland fire ignitions is especially relevant. In the Alps, however, the role of fire as a component of disturbance regimes in forest and grassland ecosystems is poorly known. The aim of this work is to model the probability of fire ignition for an Alpine region in Italy using a regional wildfire archive (1995–2009) and MaxEnt modeling. We analyzed separately (i) winter forest fires, (ii) winter fires on grasslands and fallow land, and (iii) summer fires. Predictors were related to morphology, climate, and land use; distance from infrastructures, number of farms, and number of grazing animals were used as proxies for the anthropogenic component. Collinearity among predictors was reduced by a principal component analysis. Regarding ignitions, 30 % occurred in agricultural areas and 24 % in forests. Ignitions peaked in the late winter–early spring. Negligence from agrosilvicultural activities was the main cause of ignition (64 %); lightning accounted for 9 % of causes across the study time frame, but increased from 6 to 10 % between the first and second period of analysis. Models for all groups of fire had a high goodness of fit (AUC 0.90–0.95). Temperature was proportional to the probability of ignition, and precipitation was inversely proportional. Proximity from infrastructures had an effect only on winter fires, while the density of grazing animals had a remarkably different effect on summer (positive correlation) and winter (negative) fires. Implications are discussed regarding climate change, fire regime changes, and silvicultural prevention. Such a spatially explicit approach allows us to carry out spatially targeted fire management strategies and may assist in developing better fire management plans.

In dry, inner-alpine valleys, regeneration of Scots pine after large, high-severity fires is limited by seed dispersal distance. When dispersal limitations are relaxed (small fires), colonization dynamics of Scots pine remain unclear. Our aims were (1) to assess the regeneration niche of Scots pine seedlings following small fires in a dry, inner-alpine valley and (2) to measure the influence of competition, drought, fertility, and soil pH on pine colonization. We sampled pine seedlings in six high-severity fires (1962–2006), where distance from the unburned edge was

Exposure of female rats to estradiol during the perinatal period has profound effects on GABAergic neurotransmission that are crucial to establish sexually dimorphic brain characteristics. We previously showed that neonatal β-estradiol 3-benzoate (EB) treatment decreases brain concentrations of the neurosteroid allopregnanolone, a potent positive modulator of extrasynaptic GABA

Knowledge on the range of variability of montane European forests is hampered by limited data on the natural disturbance regime and by the small size of old-growth remnants. We studied the mixed Fagus – Abies – Picea Lom forest reserve (55.8 ha) in Bosnia and Herzegovina at three different scales: a grid of 40 sampling points to describe the structural characteristics and their range of variability, three transects to analyse gap size and gap fraction, and a 1.1 ha permanent plot to reconstruct age structure and disturbance history. The forest is characterized by a high volume of living trees (763 m3·ha–1 in the 55.8 ha core area and 1160 m3·ha–1 in the permanent plot) and of coarse woody debris (327 and 383 m3·ha–1, respectively). The percentages of forest area in canopy and expanded gaps are 19% and 41%, respectively. The median canopy gap size is 76.9 m2 and ranges from 11.1 to 708.0 m2. There are large (up to 120 cm diameter at breast height) and very old trees (441, 432, and 416 years for silver fir ( Abies alba Mill.), Norway spruce ( Picea abies (L.) Karst.), and European beech ( Fagus sylvatica L.), respectively). During the last three centuries, the disturbance patterns have been characterized by single-tree or small group mortality. In central Europe, this forest is at the end of a gradient from forests characterized by intermediate disturbances to those where very small-scale processes predominate.

This study was carried out in the “La Verna” forest, located in the “Foreste Casentinesi, Monte Falterona, Campigna” National Park at the border between Arno and Tevere watersheds. The forest covers an area of 203 ha and it is owned by the Franciscan religious order. Since 1985 the “La Verna” forest has been managed by the “Casentino” Comunita montana. In 2008 a sector of about 36 ha was selected for an intensive study of the stand structure, and the quality and quantity of coarse woody debris (CWD). A regular network of 33 sampling point was established. The average stem density was 473 trees ha-1 (range 133-1283) and the growing stock of living trees was 657.1 m3ha-1 (299-1452.9). The average volume of CWD was 66.9 m3ha-1 ranging between 3.7 and 355.8 m3ha-1. Of the total volume of dead and living trees, CWD comprised 10.2%. Among the CWD the volume of logs (66.1%) was greater than the volume of snags (28.3%) and stumps (5.6%). The study has emphasized that the “La Verna” forest, besides the historical and cultural value, has an important naturalistic value. The past low-intensity silviculture, traditionally applied by the Franciscan monks, has allowed the development of the current mixed structure and the co-existence in a managed forest of some structural “old-growth” characteristics e.g. the multi-layered vertical structure, the high living biomass and the quantity and quality of CWD.

Attualmente i boschi cedui di faggio (Fagus sylvatica L.) nella Regione Piemonte coprono circa 100.000 ettari (90% delle formazioni di faggio). Questi popolamenti spesso risultano aver oltrepassato i turni consuetudinari con la conseguenza che anche gli assortimenti legnosi ottenibili non siano piu quelli prodotti in passato. Il presente lavoro ha avuto come obiettivo quello di mettere a punto una metodologia per determinarne la produzione ritraibile in termini di legname da opera. Si sono individuate 20 zone distribuite sul territorio piemontese nelle quali si e proceduto ai rilievi dendrometrici ordinari. In due popolamenti si e eseguita un’analisi di dettaglio della qualita dei fusti. Dopo una prima valutazione, durante la quale sono state individuate le piante con difetti tali da non poterne consentire la lavorabilita, si e proceduto alla misurazione di quelle ritenute di «qualita». Dall’elaborazione dei dati e sulla base della classificazione commerciale degli assortimenti si e pervenuti alla definizione della produzione in assortimenti. La metodologia sperimentata mira alla valorizzazione della produzione, in quanto permette di individuare una percentuale di prodotti di migliore qualita rispetto ai tradizionali assortimenti ritraibili. E stato possibile infatti individuare sino al 20% di assortimenti di maggior pregio. Inoltre e da rimarcare che i dati raccolti si riferiscono allo stato attuale derivante dalla mancanza di cure colturali e di indirizzi selvicolturali. La definizione delle caratteristiche qualitative degli assortimenti risulta utile a fornire indicazioni circa gli obbiettivi da conseguire con la gestione selvicolturale dei popolamenti.

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 develop- mental 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 gra- dient (a) three old-growth forests in Bosnia and Montene- gro (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 for- ests. 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 sig- nificantly 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.

Stand structure, quality and quantity of coarse woody debris (CWD) and the importance of the stumps for the Norway spruce (Picea abies (L.) Karst.) regeneration were studied in the Valbona Forest Reserve in the eastern Italian Alps. Past history, present structures, quantity and quality of coarse woody debris (CWD) are fundamental steps for increasing our knowledge of the natural forest stand dynamics. This is particularly relevant in the Italian Alps where all forests have been used by humans for millennia. Nevertheless, in the last decades there has been a noticeable reduction of the anthropogenic disturbance and, as a consequence, many forest stands have developed naturally even if their composition and structure still reflect past human activity. The mean volume of CWD in the Valbona Forest Reserve was 23.4 m3 ha−1 ranging in the sampling plots between 0.0 and 89.3 m3 ha−1. Of the total volume of dead and living trees, CWD comprised 4.9%. Among the CWD, the volume of logs (37.6%) was greater than the volume of snags (32.0%) and stumps (30.4%). There are no significant differences in the quantity of CWD among the structural categories. The decomposition classes of the CWD are different in the three CWD types and are the result of the recent land-use history of the reserve: the stumps are present mainly in the most decomposed stages (III and IV) while the snags and the logs are present mainly in the first and in the second decay class, respectively. The stumps play an important role for the regeneration of the Norway spruce: more than 57% of the present dominant trees established on stumps and the present density of the regeneration on the stumps is five times the density of the regeneration on the ground. Stumps in advanced decay classes (III and IV) are more suitable for regeneration than those in early decay classes.

Tree masting is one of the most intensively studied ecological processes. It affects nutrient fluxes of trees, regeneration dynamics in forests, animal population densities, and ultimately influences ecosystem services. Despite a large volume of research focused on masting, its evolutionary ecology, spatial and temporal variability and environmental drivers are still matter of debate. Understanding the proximate and ultimate causes of masting at broad spatial and temporal scales will enable us to predict tree reproductive strategies and their response to changing environment. Here we provide broad spatial (distribution range-wide) and temporal (century) masting data for the two main masting tree species in Europe, European beech (Fagus sylvatica L.) and Norway spruce (Picea abies (L.) H. Karst.). We collected masting data from a total of 359 sources through an extensive literature review and from unpublished surveys. The dataset has a total of 1747 series and 18348 yearly observations from 28 countries and covering a time span of years 1677-2016 and 1791-2016 for beech and spruce, respectively. For each record, the following information is available: identification code; species; year of observation; proxy of masting (flower, pollen, fruit, seed, dendrochronological reconstructions); statistical data type (ordinal, continuous); data value; unit of measurement (only in case of continuous data); geographical location (country, Nomenclature of Units for Territorial Statistics NUTS-1 level, municipality, coordinates); first and last record year and related length; type of data source (field survey, peer reviewed scientific literature, grey literature, personal observation); source identification code; date when data were added to the database; comments. To provide a ready-to-use masting index we harmonized ordinal data into five classes. Furthermore, we computed an additional field where continuous series with length >4 years where converted into a five classes ordinal index. To our knowledge, this is the most comprehensive published database on species-specific masting behaviour. It is useful to study spatial and temporal patterns of masting and its proximate and ultimate causes, to refine studies based on tree-ring chronologies, to understand dynamics of animal species and pests vectored by these animals affecting human health, and it may serve as calibration-validation data for dynamic forest models. This article is protected by copyright. All rights reserved.

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.

The structure and the spatio-temporal dynamics of the mixed beech-silver fir-Norway spruce old-growth forest of Biogradska Gora (Montenegro) have been analysed at different spatial scales: at the landscape scale, using a high-resolution SPOT5 satellite image and at the stand level with an intensive field survey. This remote-sensing approach has been used to obtain a land cover map in order to define the main vegetation types and to detect the large canopy gaps ( GT 150m(2)). The structural characteristics have been delineated in a 50-ha study area in which a regular 120-m grid was superimposed over a 1:10,000 raster map and 30 sampling points have been obtained. The forest is characterized by a high volume of living trees (1029.6m(3)ha(-1)) and coarse woody debris (420.4m(3)ha(-1)) and by small-scale disturbances (individual trees to small groups) with a low incidence of intermediate disturbances (18 forest canopy gaps GT 150m(2) over 1230ha). The two approaches have proved useful to delineate the spatio-temporal dynamics. The Biogradska Gora forest dynamics are dominated by very small-scale processes, which are partially autogenic and partially caused by allogenic factors. The influence of large-scale or intermediate disturbances has shown to be negligible.

In the southern side of the Alps, many relic species with Mediterranean and sub-Mediterranean distribution were described in mild-winter, fire-prone areas. Very few studies have modeled the importance of environmental factors on their distribution. In this paper, we assessed the effect of fire on the occurrence of euri- and steno-Mediterranean (ESM) species in Pinus sylvestris forests of Aosta Valley (Italy), by analyzing vegetation in a chronosequence of six stand-replacing fires (1962–2006). We analyzed species richness along the chronosequence, and modeled it as a function of time since fire, environment, and stand structure. We observed a strong positive association between ESM and total species richness. Temporal vegetation dynamics did not follow the direct succession pattern that is commonly observed in Mediterranean ecosystems. Two distinct maxima of ESM species richness were observed: (1) short lived, ruderal species (32 % of all ESM species) in the early post-fire stages, and (2) dry grassland species (54 %) in intermediate stages. The first were facilitated by the consumption of canopy and litter during fire, while the second by delayed tree canopy closure. In multivariate models of ESM species richness, light and elevation were the only significant predictors. Contrary to expectations, time since fire was not significant. Our study suggests that stand-replacing fires play an important role in preserving Mediterranean species in the study area by maintaining an open canopy, and promote local species diversity.

Forests provide direct protection to human settlements from hydrogeomorphic hazards. This paper proposes a method for assessing the effect of natural disturbances on the functionality of direct protection forests (DPFs) in order to prioritize management interventions. We georeferenced disturbance data for wildfires, wind and snow damage, avalanches, and insects and overlaid them to a region-wide DPF map. Within each disturbance polygon, we used a Landsat-5 TM image to identify DPFs with insufficient vegetation cover, by using a maximum likelihood classifier of 6 spectral bands plus 5 vegetation indices. For each disturbance agent, we fitted a generalized linear model of the probability of finding a forested pixel, as a function of topography, time since disturbance, distance from disturbance edge, summer precipitation, and drought in the disturbance year. DPFs covered almost half of total forest area in the study region. Disturbance by insects occurred in more than one sixth of all forests. Avalanche and wildfire occurred each in about one tenth of total forest area, and wind and snow disturbance in only 1%. In the last 50 years, disturbances had a recurrence rate of 3% every 10 years. Almost one sixth of DPFs are currently lacking sufficient forest cover. Wildfires resulted in the highest rate of nonforested pixels (42% of all DPFs), followed by avalanches (21%). Forest recovery was explained by time elapsed, distance from edge (for conifers), and aspect. Summer precipitation and drought had a mixed influence. Our approach to assessing the effect of disturbances on the functionality of DPFs is reproducible in all mountain regions using institutional or open-access geographic data and provides a tool to prioritize DPF management by indicating where restoration of protection is most urgent.

International audience; We studied structural characteristics, amount and quality of coarse woody debris (CWD), intensity of competition and mortality in two subalpine Norway spruce stands withdrawn from regular management. The stands, that we measured twice (in 1993 and 2005), have similar age and structure, but a different time has elapsed since the last silvicultural treatments (respectively 22 and about 55 y).* The main purposes were to analyze the current stage of development as compared to the old-growth one and to highlight the legacies of past management.* Although relatively old, the first plot (Valbona 1) was at the end of the pole stage. CWD was low in volume and was mainly of man-made origin (stumps). A recent thinning from below has reduced density-dependent competition and delayed the development of old-growth characteristics. The second plot (Valbona 2a) was at the beginning of the transition stage, with density-dependent and allogenic mortality both active at the same time. CWD volume was higher in plot Valbona 2a than in Valbona 1, but neither was comparable yet to the reference old-growth sites from Central Europe, both in quantity and in quality (e.g., decay rate continuity).* The effects of the past management were: (1) reducing the quality and quantity of the CWD, (2) alleviating competition, (3) increasing resistance to minor disturbances and, as a consequence, (4) delaying the development processes.* In mature or overmature subalpine Norway spruce stands withdrawn from regular management many decades are necessary to develop old-growth characteristics and a longer period of time is necessary to reach a true old-growth stage.

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.

International audience; The alluvial forests of the Ticino valley have been greatly reduced in size and are now represented by only a small number of fragmented remnants. To study the natural development of the black locust, an invasive species, on relatively undisturbed lowland forests, two permanent plots were established in 2005 in the "Siro Negri" Forest Reserve.* The black locust became established almost exclusively between 1940 and 1960. The observed dynamic of the black locust in the Reserve was very similar to what has been observed in its native North American range: following the initial colonization, the black locust firmly established itself in the dominant and intermediate layers but did not regenerate. In addition to the absence of a significant younger population, the decline of the black locust is evident in an elevated mortality rate and higher proportion of black locust biomass in the total coarse woody debris (CWD)* Our results support the hypothesis that the best strategy to control the spread of black locust is to avoid disturbances that favour black locust colonization, and to wait for natural suppression of the species by other trees. Due to the lack of past reference conditions and the future uncertainties, ongoing monitoring will be needed to fully understand the dynamics of forest ecosystem change in the Reserve.; Les forêts alluviales de la vallée du Tessin ont été fortement réduites en taille et ne sont maintenant représentées que par un petit nombre de vestiges fragmentaires. Pour étudier le développement naturel du robinier, une espèce envahissante, dans des forêts de plaine relativement intactes, deux placettes permanentes ont été établies en 2005 dans la Réserve Forestière "Siro Negri".* Le robinier s'est établi presque exclusivement entre 1940 et 1960. La dynamique d'installation observée de Robinia pseudoacacia L. dans la réserve est très similaire à ce qui a été observé dans son habitat naturel en Amérique du Nord : après la première colonisation, le robinier s'est fermement établi dans les strates dominantes et intermédiaires, mais il ne s'est pas régénéré. En plus de l'absence d'une population plus jeune, l'évidence du déclin du robinier est révélée par une élévation du taux de mortalité et une plus grande proportion de la biomasse du robinier dans le total des débris ligneux grossiers (CWD).* Nos résultats appuient l'hypothèse que la meilleure stratégie pour contrôler la propagation du robinier est d'éviter les perturbations qui favorisent sa propagation, et d'attendre la suppression physique de l'espèce par d'autres arbres. En raison de l'absence de références sur les conditions passées, et les incertitudes futures, la surveillance continue sera nécessaire pour comprendre la dynamique de l'écosystème forestier dans la réserve.