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The fundamental trade-off between current and future reproduction has long been considered to result in a tendency for species that can grow large to begin reproduction at a larger size. Due to the prolonged time required to reach maturity, estimates of tree maturation size remain very rare and we lack a global view on the generality and the shape of this trade-off. Using seed production from five continents, we estimate tree maturation sizes for 486 tree species spanning tropical to boreal climates. Results show that a species' maturation size increases with maximum size, but in a non-proportional way: the largest species begin reproduction at smaller sizes than would be expected if maturation were simply proportional to maximum size. Furthermore, the decrease in relative maturation size is steepest in cold climates. These findings on maturation size drivers are key to accurately represent forests' responses to disturbance and climate change.

Climate change effects on tree reproduction are poorly understood, even though the resilience of populations relies on sufficient regeneration to balance increasing rates of mortality. Forest‐forming tree species often mast, i.e. reproduce through synchronised year‐to‐year variation in seed production, which improves pollination and reduces seed predation. Recent observations in European beech show, however, that current climate change can dampen interannual variation and synchrony of seed production and that this masting breakdown drastically reduces the viability of seed crops. Importantly, it is unclear under which conditions masting breakdown occurs and how widespread breakdown is in this pan‐European species. Here, we analysed 50 long‐term datasets of population‐level seed production, sampled across the distribution of European beech, and identified increasing summer temperatures as the general driver of masting breakdown. Specifically, increases in site‐specific mean maximum temperatures during June and July were observed across most of the species range, while the interannual variability of population‐level seed production (CVp) decreased. The declines in CVp were greatest, where temperatures increased most rapidly. Additionally, the occurrence of crop failures and low seed years has decreased during the last four decades, signalling altered starvation effects of masting on seed predators. Notably, CVp did not vary among sites according to site mean summer temperature. Instead, masting breakdown occurs in response to warming local temperatures (i.e. increasing relative temperatures), such that the risk is not restricted to populations growing in warm average conditions. As lowered CVp can reduce viable seed production despite the overall increase in seed count, our results warn that a covert mechanism is underway that may hinder the regeneration potential of European beech under climate change, with great potential to alter forest functioning and community dynamics. [ABSTRACT FROM AUTHOR]

Forest understory may be strongly affected by silvicultural practices such as thinning, which simultaneously modulates the overstory canopy cover and influences the availability of light. However, the understory layer is rarely considered in management decisions, partly because methods to estimate understory leaf area index are poorly developed. In this study we used two different restricted view angle photographic methods to estimate overstory plant area index LO (zenith cover photography), understory leaf area index LU (nadir cover photography) and their related canopy attributes (foliage clumping, foliage cover, crown cover, crown porosity). These measurements were performed in beech stands under different management regime. Results from photography indicated that not only overstory but also understory canopy attributes were significantly influenced by forest management. In addition, a significant negative correlation was found between LO and LU. We conclude that the photographic methods are effective for monitoring (overstory and understory) canopy status in managed stands, on account of their rapid and not destructive procedures, which allows large scale implementation of the methods.

Sustainable forest management (SFM) is crucial for forest ecosystem productivity and conservation, especially in systems such as cork oak (Quercus suber L.) threatened by human activities and biotic and abiotic factors. In this study SFM indicators with particular reference to cork oak forests in the region of Sardinia (Italy) are proposed and tested. Sustainable and responsible management options specifically aimed at cork oak forest management and chain of custody certification are also provided. A set of ten indicators was proposed and assessed by an expert panel in cork oak management. Five indicators were also tested against data on structure, origin, health condition and management in 285 forest compartments managed by FoReSTAS (Regional Forest Agency for Land and Environment of Sardinia, Italy), including 361 sampling plots and 5345 trees. In order to investigate the priorities and perceptions of SFM experts and stakeholders, a survey was also carried out by completion of a questionnaire on the technical issues of cork oak woodland management. The survey results highlighted a need to improve environmental and economic performance by means of SFM and certification. The indicators tested in Sardinian cork oak woodlands showed that about 80% of the stands fulfilled management sustainability requirements. The suggested SFM indicators can effectively support proactive management and conservation measures, representing a valuable tool in the current context of growing environmental and socioeconomic awareness. [ABSTRACT FROM AUTHOR]

Despite a less intensive management in the recent decades, coppices still cover a large part of Italian woodlands. Currently, they are characterized by relatively large wood volumes, especially with respect of those stands classified as "aged". The current European and national strategies to reduce the use of fossil fuels and the related increasing demand of renewable bio-energy sources are giving a new boost to the coppice system, so that the need for an improved management of these stands is emerging. Under this perspective, this note highlights the opportunity for an overall revision of current forest laws and regulations at regional level in Italy, in order to embed recent scientific achievements and harmonize some aspects such as definitions, rotation, conversion to high stands, standards, cut size and administrative procedures. [ABSTRACT FROM AUTHOR]

We propose several guidelines for sustainable forest management of the main regional forest types based on literature review on silviculture and forest management and taking into account the results from surveys carried out in four test sites located in Calabria (Southern Italy) within the framework of ALForLAB project. The four test sites cover 16% of regional forested area, which included ten of the main silvicultural types. Results hi - ghlighted a high variability in stand structure of high forests, while coppice woods were characterised by low structural variablity. The different silvicultural treatments proposed for high forests focused on the maintenance of stand structure complexity where it is already high, and to enhance it where the past management options simplified stand structure. The proposed silvicultural treatments for conifer plantations aimed at progressive renaturalisation. In the regional context coppice management, especially simple coppice with standards, still maintains an important role for fuelwood and charcoal production, poles and posts (chestnut coppice) production, and more recently for forest biomass for energy use. Coppice management, with exception for beech stands and stands within protected areas, can still be maintained with the adoption of suitable tending and thinnings interventions and rotation periods. The management guidelines here proposed for both high forests and coppices represent an important tool for sustainable forest management in Calabria. In addition, they can be an useful and complementary tool for spatial decision support system aimed to Precision Forestry issues. [ABSTRACT FROM AUTHOR]

Based on LiDAR (Light Detection And Ranging) data, estimates of volume and biomass potentially available from coppice and high forest stands under different silvicultural options were estimated in a case study located in the Pollino National Park (Calabria - Southern Italy) within the framework of the ALForLAB project. Estimates of volume and biomass potentially available were elaborated separately for the main silvicultural types: beech, Calabrian pine and Mediterranean pines high forest stands on one hand, and for traditional coppices, outgrown coppice and coppice in conversion to high forest on the other. The estimates were per - formed taking into duly account both of the forest regional law and the restrictions due to the protected area (Natural Park). The overall standing volume ranged from 4.8 up to 7.7 M m3, while the volume potentially available ranged from 3.7 up to 6 M m3. Estimates of mass potentially available under the the adoption of different silvicultural system and options, in a sustainable forest management context, and according to the main stand structure types were analysed and discussed. [ABSTRACT FROM AUTHOR]

The economical-social change, the competitiveness and "modernity" of fossil fuels, their prompt diffusion are the concurrent factors that heavily reduced the use of coppice firewood and charcoal since the fifties of the last century. Therefore, a shift took place in the last 60 years from the homogeneous area made of intensively managed, young stands to the more and more differentiated standing crops, as for structural features, growing stocks and growth dynamics, even though all of them originated from a common matrix. Nowadays, the former coppice area includes stands managed under lengthened rotations, outgrown coppices, the coppice conversion into high forest. The 2005 National Forest Inventory reported that 87% of standing crops was included in the age-classes 20-40 and over 40 years, with variable percentages according to tree species, from beech up to thermophilous oaks. Here, the basis of historical judgment on the coppice system, the reasons underlying the outgrown coppice establishment, the current standards of cultivation under even doubled rotations, are critically analyzed. The current demand to reduce the use of fossil fuels by renewable bio-energy sources and to face up the effects of climate change (unpredictability, rainfall reduction, higher air temperature, prolonged droughts, water stress, fire risk) give a new boost to the coppice system. Main goals today are to: (i) optimize the capacity of firewood production to reduce the heavy deficit at the country level; (ii) make the best use of the regenera - tion ability inherent to the system against the more sensitive regeneration from seed in the changing environment. The positive growth trend, the maintenance of resprouting ability as well as of vital stools density in the outgrown coppice area, address to a sustainable increase of rotations up to the age of 50 years, as already highlighted by a few regional regulations. It would allow the recovery of a current volume increment of 1-1.5 M m3 to internal firewood production. Unsuitable stand locations or bio-ecological conditions as well as stands already under conversion into high forest are obviously excluded. The approach to coppice system maintenance within the variable territorial context, the possible innovation and the definition of flexible sil - vicultural models are then outlined. The useful updating and harmonization of forest regulations are finally recalled. [ABSTRACT FROM AUTHOR]

The "Bosco Fontana" natural reserve includes the last remaining mixed floodplain forest in northern Italy and one of the most endangered ecosystems in Europe. Its effective management is hindered by the complexity of interactions of mixed-tree species and the influence of environmental factors on understory plant diversity. In this study we analyzed the patterns of natural evolution in semi-natural floodplain forest stands at Bosco Fontana with the aim of better understanding its current natural processes and dynamics. Stand structure, taxonomic and functional diversity, species composition, and leaf area index (LAI) of overstory and understory layers were surveyed in permanent plots over two inventory years (1995, 2005). The influence of environmental factors on understory plant diversity was assessed using Ellenberg's indices for light, soil moisture, soil nutrient and soil reaction. Results indicated that overstory species composition varies according to the soil moisture, with hornbeam prevailing in xeric sites and deciduous oak species in mesic sites. Xeric sites showed high functional dispersion in both drought and shade tolerant traits, while it was significantly lower in both overstory and understory in the moist site. Functional dispersion of drought tolerance in the overstory and understory layers was positively correlated, while species richness was negatively correlated between the two layers. Diversity in the understory was mainly correlated with soil conditions. Understory LAI was positively correlated with overstory LAI in xeric and mesic plots, while no correlations were found in the moist plot. Overall, our results suggest that site conditions (soil conditions and water availability) are the major drivers of understory and overstory dynamics in the study forest. Hence, local site conditions and the understory should be carefully considered in the management of mixed floodplain forests. [ABSTRACT FROM AUTHOR]