Key message Considering anisotropy in image reconstruction algorithm for ultrasound computed tomography of trees resulted in a more accurate detection of defects compared to common approaches used. Context Ultrasound computed tomography is a suitable tool for nondestructive evaluation of standing trees. Until now, to simplify the image reconstruction process, the transverse cross-section of trees has

Key message In our study of colonisation of abandoned farmland by Juniperus thurifera L., environmental and geographic distances were stronger drivers of functional differentiation among trees than genetic distance and tree intrinsic features. However, these effects varied both along the colonisation gradient and across predictors’ values, highlighting the complexity of the conditions under which functional

Key message The use of reduced planting spacings is an important strategy to increase the carbon storage in the above-belowground biomass and should be recommended for future exploitation of forest energy plantations when the purpose intended is the production of biomass for energy. Context Recent concerns about global warming have resulted in more concerted studies on quantifying carbon storage in

Key message Radial variation of wood properties affects product recovery from veneer logs. In Eucalyptus nitens , the radial variation in wood density, microfibril angle and modulus of elasticity was described using non-linear models. The timing of radial change was trait-dependent, and the age at which thresholds for structural products were reached differed between sites. Context Eucalyptus nitens

Key message Pinus nigra J.F. Arnold has an ecological and economic interest in Europe, but many of the planted populations have an unknown origin and infraspecific taxonomy. Six Portuguese P. nigra populations characterised with microsatellites revealed high intra-population diversity structured into two clusters with low differentiation that might suggest two provenances or infraspecific taxa. Despite

Key message Mechanical properties of small-diameter round timber from hardwood thinnings of common alder ( Alnus glutinosa (L.) Gaertn.), European ash ( Fraxinus excelsior L.), European birch ( Betula pendula Roth. and Betula pubescens Ehrh.), and sycamore ( Acer pseudoplatanus L.) can be evaluated by non-destructive testing on either standing trees or green logs without wood density determination

Key message Species interactions implicate a complex balance of facilitation and competition, which may shift during community development, thus structuring the subalpine ecotone of Mediterranean mountain ranges through time and space. This study highlights that encroachment of grasslands and simultaneous downward/upward movement of forest tree species involve species interferences and environmental

Key message During the first summer, wood biochar amendments increased soil temperature, pH, and soil CO 2 effluxes in a xeric boreal Scots pine forest. The increase of soil CO 2 efflux could be largely explained by increases in by soil temperature. Higher biochar application rates (1.0 vs 0.5 kg m −2 ) led to higher soil CO 2 efflux while the pyrolysis temperature of biochar (500 or 650 °C) had no

Key message Acacia longifolia and Acacia mearnsii exhibit different reproductive behavior (viability, germination, and dormancy) in relation to fire and seed maturation. The potential of invasion of A. longifolia is stronger than that of A. mearnsii . A. longifolia germinates abundantly between fires and after fires, while A. mearnsii only germinates after fire and needs higher thermal thresholds to

Key message Malus sylvestris (L.) Mill., Pyrus communis (L.), Sorbus aucuparia (L.), Prunus avium (L.), Prunus padus (L.), and Cornus sanguinea (L.) are related, co-occurring species producing orthodox seeds. However, we observed differences in their response to storage conditions, such as storage at different seed moisture contents (5%, 8%, and 11%) and/or temperatures (− 3 °C, − 18 °C, and − 196

Key message The 19-year monitoring study revealed continuously positive and dynamic responses of tree growth to logging residue loadings. However, the lack of changes in soil nutrients suggested that increased growth might result from enhanced nutrient cycling with no net accumulation in the soil. Context Understanding how logging residue loadings affect soil nutrients and forest growth is critical

Key message We propose a methodology to develop a preliminary version of a growth model when tree-level growth data are unavailable. This modelling approach predicts individual tree growth using only one-time observations from temporary plots. A virtual dataset was generated by linking the whole stand and diameter distribution models. The individual tree model was parameterized using Bayesian calibration

Key message Nitrogen addition during 4 years to the canopy of Castanopsis chinensis (Sprengel) Hance promoted xylem formation, mainly by increasing radial growth during the early growth season. Context Increased atmospheric nitrogen (N) deposition caused by intensive anthropogenic activities resulted in inconsistent effects on the xylem formation of trees, in N-limited boreal and temperate forests

Key message Intra-annual wood density fluctuations are valuable indicators of the role of the local climate and provenance origins on tree growth. These intra-ring wood features were the most informative about local adaptation and phenotypic plasticity of Pinus halepensis Mill. in a provenance trial. This highlights the importance of taking provenance into account when selecting forest reproductive

Key message The ongoing global warming tends to reduce Larix decidua radial growth and ring wood density at the bottom of an elevational gradient in the French Alps, while it has a less marked effect at the top. Context The ongoing climate warming affects most tree species across their biogeographic distribution range. The bottom and the top of an elevational gradient are appropriate environments to

Key message Defoliation modality significantly affected leaf traits and carbon allocation especially in the early recovery period of two Leguminosae woody species . Robinia pseudoacacia L. recovered more quickly following defoliation than Amorpha fruticosa L. Context Defoliation resulting from anthropogenic disturbance, insects, and grazing animals affects plant growth and vegetation dynamics. Robinia

Key message Decreasing stand density increases resistance, resilience, and recovery of Quercus petraea trees to severe drought (2003), particularly on dry sites, and the effect was independent of tree social status. Context Controlling competition is an advocated strategy to modulate the response of trees to predicted changes in climate. Aims We investigated the effects of stand density (low, medium

Key message Chestnut timber is a resource that has so far been underestimated. The production of laminated chestnut beams represents important progress; it is necessary to check its market performances and the opportunities offered from non-market characteristics. To ensure competitiveness margins in the future, dedicated chestnut timber policy is required. Context European Union policies for sustainable

Key message During the past decades, a multitude of oak stands have spontaneously established across the pine-dominated landscapes of the French Landes de Gascogne. Yet their future performance under modern climate change is unknown. We show that coppiced, dominant trees are most prepared to cope with drought episodes, displaying higher basal area increment and lower sensitivity to extreme events.

Key message In this exploratory study, we show how combining the strength of tree diversity experiment with the long-term perspective offered by forest gap models allows testing the mixture yielding behavior across a full rotation period. Our results on a SW France example illustrate how mixing maritime pine with birch may produce an overyielding (i.e., a positive net biodiversity effect). Context

Key message The adoption of new silvicultural methods and approaches requires an understanding of the differences between those and “old” or “conventional” approaches, along with extensive training to break previous knowledge bias. Context Forestry is in transition towards ecosystem-based management, and new silvicultural approaches are appearing worldwide. However, the adoption of an alternative silvicultural

Key message Using the three characteristic points of a forest stand, dg (mean quadratic diameter), dmin(diameter of the smallest tree) anddmax (diameter of the largest tree), appears informative enough to determine the parameters of the whole diameter distribution and, hence, the standing volume, with an accuracy of 2–3%. This is related principally with a particular feature of the Weibull distribution

Key message The mixture of decomposing litter from three predominant tree species in a Masson pine ( Pinus massoniana Lamb.) forest showed advantages in elemental cycling, and the species component identities were found to be an important driver for the release of several metallic elements. Context Although mixed forests have long been considered essential to sustainable forestry management, little

Key message A histopathological study using one resistant and one susceptible clone ofEucalyptus urophylla × Eucalyptus grandishybrid showed that the colonization ofCeratocystis fimbriatawas limited by rapid and intense host defense responses such as closure of the vessel pits; formation of tyloses and gels; accumulation of amorphous material, starch, phenolic compounds, and calcium oxalate; and tissue

Key message An in-depth characterization of the forests of 10 dominant species by stand variables at national scale showed, that overall, stands growing in the southernmost regions of Spain display low regeneration. Otherwise, the relationships between stand variables and geographic location are species dependent. Similarly, the degree of inter and interregional variability varies strongly among species

Key message Recent afforestation in Europe might involve deep changes on landscape composition and configuration. We show that afforestation promotes defragmentation of pre-existing forests and new patch proliferation, in forest-dominated and non-forest-dominated landscapes respectively, while it is not associated to decreasing landscape diversity. These processes are modulated by geographic factors

Key message Rut depth in fine-grained boreal soils induced by an 8-wheeled forwarder is best predicted with soil moisture content, cumulative mass of machine passes, bulk density and thickness of the humus layer. Context Forest machines are today very heavy and will cause serious damage to soil and prevent future growth if forest operations are carried out at the wrong time of the year. Forest operations

Key message By combining inventory data and spatially-continuous environmental information, we were able to develop models for Atlantic populations of maritime pine ( Pinus pinaster Aiton) in Spain in order to predict suitable habitat and site index at a spatial resolution of 250 × 250 m. Context Currently available, spatially continuous environmental information was used to make reliable predictions

Key message This work analyses the rate of recovery of the spectral signal from clearcut areas of coppice Mediterranean forests using Landsat Time Series (LTS). The analysis revealed a more rapid rate of spectral signal recovery than what was found in previous investigations in boreal and temperate forests. Context The rate of post-disturbance vegetation recovery is an important component of forest

Key message Windstorms have recently caused noteworthy destruction across the Northern forests of Turkey. The intensive forest management practices applied for more than 60+ years may unknowingly have resulted in wind-sensitive forests in the region. After a storm, the forest service salvages the losses, but no further precaution is taken against future storms. To our knowledge, there has not been

Key Message A model describing species composition, density and diameter distribution of saplings was developed from operational inventory data. It could be used as an input into growth models calibrated exclusively with merchantable trees to correct some recruitment bias. Important differences in distributions were found between plantations and naturally regenerated stands. Longer-term monitoring

Key message In a mixed, Fagus sylvatica L.- Acer pseudoplatanus L., young plantation, trees of both species absorbed water from superficial soil layers despite the presence of roots and water in deeper layers. Admixture proportion and tree density were weak predictors of water acquisition depth, as well as fine root vertical distribution, although it might be due to distinct periods of root and isotope

Key message Xylem vulnerability to drought-induced embolism did not differ between stems and petioles of four woody species ( Betula pendula , Liriodendron tulipifera , Populus tremula and Olea europaea ). Our results, together with data compiled from published literature, indicate that hydraulic segmentation during drought stress is not consistently driven by difference in vulnerability to embolism

Key message Wildfire danger and burnt areas should increase over the century in southern Europe, owing to climate warming. Fire-prone area expansion to the north and to Mediterranean mountains is a concern, while climate-induced burnt area increase might be limited by fuel availability in the most arid areas. Further studies are needed to both assess and reduce uncertainties on future trends. Context

Key message Non-structural carbohydrates (NSC) are the main form of carbon storage in broadleaved trees; precise NSC quantification is relevant to predict forest resilience. Sample microwaving before drying is considered to reduce NSC losses; however, evidence is scarce. We demonstrate that microwaving leaf and branch sapwood samples before drying did not significantly reduce NSC losses with respect

Key message Under similar site conditions, leaf litter decomposition beneath Central African rainforests was largely driven by average leaf litter quality. Although significant, the additional variability related to litter mixing and to the decomposition environment was limited. Context Under given site conditions, litter decomposition is expected to mainly depend on its average quality. However, the

Key message Insect herbivory in novel Quercus ilex L. forests is a highly context- and scale-dependent process. We show that forest composition, tree height and fine-scale spatial location, as well as tree genetic relatedness and ontogeny, can all influence herbivore activity at local to landscape scale. Context Understanding the intrinsic and extrinsic drivers of herbivory in novel expanding forests

Key message Forest owners who maximize profitability with a low discount rate or whose management goals are related to conservation and recreation, rarely sell timber. These owners make it difficult to achieve the high harvesting targets of the growing bioeconomy sector of Finland. To increase timber supply, these landowners should be informed about alternative silvicultural methods. Context The round

Key message Creation of second generation Douglas-fir (Pseudotsuga menziesii (Mirb.) Franco) hybrids based on parents from geographically distant locations did not appreciably increase variance in height, frost damage and bud break. New and favorable trait combinations between height and the two adaptive traits were found in the F2 populations. Context Increased genetic variance and new trait combinations

Key message By integrating vegetation change tracker (VCT), spatial analysis (SA), and random forest regression (RF), the spectral-temporal patterns of forest stand age were mapped for three typical plantations in Southern China. The spectral-temporal distribution of age structure indicated that the plantation stands in the study area were increasingly aging. Context Plantations play a major role in

Key message The soil plant analysis development (SPAD) meter proved effective at estimating leaf Chl content of native and non-native temperate deciduous shrubs. However, due to the change in the relationship between SPAD values and Chl content during the course of autumn senescence, it may be necessary to establish separate calibration equations to cover a range of leaf Chl concentrations. Context

Key message The emerald ash borer (Agrilus planipennis Fairmaire), an alien pest native to Asia, has spread to Ukraine and 16 regions of European Russia. It severely damages Fraxinus pennsylvanica Marsh. introduced from North America, but serious damage to European ash (Fraxinus excelsior L.) has not been detected in forests. Context The first detection of A. planipennis in European Russia was in Moscow

This correction stands to correct a spelling error found in one of the contributor names. The author group request the third contributor name to cited and acknowledged as Chunyan Zhang and not Chuanyan Zhang. The original article has been corrected.

Key message Bastin et al. 2019 use two flawed assumptions: 1) that the area suitable for restoration does not contain any carbon currently, and 2) that soil organic carbon (SOC) from increased canopy cover will accumulate quickly enough to mitigate anthropogenic carbon emissions. We re-evaluated the potential carbon storage worldwide using empirical relationships of tree cover and carbon. We use global

Key message New genotypes of hybrid poplars from the Aigeiros and Tacamahaca sections have great potential for increasing genetic gain from selection. The most promising traits are associated with productivity and resistance to Sphaerulina musiva -induced canker while wood density can be selected for secondarily. A minimum age of 8 years is reliable to select fast-growing resistant clones in northern

Key Message Estimates of available nitrogen (based on topsoil nitrogen mineralisation rates) in semi-mature stands of Pinus radiata (D Don.) as well as pure species and hybrids of Pinus elliottii (Engelm.) in South Africa display a strong, significant, negative relationship with growth response to applied fertilisers in field experiments. This inexpensive technique can be incorporated in a fertiliser

The article was originally published with duplicate information appearing in the work.

The article was published with errors in figures 10 and 11.

Abstract Key Message Tree-level forest inventory data are becoming increasingly available, which motivates the use of these data for decision-making. However, airborne inventories carried out tree-by-tree typically include systematic errors, which can propagate to objective function variables used to determine optimal forest management. Effects of under-detection focused on the smallest trees on predicted

Abstract Key message Runoff decreased significantly in each soil texture group, as plot length increased (2–40 m), whereas sediment yield showed an increasing trend. Runoff and sediment yield were higher in the clayey soil than in the loamy soil texture. Context An important issue for decreasing the negative impact of ground-based skidding operations on the physical environment is the appropriate drainage

Abstract Key message Globally, mangrove forests are under threat from a range of causes. They also represent a large potential form of climate mitigation and adaptation via reforestation, and this investment may contribute to restoration efforts and reverse mangrove decline. There has been significant (c. 200,000 ha) mangrove reforestation and restoration activity in Vietnam, and these projects provide

Abstract Key message Mechanical acclimation of young poplars ( Populus tremula × Populus alba , INRA 717-1B4) submitted to periodic stem bending is mainly driven by compressive strains. Flexure wood and compressive flexure wood exhibit higher mechanical resilience and lower mechanical damage. Context It is well known that thigmomorphogenesis modulates tree growth and the anatomical structure of wood

Abstract Key message A positive effect of mixed pine forests ( Pinus sylvestris L. and Pinus pinaster Ait.) on the understory richness and tree regeneration was observed with respect to monospecific stands. Understory species typical of the native Pyrenean oak forests in the Iberian Peninsula contribute to maintaining high understory richness in such mixed pine forests. Context The influence of stands

Abstract Key message Truncating the angle count sampling plots leads to a higher stock estimate because fewer trees are missed. It also causes a higher uncertainty of the estimates. Context The Austrian National Forest Inventory changed its plot design to angle count sampling plots that are limited to circles of 300 m2. A fixed plot size is beneficial for multistage inventory systems. Aims This study

Abstract Key message There is considerable genetic gain of tree volume from clonal deployment in Norway spruce ( Picea abies (L.) H. Karst) and clonal deployment will have at least 50% more or double genetic gain than the seedling deployment. Context Genetic parameters and genetic gains for wood quality and growth traits were estimated in six large clonal progeny trials. Aims Develop the optimal clonal

Abstract Key message Prescribed burning applied after a dry year increased (fall burns) or had no effect (spring burns) on pine resilience, measured as the capacity to reach pre-drought growth levels compared with unburned pines. In fall burns, there was a larger increase in resilience when the impact of drought and burning on pines was low and burning caused a significant release from tree competition

Abstract Key message Multi-objective forest planning methods were used to assess the trade-offs between three ecosystem services: timber production, erosion protection and biodiversity. The use of trade-off analysis helps to define proper weights for the management objectives and evaluate the feasibility of obtaining economic profit from timber while controlling the erosion risk and maintaining biodiversity

Abstract Key message Emerald ash borer-caused canopy gaps alter resource availability which affects woody plant community dynamics in eastern US forests. Our findings indicate that both canopy trees and seedlings are impacted by the disturbance. Seedlings of sugar maple and introduced woody plants benefited most from ash death, perhaps because they are adapted to ephemeral resource fluctuations. Context

Abstract Key message A highly significant and positive scaling relationship between bamboo leaf dry mass and leaf surface area was observed; leaf shape (here, represented by the quotient of leaf width and length) had a significant influence on the scaling exponent of leaf dry mass vs. area. Context The scaling of leaf dry mass vs. leaf area is important for understanding how plants effectively intercept

This correction stands to correct the original article where a processing error led to the erroneous reference, Lpez-Pantoja et al. 2008. This article is part of the topical collection on Entomological issues during forest diebacks