Abstract Improving our understanding of the potential forest adaptation is an urgent task in light predicted climate change. Long‐term alternatives for susceptible yet economically important tree species such as Norway spruce ( Picea abies) are required, if frequency and intensity summer droughts will continue to increase. Although Silver fir Abies alba) Douglas (Pseudotsuga menziesii) have both been described drought‐tolerant species, their growth responses drought extremes still limited....

Despite the rapidly increasing use of resilience indices to analyze responses trees and forests disturbance events, there is so far no common framework apply interpret these for different purposes. Therefore, this review aims identify discuss various shortcomings pitfalls commonly used develop recommendations a more robust standardized procedure with particular emphasis on drought events. Growth-based are widely but some important drawbacks limitations related their application may lead...

Abstract Monitoring early tree physiological responses to drought is key understanding progressive impacts of on forests and identifying resilient species. We combined drone‐based multispectral remote sensing with measurements physiology environmental parameters over two growing seasons in a 100‐y‐old Pinus sylvestris forest subject 17‐y precipitation manipulation. Our goal was determine if photochemical reflectance index (PRI) captures stress whether are affected by long‐term acclimation....

The analysis of stable carbon and oxygen isotopes in tree-rings is a widely applied tool which allows to retrieve information about past climatic conditions, as well tree physiological responses environmental changes. This based on well-established mechanistic models firm statistical relationships with climate variables. In contrast, the hydrogen isotopic signature (δ2H) has been reported be poorly correlated or difficult explain, consequence, are far less utilized. However, recent...

Abstract The analysis of the non‐exchangeable hydrogen isotope ratio (δ 2 H ne ) in carbohydrates is mostly limited to structural component cellulose, while simple high‐throughput methods for δ values non‐structural (NSC) such as sugar and starch do not yet exist. Here, we tested if hot vapor equilibration method originally developed cellulose applicable NSC, verified by comparison with traditional nitration method. We set up a detailed analytical protocol applied plant extracts leaves from...

<title>Abstract</title> Accurate predictions of vegetation responses to global warming require a precise understanding physiological temperature responses. We investigated the effects air (10°C 40°C) under constant low vapour pressure deficit and sufficient water supply on leaf-level gas exchange, chlorophyll fluorescence, non-structural carbohydrate (NSC) concentrations, hydrogen (δ²H) oxygen (δ¹⁸O) isotopic composition leaf sugar in C₃ trees, forbs,...

Abstract Key message Urban trees can acclimate to their growth environment through changes in vessel anatomy. Vessel lumen area and frequency following a gradient from park inner-city street trees. stand potentially stressful environments occurring along gradients of urban heat impermeable surface cover and, survive, adjust function structure. The consequent tree-to-tree variations hydraulic xylem traits shed light on tree hydraulics capacity diverse conditions, as well identify limitations...

Abstract Biodiversity effects on productivity and other ecosystem functions are strongly dependent climate resource availability. Based the stress‐gradient hypothesis, under conditions of greater abiotic stress, diversity plant performance intensified due to increased relative importance positive interactions. However, whether this hypothesis is consistently applicable in forest systems remains unclear. A field trial was established test examine above‐ground biomass production young trees...

This is the first Europe-wide comprehensive assessment of climatological and physiological information recorded by hydrogen isotope ratios in tree-ring cellulose (δ2Hc) based on a unique collection annually resolved 100-year records two genera (Pinus Quercus) from 17 sites (36°N to 68°N). We observed that high-frequency climate signals δ2Hc chronologies were weaker than those carbon (δ13Cc) oxygen (δ18Oc) but similar width ones (TRW). The signal strength varied across continent was stronger...

Abstract Scots pine ( Pinus sylvestris L.) is a common European tree species, and understanding its acclimation to the rapidly changing climate through physiological, biochemical or structural adjustments vital for predicting future growth. We investigated long‐term irrigation experiment at naturally dry forest in Switzerland, comparing trees that have been continuously irrigated 17 years ) with those which was interrupted after 10 stop non‐irrigated control ), using growth, xylogenesis,...

Understanding changes in the physiological responses of trees to disturbances, and establishing proxies reconstruct past events, is high importance a changing world. Recent studies have demonstrated potential &amp;#948;2H tree-ring cellulose as proxy for carbon utilization, reflecting shifts between use current assimilates stored C sources. These findings might explain considerable annual variations strength &amp;#948;18O (O-H) relationship despite shared hydrological pathway, underlining...

Abstract Recent experiments have underlined the potential of δ2H in tree-ring cellulose as a physiological indicator shifts autotrophic versus heterotrophic processes (i.e., use fresh stored non-structural carbohydrates). However, impact these has not yet been quantified under natural conditions. Defoliator outbreaks disrupt tree functioning and carbon assimilation, stimulating remobilization, therefore providing unique opportunity to improve our understanding changes δ2H. By exploring...

Recent methodological advancements in determining the nonexchangeable hydrogen isotopic composition (δ2 Hne ) of plant carbohydrates make it possible to disentangle drivers isotope (2 H) fractionation processes plants. Here, we investigated influence phylogeny on δ2 twig xylem cellulose and water, as well leaf sugars across 73 Northern Hemisphere tree shrub species growing a common garden. 2 H followed distinct phylogenetic patterns, with reflected more than that cellulose. Phylogeny had no...

The contribution from foliage, roots, and fungi to soil organic matter (SOM) represents a key unknown in SOM dynamics. Since stable hydrogen isotope ratios (δ2Hn) can greatly differ among these sources, we explored δ2Hn elucidate sources SOM. Moreover, assessed whether addition of 2H-depleted water – providing 2H-signal that gets incorporated into allows tracing new H thus assessing turnover. In 17-year-long irrigation experiment dry pine forest, measured carbon nitrogen (δ13C, δ15N) bulk...

Abstract Picea abies (L.) Karst. and Fagus sylvatica are important tree species in Europe, the foreseen increase temperature vapour pressure deficit (VPD) could vulnerability of these species. However, their physiological performance under climate change at temperate productive sites is not yet fully understood, especially uneven-aged stands. Therefore, we investigated tree-ring width stable isotope chronologies (δ13C/δ18O) two 10 along a gradient Central Europe. In stands, compared...

Mixed-species plantations of trees with N-fixing species have the potential promoting forest productivity and soil fertility. However, few studies in literature addressed advantages mixed-species leguminous over monocultures based on situ inventories a long time period. Here, we monitored dynamics tree community composition, vegetation biomass, nutrients, microbial phospholipid fatty acids (PLFAs), an Acacia mangium monoculture plantation during 33 years development compared it A. associated...

Urban trees are subjected to numerous biotic and mechanical damage, which can affect their growth rates health. However, for most species, a systematic analysis of tree above- below-ground reactions variety damages is still lacking. Under fully factorial experimental setup, using two common urban (Celtis occidentalis, Fraxinus pennsylvanica), we tested the effects various degrees frequently occurring damage as defoliation, root reduction stem injuries total 18 treatments. We hypothesized...

Trees that grow in urban areas are confronted with a wide variety of stresses undermine their long-term survival. These include mechanical damage to the crown, root reduction and stem injury, all which remove significant parts plant tissues. The single or combined effects these generate complex array growth ecophysiological responses hard predict. Here we evaluated different individual on dynamics non-structural carbohydrates (NSC, low weight sugars plus starch) concentration new tissue...

The stable hydrogen isotope values of tree lignin methoxy groups (&amp;#948;2Hmeth) show a robust relationship with source water isotopes (&amp;#948;2HSW), enabling the reconstruction origin using an average isotopic fractionation (&amp;#949;) around -200 mUr between &amp;#948;2Hmeth and &amp;#948;2HSW (Greule et al., 2021; Keppler 2007). Reconstructed is currently mainly used for climatic temperature but could also be to better understand ecohydrological processes such as root uptake. As...

Summary Measurements of stable isotope ratios in organic compounds are widely used tools for plant ecophysiological studies. However, the complexity processes involved shaping hydrogen values (δ 2 H) carbohydrates has limited its broader application. To investigate underlying biochemical responsible H fractionation among water, sugars, and cellulose leaves, we studied three main CO fixation pathways (C 3 , C 4 CAM) their response to changes temperature vapor pressure deficit (VPD). We show...

Soil organic matter (SOM) originates from various sources such as foliar litter, roots and microbial (e.g. fungal) components. The relative contribution represents one of the key unknowns in SOM dynamics. Our study aimed to explore whether stable isotope ratios non-exchangeable hydrogen (Hn) bound can be used differentiate sources, since natural 2Hn abundance strongly differ between root tissues. We also investigated if long-term irrigation with 2H-depleted water a pine forest track Hn...

Stable isotope compositions of carbon (&amp;#948;13C) and oxygen (&amp;#948;18O) in plant carbohydrates such as photosynthetic assimilates or cellulose are widely applied tools to reconstruct climate physiological responses. In contrast, applications hydrogen composition (&amp;#948;2H) limited because previous methodological constrains knowledge on processes causing fractionations. To better understand the individual climatic drivers isotopic variations tree rings, particularly for...