- Email: [email protected]
Wood structure in plant biology and ecology
Dendrochronologia 32 (2014) 282–283
Contents lists available at ScienceDirect
Dendrochronologia journal homepage: www.elsevier.com/locate/dendro
Editorial
Wood structure in plant biology and ecology
The special section of this issue of Dendrochronologia contains five papers on research presented at The International Symposium on “Wood Structure in Plant Biology and Ecology”, held in Naples (Italy) on 17–20 April 2013. The symposium was organized by the Department of Agricultural and Food Sciences of the University of Naples Federico II and the Department of Environmental, Biological and Pharmaceutical Sciences and Technologies of the Second University of Naples, in cooperation with the Afro-European Group of the International Association of Wood Anatomists (IAWA), the Association of Treering Research (ATR) and on behalf of the COST Action FP1106 STReESS – Studying Tree Responses to extreme Events: a SynthesiS”. The main intention was to organize an interdisciplinary and interactive symposium around wood structure and its relevance in biological and ecological sciences. One aspect concerned updating participants on the latest findings in scientific disciplines working on different aspects of wood: such as xylogenesis, phenology, ecological and phylogenetic wood anatomy and ecophysiology, plant responses to climate change and tree-growth modeling. Other aspects included discussions of new concepts and methods in the different disciplines as well as the application of wood sciences in climatology, forest ecology and management for example to contribute to relevant issues such as the resilience of forest ecosystems and resource provision under changing climate conditions. The symposium sessions focused on: (1) ecological and evolutionary wood anatomy, with special attention to adaptive strategies of plants to environmental changes; (2) xylogenesis: genetics, ultrastructure and phenology related to the basic processes influencing wood formation; (3) tree-rings: climate variability and human impact, highlighting the potential of dendrochronology; (4) environmental changes and wood ecophysiology: emphasizing the relevance of long-term paleo observations and isotope records in environmental studies; (5) plant–water relations: from observed to modeled trends, specifically dedicated to the hydraulic properties of the xylem. From these sessions, five authors contributed research papers based on their talks for this special section of Dendrochronologia (Hroˇs and Vavrˇcík, 2014; Mazza et al., 2014; Piermattei et al., 2014; Seo et al., 2014; Von Arx and Carrer, 2014). This editorial will review the major findings of these papers related to the impact of global climate change on tree growth and http://dx.doi.org/10.1016/j.dendro.2014.07.004 1125-7865/© 2014 Published by Elsevier GmbH.
the application of new methods and approaches to expand current and future trends in tree-ring research. Trees are the most widespread and longest-living organisms on earth. In addition to providing great benefits to society in terms of resources, water protection and (local) climate control, trees form important archives as wood holds information on past changes in climate, forests and landscapes across large time scales. Recent work in the fields of ecology, climatology and forestry has shown that climate change will be one of the major challenges for forestry in future decades since it is expected to drastically modify growing conditions for trees and the composition of forests. It is imperative that we advance our understanding of what rules wood formation on an intra-annual timescale in order to process future scenarios of tree growth under changing environmental conditions. Three papers published in this special section used tree-rings to study the effects of climate change. Piermattei et al. (2014) reported a range-wide dendrochronology study of 658 samples of European black pine at four treeline ecotones of the Central Apennines in Italy. This study explored possible common patterns of the structural attributes of this species and assessed the influence of climate on the upward encroachment process of the pines. The findings bore out the hypothesis that the encroachment of this species above the current treeline is a recent non-linear natural process controlled by at least three different factors: (i) the presence of local seed sources of European black pine, a highly pioneering species, (ii) the decreased pressure of livestock grazing, and, possibly, (iii) the climate warming trend. Increasing the number of sites and species might clarify the observed ascending dynamics of the treeline ecotones and the specific contribution of climate change to explain this phenomenon. Mazza et al. (2014) investigated climate–growth relationships of Abies alba populations in beech forests of central Italy, taking into account different frequency domains. The authors found clear altitude-related responses to climate variables in silver-fir growth. They reported a negative correlation between summer temperature and tree-ring widths, suggesting that drought during the summer prior to growth was the most limiting factor. Further, changes of growth response to climate over time suggested that increased warming and the reduction of spring precipitation had a significant influence on tree growth over the past few decades. The authors concluded that genetic provenance
Editorial / Dendrochronologia 32 (2014) 282–283
may also be considered as a possible driver for variability and suggested that future studies should include analysis of genotypes within species. The importance of genetics in determining wood structure was also highlighted in the paper by Hroˇs and Vavrˇcík (2014), who presented a comparative analysis of tree-ring and wood-anatomy data to assess possible differences in Quercus robur and Quercus petraea, two co-existing oak species in the Czech Republic. The authors were motivated by a lack of specific research dealing with possible diagnostic features to distinguish these two oak species and succeeded in identifying “key parameters” related to vessel size and vessel distribution to differentiate between them. Specifically they confirmed that the average earlywood vessel area was higher in Q. robur than in Q. petraea. Conversely, the average area of vessels in the first row compared to the overall area of earlywood vessels of the growth ring was higher in Q. petraea. The last two papers of this special section are technical notes and report new ways to improve the measurement and analysis of wood-anatomical variables. In recent years, wood-anatomical variables have been recognized as a novel source of ecological information, however, despite the high potential interest, broad application to date has been constrained by methodological limitations and time-consuming procedures for data collection. In their technical note, Seo et al. (2014) focused on developing a strategy to efficiently make reliable measurements of tracheid variables along consecutive tree-rings. These records allow the climate–growth relationship to be calculated with high temporal resolution. The authors presented an interesting analysis to test how many radial tracheid rows have to be measured across each ring to come up with robust results to describe radial variation in tracheid variables. Their research was performed on Scots pine trees from three sites in northern Europe and they demonstrated that generally six radial rows of tracheids are sufficient to assess variation in lumen area, lumen diameter, cell-wall thickness and cell diameter with a confidence level of 90%. The authors recommend extending the number of studies and species in order to generalize the reported results. Finally, Von Arx and Carrer (2014) presented a new imageanalyses tool, ROXAS, to efficiently measure tracheid sizes and build long tracheid–lumen chronologies of entire increment cores. They showed how ROXAS automatically and accurately recognized almost all 75,000 tracheids in the 120-year sample core they selected for this evaluation. This was achieved in 3 h: from image capturing to mean tracheid–lumen data with annual resolution. Improving results manually did not significantly change most statistics and may therefore be unnecessary for most applications. The authors demonstrated how the efficiency and huge amount of data produced by the ROXAS analysis opens a door toward a completely new approach to whole-sample anatomical studies in conifers. All the papers reviewed here underline that dendrochronology is one of the most versatile disciplines in the biological and physical sciences and that the link with the wood anatomy and other disciplines could significantly expand its range of application. Treerings are unique in their ability to reveal long-term tree growth patterns in relation to environmental and climate change. Thus,
283
as things stand, it is crucial to integrate the knowledge from the various disciplines (ecology, biology, wood anatomy and genetics) to develop new indicators for assessing tree responses to climatic variations and generate a basic understanding of short to long-term physiological responses of tree species to changing environmental conditions. The Editor-in-Chief and Guest Editors would like to thank the authors for submitting their manuscripts and the reviewers for their reviews. We also wish to acknowledge the financial and logistical support received from the COST Action STReESS for the meeting.
Hroˇs, M., Vavrˇcík, H., 2014. Comparison of earlywood vessel variables in the wood of Quercus robur L. and Quercus petraea (Mattuschka) Liebl. growing at the same site. Dendrochronologia 32, 284–289. Mazza, G., Gallucci, V., Manetti, M.C., Urbinati, C., 2014. Climate–growth relationships of silver fir (Abies alba Mill.) in marginal populations of Central Italy. Dendrochronologia 32, 181–190. Piermattei, A., Garbarino, M., Urbinati, C., 2014. Structural attributes, tree-ring growth and climate sensitivity of Pinus nigra Arn. at high altitude: common patterns of a possible treeline shift in the central Apennines (Italy). Dendrochronologia 32, 210–219. Seo, J.W., Smiljanic, M., Wilmking, M., 2014. Optimizing cell-anatomical chronologies of Scots pine by stepwise increasing the number of radial tracheid rows included – case study based on three Scandinavian sites. Dendrochronologia 32, 205–209. Von Arx, G., Carrer, M., 1992. ROXAS – a new tool to build centuries-long tracheid–lumen chronologies in conifers. Dendrochronologia 32, 290–293.
Giovanna Battipaglia a,b,∗ Department of Environmental, Biological and Pharmaceutical Sciences and Technologies, Second University of Naples, via Vivaldi 43, 81100 Caserta, Italy b Ecole Pratique des Hautes Etudes (PALECO EPHE), Centre for Bio-Archaeology and Ecology, Institut de Botanique, F-34090 Montpellier, France a
Veronica De Micco Department of Agricultural and Food Sciences, University of Naples Federico II, via Università 100, I-80055 Portici, Naples, Italy Ute Sass-Klaassen Forest Ecology and Forest Management Group, Wageningen University, P.O. Box 47, 6700 AA Wageningen, The Netherlands Paolo Charubini WSL Swiss Federal Institute for Forest, Snow and Landscape Research, CH-8903 Birmensdorf, Switzerland ∗ Corresponding
author at: Department of Environmental, Biological and Pharmaceutical Sciences and Technologies, Second University of Naples, via Vivaldi 43, 81100 Caserta, Italy. Tel.: +39 0823 274647; fax: +39 0823 274605. E-mail address: [email protected] (G. Battipaglia)
Contents lists available at ScienceDirect
Dendrochronologia journal homepage: www.elsevier.com/locate/dendro
Editorial
Wood structure in plant biology and ecology
The special section of this issue of Dendrochronologia contains five papers on research presented at The International Symposium on “Wood Structure in Plant Biology and Ecology”, held in Naples (Italy) on 17–20 April 2013. The symposium was organized by the Department of Agricultural and Food Sciences of the University of Naples Federico II and the Department of Environmental, Biological and Pharmaceutical Sciences and Technologies of the Second University of Naples, in cooperation with the Afro-European Group of the International Association of Wood Anatomists (IAWA), the Association of Treering Research (ATR) and on behalf of the COST Action FP1106 STReESS – Studying Tree Responses to extreme Events: a SynthesiS”. The main intention was to organize an interdisciplinary and interactive symposium around wood structure and its relevance in biological and ecological sciences. One aspect concerned updating participants on the latest findings in scientific disciplines working on different aspects of wood: such as xylogenesis, phenology, ecological and phylogenetic wood anatomy and ecophysiology, plant responses to climate change and tree-growth modeling. Other aspects included discussions of new concepts and methods in the different disciplines as well as the application of wood sciences in climatology, forest ecology and management for example to contribute to relevant issues such as the resilience of forest ecosystems and resource provision under changing climate conditions. The symposium sessions focused on: (1) ecological and evolutionary wood anatomy, with special attention to adaptive strategies of plants to environmental changes; (2) xylogenesis: genetics, ultrastructure and phenology related to the basic processes influencing wood formation; (3) tree-rings: climate variability and human impact, highlighting the potential of dendrochronology; (4) environmental changes and wood ecophysiology: emphasizing the relevance of long-term paleo observations and isotope records in environmental studies; (5) plant–water relations: from observed to modeled trends, specifically dedicated to the hydraulic properties of the xylem. From these sessions, five authors contributed research papers based on their talks for this special section of Dendrochronologia (Hroˇs and Vavrˇcík, 2014; Mazza et al., 2014; Piermattei et al., 2014; Seo et al., 2014; Von Arx and Carrer, 2014). This editorial will review the major findings of these papers related to the impact of global climate change on tree growth and http://dx.doi.org/10.1016/j.dendro.2014.07.004 1125-7865/© 2014 Published by Elsevier GmbH.
the application of new methods and approaches to expand current and future trends in tree-ring research. Trees are the most widespread and longest-living organisms on earth. In addition to providing great benefits to society in terms of resources, water protection and (local) climate control, trees form important archives as wood holds information on past changes in climate, forests and landscapes across large time scales. Recent work in the fields of ecology, climatology and forestry has shown that climate change will be one of the major challenges for forestry in future decades since it is expected to drastically modify growing conditions for trees and the composition of forests. It is imperative that we advance our understanding of what rules wood formation on an intra-annual timescale in order to process future scenarios of tree growth under changing environmental conditions. Three papers published in this special section used tree-rings to study the effects of climate change. Piermattei et al. (2014) reported a range-wide dendrochronology study of 658 samples of European black pine at four treeline ecotones of the Central Apennines in Italy. This study explored possible common patterns of the structural attributes of this species and assessed the influence of climate on the upward encroachment process of the pines. The findings bore out the hypothesis that the encroachment of this species above the current treeline is a recent non-linear natural process controlled by at least three different factors: (i) the presence of local seed sources of European black pine, a highly pioneering species, (ii) the decreased pressure of livestock grazing, and, possibly, (iii) the climate warming trend. Increasing the number of sites and species might clarify the observed ascending dynamics of the treeline ecotones and the specific contribution of climate change to explain this phenomenon. Mazza et al. (2014) investigated climate–growth relationships of Abies alba populations in beech forests of central Italy, taking into account different frequency domains. The authors found clear altitude-related responses to climate variables in silver-fir growth. They reported a negative correlation between summer temperature and tree-ring widths, suggesting that drought during the summer prior to growth was the most limiting factor. Further, changes of growth response to climate over time suggested that increased warming and the reduction of spring precipitation had a significant influence on tree growth over the past few decades. The authors concluded that genetic provenance
Editorial / Dendrochronologia 32 (2014) 282–283
may also be considered as a possible driver for variability and suggested that future studies should include analysis of genotypes within species. The importance of genetics in determining wood structure was also highlighted in the paper by Hroˇs and Vavrˇcík (2014), who presented a comparative analysis of tree-ring and wood-anatomy data to assess possible differences in Quercus robur and Quercus petraea, two co-existing oak species in the Czech Republic. The authors were motivated by a lack of specific research dealing with possible diagnostic features to distinguish these two oak species and succeeded in identifying “key parameters” related to vessel size and vessel distribution to differentiate between them. Specifically they confirmed that the average earlywood vessel area was higher in Q. robur than in Q. petraea. Conversely, the average area of vessels in the first row compared to the overall area of earlywood vessels of the growth ring was higher in Q. petraea. The last two papers of this special section are technical notes and report new ways to improve the measurement and analysis of wood-anatomical variables. In recent years, wood-anatomical variables have been recognized as a novel source of ecological information, however, despite the high potential interest, broad application to date has been constrained by methodological limitations and time-consuming procedures for data collection. In their technical note, Seo et al. (2014) focused on developing a strategy to efficiently make reliable measurements of tracheid variables along consecutive tree-rings. These records allow the climate–growth relationship to be calculated with high temporal resolution. The authors presented an interesting analysis to test how many radial tracheid rows have to be measured across each ring to come up with robust results to describe radial variation in tracheid variables. Their research was performed on Scots pine trees from three sites in northern Europe and they demonstrated that generally six radial rows of tracheids are sufficient to assess variation in lumen area, lumen diameter, cell-wall thickness and cell diameter with a confidence level of 90%. The authors recommend extending the number of studies and species in order to generalize the reported results. Finally, Von Arx and Carrer (2014) presented a new imageanalyses tool, ROXAS, to efficiently measure tracheid sizes and build long tracheid–lumen chronologies of entire increment cores. They showed how ROXAS automatically and accurately recognized almost all 75,000 tracheids in the 120-year sample core they selected for this evaluation. This was achieved in 3 h: from image capturing to mean tracheid–lumen data with annual resolution. Improving results manually did not significantly change most statistics and may therefore be unnecessary for most applications. The authors demonstrated how the efficiency and huge amount of data produced by the ROXAS analysis opens a door toward a completely new approach to whole-sample anatomical studies in conifers. All the papers reviewed here underline that dendrochronology is one of the most versatile disciplines in the biological and physical sciences and that the link with the wood anatomy and other disciplines could significantly expand its range of application. Treerings are unique in their ability to reveal long-term tree growth patterns in relation to environmental and climate change. Thus,
283
as things stand, it is crucial to integrate the knowledge from the various disciplines (ecology, biology, wood anatomy and genetics) to develop new indicators for assessing tree responses to climatic variations and generate a basic understanding of short to long-term physiological responses of tree species to changing environmental conditions. The Editor-in-Chief and Guest Editors would like to thank the authors for submitting their manuscripts and the reviewers for their reviews. We also wish to acknowledge the financial and logistical support received from the COST Action STReESS for the meeting.
Hroˇs, M., Vavrˇcík, H., 2014. Comparison of earlywood vessel variables in the wood of Quercus robur L. and Quercus petraea (Mattuschka) Liebl. growing at the same site. Dendrochronologia 32, 284–289. Mazza, G., Gallucci, V., Manetti, M.C., Urbinati, C., 2014. Climate–growth relationships of silver fir (Abies alba Mill.) in marginal populations of Central Italy. Dendrochronologia 32, 181–190. Piermattei, A., Garbarino, M., Urbinati, C., 2014. Structural attributes, tree-ring growth and climate sensitivity of Pinus nigra Arn. at high altitude: common patterns of a possible treeline shift in the central Apennines (Italy). Dendrochronologia 32, 210–219. Seo, J.W., Smiljanic, M., Wilmking, M., 2014. Optimizing cell-anatomical chronologies of Scots pine by stepwise increasing the number of radial tracheid rows included – case study based on three Scandinavian sites. Dendrochronologia 32, 205–209. Von Arx, G., Carrer, M., 1992. ROXAS – a new tool to build centuries-long tracheid–lumen chronologies in conifers. Dendrochronologia 32, 290–293.
Giovanna Battipaglia a,b,∗ Department of Environmental, Biological and Pharmaceutical Sciences and Technologies, Second University of Naples, via Vivaldi 43, 81100 Caserta, Italy b Ecole Pratique des Hautes Etudes (PALECO EPHE), Centre for Bio-Archaeology and Ecology, Institut de Botanique, F-34090 Montpellier, France a
Veronica De Micco Department of Agricultural and Food Sciences, University of Naples Federico II, via Università 100, I-80055 Portici, Naples, Italy Ute Sass-Klaassen Forest Ecology and Forest Management Group, Wageningen University, P.O. Box 47, 6700 AA Wageningen, The Netherlands Paolo Charubini WSL Swiss Federal Institute for Forest, Snow and Landscape Research, CH-8903 Birmensdorf, Switzerland ∗ Corresponding
author at: Department of Environmental, Biological and Pharmaceutical Sciences and Technologies, Second University of Naples, via Vivaldi 43, 81100 Caserta, Italy. Tel.: +39 0823 274647; fax: +39 0823 274605. E-mail address: [email protected] (G. Battipaglia)