No Future Growth Enhancement Expected at the Northern Edge for European Beech due to Continued Water Limitation.

With ongoing global warming, increasing water deficits promote physiological stress on forest ecosystems with negative impacts on tree growth, vitality, and survival. How individual tree species will react to increased drought stress is therefore a key research question to address for carbon accounting and the development of climate change mitigation strategies. Recent tree-ring studies have shown that trees at higher latitudes will benefit from warmer temperatures, yet this is likely highly species-dependent and less well-known for more temperate tree species.

An in situ 15N labeling experiment unveils distinct responses to N application approaches in a mountain beech forest.

Atmospheric nitrogen (N) deposition has notably increased since the industrial revolution, doubling N inputs to terrestrial ecosystems. This could mitigate N limitations in forests, potentially enhancing productivity and carbon sequestration. However, excessive N can lead to forest N saturation, causing issues like soil acidification, nutrient imbalances, biodiversity loss, increased tree mortality and a potential net greenhouse gas emission.

Exploring climate-smart forestry in Mediterranean forests through an innovative composite climate-smart index.

In recent years, Climate-Smart Forestry (CSF) has emerged as an innovative approach to sustainable forest management, aiming to enhance forest resilience and to balance the provision of ecosystem services facing climate-related threats. This study introduces for the first time a new composite climate-smart index (I) to assess CSF. The methodological approach comprises the following steps: (i) the selection and evaluation of CSF indicators; (ii) the weighting of these indicators; and (iii) the assessment of CSF for Mediterranean forests in two distinct periods, specifically 2005 and 2015.

Partial asynchrony of coniferous forest carbon sources and sinks at the intra-annual time scale.

As major terrestrial carbon sinks, forests play an important role in mitigating climate change. The relationship between the seasonal uptake of carbon and its allocation to woody biomass remains poorly understood, leaving a significant gap in our capacity to predict carbon sequestration by forests. Here, we compare the intra-annual dynamics of carbon fluxes and wood formation across the Northern hemisphere, from carbon assimilation and the formation of non-structural carbon compounds to their incorporation in woody tissues.

Contrasting patterns of water use efficiency and annual radial growth among European beech forests along the Italian peninsula.

Tree mortality and forest dieback episodes are increasing due to drought and heat stress. Nevertheless, a comprehensive understanding of mechanisms enabling trees to withstand and survive droughts remains lacking. Our study investigated basal area increment (BAI), and δC-derived intrinsic water-use-efficiency (WUE), to elucidate beech resilience across four healthy stands in Italy with varying climates and soil water availability.

High preseason temperature variability drives convergence of xylem phenology in the Northern Hemisphere conifers.

Wood growth is key to understanding the feedback of forest ecosystems to the ongoing climate warming. An increase in spatial synchrony (i.e.

Empirical and process-based models predict enhanced beech growth in European mountains under climate change scenarios: A multimodel approach.

Process-based models and empirical modelling techniques are frequently used to (i) explore the sensitivity of tree growth to environmental variables, and (ii) predict the future growth of trees and forest stands under climate change scenarios. However, modelling approaches substantially influence predictions of the sensitivity of trees to environmental factors. Here, we used tree-ring width (TRW) data from 1630 beech trees from a network of 70 plots established across European mountains to build empirical predictive growth models using various modelling approaches.

Spatial distribution and source identification of heavy metals in European mountain beech forests soils.

The main objectives of this research were to (i) investigate the concentration; (ii) characterize the distribution; (iii) determine the sources apportionment; (iv) estimate environmental and health risks of heavy metals in soil from mountain beech forest. A total of 76 soil samples from 20 pure beech forest stands from Bosnia and Herzegovina (BA), Bulgaria (BG), Check Republic (CZ), Germany (DE), Italy (IT), Poland (PL), Romania (RO), Serbia (RS), Slovakia (SK), Slovenia (SL), and Spain (ES) were collected. The content of major elements was measured by X-ray fluorescence spectroscopy (XRF).

Wood Anatomical Responses of European Beech to Elevation, Land Use Change, and Climate Variability in the Central Apennines, Italy.

European beech ( L.) is a widespread and economically important temperate tree species in Europe. The warmer temperatures and severe drought events expected in the future, especially in Mediterranean areas, could affect the vitality and productivity of beech stands that have been intensively used in these areas in the past.

White rot fungal impact on the evolution of simple phenols during decay of silver fir wood by UHPLC-HQOMS.

Introduction: Silver fir (Abies alba Mill.) is one of the most valuable conifer wood species in Europe. Among the main opportunistic pathogens that cause root and butt rot on silver fir are Armillaria ostoyae and Heterobasidion abietinum.

A meta-analysis of mesophyll conductance to CO2 in relation to major abiotic stresses in poplar species.

Mesophyll conductance (gm) determines the diffusion of CO2 from the substomatal cavities to the site of carboxylation in the chloroplasts and represents a critical component of the diffusive limitation of photosynthesis. In this study, we evaluated the average effect sizes of different environmental constraints on gm in Populus spp., a forest tree model.

Photoperiod and temperature as dominant environmental drivers triggering secondary growth resumption in Northern Hemisphere conifers.

Wood formation consumes around 15% of the anthropogenic CO emissions per year and plays a critical role in long-term sequestration of carbon on Earth. However, the exogenous factors driving wood formation onset and the underlying cellular mechanisms are still poorly understood and quantified, and this hampers an effective assessment of terrestrial forest productivity and carbon budget under global warming. Here, we used an extensive collection of unique datasets of weekly xylem tissue formation (wood formation) from 21 coniferous species across the Northern Hemisphere (latitudes 23 to 67°N) to present a quantitative demonstration that the onset of wood formation in Northern Hemisphere conifers is primarily driven by photoperiod and mean annual temperature (MAT), and only secondarily by spring forcing, winter chilling, and moisture availability.

The excess of phosphorus in soil reduces physiological performances over time but enhances prompt recovery of salt-stressed Arundo donax plants.

Arundo donax L. is an invasive grass species with high tolerance to a wide range of environmental stresses. The response of potted A.

A Comparison of the Variable J and Carbon-Isotopic Composition of Sugars Methods to Assess Mesophyll Conductance from the Leaf to the Canopy Scale in Drought-Stressed Cherry.

Conductance of CO across the mesophyll () frequently constrains photosynthesis () but cannot be measured directly. We examined of cherry ( L) subjected to severe drought using the variable method and carbon-isotopic composition (C) of sugars from the centre of the leaf, the leaf petiole sap, and sap from the largest branch. Depending upon the location of the plant from which sugars are sampled, may be estimated over scales ranging from a portion of the leaf to a canopy of leaves.

Impact of high or low levels of phosphorus and high sodium in soils on productivity and stress tolerance of Arundo donax plants.

The potential of Arundo donax to grow in degraded soils, characterized by excess of salinity (Na+), and phosphorus deficiency (-P) or excess (+P) also coupled with salinity (+NaP), was investigated by combining in vivo plant phenotyping, quantification of metabolites and ultrastructural imaging of leaves with a transcriptome-wide screening. Photosynthesis and growth were impaired by + Na, -P and + NaP. While + Na caused stomatal closure, enhanced biosynthesis of carotenoids, sucrose and isoprene and impaired anatomy of cell walls, +P negatively affected starch production and isoprene emission, and damaged chloroplasts.

Elevation alters carbon and nutrient concentrations and stoichiometry in Quercus aquifolioides in southwestern China.

Elevation is a complex environmental factor altering temperature, light, moisture and soil nutrient availability, and thus may affect plant growth and physiology. Such effects of elevation may also depend on seasons. Along an elevational gradient of the Balang Mountain, southwestern China, we sampled soil and 2-year old leaves, 2-year old shoots, stem sapwood and fine roots (diameter<5mm) of Quercus aquifolioides at 2843, 2978, 3159, 3327, 3441 and 3589m a.

A tree from waste: Decontaminated dredged sediments for growing forest tree seedlings.

The sediments dredged from a waterway and decontaminated through a phytoremediation process have been used as substrates alternatively to the traditional forest nursery substrate for pot productions of holm oak (Quercus ilex L.) planting stocks. The substrates, made by mixing decontaminated sediments to agricultural soil at different degrees, were tested in order to evaluate their suitability as growth substrates.

Cd and Cu accumulation, translocation and tolerance in Populus alba clone (Villafranca) in autotrophic in vitro screening.

The present study investigated accumulation, translocation and tolerance of autotrophic Populus alba clone "Villafranca" in response to excess concentrations of cadmium (Cd) and copper (Cu) provided to the plants. For this purpose, increasing concentrations of Cd (0, 5, 50 and 250 μM) and Cu (0, 5, 50, 250 and 500 μM) were administered to the growth medium in which micropropagated poplar plantlets were exposed to metal treatments for 15 days. Filter bags, instead of the conventional in vitro screening, were applied to improve the experimental design.

Dissecting the role of isoprene and stress-related hormones (ABA and ethylene) in Populus nigra exposed to unequal root zone water stress.

Isoprene is synthesized through the 2-C-methylerythritol-5-phosphate (MEP) pathway that also produces abscisic acid (ABA). Increases in foliar free ABA concentration during drought induce stomatal closure and may also alter ethylene biosynthesis. We hypothesized a role of isoprene biosynthesis in protecting plants challenged by increasing water deficit, by influencing ABA production and ethylene evolution.

Insensitivity of Tree-Ring Growth to Temperature and Precipitation Sharpens the Puzzle of Enhanced Pre-Eruption NDVI on Mt. Etna (Italy).

On Mt. Etna (Italy), an enhanced Normalized Difference in Vegetation Index (NDVI) signature was detected in the summers of 2001 and 2002 along a distinct line where, in November 2002, a flank eruption subsequently occurred. These observations suggest that pre-eruptive volcanic activity may have enhanced photosynthesis along the future eruptive fissure.

A synthesis of radial growth patterns preceding tree mortality.

Tree mortality is a key factor influencing forest functions and dynamics, but our understanding of the mechanisms leading to mortality and the associated changes in tree growth rates are still limited. We compiled a new pan-continental tree-ring width database from sites where both dead and living trees were sampled (2970 dead and 4224 living trees from 190 sites, including 36 species), and compared early and recent growth rates between trees that died and those that survived a given mortality event. We observed a decrease in radial growth before death in ca.