Trees最新文献

{"title":"Effect of water stress and UV-B on the production of outer stem waxes of Bulnesia retama seedlings from different eco-regions: alternatives for non-timber resources in drylands","authors":"Federico J. M. Peralta,&nbsp;Fidel A. Roig,&nbsp;Alejandra V. Medero,&nbsp;Carla V. Giordano","doi":"10.1007/s00468-024-02516-7","DOIUrl":"10.1007/s00468-024-02516-7","url":null,"abstract":"<div><h3>Key message</h3><p>The yield of epicuticular waxes of <i>Bulnesia retama</i> was increased mainly by water stress, and marginally by UV-B. Natural populations from the most stressful ecoregions showed higher productivity and plasticity.</p><h3>Abstract</h3><p><i>Bulnesia retama</i> is a tree/shrub endemic to the arid and semi-arid zones of South America. This species produces outer stem waxes that can be used in industry, and has been exploited in the past degrading natural populations. Considering the need to diversify marginal dryland economies by making sustainable use of local resources, we aimed to study the productivity of outer stem waxes of natural populations of <i>B. retama</i> from three eco-regions with different environmental stress (rainfall and altitude). We studied the wax productivity of the three populations in response to water stress and UV-B. We conducted two pot experiments with seedlings propagated from seeds of the different environmental backgrounds. We regulated water availability by differential irrigation and manipulated UV-B using selective absorbance filters. We collected stem waxes by the traditional method of brushing dry stems. We found that water stress was the main promoter of stem wax production in this species, while the effect of UV-B was marginal, and was only detected in combination with water stress. Seedlings from the most stressful eco-regions showed the highest stem wax productivity and were the most plastic to variations in environmental conditions<i>.</i> Environmental stress, particularly water stress, was the determining factor in the outer stem wax yield of this species, and in the productive potential of different natural populations, which could be related to ecotypes with different wax yield potential. This knowledge can be used for exploiting this resource sustainably, to select ecotypes for cultivation, and to develop productive varieties through classical breeding.</p></div>","PeriodicalId":805,"journal":{"name":"Trees","volume":"38 3","pages":"793 - 806"},"PeriodicalIF":2.1,"publicationDate":"2024-04-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140613439","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}

{"title":"Variation of anatomical characteristics of Nothofagus alpina wood grown under three silvicultural conditions","authors":"Angela Aucapán,&nbsp;Maximilian Wentzel,&nbsp;Alfredo Aguilera,&nbsp;Aldo Rolleri","doi":"10.1007/s00468-024-02515-8","DOIUrl":"10.1007/s00468-024-02515-8","url":null,"abstract":"<div><h3>Key message</h3><p>There were significant differences in the anatomical characteristics of Nothofagus alpina between the site with silvicultural condition similar to a regrowth forest, and with the sites with plantation regime.</p><h3>Abstract</h3><p><i>Nothofagus alpina</i> has been a species of interest due to the high quality of its wood. To evaluate the early use of this wood in plantation regimes, wood from intermediate cuts has to be studied. Therefore, the variations in some anatomical characteristics of juvenile wood obtained from thinning of <i>N. alpina</i> trees growing under three different silvicultural conditions were evaluated. Using the decreasing granulometry sanding technique, wood samples were prepared to capture images from the transverse plane using reflectance microscopy. The anatomical characteristics considered in this work vary, from pith to bark, with statistically significant differences being found in the position closest to the bark. On the other hand, there were some similarities between the specimens that came from sites with a plantation regime and differences with the sites similar to a regrowth forest. Therefore, the possible impact of silvicultural conditions on the anatomical characteristics of <i>N. alpina</i> wood was pointed out, mainly the diameter of the vessels and wall thickness.</p></div>","PeriodicalId":805,"journal":{"name":"Trees","volume":"38 3","pages":"767 - 776"},"PeriodicalIF":2.1,"publicationDate":"2024-04-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140592256","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}

{"title":"A systematic review of leaf and wood traits in the Neotropics: environmental gradients and functionality","authors":"Gustavo Viana de Freitas,&nbsp;Maura Da Cunha,&nbsp;Angela Pierre Vitória","doi":"10.1007/s00468-024-02508-7","DOIUrl":"10.1007/s00468-024-02508-7","url":null,"abstract":"<div><h3>Key message</h3><p>Resource-limited environments showed a tendency towards conservative and coupled leaf and wood traits, while displaying an acquisitive and decoupled pattern in resource-rich ones. Water and elevation were the most studied gradients.</p><h3>Abstract</h3><p>In the Neotropics, spatial and temporal environmental gradients subject plants to distinct abiotic conditions, requiring functional adjustments. This promotes changes in trait expression, resulting in individual trait variation or covariation. We have systematically reviewed the literature focusing on leaf and wood traits in the Neotropics along major abiotic gradients (water, irradiance, temperature, soil fertility, and elevation), and assessed their spatial and temporal variation and covariation trends. Thus, we compiled 141 published papers from 2010 to 2022. Most of the studies of leaf and wood traits were related to: (1) the gradients of water avalability and elevation, (2) leaf traits at the expense of wood traits, with specific leaf area and wood density the most studied traits, respectively, (3) the morphological leaf traits to a greater extent than to biochemical, ecophysiological, or anatomical ones. In general, more conservative traits were observed in environments with lower resource availability. Although there is still no consensus, coupling was predominantly linked to water balance during periods of water restriction or in dry ecosystems, and papers have focused on single ecosystems rather than making comparisons across multiple ecosystems. This systematic review highlights the tendency for systems with fewer resources to show a bias towards greater coordination between leaf and wood traits compared to systems with more resources. This review also adresses how traits are expressed based on the integration of more than one environmental driver and the qualitative variation of these resources. Finally, we emphasize the importance of analyzing different aspects of trait expression when assessing species’ responses to environmental gradients, especially in megadiverse regions such as the Neotropics.</p></div>","PeriodicalId":805,"journal":{"name":"Trees","volume":"38 3","pages":"551 - 572"},"PeriodicalIF":2.1,"publicationDate":"2024-04-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140592388","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}

{"title":"Could different structural features affect flammability traits in Mediterranean forest ecosystems?","authors":"Onofrio Cappelluti,&nbsp;Mario Elia,&nbsp;Giovanni Sanesi","doi":"10.1007/s00468-024-02513-w","DOIUrl":"10.1007/s00468-024-02513-w","url":null,"abstract":"<div><h3>Key message</h3><p>Mediterranean forest stands manifest diverse flammability traits according to their potential ecological successional stage and promoting a gradient from flammable to less flammable ecosystem.</p><p>From a general consideration of vegetation as ‘fuel’, it has been well proven that plant traits have the potential to promote the forest stand gradient from flammable to less flammable. While the ever-growing literature helps to assess the relationship between plants and their flammability at species level, at the landscape scale this relationship should be evaluated along with a variety of forest features such as structural and stand parameters and from the perspective of successional forest stages. To this end, we clustered several forest stands in Southern Europe (Apulia region, Italy), characterized by oaks, conifers, and arboreal shrub species, according to their flammability traits. We hypothesized that flammability traits change along different horizontal and vertical structural features of forest stands, shifting from high to low-flammability propensity. The results confirmed that forest stands with greater height and diameter classes are associated with traits with a low-flammability propensity. It is worth highlighting the importance of shrub coverage in differentiating the clusters denoting their strong influence in increasing fuel load (litter and fuel bed traits). Finally, our findings lead us to assume that high-flammability propensity traits are associated with typical pioneer successional stages, supporting the notion that later successional forest stands are less flammable and, therefore, that flammability decreases along with succession.</p></div>","PeriodicalId":805,"journal":{"name":"Trees","volume":"38 3","pages":"753 - 765"},"PeriodicalIF":2.1,"publicationDate":"2024-03-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://link.springer.com/content/pdf/10.1007/s00468-024-02513-w.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140325453","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}

{"title":"Climate triggers and growth effects of cold damage in silver fir (Abies alba Mill.) populations from Eastern Carpathians","authors":"Anca Semeniuc Fecioru,&nbsp;Maria Teodosiu,&nbsp;Anca Botezatu","doi":"10.1007/s00468-024-02505-w","DOIUrl":"10.1007/s00468-024-02505-w","url":null,"abstract":"<div><h3>Key message</h3><p>At the eastern range limit of silver fir, there is moderate population differentiation in tolerance to frost damages. Differentiated management measures accounting for climate change are required, as some populations are not responding similar to drought and frost damage.</p><h3>Abstract</h3><p>Under ongoing climate change, it is expected that in Europe 35% of forests will be at risk of frost, especially in the eastern part. In trees, frost effects are imprinted in rings and our study was conducted in juvenile individuals of silver fir from a trial comprising nine provenances from the eastern species distribution range. We analyzed the main characteristics of frost rings, their climate determinants and influence on height growth. Compared with other species, we found a slightly higher proportion of frost rings, and that the tracheid form was significantly influenced by the position within the ring and the intensity of damage. The climate covariates best explaining the frost damage in the initial and late frost rings were the March minimum temperature and the May mean temperature, respectively. A test of local adaptation indicated two characteristics related to the climatic determined late frost—the growing degree days accumulations until late frost and its day of the year, as significant triggers of the initial and late frost rings. In the initial frost ring, the height growth was negatively influenced by the proportion of annual rings affected over 50% by frost; in the late frost ring, an unexpected-positive influence on height growth of the proportion of total damaged annual rings was identified, possibly related to favorable growing seasons with prolonged autumn activity. Our study identified differentiation between provenances, which was more evident in the initial frost ring, suggesting maladaptation of eastern populations to frost-related events.</p></div>","PeriodicalId":805,"journal":{"name":"Trees","volume":"38 3","pages":"667 - 679"},"PeriodicalIF":2.1,"publicationDate":"2024-03-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140317024","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}

{"title":"Spatiotemporal variation of bark pH on the bole of a mature Cryptomeria japonica D. Don (Japanese cedar) tree","authors":"Desmond C. C. Teh,&nbsp;Delphis F. Levia,&nbsp;Taro Nakai","doi":"10.1007/s00468-024-02498-6","DOIUrl":"10.1007/s00468-024-02498-6","url":null,"abstract":"<div><h3>Key Message</h3><p>The agar–agar panel method identified circumferential, vertical, and temporal variations in the bark pH of a Japanese cedar tree in detail, including high-resolution distribution reflecting the bark’s microrelief.</p><h3>Abstract</h3><p>The morphology of bark surfaces is heterogeneous on any given tree, especially rough-barked trees, often changing along a vertical gradient from top to bottom and circumferentially. This study sought to better understand the intricacies of the spatiotemporal changes of bark pH distribution on the bole of a mature <i>Cryptomeria japonica</i> D. Don (Japanese cedar) tree in Taiwan by using agar–agar panels. Agar–agar panels were positioned at the four cardinal directions at seven different heights along the tree bole on six separate sampling dates (<span>(n = 134)</span>) to study the temporal variation of bark pH, while an additional 48.5 agar–agar panels were arranged radially at three tree heights (in zones 2 (30 m), 4 (20 m), and 7 (5 m)) to study the circumferential variation of bark pH. The changes in bark pH were found to vary across time, direction, height, and circumferential position, presumably due to the abiotic factors (e.g., fog) prior to sampling as well as changes in bark morphological patterns around the tree bole. This study demonstrates the highly dynamic temporal and spatial variability of bark pH. In particular, bark pH was found to be lower in the furrows as compared to the bark ridges, albeit with differing pH at different times. Future work should couple the use of agar–agar panels with mathematical modeling to quantify the interrelationships among bark morphology, bark pH, solute leaching, and mass flux along the complex network of interconnected furrows and ridges of tree stems.</p></div>","PeriodicalId":805,"journal":{"name":"Trees","volume":"38 3","pages":"591 - 605"},"PeriodicalIF":2.1,"publicationDate":"2024-03-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140310984","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}

{"title":"Physiological characteristics of pistil abortion in Prunus sibirica","authors":"Jianhua Chen,&nbsp;Jian Zhang,&nbsp;Yuncheng Zhang,&nbsp;Quangang Liu,&nbsp;Pengkai Wang,&nbsp;Yongqiang Sun,&nbsp;Shengjun Dong","doi":"10.1007/s00468-024-02504-x","DOIUrl":"10.1007/s00468-024-02504-x","url":null,"abstract":"<div><h3>Key message</h3><p>Pistil abortion in <i>Prunus sibirica</i> was associated with insufficient supply of nutrient, auxins, and gibberellins in flower buds, which promotes pistil development, and accumulation of cytokinins, which inhibits pistil development.</p><h3>Abstract</h3><p><i>Prunus sibirica</i> is an important ecological and economic tree species with high utilization potential and broad application prospects. However, pistil abortion affects its fruit setting, yield, and quality, restricting its industrial development. In this study, the type and stage of pistil abortion in <i>P. sibirica</i> were identified using flower buds with abortive and fertile pistil. The effects of different nutrients and endogenous hormones on pistil abortion were analyzed. The pistil abortion type of <i>P. sibirica</i> clone belonged to abnormal style structure, and the key stage of pistil abortion was the dew white stage, characterized by pistil degeneration and dissolution at the dew white stage and complete pistil disintegration and disappearance at the full blooming stage. The soluble protein, soluble sugar, and total sugar contents of flower buds with abortive pistils were significantly lower than those of flower buds with fertile pistils at the dew white, initial blooming, and full blooming stages. Among the 44 hormones detected in flower buds of <i>P. sibirica</i>, majority were cytokinins (CKs 25), followed by auxins (13). At the dew white stage, the CK content in flower buds with abortive pistils was significantly higher than that in flower buds with fertile pistils. Pistil abortion in <i>P. sibirica</i> was mainly due to insufficient supply of soluble protein, soluble sugar, and total sugar in flower buds; insufficient supply of auxins and gibberellins, which promotes pistil development; and accumulation of cytokinins, which inhibits pistil development.</p></div>","PeriodicalId":805,"journal":{"name":"Trees","volume":"38 3","pages":"655 - 666"},"PeriodicalIF":2.1,"publicationDate":"2024-03-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140310905","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}

{"title":"How beech provenance affects the structure of secondary xylem, leaf traits, and the ectomycorrhizal community under optimal growth conditions","authors":"Tanja Mrak,&nbsp;Jožica Gričar,&nbsp;Tina Unuk Nahberger,&nbsp;Gregor Božič,&nbsp;Luka Krajnc,&nbsp;Peter Prislan,&nbsp;Domen Arnič,&nbsp;Tom Levanič,&nbsp;Hojka Kraigher","doi":"10.1007/s00468-024-02502-z","DOIUrl":"10.1007/s00468-024-02502-z","url":null,"abstract":"<div><h3>Key message</h3><p>Provenance controls conductive area of stem secondary xylem, leaf area, and stable isotope (C, N, and O) ratios of beech leaves, while no significant effects were observed for ectomycorrhizal community composition.</p><h3>Abstract</h3><p>Beyond growth parameters and drought tolerance, comparatively little is known about the functioning of different beech (<i>Fagus sylvatica</i> L.) provenances. We investigated properties of leaves, stem secondary xylem, and ectomycorrhiza (ECM), and explored their interdependencies to identify the best performing beech provenance in optimal growth conditions. The study was conducted on 23-year-old trees in a provenance trial. The investigated provenances originated from Atlantic (Belgium—BE), Alpine (Italy—IT, Slovenia—SI), and continental climates (the Czech Republic—CZ). A significant effect of provenance was observed for stem vessel diameters and conductive area, as well as for foliar %C, δ¹³C, δ¹⁵N, and δ¹⁸O. δ¹³C as a proxy of intrinsic water use efficiency (iWUE) showed that the highest iWUE was achieved in BE provenance. Individuals with a better iWUE had wider growth rings regardless of provenance. Better iWUE was associated with lower specific leaf area (SLA). ECM community composition and diversity indices did not differ significantly among the provenances. Specific ECM taxa were associated with individuals with high SLA, δ¹³C, δ¹⁵N, and δ¹⁸O. In optimal growth conditions with no stress events, BE is a promising provenance due to an efficient water conducting system with high vessel diameters and conductive area, and high iWUE, while Alpine provenances showed an adaptation of their water conducting system to freezing conditions at their original locations. Integrating findings from different compartments improves our understanding of functioning of different beech provenances.</p></div>","PeriodicalId":805,"journal":{"name":"Trees","volume":"38 3","pages":"637 - 653"},"PeriodicalIF":2.1,"publicationDate":"2024-03-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://link.springer.com/content/pdf/10.1007/s00468-024-02502-z.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140298526","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}

{"title":"Physiological and transcriptome analysis provided insights for the response of yellowhorn to drought stress","authors":"Yingying Yang,&nbsp;Xiaojuan Liu,&nbsp;Huihui Xu,&nbsp;Zhuo Ban,&nbsp;Ziquan Zhao,&nbsp;Quanxin Bi,&nbsp;Libing Wang","doi":"10.1007/s00468-024-02511-y","DOIUrl":"10.1007/s00468-024-02511-y","url":null,"abstract":"<div><h3>Key message</h3><p>This study not only provide a theoretical basis for screening drought-resistant yellowhorn rootstocks but also lay the foundation for the research on the drought resistance mechanism of yellowhorn.</p><h3>Abstract</h3><p>Drought is a major limiting factor in the production and cultivation of yellowhorn, an important woody oil species in China. It is important to select excellent drought-resistant rootstocks, and the current reproduction of rootstocks of yellowhorn is mainly through seed propagation. In this study, we analyzed the phenotypes, physiology and anatomy of the F1 generation of five yellowhorn varieties (‘Zhongshi 1’, ‘Zhongshi 4’, ‘Zhongshi 7’, ‘Zhongshi 9’ and ‘Yuanda’) which are currently the main promoted varieties of yellowhorn. The changes in physiological traits were used to comprehensively rank drought resistance by the membership function method. The results showed that the drought resistance of different varieties was in the order ‘Zhongshi 9’ &gt; ‘Zhongshi 4’ &gt;  ‘Yuanda’ &gt;  ‘Zhongshi 7’ &gt;  ‘Zhongshi 1’. In addition, we investigated the molecular signature of two yellowhorn varieties exhibiting a large difference in levels of drought resistance using transcriptome data. A total of 119 differentially expressed genes (DEGs) were found between the 2 yellowhorn varieties under drought stress. Based on KEGG analysis, DEGs were mostly enriched in three pathways. According to the correlation analysis between weighted gene co-expression network analysis (WGCNA) and physiological traits, a total of four co-expression networks with high correlation were constructed, and some hub genes of yellowhorn in response to drought stress were found. We carried out a comprehensive evaluation of yellowhorn drought tolerance based on parental lines. It solves the current problems faced in the breeding of yellowhorn and lays the foundation for studying the molecular mechanism of drought resistance in yellowhorn.</p></div>","PeriodicalId":805,"journal":{"name":"Trees","volume":"38 3","pages":"725 - 742"},"PeriodicalIF":2.1,"publicationDate":"2024-03-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140204203","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}

{"title":"Xylem safety in relation to the stringency of plant water potential regulation of European beech, Norway spruce, and Douglas-fir trees during severe drought","authors":"Katja Schumann,&nbsp;Bernhard Schuldt,&nbsp;Miriam Fischer,&nbsp;Christian Ammer,&nbsp;Christoph Leuschner","doi":"10.1007/s00468-024-02499-5","DOIUrl":"10.1007/s00468-024-02499-5","url":null,"abstract":"<div><h3>Key message</h3><p>Norway spruce operates with larger hydraulic safety margins (HSM) than beech and Douglas-fir despite the known drought sensitivity of spruce, questioning a pivotal role of HSM in drought tolerance.</p><h3>Abstract</h3><p>The exceptional 2018/2019 drought exposed Central Europe’s forests to severe stress, highlighting the need to better understand stomatal regulation strategies and their relationship to xylem safety under extreme drought. We studied diurnal, seasonal, and inter-annual variation in stomatal conductance (<i>g</i>_s) and leaf water potential (<i>Ψ</i>_Leaf) in co-occurring European beech (<i>F. sylvatica</i>), Norway spruce (<i>P. abies</i>), and Douglas-fir (<i>P. menziesii</i>) trees in the two summers and related them to hydraulic traits characterizing drought resistance. In 2018, <i>F. sylvatica</i> exhibited a continuous <i>Ψ</i>_Leaf decline from June to September, as is characteristic for an anisohydric strategy, while <i>P. abies</i> closed stomata early and reached the least negative <i>Ψ</i>_Leaf-values at the end of summer. <i>P. menziesii</i> showed low <i>Ψ</i>_Leaf-values close to <i>P</i>₁₂ (the xylem pressure at onset of embolism) already in July. Both conifers closed stomata when approaching <i>P</i>₁₂ and maintained low <i>g</i>_s-levels throughout summer, indicative for isohydric regulation. In 2019, all three species showed a linear decline in <i>Ψ</i>_Leaf, but <i>F. sylvatica</i> crossed P₁₂ in contrast to the conifers. The three species exhibited similar water potentials at turgor loss point (− 2.44 to − 2.51 MPa) and branch <i>P</i>₅₀ (xylem pressure at 50% loss of hydraulic conductance; − 3.3 to − 3.8 MPa). Yet, <i>F. sylvatica</i> and <i>P. menziesii</i> operated with smaller hydraulic safety margins (HSM means: 0.79 and 0.77 MPa) than <i>P. abies</i> (1.28 MPa). <i>F. sylvatica</i> reduced leaf size and specific leaf area in 2019 and increased Huber value. Our species comparison during extreme drought contradicts the general assumption that conifers operate with larger HSMs than angiosperm trees. Contrary to expectation, <i>P. abies</i> appeared as hydraulically less vulnerable than Douglas-fir.</p></div>","PeriodicalId":805,"journal":{"name":"Trees","volume":"38 3","pages":"607 - 623"},"PeriodicalIF":2.1,"publicationDate":"2024-03-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://link.springer.com/content/pdf/10.1007/s00468-024-02499-5.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140204204","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}