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Povzetek: Understanding wood formation is critical for interpreting tree growth and carbon allocation under changing environmental conditions. While major progress has been made for gymnosperms, harmonized approaches for studying xylogenesis in angiosperms remain limited. Here, we present practical recommendations for observing and analysing xylogenesis in angiosperm trees, illustrated from examples from temperate and sub-Mediterranean forests. The perspective includes guidance on identifying xylem cell types in histological sections, defining developmental phenophases and establishing a workflow for data collection (and analysis). Annotated images are provided to support reproducibility and inter-observer consistency. We also discuss key challenges unique to angiosperms, including cell-type-specificities and wood type differences. Future research priorities include conserving histological images, extending xylogenesis to branches and coarse roots, enabling cross-biome comparisons and advancing kinetic analysis. This framework supports the coordinated expansion of angiosperm xylogenesis studies, enabling deeper insights into tree functioning in a changing world.
Ključne besede: wood formation, xylem cell types, wood type, methodology
Objavljeno v DiRROS: 19.02.2026; Ogledov: 288; Prenosov: 80
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Povzetek: Cambium phenology is a crucial process in wood production and carbon sequestration of forest ecosystems. Although cambium phenology has been widely studied, research specifically focusing on the cessation of wood formation remains limited. To better understand the influence of environmental and intrinsic factors on the cessation of wood formation, we built and compared three ecophysiological models (temperature sum model, photoperiod-influenced temperature sum model and soil moisture- and photoperiod-influenced temperature sum model) in their ability to predict the date of cessation of xylem cell enlargement (cE) in three major Northern Hemisphere conifer species (Black spruce, Norway spruce and Scots pine). We developed these models based on xylogenesis data collected for 130 site‐years across Europe and Canada. Our results demonstrate that the photoperiod-influenced temperature sum model is well-supported by data across all conifer species, with a RMSE of 9.2 days, suggesting that both temperature and photoperiod are critical drivers of wood growth cessation. However, incorporating soil moisture effects does not improve model performance. Our model effectively captures the inter-site variability in cE across a wide environmental gradient, with a fair model efficiency (ME = 0.51 ± 0.22), but performed less well for annual anomalies (ME = 0.10 ± 0.09). Additionally, we found that the total ring cell number also affected prediction accuracy. Using this model, we reconstructed historical trends in cE over the past six decades and found a trend to delayed cessation dates. This delay varied geographically, with slower shifts at higher latitudes and elevations, likely due to constrained cambial responses and conservative growth strategies in colder regions. Our model framework offers a simple yet accurate approach for predicting wood growth cessation at large spatial scales, providing a basis for integrating cambium phenology into land surface models and forest productivity assessments.
Ključne besede: cambium phenology, ecophysiological models, xylem formation, climate change, global warming, northern hemisphere forests
Objavljeno v DiRROS: 12.02.2026; Ogledov: 371; Prenosov: 98
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Povzetek: Poznavanje strukture in lastnosti lesa je ključno z vidika njegove smotrnejše obdelave, predelave in končne rabe. V članku opisujemo in primerjamo značilnosti zgradbe lesa triletnih sadik bora (Pinus sylvestris) in bukve (Fagus sylvatica) izpostavljene trem različnim temperaturnim režimom v rastnih sezonah 2010–2011: kontrola (K, na prostem, povprečna temperatura v času rastne sezone = 17–19°C), rastlinjak (G, povprečna temperatura v času rastne sezone = 22–24°C) in hladilna komora (C, povprečna temperatura v času rastne sezone = 15–17°C). Na preparatih prečnih prerezov lesa smo tako preverili prisotnost in delež reakcijskega lesa, prisotnost gostotnih fluktuacij, prisotnost kalusa ter za bor še gostoto in položaj aksialnih smolnih kanalov. Rezultati kažejo na vrstno specifičen odziv pionirskega rdečega bora in sencovzdržne bukve na različne okoljske razmere v smislu debelinske rasti in strukturnih posebnosti lesa. Pojavnost lesno-anatomskih značilnosti je bila v splošnem večja v letu 2010 kot v 2011. To bi lahko pojasnili s presaditvenim šokom in z večjo verjetnostjo povzročitve mehanskih poškodb ob manipulaciji sadik, ki so negativno vplivali na kakovost lesa. Razlike v strukturnih posebnosti lesnih prirastkov v obeh proučevanih letih tudi kažejo na nujnost večletnih tovrstnih poskusov v nadzorovanih razmerah, saj se nekateri odzivi lahko pokažejo šele v daljšem časovnem obdobju. Širina lesnega prirastka in lesno-anatomske značilnosti niso nujno povezane, zato na podlagi priraščanja ne moremo sklepati o kakovosti lesa.
Ključne besede: rdeči bor, navadna bukev, reakcijski les, smolni kanal, gostotne fluktuacije, juvenilni les, anatomija, kakovost lesa
Objavljeno v DiRROS: 28.01.2026; Ogledov: 229; Prenosov: 111
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Ključne besede: raziskovalni projekti, gozdarstvo
Objavljeno v DiRROS: 27.01.2026; Ogledov: 261; Prenosov: 66
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Povzetek: Since the impact of temperature on seedling growth and biomass allocation of different tree species remains relatively unknown, the influence of different temperature conditions on stem diameter (xylem and bark), stem and root extensions, as well as below- and aboveground woody biomass, in three-year old European beech (Fagus sylvatica L.) and Scots pine (Pinus sylvestris L.) seedlings in 2010–2011 were studied. One-year-old seedlings were grown outdoors (mean temperature during the growing season = 17–19°C), in the greenhouse (mean temperature during the growing season = 22–24°C) and climatized room (mean temperature during the growing season = 15–17°C) for two years. In terms of radial increment, xylem increments were narrowest in the case of increased temperature for beech and decreased temperature for pine. There was no difference in the thickness of the bark in beech seedlings exposed to different temperature conditions whereas in pine, the bark proportion was highest in control seedlings with the widest diameters. The periderm thickness was comparable in seedlings exposed to different temperatures and represented 10–14 % and 15 % of the bark tissue in pine and beech, respectively. Comparison of the total radial increments of seedlings of the two species under different temperature conditions showed that they were wider in pine in all three regimes. Increment of the main root was considerably higher in both species and represented about 90 % of the total length increment in beech and 74–87 % in pine. In addition, woody biomass was substantially higher aboveground in both tree species (by about 70–80 %). With beech, above- and belowground biomass was reduced in the case of elevated temperature, with the smallest share of roots. In pine, lower temperature diminished amount of biomass and caused its greatest allocation to belowground, which represented almost half of the total biomass accumulation. The short-term treatments clearly show that biomass allocation shifts of pine and beech in response to temperature seem to be a species-specific. The observed differences could be viewed as a plastic adjustment to environmental heterogeneity.
Ključne besede: European beech, Scots pine, radial increment, stem, root, bark, xylem
Objavljeno v DiRROS: 27.01.2026; Ogledov: 206; Prenosov: 96
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