TreesPub Date : 2026-06-03DOI: 10.1007/s00468-026-02787-2
P.W. West
{"title":"Factors determining the behaviour of dynamic self-thinning lines in Canadian interior spruce forests","authors":"P.W. West","doi":"10.1007/s00468-026-02787-2","DOIUrl":"10.1007/s00468-026-02787-2","url":null,"abstract":"<div><h3>Key message</h3><p>Extrapolation of dynamic self-thinning lines in Canadian interior spruce forest stands intersected at a common point when quadratic mean diameter was used for average plant size but are the same line asymptotically when stand top height is used.</p><h3>Abstract</h3><p>In a forest stand undergoing steady and ongoing tree mortality, the self-thinning rule applies. This relates progressive stand stocking densities to average plant sizes with a power law. Often, quadratic mean diameter has been used as the measure of average size. It was found recently for a number of forest species, that when extrapolated in stands of differing site indices and initial stocking densities, such relationships intersect near a common point. This appeared to add a new concept to the self-thinning rule, but no explanation for it was immediately apparent. The present work applied an existing stand growth model for even-aged, Canadian interior spruce forests; these contain a mixture of two spruce species but are generally treated as monospecific, even-aged forests. It predicted the intersection at a common point of the self-thinning relationship for many stands. However, if average heights of tallest trees (top height) was used to represent average tree size at any age, the self-thinning relationship became a single relationship for different stands probably reflecting a balancing out with age of the competitive interactions between trees. It is clear that much further research is required to better understand how and why the self-thinning rule applies.</p></div>","PeriodicalId":805,"journal":{"name":"Trees","volume":"40 4","pages":""},"PeriodicalIF":2.1,"publicationDate":"2026-06-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://link.springer.com/content/pdf/10.1007/s00468-026-02787-2.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148141703","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
TreesPub Date : 2026-06-03DOI: 10.1007/s00468-026-02784-5
Laura Würzberg, Jürgen Homeier, Heinz Coners, Roger Mundry, Jorge A Gonzaga Poma, David Windhorst, Katja Trachte, Sebastian Scholz, Jörg Bendix, Christoph Leuschner
{"title":"Contrasting diurnal and seasonal root water uptake patterns among different plant life forms in a neotropical dry forest","authors":"Laura Würzberg, Jürgen Homeier, Heinz Coners, Roger Mundry, Jorge A Gonzaga Poma, David Windhorst, Katja Trachte, Sebastian Scholz, Jörg Bendix, Christoph Leuschner","doi":"10.1007/s00468-026-02784-5","DOIUrl":"10.1007/s00468-026-02784-5","url":null,"abstract":"<div><h3>Key message</h3><p>The woody plant life forms in a tropical dry forest differ largely in their diurnal and seasonal patterns of root water uptake and the related atmospheric and edaphic drivers.</p><h3>Abstract</h3><p>As a consequence of global climate change, the frequency and intensity of drought events in tropical forest ecosystems is expected to increase. Woody species in tropical dry forests (TDFs) exhibit diverse strategies to withstand drought such as leaf-shedding or stem succulence that have mainly been studied from an aboveground perspective. Much less is known about the functioning of small and fine roots during the dry season and their response to soil re-wetting. We measured sap flux in small-diameter roots (2–6 mm) of four woody Ecuadorian TDF species using calibrated miniature sap flow gauges based on the heat-ratio method to unravel seasonal and diurnal patterns in root water uptake in dependence on phenology, soil moisture, and climatic drivers. Continuous data from 17 months showed that water uptake in the deciduous trees <i>Eriotheca ruizii</i>, <i>Ceiba trischistandra</i>, and <i>Vachellia macracantha</i> was closely linked to leaf phenology, soil moisture, and, in wet soil, vapor pressure deficit (VPD), while the tall, stem-succulent cactus <i>Armatocereus laetus</i> revealed a highly opportunistic water uptake pattern with rapid responses to small rainfall amounts in the dry season and decoupling from atmospheric drivers. While root sap flux density was on average highest in <i>C. trischistandra</i> with largest foliage area, the cactus roots were able to absorb water all day round without daytime dormancy and thus outperformed the other two species even during wetter periods. Deeper insights into small-root functionality across seasons is essential for a more mechanistic understanding of the water relations of TDF perennials with different drought response strategies.</p></div>","PeriodicalId":805,"journal":{"name":"Trees","volume":"40 4","pages":""},"PeriodicalIF":2.1,"publicationDate":"2026-06-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://link.springer.com/content/pdf/10.1007/s00468-026-02784-5.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148141702","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
TreesPub Date : 2026-06-02DOI: 10.1007/s00468-026-02789-0
Naomi C. Housego, Thomas C. Parker, Lorna E. Street, Elena I. Vanguelova, Ruth J. Mitchell
{"title":"Localised effects of sparse natural tree colonisation on soil physicochemical properties","authors":"Naomi C. Housego, Thomas C. Parker, Lorna E. Street, Elena I. Vanguelova, Ruth J. Mitchell","doi":"10.1007/s00468-026-02789-0","DOIUrl":"10.1007/s00468-026-02789-0","url":null,"abstract":"<div><p>Tree establishment via natural colonisation is increasing globally, due to treeline expansion under climate change, and changing land management practices, such as reduced grazing pressure, land abandonment, and initiatives to increase tree cover such as restoration and rewilding. Natural colonisation of organo-mineral soils at high densities is associated with altered soil physicochemical properties, with consequences for ecosystem services such as soil carbon stocks, biodiversity, and hydrology. But whether sparse natural colonisation of organo-mineral soils has similar effects on soil physicochemical properties to dense natural colonisation is not known. To investigate the effects of sparse natural colonisation on organo-mineral soils, we measured soil physicochemical properties at increasing distances up to 8 metres from single, native (<i>Pinus sylvestris</i> L. or <i>Betula</i> spp.) naturally colonised trees in Cairngorms, Scotland, UK. Distance from single, native, naturally colonised trees was associated with increased soil moisture and decreased carbon-to-nitrogen and carbon-to-phosphorus ratios, but not associated with changes in bulk density, decomposition rates, or pH, in the organic horizon of organo-mineral soils. Sparse natural colonisation (in this study, 43 trees ha<sup>− 1</sup>) of organo-mineral soils has some, localised effects on the physicochemical properties of the organic horizon, which might affect biodiversity and hydrology in patches around trees. These effects did not extend beyond 2 metres distance from the trees. This suggests that early, sparse tree colonisation has minimal impacts on soil physicochemical properties at the ecosystem scale.</p></div>","PeriodicalId":805,"journal":{"name":"Trees","volume":"40 3","pages":""},"PeriodicalIF":2.1,"publicationDate":"2026-06-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC13230319/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148161625","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
TreesPub Date : 2026-05-24DOI: 10.1007/s00468-026-02776-5
Carol L. Wenzel, Anson Mo, Bonita Chan, Anny Xia, Chantelle Westgate, Rebecca Saunders, Han Han Ly, David M. Holloway
{"title":"Early development of stem units and the modular organization of the branch in Norway spruce","authors":"Carol L. Wenzel, Anson Mo, Bonita Chan, Anny Xia, Chantelle Westgate, Rebecca Saunders, Han Han Ly, David M. Holloway","doi":"10.1007/s00468-026-02776-5","DOIUrl":"10.1007/s00468-026-02776-5","url":null,"abstract":"<div><h3>Key message</h3><p>The modular organization of the conifer stem is established between needle primordia initiation in the bud through flush the subsequent spring, with elaboration on the early plan in following years.</p><h3>Abstract</h3><p>Plant stems are organized in modular units or phytomers, composed of a node (leaf or leaves), axillary bud and internode. In conifers, these modules, also termed stem units (SUs), develop over multiple growing seasons. Needle primordia are initiated in a vegetative bud at the distal end of a branch in the summer/fall of one year (Y1). This tissue then expands and differentiates during spring/summer flush the following year (Y2), generating the branch’s annual longitudinal growth. Previous studies explored the relation between the SU modules and overall stem length in Y2. We extend the work back into Y1, showing that stem length already depends, weakly but significantly, on needle count and SU length by the end of Y1. Needle count becomes a significantly stronger predictor of stem length in Y2. Longitudinal changes from the compact Y1 shoot apex to the extended Y2 stem are associated with radial tissue differentiation. Y1 needle primordia are initiated at the surface. Radial tissue layers are present but simple as flush begins in Y2. By the end of Y2 flush extension these have become far more differentiated, with distinct inner and outer cortex, vascular cambium, and localized lignification. SUs incorporate cells originally from the shoot apical meristem and the rib meristem and thus extend from the margin to the stem centre. This work provides new data on the early Y1 and Y2 developmental events that establish the modular organization of the branch.</p></div>","PeriodicalId":805,"journal":{"name":"Trees","volume":"40 3","pages":""},"PeriodicalIF":2.1,"publicationDate":"2026-05-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148009710","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
TreesPub Date : 2026-05-24DOI: 10.1007/s00468-026-02785-4
Yukine Fujioka, Maki Suzuki
{"title":"Disentangling the effects of tree size and light environment on reproductive onset and allocation in three sympatric wild Acer species","authors":"Yukine Fujioka, Maki Suzuki","doi":"10.1007/s00468-026-02785-4","DOIUrl":"10.1007/s00468-026-02785-4","url":null,"abstract":"<div><h3>\u0000 <b><i>Key message</i></b>\u0000 </h3><p><b>Flower production in three</b> <b><i>Acer</i></b> <b>species is primarily determined by individual size, with local light exerting secondary effects depending on species-specific responsiveness.</b></p><h3>Abstract</h3><p>Reproductive and growth strategies of long-lived trees depend on both the timing of reproductive onset and the regulation of reproductive allocation, which are shaped by internal and external factors. We investigated how flowering in three <i>Acer</i> species—<i>Acer mono</i>, <i>Acer japonicum</i>, and <i>Acer amoenum</i>—is influenced by individual size, light conditions, and position within the crown. Tree height and diameter at breast height (DBH) were measured along with light metrics (relative photosynthetic photon flux density [RPFD], canopy layer, and gap status), and their effects were evaluated at the individual, branch, and shoot levels. Statistical analyses showed that reproductive onset in <i>A. mono</i> and <i>A. japonicum</i> was primarily determined by tree size, whereas light conditions additionally influenced <i>A. amoenum</i>. Although tree-level flowering intensity was similarly affected by size and light across all species, species-specific trends appeared at the shoot and branch scales. <i>A. mono</i>, a light-demanding species, produced more flowers on current-year shoots with greater relative length (RL). No shoot-level trend was evident in <i>A. japonicum</i>, a shade-tolerant species. By contrast, <i>A. amoenum</i> produced more flowers on relatively short current-year shoots in partially shaded, growth-demanding trees, while flowering was more uniform in isolated trees. A light-manipulation experiment further supported the light-sensitive flowering of <i>A. amoenum</i>, highlighting the role of the red-to-far-red (R: FR) ratio, in contrast to the minor response of <i>A. mono</i>. Overall, size establishes the threshold for reproductive onset, while light regulates reproductive allocation; flowering patterns reflect species-specific strategies linking growth, reproduction, and light use.</p></div>","PeriodicalId":805,"journal":{"name":"Trees","volume":"40 3","pages":""},"PeriodicalIF":2.1,"publicationDate":"2026-05-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://link.springer.com/content/pdf/10.1007/s00468-026-02785-4.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148009711","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
TreesPub Date : 2026-05-22DOI: 10.1007/s00468-026-02777-4
Tamyris de Mello, Rachel Garcia Medeiros, Ingridh Medeiros Simões, Caroline Palacio de Araujo, Julcinara Oliveira Baptista, Thuanny Lins Monteiro, Breno Benvindo dos Anjos, Clovis Eduardo Nunes Hegedus, Tércio da Silva de Souza, Edilson Romais Schmildt, Adésio Ferreira, Márcio Paulo Czepak, João Paulo Bestete de Oliveira, Wagner Campos Otoni, José Carlos Lopes, Rodrigo Sobreira Alexandre
{"title":"Correction: From fruits to seeds: an integrated approach for the sustainable exploitation of Euterpe edulis Martius grown at different altitudes, with bibliometric, genotypic, morphophysiological and physicochemical analyses","authors":"Tamyris de Mello, Rachel Garcia Medeiros, Ingridh Medeiros Simões, Caroline Palacio de Araujo, Julcinara Oliveira Baptista, Thuanny Lins Monteiro, Breno Benvindo dos Anjos, Clovis Eduardo Nunes Hegedus, Tércio da Silva de Souza, Edilson Romais Schmildt, Adésio Ferreira, Márcio Paulo Czepak, João Paulo Bestete de Oliveira, Wagner Campos Otoni, José Carlos Lopes, Rodrigo Sobreira Alexandre","doi":"10.1007/s00468-026-02777-4","DOIUrl":"10.1007/s00468-026-02777-4","url":null,"abstract":"","PeriodicalId":805,"journal":{"name":"Trees","volume":"40 3","pages":""},"PeriodicalIF":2.1,"publicationDate":"2026-05-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://link.springer.com/content/pdf/10.1007/s00468-026-02777-4.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148009189","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
TreesPub Date : 2026-05-21DOI: 10.1007/s00468-026-02783-6
Josefa Fernández-López, Javier Fernández-Cruz, Beatriz Míguez-Soto, Roberto Carlos Costas-Gándara
{"title":"Male sterility in natural, domesticated and feral populations of the gynodioecious European chestnut (Castanea sativa)","authors":"Josefa Fernández-López, Javier Fernández-Cruz, Beatriz Míguez-Soto, Roberto Carlos Costas-Gándara","doi":"10.1007/s00468-026-02783-6","DOIUrl":"10.1007/s00468-026-02783-6","url":null,"abstract":"<div><p>European chestnut (<i>Castanea sativa</i> Mill.) has undergone centuries of selection for nut production, yet its domestication syndrome remains poorly characterised. This study investigates evolutionary shifts in sexual expression, genetic ancestry, and morphological traits across a human-impact gradient in Northwest Iberia: natural (Wild Atlantic), domesticated, and feral (Wild Inland) chestnut germplasm. We analysed 292 accessions using nuclear microsatellites and morphological characterisation of male catkin types, alongside several traits potentially related to female advantage and domestication. Genetic structure analysis highlighted a stark contrast between Wild Atlantic populations—dominated by North Iberian (Nib) ancestry and male-fertile (longistaminate) individuals—and Wild Inland/Domesticated groups, predominantly comprising intraspecific hybrids between Nib and Mediterranean demes exhibiting a high sex ratio (up to 89%). Our results reveal a clear functional signal associated with male sterility: male-sterile accessions exhibit significantly higher individual heterozygosity, higher fruit set (0.82 vs. 0.74), and 88% more female inflorescences per bisexual catkin (3.61 vs. 1.92) compared to fertile ones. Furthermore, we identified significant differences in male catkin length across sexual types, a finding that emerges when analysed across a diverse collection of wild trees of a similar age. These results provide robust evidence for the female advantage as a driver of chestnut domestication, indicating that selection for nut yield favoured male-sterile intraspecific hybrids stabilised through grafting. This study clarifies the anthropogenic evolutionary history of <i>C. sativa</i> and underscores the role of feral populations—genetic mosaics of Mediterranean and indigenous demes—as a source of new varieties.</p></div>","PeriodicalId":805,"journal":{"name":"Trees","volume":"40 3","pages":""},"PeriodicalIF":2.1,"publicationDate":"2026-05-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://link.springer.com/content/pdf/10.1007/s00468-026-02783-6.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148009601","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
TreesPub Date : 2026-05-16DOI: 10.1007/s00468-026-02781-8
Hanzhou Qiu, Peijian Shi, Danyu Zhou, Dirk Hölscher, Karl J. Niklas
{"title":"Variation in leaf shape affects the validity of the leaf area and length square-law relationship: evidence from the bamboo Semiarundinaria densiflora","authors":"Hanzhou Qiu, Peijian Shi, Danyu Zhou, Dirk Hölscher, Karl J. Niklas","doi":"10.1007/s00468-026-02781-8","DOIUrl":"10.1007/s00468-026-02781-8","url":null,"abstract":"<div><h3>\u0000 <b><i>Key message</i></b>\u0000 </h3><p><b>Leaf-shape variation significantly affects the robustness of the square relationship between leaf area and leaf length.</b></p><h3>Abstract</h3><p>Leaf area (<i>A</i>) for many broad-leaved plants is reported to be proportional to the product of leaf length (<i>L</i>) and width (<i>W</i>), which conforms with the Montgomery equation (ME), as shown by previous studies using leaves pooled from multiple individuals across species or from specific crown positions within a species. However, Thompson’s principle of similarity asserts that <i>A</i> ∝ <i>L</i><sup>2</sup>, which is referred to as the square-law equation (SLE). Given that leaf functional traits can vary as a function of crown position, the ME vs. SLE inconsistency can be resolved by sampling all leaves for each plant to test the influence of plant size on leaf shape, size, and their variation across plants. In this study, we sampled 121 <i>Semiarundinaria densiflora</i> culms, measured the lamina area of every leaf, and above-ground height of each culm to examine the validity of the ME and SLE, and the influence of culm size on leaf shape, size, and their variation. The data show that (i) the ME provides a better goodness-of-fit than the SLE, (ii) leaf-shape variation reduces the reliability of the SLE, and (iii) mean leaf area increases with increasing culm height. Thus, culm height affects leaf shape, leaf area, and therefore affects the performance of SLE. These findings indicate that mixed sampling from plants differing in height can potentially lead to biased assessments of leaf functional traits.</p></div>","PeriodicalId":805,"journal":{"name":"Trees","volume":"40 3","pages":""},"PeriodicalIF":2.1,"publicationDate":"2026-05-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148008982","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
TreesPub Date : 2026-05-13DOI: 10.1007/s00468-026-02780-9
Marco Garrido-Salinas, María José Peralta-Scholz, Cristian Ibáñez, Horacio Bown, Edmundo Acevedo
{"title":"Assessing the hydraulic strategy of Neltuma tamarugo: insights into the conservation of a key strict phreatophyte species under decline of the phreatic level in the Atacama Desert","authors":"Marco Garrido-Salinas, María José Peralta-Scholz, Cristian Ibáñez, Horacio Bown, Edmundo Acevedo","doi":"10.1007/s00468-026-02780-9","DOIUrl":"10.1007/s00468-026-02780-9","url":null,"abstract":"<div><p><i>Neltuma tamarugo</i> is a strict phreatophyte endemic to the Atacama Desert whose persistence is threatened by groundwater decline. To characterize its hydraulic strategy, we assessed stomatal conductance, leaf hydraulic conductance, and whole-plant hydraulic conductance under semi-controlled water stress, and analyzed the relationship between predawn and midday water potential under both semi-controlled and field conditions in the Llamara Salt Flat under contrasting levels of groundwater decline. Under semi-controlled conditions, stomatal closure and near-zero whole-plant hydraulic conductance occurred at very negative midday water potentials (approximately − 4.33 and − 4.49 MPa, respectively), well below the turgor loss point and leaf hydraulic P<sub>50</sub>, and close to leaf hydraulic P<sub>88</sub>. Water stress also reduced branch growth and leaf area, followed by leaf shedding. In both semi-controlled and field conditions, predawn and midday stem water potentials were strongly coupled, with slopes near unity and relatively large Hydroscape Areas, indicating predominantly anisohydric behavior. In the field, trees under severe groundwater decline showed a lower Ψ<sub>tlp</sub>, suggesting some acclimation, although midday water potentials still frequently fell below the turgor loss point. These results indicate that <i>N. tamarugo</i> maintains function under severe water deficit through anisohydric regulation and canopy-level adjustment. However, continued groundwater decline likely reduces functional performance and increases long-term mortality risk, highlighting the need to prevent further phreatic decline in this threatened species.</p></div>","PeriodicalId":805,"journal":{"name":"Trees","volume":"40 3","pages":""},"PeriodicalIF":2.1,"publicationDate":"2026-05-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"147938399","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
TreesPub Date : 2026-05-11DOI: 10.1007/s00468-026-02782-7
Marzieh Esmaiili, Ehsan Abdi, Elyas Hayati
{"title":"Seasonal modulation of root mechanical properties in contrasting tree species under uniform environmental conditions","authors":"Marzieh Esmaiili, Ehsan Abdi, Elyas Hayati","doi":"10.1007/s00468-026-02782-7","DOIUrl":"10.1007/s00468-026-02782-7","url":null,"abstract":"<div><h3>\u0000 <b><i>Key message</i></b>\u0000 </h3><p><b>Seasonal enhancement of root tensile strength in contrasting tree species indicates that environmental conditions, rather than species dormancy behavior, predominantly control root reinforcement potential in bioengineering applications.</b></p><h3>Abstract</h3><p>Root tensile strength is a critical factor in soil reinforcement and vegetation-based slope stabilization, yet its seasonal variability remains insufficiently explored, particularly among tree species with contrasting dormancy patterns. This study examined how root mechanical properties, in particular how tensile strength varies between leaf-off (winter) and leaf-on (summer) in two functionally distinct (evergreen vs. deciduous) tree species (i.e. <i>Picea abies</i> and <i>Fraxinus excelsior</i>), growing on adjacent hillslopes with uniform soil and climatic conditions in the Hyrcanian Forest, Iran. Live root samples were collected at 30 cm depth and tested using an Instron Universal Testing Machine to assess the tensile force and strength over a range of root diameters (0.32–4.97 mm). In both species, tensile force increased with diameter, while tensile strength decreased, following a power-law regression. More importantly, mean tensile strength was significantly higher in leaf-off than in leaf-on in both species. An ANCOVA further revealed a significant Season × Species interaction, indicating that although both species exhibited higher tensile strength during leaf-off, the magnitude of seasonal change differed between them. This seasonal enhancement is likely driven by physiological changes such as reduced moisture content and internal pressure during colder months. These results suggest that seasonal environmental conditions influence root mechanical properties in both functional types, while species-specific traits modulate the strength of this response. These findings provide a more comprehensive understanding of how seasonal dynamics affect root biomechanics and highlight importance of accounting for temporal variability when selecting species for bioengineering applications, particularly in environments with pronounced seasonal change.</p></div>","PeriodicalId":805,"journal":{"name":"Trees","volume":"40 3","pages":""},"PeriodicalIF":2.1,"publicationDate":"2026-05-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"147937876","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}