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Deciphering the spatial patterns of alpine treelines is critical for understanding the ecosystem processes involved in the persistence of tree species and their altitudinal limit. Treelines are thought to be controlled by temperature, and other environmental variables but they have rarely been investigated in regions with different land‐use change legacies. Here, we systematically investigated treeline elevation in the Apennines (Italy) and Southern Alps (New Zealand) with contrasting human history but similar biogeographic trajectories, intending to identify distinct drivers that affect their current elevation and highlight their respective peculiarities. Over 3622 km of Apennines, treeline elevation was assessed in 302 mountain peaks and in 294 peaks along 4504 km of Southern Alps. The major difference between the Southern Alps and Apennines treeline limit is associated with their mountain aspects. In the Southern Alps, the scarcely anthropized Nothofagus treeline elevation was higher on the warmer equator‐facing slopes than on the pole‐facing ones. Contrary to what would be expected based on temperature limitation, the elevation of Fagus sylvatica treelines in the Apennines was higher on colder, pole‐facing slopes than on human‐shaped equator‐facing, warmer mountainsides. Pervasive positive correlations were found between treeline elevation and temperature in the Southern Alps but not in the Apennines. While the position of the Fagus and Nothofagus treelines converge on similar isotherms of annual average temperature, a striking isothermal difference between the temperatures of the hottest month on which the two taxonomic groups grow exists. We conclude that actual treeline elevation reflects the ecological processes driven by a combination of local‐scale topoclimatic conditions, and human disturbance legacy. Predicting dynamic processes affecting current and future alpine treeline position requires further insight into the modulating influences that are currently understood at a regional scale. [ABSTRACT FROM AUTHOR]

In this paper, we present a detailed record of the plant remains recovered on the palaeo-seafloors of Neapolis harbour, spanning ≈700 years, between the 2nd century BC and the 5th century AD, thus intersecting the entire Roman Imperial Age. The site preserved many cultivated or cultivable plant remains, especially from food related trees. This particular feature provided the opportunity to reconstruct the puzzling history of planting them and the Roman economy, especially with respect to food production, the market and to dietary habits. The evidence suggests that Prunus persica, Castanea sativa, Juglans regia and Pinus pinea were locally grown all along the investigated period, testifying for a well advanced arboriculture. A broad presence of P. pinea cones could be related to their large use as stoppers for amphorae which probably was among the driving force for planting it actually influencing its original range. The seafarers had extensive access to dry fruit such as walnut, hazelnut and chestnut that for its imperishable nature and the high energy density, would probably have been part of the food-stocks of the galleys. Chestnut consumption, attested throughout the entire period in the harbour, represents the first strong archaeobotanical evidence of chestnut as food in the Western Mediterranean in Roman time. This evidence shed light on the cultural-social significance of these fruits that was probably eaten mainly or almost exclusively by low social classes. The exceptional find of Hyphaene thebaica for the first time outside its native range is also reported. [ABSTRACT FROM AUTHOR]

Anthracological analysis has been carried out in the Medieval site of Miranduolo, a rural settlement in southern Tuscany with a sequence of occupation between the 7th and 14th century AD. Between the 7th and mid-9th century AD, during the phase of a Lombard farming village, the strong presence of Castanea sativa as timber for building showed that chestnut was the preferred species for carpentry and fuelwood, suggesting coppice management of chestnut woods for timber production. The Miranduolo data, set against the archaeobotanical data in the literature, rejected the hypothesis of chestnut cultivation as a fruit tree and corroborated the hypothesis that the plant was initially used for timber production during the Early Middle Ages, continuing the woodworking tradition of the Roman period. From the mid-9th century AD, during the Carolingian feudal system, chestnut in the feudal estate of Miranduolo ceased to be used for building and firewood, while deciduous Quercus was preferred. At the same time, chestnut fruits began to be picked and kept in warehouses at the disposal of the feudal lord, suggesting the management of chestnut woods for fruit production. Comparison with existing archaeobotanical data revealed that chestnut cultivation for fruits began in this period in other Italian regions also, encouraged by different economic systems. From the 10th century, in Miranduolo chestnut was exploited both for timber and fruit suggesting the abundance of this resource in high managed stands. Comparison with coeval archaeological sources, archaeobotanical data and pollen records suggested from this period the strong expansion of this species that gradually took place throughout central and southern Italy, becoming a ‘multifunctional’ high-forest. The current chestnut forest landscape in central Italy is thus of human origin, expanding and changing over about 1000 years of cultivation. [ABSTRACT FROM AUTHOR]

In a Pinus halepensis Mill. forest, a field experiment was designed to evaluate post-fire seed predation as affected by combinations of seed colour and soil substrates: light grey and black seeds combined with light grey ash, dark grey ash and pale brown sand. A survey of bird species inhabiting the area was also carried out and polyphenolic content of seed coat was assessed in seed lots of different colour. Light grey seeds were observed to be less predated on light grey ash, suggesting eucrypsis as a protective strategy against bird predation. On the contrary, no clear pattern was observed for the predation of black seeds on different substrates. In the study area both bird species breaking the seed coat and eating the endosperm and bird species swallowing the whole seed were monitored. We have estimated that more seeds were swallowed than broken, in all colour categories. Light grey seeds, which were found to have a higher content of polyphenols, were predated more than black seeds when exposed on the same substrate. Thus, no evidence was produced that the amount of polyphenols in seed coat could protect seeds from predation. [Copyright &y& Elsevier]

We describe a case of a voluminous rhabdomyoma (R) detected by fetal echocardiography at 32 weeks' gestation (w.g.) obstructing the left ventricular inflow and aortic outflow tract, with a moderate aortic gradient at birth, not needing immediate surgery. At follow-up, the mass progressively regressed, leaving the aortic valve partly damaged, with a gradient that increased to a maximum of 100 mmHg at 9 years. The girl was then operated on successfully by a plasty of the aortic valve. The literature regarding R is discussed. [ABSTRACT FROM AUTHOR]

Sperry's packing rule predicts the optimum packing of xylem conduits in woody plants, where the frequency of xylem conduits varies approximately inversely with the square of the conduit radius. However, it is well established that such anatomical disposition does not remain fixed but is subject to a suite of adaptations induced by physiological constraints driven by both ontogenetic development and environmental characteristics. Here we challenge the hypothesis that increasing frequency of xylem conduits, concomitant with the decrease in their lumen area along the xylem pathway, would affect the spatial distribution of vessels inside tree-rings and their aggregation. To this end, we measured the vessels' anatomical characteristics inside each tree-ring along with a complete radial series taken at different stem heights of Fagus sylvatica L. trees. Point pattern analysis indicated a significant effect of the distance from the tree base and a weak effect of cambial age on the nearest neighbour distance among xylem vessels, suggesting that vessels were closer to each other near the apex, and became progressively more distant toward the base. The spatial pattern of xylem vessels violated the assumption of complete spatial randomness, vessel spatial arrangement followed a uniform distribution at different distances from the tree base. Although there was an increase in the intensity and proximity among vessels, we demonstrated that no patterns of aggregation between vessels were found in sampled F. sylvatica trees. Rather, point pattern profiles clearly highlighted a lack of aggregation of vessels in the face of a regular spatial distribution in the annual growth rings along the stems. [ABSTRACT FROM AUTHOR]

Background: Post-operative infections are a substantial cause of morbidity and mortality worldwide. Polyhexamethylene biguanide (PHMB) is an antimicrobial agent that has been used in various surgical settings to prevent infections. However, the literature on its efficacy in reducing post-operative infections remains unclear. Materials and Methods: We conducted a systematic review and meta-analysis of randomized controlled trials (RCTs) to evaluate the efficacy of PHMB in reducing post-operative infections. The risk of bias and methodologic quality of the included studies were also assessed. Results: The systematic review included nine RCTs, and eight were included in the meta-analysis that showed that the use of PHMB was associated with a reduction in the rate of post-operative infections. The overall effect size was statistically significant, with moderate heterogeneity across the included studies (log Peto's odds ratio [OR], −0.890; 95% confidence interval [CI], −1.411 to −0.369; I2 = 41.89%). However, the diversity in the application of PHMB and the potential influence of other factors, such as adherence to infection prevention protocols and organizational-level variables, underscore the need for further primary studies. Conclusions: Polyhexamethylene biguanide appears to be a promising intervention for reducing post-operative infections. However, more high-quality, well-designed RCTs are needed to confirm these findings and to explore the most effective ways to use PHMB within specific infection prevention bundles. Future research should also aim to control for potential confounding factors to provide a more comprehensive understanding of the efficacy of PHMB in reducing post-operative infections. [ABSTRACT FROM AUTHOR]

Developing long-term chronologies of tree-ring anatomical features to evaluate climatic relationships within species might serve as an annual proxy to explore and elucidate the climatic drivers affecting xylem differentiation. Pinus leucodermis response to climate was examined by analyzing vertical xylem resin ducts in wood growing at high elevation in the Apennines of peninsular Southern Italy. Early- and latewood tree-ring resin duct chronologies, spanning the 1804–2010 time period, were constructed. We analyzed the relationships between resin duct chronologies and climate over the last century using correlation and response function analyses. Overall, results showed that ring width and resin duct relationships differed between early- and latewood, which indicated conditions affecting growth were not associated with resin duct production. Results also revealed differential responses to climate between early- and latewood resin duct chronologies. A notable observation was a positive and stable relationship between latewood resin duct number chronology and July maximum temperature throughout the twentieth century. This result suggested resin ducts might be a suitable proxy to evaluate P. leucodermis response to climate in the study area.Developing long-term chronologies of tree-ring anatomical features to evaluate climatic relationships within species might serve as an annual proxy to explore and elucidate the climatic drivers affecting xylem differentiation. Pinus leucodermis response to climate was examined by analyzing vertical xylem resin ducts in wood growing at high elevation in the Apennines of peninsular Southern Italy. Early- and latewood tree-ring resin duct chronologies, spanning the 1804–2010 time period, were constructed. We analyzed the relationships between resin duct chronologies and climate over the last century using correlation and response function analyses. Overall, results showed that ring width and resin duct relationships differed between early- and latewood, which indicated conditions affecting growth were not associated with resin duct production. Results also revealed differential responses to climate between early- and latewood resin duct chronologies. A notable observation was a positive and stable relationship between latewood resin duct number chronology and July maximum temperature throughout the twentieth century. This result suggested resin ducts might be a suitable proxy to evaluate P. leucodermis response to climate in the study area.Developing long-term chronologies of tree-ring anatomical features to evaluate climatic relationships within species might serve as an annual proxy to explore and elucidate the climatic drivers affecting xylem differentiation. Pinus leucodermis response to climate was examined by analyzing vertical xylem resin ducts in wood growing at high elevation in the Apennines of peninsular Southern Italy. Early- and latewood tree-ring resin duct chronologies, spanning the 1804–2010 time period, were constructed. We analyzed the relationships between resin duct chronologies and climate over the last century using correlation and response function analyses. Overall, results showed that ring width and resin duct relationships differed between early- and latewood, which indicated conditions affecting growth were not associated with resin duct production. Results also revealed differential responses to climate between early- and latewood resin duct chronologies. A notable observation was a positive and stable relationship between latewood resin duct number chronology and July maximum temperature throughout the twentieth century. This result suggested resin ducts might be a suitable proxy to evaluate P. leucodermis response to climate in the study area.Developing long-term chronologies of tree-ring anatomical features to evaluate climatic relationships within species might serve as an annual proxy to explore and elucidate the climatic drivers affecting xylem differentiation. Pinus leucodermis response to climate was examined by analyzing vertical xylem resin ducts in wood growing at high elevation in the Apennines of peninsular Southern Italy. Early- and latewood tree-ring resin duct chronologies, spanning the 1804–2010 time period, were constructed. We analyzed the relationships between resin duct chronologies and climate over the last century using correlation and response function analyses. Overall, results showed that ring width and resin duct relationships differed between early- and latewood, which indicated conditions affecting growth were not associated with resin duct production. Results also revealed differential responses to climate between early- and latewood resin duct chronologies. A notable observation was a positive and stable relationship between latewood resin duct number chronology and July maximum temperature throughout the twentieth century. This result suggested resin ducts might be a suitable proxy to evaluate P. leucodermis response to climate in the study area.Developing long-term chronologies of tree-ring anatomical features to evaluate climatic relationships within species might serve as an annual proxy to explore and elucidate the climatic drivers affecting xylem differentiation. Pinus leucodermis response to climate was examined by analyzing vertical xylem resin ducts in wood growing at high elevation in the Apennines of peninsular Southern Italy. Early- and latewood tree-ring resin duct chronologies, spanning the 1804–2010 time period, were constructed. We analyzed the relationships between resin duct chronologies and climate over the last century using correlation and response function analyses. Overall, results showed that ring width and resin duct relationships differed between early- and latewood, which indicated conditions affecting growth were not associated with resin duct production. Results also revealed differential responses to climate between early- and latewood resin duct chronologies. A notable observation was a positive and stable relationship between latewood resin duct number chronology and July maximum temperature throughout the twentieth century. This result suggested resin ducts might be a suitable proxy to evaluate P. leucodermis response to climate in the study area. [ABSTRACT FROM AUTHOR]

Background and aim: Fires affect what happens to litter in ecosystems. Biological and chemical effects of burnt litter on plants are not as of yet fully understood. We aimed to assess the effects of heat-treated leaf litter on germination and seedling root growth of Eucalyptus globulus.Methods: Litter from E. globulus, Acacia dealbata, Pinus pinaster, and Quercus suber was collected in Portugal, on Humic Cambisol, and heated between 25 °C and 600 °C. Those materials were then characterized by: 13C CPMAS NMR spectroscopy, proximate lignin and cellulose, and elemental analyses. Afterwards, they were used as substrate in bioassays with Eucalyptus seeds.Results: Heating changed litter composition (P < 0.05), consistently across species: alkyl C, O-alkyl C, and methoxyl + N-alkyl C decreased more than 50%; and aromatic C increased more than 5-fold. Unheated and lightly heated litters inhibited germination and growth, with maximum inhibition by Quercus and Eucalyptus litters, down to 17% of the control (P < 0.05). Severely charred materials had neutral or stimulatory effects, up to 191% of the control (P < 0.05). These responses were associated with concentrations of dominant C types in litters (P < 0.05).Conclusion: Litter charring, as it occurs during wildfires, is potentially critical for the success of E. globulus’s regeneration from seeds. [ABSTRACT FROM AUTHOR]

Aortic valve replacement early in life may be inevitable. Ross operation, until present day, remains the favorite surgical option in pediatrics with irreparable aortic valve disease. Nonetheless, the necessity for re-operation was always its principal limitation due to aortic valve failure or homograft degeneration. We present our 25 years of experience in the pediatric population. From August 1994 until June 2018, 157 children below 18 years underwent the Ross operation. This retrospective review aims at assessing the long-term outcomes, as well as the risk factors for re-operation after Ross procedure. Median age was 10.9 years, of which seven patients were infants, 79 children, and 71 adolescents. The median follow-up time was 14 years. Hospital mortality was 0.6%. Freedom from autograft re-operation for children was 96.7% and 94.1% at 10 and 20 years, respectively; whereas for adolescents, it was 92.6% and 74.9% at 10 and 20 years. For children, freedom from homograft re-operation was 92.5%, 83.5%, and 56.2% at 10, 15, and 20 years; while for adolescents, it was 96.8%, 91.8%, and 86.7% at 10, 15, and 20 years. Homograft size (p = 0.008) and childhood (p = 0.05) were risk factors for homograft re-operation. Pulmonary valve diameter > 24 mm (p = 0.044) and adolescence (p = 0.032) were risk factors for autograft re-operation. Our experience demonstrated excellent early and late survival. While children have preferential outcomes concerning autograft re-operation, those who received a smaller homograft had a higher right-sided re-intervention incidence than adolescents. Pulmonary diameter > 24 mm at surgery was an indicator of future autograft failure. [ABSTRACT FROM AUTHOR]

Wildfires are one of the most important natural disturbances in vegetation biomes. In recent decades, both the number and severity of fires have significantly increased in Mediterranean forests, frequently resulting in catastrophic events. In this scenario, we aimed to explore the flow of ecosystem services and their related economic value that was disrupted by human-induced megafires in the Mediterranean forest of Vesuvius National Park in the summer of 2017. We adopted an innovative approach by merging two methodologies: an ecological approach to evaluate the status of the forest ecosystem after the wildfires and an economics methodology to estimate the monetary value of the interruption to ecosystem services. Losses related to the following six services were estimated: woody biomass, soil erosion control, habitat maintenance, pollination, carbon stock, and ecotourism. In 2017, 3350 ha of forest (88% of the total forested area of Vesuvius National Park) burnt over a period of 49 days. The total estimated monetary loss amounted to €14.363 M, 56.9% of which comprised of provisioning ecosystem services, while 34.7% encompassed maintenance and regulation services, and 8.5% were so-called cultural services. Suppression costs accounted for 16% of the total estimated economic loss of ecosystem services. Our results provide useful insights for decision-makers when allocating financial resources, suggesting that they should invest in fire prevention rather than fire suppression and post-fire restoration. This explicit valuation of the footprint of the wildfires, although not exhaustive, can also lead to greater awareness among the public regarding the benefits conferred by Mediterranean forest ecosystems. This is the first study to economically evaluate the interruption of ecosystem services after megafires in the Mediterranean basin. [ABSTRACT FROM AUTHOR]

Visuo-perceptual deficits and visual hallucinations (VHs) are common disturbances in patients with dementia with Lewy bodies (DLB) and those with Parkinson's disease (PD). In particular, delays in visual evoked potential (VEP), reversed by l -dopa administration, have previously been observed in PD patients. Impairment in metabolic functions of dopaminergic amacrine cells within the inner plexiform layer of the retina has been largely documented and has been posited as the underlying cause of visual and retinal alterations in PD. The aims of the present study were to investigate the presence of VEP abnormalities in DLB patients, as compared to a PD control group, and to assess the presence of significant correlations between neurophysiological measures and clinical symptoms (i.e., presence of visuospatial deficits and/or visual hallucinations). Fifteen DLB patients and fifteen matched PD patients underwent pattern reversal before and after l -dopa administration, and a short neuropsychological assessment. In DLB patients, we observed delay of the P100 latency to foveal stimuli in both eyes compared to normative values. Compared to PD, DLB patients showed higher values of the P100 latency for foveal stimulation from the right eye prior to l -dopa administration (p = 0.018). No correlations between VEP alterations, visuo-spatial deficit and visual hallucinations were found. Our findings demonstrated a longer P100 delay in DLB than in PD patients, especially along the right visual pathway. In contrast to previous studies, which focused on a dopaminergic pre-geniculate impairment of visual pathways, our evidence suggests that other mechanisms, possibly relying on thalamic involvement, which is known to be dysfunctional in DLB, can interfere with VEP abnormalities. [ABSTRACT FROM AUTHOR]

Questions: Elevational treelines are expected to shift upwards in response to warming climate. However, worldwide upward shifts of treelines are inconsistent because local scale factors can affect the response to temperature. In this study, we explore the hypothesis that in the Apennines, where the current altitudinal treeline position is largely depressed because of past human activity, shrubs act as nurse plants promoting the upward migration of Fagus sylvatica. Location: A 500–km-long latitudinal gradient in the Apennines, Italy. Methods: We selected, along this gradient, nine treeline sites with different elevations, rock substrates, and physiognomic types including Juniperus communis, Pinus mugo, Vaccinium myrtillus shrublands, and grasslands. Here, in 68 transects we collected and analysed spatially fine-scale distribution data of F. sylvatica individuals in relation to both their age and their position, associated or not with shrubs. Results: Fagus sylvatica regeneration is rare in open secondary grasslands at 1,600–2,100 m a.s.l., highlighting a bottleneck in the regeneration phase of this species. On the contrary, we systematically observed a strong association between shrubs and F. sylvatica individuals. Compared with the adjacent grassland, F. sylvatica regeneration was 58.3 times higher under Pinus mugo, 131.5 timeshigher under Juniperus communis and 102.4 times higher under Vaccinium myrtillus. The age structure of F. sylvatica population indicates that, in the last 50 years, recruitment under shrubs is continuous, while in grassland it is episodic. Conclusions: Above the current treeline of the Apennines, F. sylvatica individuals develop only in the presence of shrubs, which act as nurse species. Shrubs are a necessary condition for F. sylvatica re-colonization of the high-altitude open areas affected, in the last centuries, by intense human land use. [ABSTRACT FROM AUTHOR]

Understanding processes controlling forest dynamics has become particularly important in the context of ongoing climate change, which is altering the ecological fitness and resilience of species worldwide. However, whether forest communities would be threatened by projected macroclimate change or unaffected due to the controlling effect of local site conditions is still a matter for debate. After all, forest canopy buffer climate extremes and promote microclimatic conditions, which matters for functional plant response, and act as refugia for understory species in a changing climate. Yet precisely how microclimatic conditions change in response to climate warming will depend on the extent to which vegetation structure and local topography shape air and soil temperature. In this study, we posited that forest microclimatic buffering is sensitive to local topographic conditions and canopy cover, and using meteorological stations equipped with data-loggers we measured this effect during 1 year across a climate gradient (considering aspect as a surrogate of local topography) in a Mediterranean beech treeline growing in contrasting aspects in southern Italy. During the growing season, the below-canopy near-ground temperatures were, on average, 2.4 and 1.0 °C cooler than open-field temperatures for south and north-west aspects, respectively. Overall, the temperature offset became more negative (that is, lower under-canopy temperatures at the treeline) as the open-field temperature increased, and more positive (that is, higher under-canopy temperatures at the treeline) as the open-field temperature decreased. The buffering effect was particularly evident for the treeline on the south-facing slope, where cooling of near-ground temperature was as high as 8.6 °C for the maximum temperature (in August the offset peaked at 10 °C) and as high as 2.5 °C for the average temperature. In addition, compared to the south-facing slope, the northern site exhibited less decoupling from free-air environment conditions and low variability in microclimate trends that closely track the free-air biophysical environment. Although such a decoupling effect cannot wholly isolate forest climatic conditions from macroclimate regional variability in the south-facing treeline, it has the potential to partly offset the regional macroclimatic warming experienced in the forest understory due to anthropogenic climate change. [ABSTRACT FROM AUTHOR]

Aims: Data about woody debris (WD) decomposition are very scarce for the Mediterranean basin. The specific aim of this work is to explore the relationships between WD traits with the decay rate. Methods: We carried out a three-year litterbag decomposition experiment using ten WD types incubated in two plant communities (i.e. shrubland and woodland) and in laboratory conditions. WD was characterized for 31 chemical and anatomical traits, including macro- and micronutrients, lignin, and cellulose as well as organic chemistry by Solid-state Cross-Polarization Magic Angle Spinning Carbon-13 Nuclear Magnetic Resonance (13C CPMAS NMR) and Fourier transform infrared spectroscopy/ Attenuated Total Reflection (FT-IR/ATR spectroscopy). Results: WD decay rate was negatively associated with di-O-alkyl, lignin/N and C/N ratios, but positively with N concentration. Less consistent but positive correlations were recored for K, Mn, and Na concentration. The alkyl C and carboxylic C regions, associated with aliphatic and amide compounds, was positively correlated with WD decomposition. Conversely, di-O-alkyl C and O-alkyl C fractions, largely associated with cellulose and hemicellulose, were negatively correlated with WD decay rate. Finally, the positive correlation between Na concentration and WD mass loss in field conditions suggest a role of this neglected micronutrient for wood decomposition. WD specific density and anatomical features, have a minor capability to explain decomposition rate. Conclusions: Our findings demonstrate a major role of WD chemical traits in explaining the variability of decomposition in Mediterranean ecosystems. [ABSTRACT FROM AUTHOR]

Aim: The aim was to decipher Europe‐wide spatio‐temporal patterns of forest growth dynamics and their associations with carbon isotope fractionation processes inferred from tree rings as modulated by climate warming. Location: Europe and North Africa (30‒70° N, 10° W‒35° E). Time period: 1901‒2003. Major taxa studied: Temperate and Euro‐Siberian trees. Methods: We characterize changes in the relationship between tree growth and carbon isotope fractionation over the 20th century using a European network consisting of 20 site chronologies. Using indexed tree‐ring widths (TRWi), we assess shifts in the temporal coherence of radial growth across sites (synchrony) for five forest ecosystems (Atlantic, boreal, cold continental, Mediterranean and temperate). We also examine whether TRWi shows variable coupling with leaf‐level gas exchange, inferred from indexed carbon isotope discrimination of tree‐ring cellulose (Δ13Ci). Results: We find spatial autocorrelation for TRWi and Δ13Ci extending over a maximum of 1,000 km among forest stands. However, growth synchrony is not uniform across Europe, but increases along a latitudinal gradient concurrent with decreasing temperature and evapotranspiration. Latitudinal relationships between TRWi and Δ13Ci (changing from negative to positive southwards) point to drought impairing carbon uptake via stomatal regulation for water saving occurring at forests below 60° N in continental Europe. An increase in forest growth synchrony over the 20th century together with increasingly positive relationships between TRWi and Δ13Ci indicate intensifying impacts of drought on tree performance. These effects are noticeable in drought‐prone biomes (Mediterranean, temperate and cold continental). Main conclusions: At the turn of this century, convergence in growth synchrony across European forest ecosystems is coupled with coordinated warming‐induced effects of drought on leaf physiology and tree growth spreading northwards. Such a tendency towards exacerbated moisture‐sensitive growth and physiology could override positive effects of enhanced leaf intercellular CO2 concentrations, possibly resulting in Europe‐wide declines of forest carbon gain in the coming decades. [ABSTRACT FROM AUTHOR]

Late spring frost plays a major role in the structure and function of forest ecosystems with potential consequences on species distribution at both local and regional scales. Paradoxically, in a warmer world the incidence and impact of frost is increasing because of earlier leaf unfolding and flowering as a response to warmer temperatures. In this regard, European Beech (Fagus sylvatica L.), a native tree species widely distributed in European forests, is considered particularly sensitive to changes in spring temperature regimes associated with climate change and thus especially subject to the risk of frost damage. Although several studies concerning F. sylvatica frost damage have been conducted in northern and central Europe, no extensive studies are available for the southern part of its range, i.e. central and southern Italy as well as Greece. In this paper the effect of a late spring frost occurring at the end of April 2016 is extensively documented with high spatial detail all along the Apennine Chain through satellite image data. Three different remote-sensing greenness indexes, namely the normalized difference vegetation index (NDVI), enhanced vegetation index (EVI), and the greenness index (GI) derived from Landsat-8 satellite images acquired from May to July in the years 2014, 2015, and 2016 at a spatial resolution of 30 m, were used to gauge the spatial response of common beech forests to this late frost event with relation to latitude, altitude and slope exposure. Frost damage was evaluated as a difference (Δ) of NDVI, GI and EVI between the mean of years 2014 and 2015 (i.e. MRY, mean of reference years), and 2016 (i.e. FEY, frost reference year). The three satellite remote-sensing indexes were efficient at detecting leaf damage with detailed spatial resolution and proved consistent with one another. The greatest damage occurred in the middle altitudinal range between 1500 and 1700 m a.s.l. with a decreasing trend toward both lower and higher elevations due to warmer temperatures below, and delayed phenology above. Exposure also influenced frost injury, with south-facing slopes of the mountain more damaged than the north. This difference was due to earlier spring leaf phenology of southern beech trees in response to a greater heat sum in the warm weeks preceding. Less damage in the northern Apennines is consistent with the spatial extent of minimum freezing temperatures. To sum up, frost damage is strongly related to site-specific conditions, i.e. on the one hand to minimum temperatures, and on the other to the phenological stage of the trees involving both altitude and exposure. Hence focusing on detailed sub-regional studies can be helpful for predicting future consequences of climate change on forests. • Spring frost canopy damage of European beech in Apennines is related to site-specific conditions. • Damage severity depends by freezing temperatures coupled with phenological stage. • Frost damage is greater in the southern aspect and at the middle belts rather than at higher ones. • NDVI, EVI and GI are efficient to detect leaf damage with detailed spatial resolution. [ABSTRACT FROM AUTHOR]

Abstract In short-rotation coppice, shoots grow at high density and compete for limiting resources with their neighbours. Interactions among shoots translate into individual size differences due to resource apportionment. In the present study we compared shoot dynamics of six hybrid poplars and three wild river genotypes of Populus nigra under the first three-year cycle of multi-stem short-rotation coppice. We investigated changes over time in diameter frequency distribution, mortality and biomass partitioning according to crown classes of the shoots. Unimodal shoot diameter distributions during rotation modelled by a two-parameter Weibull probability density distribution show that the values of the α scale parameter are higher in hybrid genotypes compared to wild black poplars (α ≥ 2.0 and α ≤ 2.0, respectively) in all three years. The values of the β shape parameter mostly decrease over time in hybrid genotypes and increase in wild black poplars in the narrow range from 1.42 to 2.38 and from 1.47 to 2.03, respectively. With regard to biomass partitioning among shoot crown classes, differences in size attributes are more pronounced in hybrids than native black poplar genotypes. In hybrid genotypes, 83.7% of the biomass is allocated to dominant shoots, while wild black poplars share 71.6% of the biomass in the dominant and 24.8% in the intermediate shoots. This disproportional biomass allocation among crown classes of hybrid compared to native genotypes could be related to their different origin of selection. Highlights • Two-parms Weibull PDF depicts shoot diameter distribution over time of poplars in SRC. • Weibull PDF diameter distributions change over time due to population dynamic. • Different biomass partitioning characterizes native wild and domesticated poplars. • Differences in size attributes are more pronounced in hybrids than native black poplar genotypes. [ABSTRACT FROM AUTHOR]

Aim: High‐elevation forest line or tree line is an ecological ecotone representing the upper elevation thermal limit for forest development. The current tree line position is the result of the past human activity interacting with climatic and topographic conditions. In this study, we investigate how climate, local topographic factors and anthropogenic disturbance currently affect tree line distribution. Location: Apennine Mountains, 900 km latitudinal gradient along the Italian Peninsula. Methods: Overall, 302 mountain peaks were studied, comprising 3,622 km of measured tree lines. The position of the Fagus sylvatica tree line in all peaks was assessed and correlated with 58 selected variables representing climate, topography and human disturbance. Results: The mean tree line elevation was 1,589 m a.s.l., with considerable variability among peaks. Contrary to our expectations, the tree line elevation was lower in the warmer southerly exposed slopes compared to north‐facing aspects, where we found the highest tree line (2,141 m a.s.l.). Correlation analysis indicates that both climatic and human density variables are associated with tree line elevation, with the climate having more influence in high elevation mountains, while human impact plays a prominent role in low elevation mountain peaks. Specifically, we found negative correlations between density of the resident population around each peak and tree line elevation at all examined dates (1861, 1921, and 2011), suggesting a pervasive negative impact of human activity on tree lines. As regards climatic variables, tree line elevation showed a stronger negative correlation with winter and spring months temperature than with mean annual temperature. Noteworthy, climatic variables had stronger effect on high elevation peaks (>1,900 m a.s.l.) compared with low elevation ones (<1,900 m a.s.l.). Main Conclusion: Our data provide evidence that the current position of the F. sylvatica tree line in the Apennines is heavily depressed as a result of a complex interaction between climatic factors and the past human pressure. [ABSTRACT FROM AUTHOR]

Plant invasion in forest ecosystems is a serious ecological and economic issue, deserving attention by researchers, managers and policy-makers worldwide. Many invasive plants have been reported as early successional species able to colonize disturbed areas following abrupt changes in microhabitat and resource availability. We investigated disturbance effects of a severe windstorm generated by a wet microburst (hail and rain at 160 mm h-1) remarkably affecting the canopy cover of an old-growth Quercus ilex urban forest in Southern Italy. This stand-replacing disturbance produced a mosaic of 103 gaps, 5.6 to 1632 m2 in size, over an area of 1.53 ha, uprooting 76% of the trees and decreasing thereby 85% of the standing above-ground dry biomass into the gaps. By intensive monitoring we compared above- and below-ground microclimate, soil moisture and mineral N availability in paired disturbed and control areas of the study forest. Within newly formed gaps we observed a seasonally consistent 70% higher content of nitrate nitrogen, 29% and 47% decreases of ammonia nitrogen in summer and autumn, respectively, and a higher moisture in topsoil, in addition to different above- and below-ground microclimatic conditions, with canopy cover mitigating extreme temperatures. One year after the windstorm, the microhabitat shift promoted the establishment in gaps of 15 native and 10 alien taxa previously absent in both disturbed and control plots. In such conditions, the rarefaction of the dominant Q. ilex canopy cover and the occurrence of empty niches prone to invasion could dramatically affect the local community structure and diversity. Our data indicate that stand-replacing windstorm can transiently transform the studied urban evergreen forest to an early allogenic successional community dominated, in the medium and large gaps, by annual and perennial non-native species. This is particularly relevant under a perspective of possible increasing frequency of windstorm events in the Mediterranean region in the near future. [ABSTRACT FROM AUTHOR]

Litter burning and biological decomposition are oxidative processes co-occurring in many terrestrial ecosystems, producing organic matter with different chemical properties and differently affecting plant growth and soil microbial activity. We tested the chemical convergence hypothesis, i.e., materials with different initial chemistry converge toward a common profile, with similar biological effects, as the oxidative process advances, for burning and decomposition. We compared the molecular composition, assessed by 13C NMR, of seven plant litter types either fresh, decomposed for 30, 90, 180 d in a microcosms incubation experiment, or heated at 100°C, 200°C, 300°C, 400°C, 500°C for 30 minutes. We used litter water extracts (5% dry weight) as treatments in bioassays on plant ( Lepidium sativum) and fungal ( Aspergillus niger) growth, and a washed quartz sand amended with litter (0.5% dw) to assess heterotrophic respiration by flux chamber (i.e., [μg of CO2 released]·[g added litter]−1·d−1). We observed different molecular variations for materials either burning (i.e., a sharp increase of aromatic C and a decrease of other fractions above 200°C) or decomposing (i.e., early increase of alkyl, methoxyl, and N-alkyl C and decrease of O-alkyl and di- O-alkyl C fractions). Soil respiration and fungal growth decreased with litter age and heating severity, down to 20% relative to fresh litter. Plants were inhibited on fresh litter (on average 13% of the control), but recovered on aged (180 d) and heated (30 min at 500°C) materials, up to 126% and 63% of the control, respectively. Correlation between the intensity of 13C NMR signals in litter spectra and bioassay results showed that O-alkyl, methoxyl, and aromatic C fractions are crucial to understand organic matter effects, with plant response negatively affected by labile C but positively associated to lignification and pyrogenic C. The pattern of association of soil respiration and fungal growth to these C fractions was essentially opposite to that observed for plant root growth. Our findings suggest a functional convergence of decomposed and burned organic substrates, emerging from the balance between the bioavailability of labile C sources and the presence of recalcitrant and pyrogenic compounds, oppositely affecting different trophic levels. [ABSTRACT FROM AUTHOR]

During the second half of the 20th century farming systems in hilly and mountainous areas of Mediterranean Europe were progressively abandoned and the forest cover subsequently re-expanded. This paper investigates the environmental impacts of land-use/land-cover (LULC) changes on hydrological ecosystem functions (HEFs) in the Upper Alento River Catchment (UARC) in southern Italy. We document the human-driven post-war landscape in 1955 with its maximum expansion of pasture and crops. By 1998 forest cover had doubled and cropland had roughly halved due to decades of land abandonment and reduction in human pressure. In 2015 secondary forests occupied about 70% of the catchment and orchards about 20%. The 1998 land-use scenario was implemented within the Automated Geospatial Watershed Assessment (AGWA) model which was calibrated and validated by direct water yield measurements recorded in the period 1995–2004 in the water reservoir delimited by an earth-dam located at the UARC outlet. Numerical simulations, assumed under “steady” climate conditions, offer “pseudo-realistic” scenarios that help interpret differences in water budget and sediment transport when the 1998 land-use scenario is compared to those of 1955 and 2015. With reference to funding opportunities offered by the European Union in the recent decades, this study provides some practical guidance on the impact of cropland reconversion on HEFs and on measures to mitigate soil erosion in this Mediterranean area. Viewed from the demand-side perspective, natural re-expansion of forest and afforestation reduce water yield and increase actual evapotranspiration. However, our modeling results are framed also within a supply - side approach examining the sensitivity of water yield to precipitation characteristics. [ABSTRACT FROM AUTHOR]

Anthracological analysis was carried out in the archaeological site of Punta di Zambrone on the Tyrrhenian coast of Calabria in southern Italy. Archaeological excavation documented at the site settlement deposits dated mainly to Early Bronze Age (EBA, 21st-18th century BC) and the Recent Bronze Age (RBA, 13th to early 12th century BC). In the phase of the EBA village, the high frequency of Olea europaea in the charcoal data suggests the tree may well have been cultivated by favouring the spread of the scant olive trees growing wild. Comparison with existing archaeobotanical data indicates that olive cultivation spread over a large portion of southern Italy from the EBA and the early Middle Bronze Age (MBA, 17th-15th century BC), thus calling into question the hypothesis of its first cultivation related to the interaction between Mycenaean Greece and local cultures in southern Italy. The early domestication event at Punta di Zambrone supports the idea of multiple independent primary events of olive domestication throughout the Mediterranean basin. In the following phase of the fortified settlement dated to the RBA, the frequency of olive charcoal diminished and the expansion of a more or less dense forest dominated by Quercus was judged to be a consequence of human depopulation that characterises the end of MBA and also a different land use of RBA. This forest increase, also recorded by other archaeobotanical proxies in the central and southern Italian peninsula, is found to be related to the diffusion in southern Calabria of the Subapennine culture, spreading from more northerly areas of Italy and bringing different economic systems and agronomic knowledge. These far-reaching changes appear to have brought to a halt the first event of olive cultivation recorded at Punta di Zambrone. [ABSTRACT FROM AUTHOR]

A methodological approach based on detailed land-use map, high-resolution LiDAR data and field surveys was developed to categorize productive and non-productive mixed forests, both in term of stand attributes and structural diversity. In 2011, leaf-off dedicated airborne LiDAR data were collected in a 20,000 ha inland patchy area which was representative of soil land use in the Apennines mountains of southern Italy. By combining field and LiDAR data in 5574 ha of forests with coexisting evergreen and deciduous species, we modelled common forest stand variables (height, diameter, volume and biomass) with high accuracy (0.60 ≤ Adj.R 2 ≤ 0.89). Moreover, a moderate correlation (0.425 ≤ τ ≤ 0.462) between field- and LiDAR-derived diversity indices was found. About 3393 ha of forests are enclosed in protected areas of the Natura 2000 network, which in turn possesses 77% (~ 576,286 Mg) of total aboveground dry biomass. Overall, eight forest types were identified, one of which, the European beech, is only found in the Natura 2000 sites, while other forest types are also found elsewhere. This is the first study to undertake a LiDAR analysis of Mediterranean forests in the Campania Region and might help better evaluate trade-off, especially in protected areas, in order to enhance multiple benefits and support sustainable management of forests. [ABSTRACT FROM AUTHOR]

The stress-gradient hypothesis ( SGH) predicts that the balance of plant-plant interactions shifts along abiotic environmental gradients, with facilitation becoming more frequent under stressful conditions. However, recent studies have challenged this perspective, reporting that positive interactions are, in some cases, more common at the intermediate level of environmental severity gradients. Here, we test whether and how neighbour effects by Silene acaulis cushions vary along a 700 m wide altitudinal transect, in relation to cushion morphological traits and environmental severity., Field measurements along the gradient, within and outside cushions, included (i) species richness and cover of coexisting vascular plants; (ii) cushion morphology; (iii) above- and below-ground microclimate; and (iv) soil quality. We used the relative interaction index to decouple neighbour trait effects and environmental severity effects on plant diversity at different elevations., The ability of the cushion plant to facilitate heterospecifics shifts considerably along the elevation gradient, being greatest at the intermediate level. On the other hand, Silene morphological traits steadily change along the gradient, from lax, soft and flat-shaped cushion habits at low elevation to tightly knit and dome-shaped habits at high elevation., Cushion morphological changes are associated with mitigating effects on microclimate, indicating that cushions effectively act as a heat-trap at medium and high elevations, while at low elevations the soft and flat cushions avoid excessive heat accumulation by tight coupling with the surrounding atmosphere. At the upper end of the gradient, cushion cespitose-pulvinate compactness and high stem density appear to be critical traits in modulating the net effect of plant-plant interaction, since the space available for hosting other vascular species is considerably reduced., In conclusion, this work provides a mechanistic link between plant morphological traits, associated biogenic microclimate changes and variation in net plant-plant interactions along the explored severity gradient. Our findings support an alternative conceptual model to SGH, with plant facilitation collapsing at the upper extreme of the abiotic stress gradient. [ABSTRACT FROM AUTHOR]

Fire, besides affecting plant litter fate in natural ecosystems, is a widely used tool to manage crop residues in agro-ecosystems. In both cases, burning of plant residues produces highly heterogeneous materials, ranging from little affected plant tissues, to charred substrates, up to mineral ashes, whose chemical nature and biological effects are not yet fully clarified. The aim of our study was to assess the effects of litter treated at different temperatures (100, 200, 300, 400 and 500 °C) on saprotrophic fungi, plant pathogenic microbes, and higher plants. To this purpose, we combined a characterization of 48 organic materials by 13C-CPMAS NMR spectroscopy with a multi-species laboratory bioassay on seven target organisms (one plant and six microbes). Consistent with previous observations, we showed that, as charring temperature increased, litter quality significantly changed, with a progressive loss of O-alkyl C, di-O-alkyl C, and methoxyl and N-alkyl C, coupled with an enrichment in aromatic C, irrespective of plant litter types. Noteworthy, the bioassay showed that untreated litter had a major inhibitory effect on the test plant, while it acted as a suitable substrate sustaining microbial growth. On the contrary, as litter was charred its biochemical quality decreased with increasing temperature because of a progressive disappearance of easily degradable C sources and enrichment of recalcitrant aromatic fractions. Therefore, charred litter became an organic material suitable to sustain plant growth, but was largely inhibitory for microbial saprotrophic growth. This work demonstrates that defining litter quality by 13CCPMAS NMR improves our understanding of the substrate preferences of both plant and microbes for different litter types as well as for charred organic materials. [ABSTRACT FROM AUTHOR]

Quercus pubescens Willd. is a common oak species in the Mediterranean area, where it is currently exploited mainly for purposes such as firewood. To improve the technological properties of its wood, various steaming and/or heat treatments were applied to 160 wood samples from a southern Italian stand, cut from either sapwood or heartwood, while 20 samples served as controls. Steaming was carried out in an autoclave at 120 °C, whereas heat treatments were performed in an oven at 150 or 200 °C for 3 or 6 h. The equilibrium moisture content, swelling, mass loss, wood density, compression strength, color variation, and lignin content of the samples were measured and compared among treatments. The swelling and water adsorption of wood samples decreased due to the hydrothermal treatments. The mass loss was strictly related to the temperature and duration of the heat treatments, whereas it was not influenced by the steaming treatment. The average axial compression strength value was positively influenced by the combination of steaming and heat treatments. A significant and general darkening of color was also observed for the harshest treatments, while an increase of lignin content was detected mainly in the sapwood. Thus, pubescent oak wood subjected to steaming and heat treatments may acquire useful characteristics suitable for its industrial use. [ABSTRACT FROM AUTHOR]

Background: The populations of Soldanella (Primulaceae) of the southern Apennines (Italy) are unique within the genus for their distribution and ecology. Their highly fragmented distribution range, with three main metapopulations on some of the highest mountains (Gelbison, Sila and Aspromonte massifs) of the area, poses intriguing questions about their evolutionary history and biogeography, and about the possibility of local endemisms. Aims and methods: In order to clarify the phylogeny and biogeography of the three metapopulations of Soldanella in the southern Apennines, attributed to S. calabrella to date, and to identify possible local endemisms, a comparative approach based on the study of molecular, morphological and ecological characteristics of the populations was employed. Specifically, one nuclear (total ITS) and two plastid (rbcL and trnL) markers were used for the phylogenetic analyses, performed through both maximum likelihood and Bayesian techniques. Among the morphological features, the glandular hair and leaf biometric traits were analysed, and the environment in which the populations grew was characterised for altitude, forest canopy composition and soil pH, C, N and organic matter. Results and conclusions: Our findings demonstrate that the lineage of Soldanella of southern Italy diverged from the Carpathians lineage during theMiddle Pleistocene, and underwent an evolutionary radiation during the Late Pleistocene. The populations of the Sila and Aspromonte massifs diverged from the populations of the Gelbison massif around 380000 years ago and are probably undergoing a progressive differentiation due to their isolation. The populations on the Gelbison massif, moreover, have different morphological features from those of the Sila and Aspromonte massifs and a different ecological niche. The molecular, morphological and ecological data clearly demonstrate that the metapopulation of Soldanella on the Gelbison massif belongs to a new taxonomic unit at the species level, which we name Soldanella sacra A. & L. Bellino from the name of the massif on which it was discovered, the "Holy Mountain". [ABSTRACT FROM AUTHOR]

Background A high slope of the ventilation vs. carbon dioxide relationship (VE/VCO2 slope) during incremental exercise has been reported in several congenital heart disease (CHD) types, but it is not clear whether the main cause of high VE/VCO2 slope is excessive ventilation or reduced perfusion. Methods We studied 169 adolescent and adult patients with repaired, noncyanotic CHD, divided into 2 groups according to VE/VCO2 slope %predicted values (≤ 120 and > 120), and 15 age- and sex-matched normals. VCO2/VE max and VO2/VE max were considered proxies of the perfusion/ventilation relationship, with VCO2 and VO2 as indirect descriptors of cardiac output. Results VCO2/VE max was significantly and inversely related to VE/VCO2 slope (r = - 0.73, p < 0.0001), and higher in normals and ≤ 120 than in > 120 (39.6 ± 7.7, 36.1 ± 5.3 and 28.5 ± 4.1, respectively, p < 0.0001). Similarly, VCO2 at VCO2/VE max was higher in normals and ≤ 120 than in > 120 (1701 ± 474, 1480 ± 492 and 1169 ± 388 ml/min, respectively, p < 0.0001), whereas ventilation at VCO2/VE max showed no changes (43 ± 8, 41 ± 12, 41 ± 11 and 41 ± 9 l/min, respectively, p = 0.82) between groups. Thus, differences in VCO2/VE max and VE/VCO2 slope between groups were due mostly to changes in VCO2, i.e. in cardiac output, rather than ventilation. The same behavior was observed for VO2/VE max. Conclusions A high VE/VCO2 slope observed in patients with repaired, noncyanotic CHD seems not to depend on excessive ventilation but on hypoperfusion due to impaired cardiac output response to incremental exercise. This finding should focus researchers' attention mainly on the heart when addressing exercise pathophysiology of this patient population. [ABSTRACT FROM AUTHOR]

Anthracological analysis has been carried out in three sites located on the Tyrrhenian coast of central Italy (ancient northern Etruria: the castle of Donoratico, the town of Populonia and the port of Alberese), spanning between the Roman Republican Period and the Late Middle Ages (3rd century bc–13th century ad). The integrated comparison of three different local charcoal data with the regional pollen and microcharcoal data available from northern Etruria showed well that vegetation changes are completely independent of climate and strictly connected to economic and social dynamics characterising the history of this part of central Italy. Indeed, Quercus ilex forests progressively retracted from the 3rd century bc in favour of open macchia formations just during the growing human impact of the Romanisation when intensive agriculture and livestock grazing characterised the economic system. The transition from macchia to deciduous Quercus forest at the end of the Roman Period from the mid-4th to the mid-5th centuries ad and long lasting until the 9th–10th centuries ad was related to economic and cultural factors which led to a phase of land abandonment. Finally, between the 11th and 13th centuries ad, the vegetation cover shifted again towards an open macchia environment at the same time of a re-settlement phase well evidenced also by intensive orcharding. Charcoal data also showed that the expansion of olive and chestnut in central Italy only began in the Late Medieval Period (11th century ad) and not in the Roman Period. This means that extensive cultivation of chestnut and olive has very recent origins and should be attributed to one and the same macro-factor such as the set-up of the economic establishment of the feudal system and the later political organism of the Medieval town. [ABSTRACT FROM PUBLISHER]

Questions: Pollen data for Abies alba Mill., a key European tree species, show broad occurrence in the Italian peninsula in the early to mid-Holocene diffusion (until ca. 6000 yr ago) along the Italian peninsula and a strong decline/local extinction starting ca. 5000 yr ago. This decline has been attributed to climate change. Recently, high-resolution pollen studies, mainly in northern Italian sites claim that A. alba disappearance was mainly due to human impact. We examined the presence of A. alba in archaeological sites of southern and central Italy in order to trace the late Holocene history (last 3000 yr) of this tree and enhance understanding of its role in pre-anthropic vegetation and of human involvement in its decline. Location: Central and southern Italy. Methods: Anthracological analysis was conducted in six archaeological layers at the archaeological site of Trebbio-Spinellina (800-600 BC, Sansepolcro, Tuscany). A critical analysis of wood/charcoal literature relevant to Abies in central and southern Italy was used to corroborate the results of Trebbio-Spinellina. Charcoal records fromarchaeological sites have been compared with the current distribution of A. alba. Results: At Trebbio-Spinellina, A. alba charcoal is present in all contexts examined, together with mesophilous broad-leaf taxa (Quercus deciduous, Carpinus betulus, Ostrya carpinifolia, Corylus avellana). A low charcoal percentage of Fagus sylvatica and Taxus baccata is also found; evergreen taxa are mainly represented by Quercus ilex with occasional shrubs (i.e. Viburnum, Cistus, Erica). In the literature, we identified several peninsular and insular Italian archaeological sites showing charcoal evidence of Abies, accompanied by deciduous oaks, mainly Q. cerris, and other broad-leafmesophilous trees, dating from the Iron Age to the Middle Ages. All sites, except one, lie at less than 600 m a.s.l., and far from present- day A. alba communities. Conclusion: Results call for a reworking of the prevailing paradigmof A. alba as a relic mountain species. Indeed, A. alba once grew at lower altitudes than currently and was associated with deciduous oaks, mainly Q. cerris, and other mesophilous broad-leaf trees. This evidence calls into question the suitability of the Potential Natural Vegetation (PNV) concept usually applied in the floristic approach. The recent population decline is attributable to human activity rather than to climate change. Finally, the persistence of A. alba until the late Holocene calls into question the assumptions that it is a relic species with no potential to expand its spatial range. [ABSTRACT FROM AUTHOR]

Poplar short rotation coppice (SRC) plantations have great potential for supplying environmentally friendly bio-based industries. However, little research has focussed on the linkages between SRC management regimes and the consumption of water for biomass production in the Mediterranean environment. Therefore, we compared six hybrid clones and four native black poplar genotypes with an aim to examine how two different lengthening periods (3 vs. 5 years) of single-stem rotation affected growth performance in the following three years of multi-stem rotation coppice. To achieve this goal, we assessed the aboveground dry biomass production and variation in water use efficiency (WUE) of the genotypes annually. A longer single-stem rotation increased biomass productivity and WUE in the multi-stem rotation of the native black poplar, rather than that of the hybrid genotypes. In contrast, biomass and WUE performances did not diverge between the native and hybrid genotypes under the shorter single-stem phase. These findings underline the importance of lengthening the rotation of single-stem SRC plantations in hot and dry Mediterranean climates. Native black poplar genotypes managed in SRC should be strongly considered as environmentally compatible genetic resources both in protected areas and in areas where water supply constrains biomass production. • Lengthening single-stem rotation improves yield of wild black poplar genotypes. • Wild black poplars represent an alternative to studied hybrid clones in Mediterranean climate. • Black poplar genotypes with high WUE enhance sustainability of SRC crop system. [ABSTRACT FROM AUTHOR]

To evaluate acute change of right and left ventricle after percutaneous closure of isolated atrial septal defect (ASD) 21 adult patients (13 F; 8 M) aged 28 ± 9.5 range 18-49 years have been examined by echocardiography before and 24 hours after percutaneous closure of ASD. Twenty-one normal adult subjects, as control group were included. A MyLab25 echo machine equipped with a multifrequency 2.5-3.5 MHz transducer was used. Offline computer-based analysis for strain and SR were performed using XStrain software based on a feature tracking algorithm. All patients had ASD OS2 with right ventricular dilatation and diastolic areas were larger than in controls: P = 0.0158. Global right ventricular longitudinal strain was higher P = 0.0438. Twenty-four hours after ASD closure, right ventricular diastolic and systolic areas were significantly reduced. Right ventricular global longitudinal systolic strain decreased: P = 0.00016, as well as global right ventricular longitudinal SR -1.56/sec ± 0.57 vs. -1.28/sec ± 0.31, P = 0.02646. At the mean time left ventricular end diastolic volume and left ventricular cardiac output measured by two-dimensional echocardiography both increased significantly P = 0.002145 and 0.013409. Global circumferential strain at mitral level augmented significantly -20.3%± 4.64 vs. -25.39%± 5.22, P = 0.00003. Longitudinal strain of the right ventricle works as indicator of right ventricular function dependent on loading conditions while SR seems to be less dependent on it. Circumferential strain could be used as an indicator of left ventricular response to normalized loading conditions. (Echocardiography 2011;28:730-737) [ABSTRACT FROM AUTHOR]

Xylogenesis was monitored during 2003 and 2004 in a timberline environment in southern Italy to assess links between temperature, cambial phenology and wood formation on a short-time scale. Wood microcores were collected weekly from May to October from 10 trees of Pinus leucodermis Ant., histological sections were cut with a rotary microtome and anatomical features of the developing and mature tracheids were observed and measured along the growing tree ring. Spring 2003 was hotter than spring 2004, with temperatures up to 2.6 °C above historical means. The hotter conditions resulted in an earlier onset of cambial activity and all differentiation phases of about 20 days, resulting in an increased duration of xylogenesis of about 23 days. Air and stem temperatures at which xylogenesis had a 0.5 probability of being active were calculated with logistic regressions fitted on binary responses. In both years, similar thresholds were estimated with daily mean values of 8.2 and 9.5 °C for air and stem temperatures, respectively. The observed convergent responses of cambium phenology to temperature during the two contrasting springs confirm the key role of this environmental factor in determining the onset and duration of wood formation in timberline areas. The intra-annual dynamics of ring-width increase differed between years, with significantly narrower rings formed in 2004 than in 2003. These differences were mainly related to cell size because larger earlywood tracheids were produced in 2003. This study demonstrates the plasticity of tree-ring formation in response to high temperatures as a result of modifications in the onset and duration of differentiation. [ABSTRACT FROM PUBLISHER]

Pinus leucodermis (=P. heldreichii var. leucodermis) is widespread in the Balkan Peninsula and is present as a post-glacial relict in Southern Italy. The oldest Italian populations of this species are located at high elevation in the National Park of Pollino, where grazing and logging had endangered their survival, especially during the 20th century. In 1993 the National Park was founded and anthropogenic activities were restricted. To understand the response of P. leucodermis at the upper tree-line to climatic and anthropogenic activity variations, we developed a tree-ring width chronology (1464–2003). For the period 1804–2003 separate chronologies for the earlywood and latewood were built, and resin duct density was assessed on total ring, earlywood and latewood. Age structure of saplings was also determined. After 1950 a steep decline in tree-ring width was followed by a recovery since 1981. During the 20th century radial growth response to climate was not strong and not stable. In the period 1953–2000 P. leucodermis radial growth seemed to take advantage of high temperatures and low precipitation. Resin duct density chronologies were not a reliable dendroecological variable, but they documented a metabolic trade-off between growth and differentiation processes. The gap in the age structure between long-lived trees (over 200 years old) and saplings around 40 years old, which mainly grow in protected microsites between rocks, could indicate a negative influence of grazing and related human activities. We suggest that the protection strategies introduced by the National Park could play a positive role in the recruitment of new saplings and in the ring growth recovery of old trees of P. leucodermis. [Copyright &y& Elsevier]

• Intra-annual radial growth rates and durations in trees are reported to differ greatly in relation to species, site and environmental conditions. However, very similar dynamics of cambial activity and wood formation are observed in temperate and boreal zones. • Here, we compared weekly xylem cell production and variation in stem circumference in the main northern hemisphere conifer species (genera Picea, Pinus, Abies and Larix) from 1996 to 2003. Dynamics of radial growth were modeled with a Gompertz function, defining the upper asymptote ( A), x-axis placement (β) and rate of change (κ). • A strong linear relationship was found between the constants β and κ for both types of analysis. The slope of the linear regression, which corresponds to the time at which maximum growth rate occurred, appeared to converge towards the summer solstice. • The maximum growth rate occurred around the time of maximum day length, and not during the warmest period of the year as previously suggested. The achievements of photoperiod could act as a growth constraint or a limit after which the rate of tree-ring formation tends to decrease, thus allowing plants to safely complete secondary cell wall lignification before winter. [ABSTRACT FROM AUTHOR]

In Mediterranean countries, in the year 2017, extensive surfaces of forests were damaged by wildfires. In the Vesuvius National Park, multiple summer wildfires burned 88% of the Mediterranean forest. This unprecedented event in an environmentally vulnerable area suggests conducting spatial assessment of the mixed-severity fire effects for identifying priority areas and support decision-making in post-fire restoration. The main objective of this study was to compare the ability of the delta Normalized Burn Ratio (dNBR) spectral index obtained from Landsat-8 and Sentinel-2A satellites in retrieving burn severity levels. Burn severity levels experienced by the Mediterranean forest communities were defined by using two quali-quantitative field-based composite burn indices (FBIs), namely the Composite Burn Index (CBI), its geometrically modified version CBI (GeoCBI), and the dNBR derived from the two medium-resolution multispectral remote sensors. The accuracy of the burn severity map produced by using the dNBR thresholds developed by Key and Benson (2006) was first evaluated. We found very low agreement (0.15 < K < 0.21) between the burn severity class obtained from field-based indices (CBI and GeoCBI) and satellite-derived metrics (dNBR) from both Landsat-8 and Sentinel-2A. Therefore, the most appropriate dNBR thresholds were rebuilt by analyzing the relationships between two field-based (CBI and GeoCBI) and dNBR from Landsat-8 and Sentinel-2A. By regressing alternatively FBIs and dNBRs, a slightly stronger relationship between GeoCBI and dNBR metrics obtained from the Sentinel-2A remote sensor (R2 = 0.69) was found. The regressed dNBR thresholds showed moderately high classification accuracy (K = 0.77, OA = 83%) for Sentinel-2A, suggesting the appropriateness of dNBR-Sentinel 2A in assessing mixed-severity Mediterranean wildfires. Our results suggest that there is no single set of dNBR thresholds that are appropriate for all burnt biomes, especially for the low levels of burn severity, as biotic factors could affect satellite observations. [ABSTRACT FROM AUTHOR]