Key message Higher solar radiation leads to higher crown temperatures, sap flow, and airborne volatile concentrations as well as altered bark chemical composition in trees at fresh forest edge. Abstract Spruce bark beetles are likely to attack trees that are at newly opened forest edges after wind disturbance due to higher temperatures and higher emission of primary attractants. The mechanisms behind

Key message Drivers of the abundance and richness of tree-related microhabitats are similar in mountain forests of Europe and North America and their occurrence may be explained by tree functional groups. Abstract A common approach to support forest-dwelling species in managed forests is to preserve valuable habitat trees. To assess the quality of habitat trees, a hierarchical typology of tree-related

Key message When Populus wutunensis seedlings are salt stressed, many genes involved in cellular metabolism, signal transduction, transport, osmotic regulation, and reactive oxygen species scavenging show elevated expression levels. Abstract Populus wutunensis, a natural hybrid individual resulting from a cross between Populus × xiaozhuanica W. Y. Hsu et Liang, shows salt and drought tolerance and

Key message Resilience to xylem embolism and the accumulation of cyclitols are promising criteria for the selection of drought-resilient Eucalyptus species. Abstract Due to the aridity of the climate in the southern Mediterranean region, the choice of suitable species for afforestation projects is crucial. The present study aims to compare resilience mechanisms against drought in two frequently used

Key message Our results from iTRAQ-based proteomics extend the understanding of the mechanisms employed by AMF to defend against drought stress in blueberry. Abstract Arbuscular mycorrhizal fungi (AMF) can substantially contribute to plant drought tolerance. In this work, south highbush blueberry (Vaccinium corymbosum) ‘O’Neal’ cultivated with or without Funneliformis mosseae inoculation under well-watered

The impact of plants on soil enzymatic activity and their potential for remediation of oil-contaminated soil has been widely studied but information about tree species is scarce. Here, we used seedlings of four tree species (Ailanthus altissima Mill, Fraxinus rotundifolia Mill, Melia azedarach L. and Robinia pseudoacacia L.) to investigate rhizosphere effects on key soil enzymes (dehydrogenase, urease

Key message The dioecious Idesia polycarpa all that males and females do not invest in the same way in growth and branching in quantity, type of axes and in time (annual growth and sequence of these events over time). Abstract The annual growth of plants is an important indicator for growth and development, especially for younger trees. The aim of this study was to decide the physiological basis for

Key message Local adaptation largely segregates between traits affecting light responses and water relations, but population-level differences in stomatal conductance when growth is unconstrained converge among populations under water stress. Abstract Warming temperatures and altered precipitation patterns threaten plant populations worldwide. European beech (Fagus sylvatica) is a species that expresses

Key message A flexible stem respiration chamber was developed and successfully employed in a feasibility study in a tropical forest. Abstract We present a flexible chamber to measure the CO2 efflux from tree bark. The easy-to-use chamber is made of stainless steel and is clamped around an individual tree stem section; it uses a portable gas analyzer to retrieve the stem respiration value. Using the

Key message The extreme hydroclimatic events in the Conchos River Basin, are strongly associated with ocean–atmospheric phenomena such as the El Niño Southern Oscillation, Pacific Decadal Oscillation, and Atlantic Multidecadal Oscillation, the streamflow reconstruction showed the occurrence of up to 10-year droughts. Abstract Dendrochronology is a modern science used to study hydroclimatic events through

Key message The optimization of plant hormone application to achieve better rhizogenesis in eucalypt cuttings has been demonstrated using a machine learning approach. Abstract This study focuses on reducing the human bias in treatment selection in case of adventitious rhizogenesis in eucalypts. The effect of different concentrations of indole-3-butyric acid (IBA) on rhizogenesis was studied and differential

Key message Juveniles and canopy trees may not exhibit similar nitrogen acquisition responses to soil temperature change caused by variation in snow cover over winter. Abstract The use of 15N tracer is a powerful tool for tracking the effects of variation in soil frost on plant nitrogen acquisition. While the responses of juvenile trees to environmental change are often used to infer the responses

Key message Juniperus communis males are better adapted than females to changing, seasonal environmental conditions due to their higher photosynthetic capacity and the higher concentration of photosynthetic pigments in their needles. Males cope with ROS more efficiently than females having greater carotenoids concentration in needles. Abstract In dioecious woody plants, females often exhibit greater

Key message A random sampling between 30 and 50 trees is sufficient for forest-level wood density estimates. Abstract Wood density (WD) is a key trait used to determine forest biomass and carbon stocks, but determining WD accurately is logistically demanding and expensive. These challenges also hamper comparisons across studies and different forest types, because sampling intensity within forests and

Key message Crown variables and height can improve biomass predictions and may help to quantify how tree biomass is influenced by inter-tree competition (stand density, species composition), climate, edaphic conditions, and age. Abstract Tree biomass is influenced by tree age, stand structural characteristics, and climatic and edaphic site factors. However, most allometric equations for predicting

Key message Leaf area index and species composition influence red-to-near-infrared and red-to-shortwave-infrared transmittance ratios of boreal and temperate forest canopies. In this short communication paper, we present how the spectral composition of transmitted shortwave radiation (350–2200 nm) varies in boreal and temperate forests based on a detailed set of measurements conducted in Finland and

Key message Geography and tree diameter were the major factors in determining oleoresin yield in Sindora glabra. The tangential diameter and area of secretory canals are reliable indicators of the oleoresin amount. Abstract Sindora glabra is a native tropical plant of China that exudes copious amounts of oleoresin from wounds on the stem. Elucidation of the mechanism affecting the oleoresin yield is

Some studies suggest that tapping sugar maple (Acer saccharum Marshall) trees can cause their growth to decline, particularly on poor and acidic soils. We tested this hypothesis in seven sugar bushes located in the Quebec Appalachians by comparing the growth of tapped trees with nearby untapped trees. The sites represented a range of soil fertility, from very good for sugar maple to strongly deficient

Key message Black spruce ecotypes exhibit temperature-adapted bud burst, while bud set is independent of temperature. Warmer conditions could advance bud burst, but no direct effect is expected for bud set Abstract Phenological adjustment is a key adaptive trait closely associated with the environment. Species spreading over a wide geographical range can evolve ecotypes that are able to grow and reproduce

Key message Functional stomata can be generated by in vitro ABA applications. This mitigates the desiccation responses of Persian walnut leaves in their early stage of ex vitro exposure. This finding paves the way for discovering a solution for the uncontrollable water loss problem of in vitro-generated walnut plantlets. Abstract Most in vitro-generated plants are susceptible to wilting when they are

Key message We identified 15 genes encoding enzymes for phenylpropanoid biosynthesis in the genome of birch by combining phylogenetic analysis and tissue-specific expression data. Abstract Lignin is one of the most abundant terrestrial biopolymers and is essential for plant structure and defense. An essential step in lignin formation is phenylpropanoid synthesis, we identified 120 gene models in 10

Key message Canopy tree species with a large mean xylem vessel diameter has a high sensitivity of stomatal conductance to vapor pressure deficit in a wet tropical rainforest in Malaysia. Abstract We investigated the diurnal variation of stomatal conductance to water vapor (gs) and leaf water relations in nine tropical rainforest canopy tree species in Malaysia to investigate the sensitivity of stomatal

Key message Phloem cell production was less influenced by environmental factors than xylem cell production. The moment of maximum number of conducting phloem cells occurred at the end of the growing season. Abstract The understanding of the seasonality of phloem production, its dependence on climatic factors and potential trade-offs with xylem cell production is still limited. This study determined

SUMOylation in plants is associated with biotic and abiotic stress responses, flowering, and other aspects of development. ICE1 protein SUMOylation by the SUMO E3 ligase SIZ1 plays important roles in plant cold tolerance. Here, we reported the subcellular localization of EcaICE1 and its interaction with EcaSIZ1 in Eucalyptus camaldulensis. The genes EcaICE1 and EcaSIZ1 were isolated by homologous cloning

Key message This study proposed the combination of PR26S and PP1 as a good choice for RT-qPCR normalization in pecan under abiotic stress, developing kernels, grafting, and various tissues. Abstract Reference gene selection is an essential pre-requisite to generate reliable results in real-time quantitative polymerase chain reaction (RT-qPCR) analysis. However, studies regarding systematic validation

The net photosynthetic rate (A), stomatal conductance (gs), and transpiration rate (E), chlorophyll content, and midday xylem water potential (Ψmd) of Pinus nigra Arn. subsp. pallasiana (Lamb.) Holmboe trees were studied in a natural stand (Burdur-Aziziye, Turkey) for the first (2015), second (2016) and third (2017) years after precommercial thinning (PCT) to better understand the physiological and

Key message We performed a comparative transcriptome combined with morpho-physiological analyses between two differential cold tolerance in two contrasting apricot cultivars. The revealed candidate genes potentially were identified by differential expression analysis. Apricot (Prunus armeniaca L.) is a major (non-wood product) forest tree species that is adversely affected by spring frost. However

Key message Flow within internal secretory systems derived from autolyzing epithelia in kino-producing angiosperms may have lower metabolic energy costs. This presents physiological advantages and possibly constitutes an evolutionary step of these species compared to resin flow in conifers in using internal secretory systems in plant defence mechanisms. Abstract Kino is a plant exudate, rich in polyphenols

Black walnut (Juglans nigra L.) is a light-demanding, competition-intolerant, and tall forest tree species, introduced in Europe from North America at the beginning of the seventeenth century. It has an important economic role in Europe for producing wood and fruits, in agroforestry systems, as an ornamental tree for parks and avenues, for rehabilitation/restoration of degraded lands. The best sites

Key message The diameter at breast height of the largest sprout per coppiced stool proved to be accurate for the total sprout biomass estimates at stand level. Abstract Traditional coppicing is one of the oldest silvicultural systems for biomass production. However, a quick and simple biomass estimate methodology across the entire growth period is lacking. The objective of this study was to find the

Key message The investigation provides initial knowledge on the distribution and evolution of the high and low methyl salicylate-producing trait in the Betula genus. Mislabelled birch species could be identified and removed. Abstract The genus Betula is the largest group of ecologically and economically dominant perennial woody plants in subalpine forests. The taxonomy of Betula is complex due to an

Key message Xylem functionality is the primary determinant of the Ca relations of developing sweet cherry. Calcium influx is positively related to transpiration and decreases as xylem functionality is progressively lost during development. Abstract Fruit calcium (Ca) may be associated with susceptibility to rain cracking in sweet cherry but little background information is available on the fruits’

Changes in leaf size have been demonstrated to considerably affect leaf hydraulic properties, which in turn impact plant photosynthesis and productivity. In this study, we selected five genotypes from four coffee species (Coffea spp.) with highly contrasting individual leaf areas (from 25 to 280 cm2) to test whether changes in foliar area result in anatomical alterations and ultimately changes in leaf

Key message Beech trees growing in biodiverse patches in Belgium have higher radial growth and are less physiologically sensitive to drought than those in monocultures. Forest diversification therefore alleviates the negative effects of drought on beech. Abstract Common beech, a widespread and economically important tree species in Europe, is known to be drought sensitive. For ensuring its survival

Key message This study revealed the ABA-dependent signaling pathway and flavonoid synthesis pathway of sea buckthorn under drought conditions from plant physiology and gene expression levels. Abstract As climate changes and temperatures rise, sea buckthorn (Hippophae rhamnoides L.) is increasingly exposed to numerous challenges, particularly aridity. In this study, the leaves of sea buckthorn were

Key message Restricted access of light for stems reduced carbon acquisition there and limited the biomass growth of the roots. Abstract Light access can affect the microatmosphere within stems, creating favourable conditions for photosynthesis. We tested the hypothesis that stem photosynthesis modifies carbon allocation within plants and also can affect root growth. To verify this hypothesis, parts

Key message This paper shows the intraspecific plant responses in leaf morphology, herbivory and FA between mature and successional tropical dry forests, as well as the difficulty associated with understanding the relationship between FA and herbivory Abstract Understanding the processes that affect biotic interactions during secondary succession has implications for the maintenance of species diversity

Key message Understory dwarf bamboo mitigated soil N competition with co-existing canopy oak trees by foraging in deeper soils and increasing dependence on N forms that differ from those used by canopy trees. Abstract Nitrogen (N) competition among co-existing plant species utilizing different mycorrhiza types was explored through the investigation of N sources of oak trees and dwarf bamboo. Vertical

Key message K/Zn application by spraying at bud swell stage and green tip stage improved freezing tolerance of pistachio flowers due to increased antioxidant enzymes, soluble proteins, soluble carbohydrates, total phenolic and proline contents as well as decreased lipid peroxidation and H2O2 content in flower. Abstract Spring frost injury to blossoms has been a severe problem in pistachio-harvesting

Key message Year-round observation suggests that sap flow in growing season represents species-specific transpiration characteristics and sap flow of deciduous broadleaved species in non-growing season is related to daily changes in stem diameter. Abstract Year-round observation is necessary to investigate species-specific characteristics of sap flow and its possible contribution in non-growing season

Key message The lack of elevational changes in electrical resistivity in Pinus cembra trunks indicated consistent growth and hydraulics across elevations. Though, electrical resistivity tomograms exhibited pronounced temperature-driven seasonal changes. Abstract Alpine conifers growing at high elevation are exposed to low temperatures, which may limit xylogenesis and cause pronounced seasonal changes

Key message Genome-wide characterization and development of first set of polymorphic Class I SSRs markers in pomegranate (Punica granatum L.) through in silico analysis using the draft genome sequence of pomegranate cv. Dabenzi (296 Mb) as reported by Qin et al. (2017). Abstract The availability of the draft genome sequence of pomegranate cv. Dabenzi presents unprecedented opportunities for the development

Key message Under severe drought, growth of Norway spruce suffered much more than European beech. Norway spruce benefited from growing in the environment of beech, and both species acclimated slightly to 5 years of experimentally extended drought. Abstract Recent studies show that the detrimental effects of drought on stand growth are mitigated when the stand contains mixed tree species. We analysed

Key message The article presents the existing genetic resources of historical mulberry trees in Slovenia and reveals that pruning management and geographical distribution exhibit significant effect on certain biochemical traits. Abstract Former sericultural regions in Europe retained a number of centuries-old white mulberry (Morus alba L.) trees, which represent both, a valuable natural heritage and

Key Message Carbon competition between starch and oil biosynthesis during seed development of Styrax tonkinensis has been reported, but reserve dynamics indicate an absence of significant carbon competition in other Styrax species. Abstract The accumulation of different storage reserves during seed development can be competitive. Carbon competition (i.e., carbon flow into starch instead of oil) has

Key message Fine-root biomass relates to environmental variables differently along a rainfall gradient in Ghana. Abstract Understanding changes in root dynamics in response to environmental factors is crucial for projections of climate change, yet information on controls of root dynamics is limited in the tropics. This study quantified fine-root dynamics along a rainfall gradient in Ghana, ranging

Key message Vegetative regeneration and horizontal spreading, supported by a large bud bank dependent on rhizome length, are specific functions of Quercus coccifera rhizomes, while anchoring and storing reserves are also root functions. Abstract The ability to reproduce vegetatively through rhizomes has mainly been ignored in woody species and the roles attributed to them are little documented, despite

Key message Severe insect defoliation induced non-lignified tracheids and thin-walled latewood tracheids in the defoliation year in Larix kaempferi. These anomalous tracheids had heterogenous lignin deposition of S2 layer. Abstract Severe insect defoliation induces the formation of light ring consisted of thin-walled latewood tracheids in larch trees, which would affect wood quality. However, the identity

Key message In this review, the main internal and environmental hypotheses regarding alternate bearing and abscission of inflorescence buds and also, the methods to mitigate this physiological phenomenon have been investigated. Abstract Alternate bearing is annually fluctuating heavy (‘on’) and light (‘off’) crops, which occurs in most fruit trees. There are multiple visible causes, decreased shoot

Key message Root grafting occurs in 15-year-old hybrid poplar clones; and tree proximity, tree and root sizes are key factors enhancing its frequency. Abstract Root grafting in trees is a well-recognized phenomenon allowing nutrient and photosynthate redistribution between connected trees. This study assessed the influence of tree spacing on root graft formation in a 15-year-old hybrid poplar plantation

Abstract Key message Young Pinus taeda trees may tolerate Leptographium terebrantis infection when stand conditions support new sapwood growth devoid of pathogen-induced occlusion. Abstract Leptographium terebrantis S. J. Barras and T. J. Perry is an opportunistic root pathogen that compromises the xylem function of infected trees and is commonly associated with Pinus taeda L. stands that experience

Key message A survey of theEucalyptus grandis genome revealed the presence of 54 laccase genes. Their tissue-specific and stress-induced expression patterns suggest a role in lignification and adaptation to abiotic stresses. Abstract Laccases are multicopper oxidases that play important roles in the oxidation of monolignols during lignin biosynthesis and are reported to be functionally involved in

Key message A new Tau class GST gene was cloned from Pinus brutia Ten. cDNA sequence was analysed for conserved sequences. Substrate specificity, optimum pH, and temperature values of the recombinant PbGST Tau enzyme were determined. Abstract Tau class glutathione S-transferases (GSTs) are essential enzymes for detoxification in plants. To date, a lot of the members of this family have been characterized

Key message Autumn flooding reduced nitrogen uptake and fine root mass. Leaf nitrogen resorption increased, but overall autumn nitrogen accumulation was negligible in flooded seedlings. Subsequently, spring survival and growth were decreased. Abstract Since nitrogen (N) is often limiting in terrestrial ecosystems, N is conserved in trees by resorption before leaf senescence. Bottomland forests are

Key message This non-invasive clearing technique allows for deep clear imaging of plant tissue and 3D structural analysis of leaf cells. Abstract Optical-clearing technology allows the reduction of light scattering and absorption in internal biological tissues. This technology allows microscopy techniques, such as confocal laser scanning microscopy, to obtain structural information deep within the

Key message Our study shows for the first time a complete guabiroba micropropagation system with acclimatized plants. BA was the best plant growth regulator for multiplication and IBA for rooting. Abstract Campomanesia xanthocarpa O. Berg (Myrtaceae), popularly known as guabiroba, is a woody species native to Brazil, important for its potential as a medicinal plant and fruit tree. For the first time

Key message BplSPL1 gene was identified in Betula platyphylla Suk, and its sequence features and gene function expression have provided useful information for further studies on function. Abstract SQUAMOSA promoter-binding protein-like (SPL) are plant-specific transcription factors that play an important regulatory role in plant growth and development. In this study, an SPL gene, BplSPL1, was cloned

Key message Ca2+ induces adaptive response to low P stress through increased root growth and expansion, but plays minor or no role in remobilization of P in leaf tissues or in maintaining membrane integrity. Abstract The role of calcium (Ca2+) in signaling environmental stress has been demonstrated; however, its role in signaling low phosphorus (P) stress and subsequent adaptive responses in trees

Although wood anatomical features can provide yearly resolved climatic information at sub-seasonal resolution, the occurrence of intra-annual density fluctuations (IADFs) might be triggered by several abiotic factors under different ecological settings. Here, we use information on cambial age and tree-ring width to standardize the frequency of IADFs in European black pines from three different mountain

Key message This is a descriptive study on leaf ontogeny, showing the main morphological and physiological changes during development of leaves from young plants in three Eucalyptus genotypes. Abstract A descriptive study on key morphological and physiological features during leaf ontogeny in three genotypes—AEC 144, CO 1407 and VCC 865—of Eucalyptus young plants was performed. The work was developed