English (United Kingdom)

https://curated-unify.zendy.io/wp-json/zendy-region/v1/featured_content/oa?rat=en

https://curated-unify.zendy.io/wp-json/zendy-region/v1/highlighted_journal/

Global: Zendy Plus annual

Presents the access of premium content as premium feature

Premium Content

Presents the keyphrase highlighting as premium feature

Keyphrase Highlighting

Presents the summarisation as premium feature

Summarisation

Insights

Presents the pdf analysis as premium feature

PDF Analysis

Presents the zaia usage as premium feature

ZAIA

Global: Zendy Plus monthly

Global: Zendy Tools annual

Global: Zendy Tools monthly

Global: Zendy Free Plan

As the proportion of sapwood (SW) transformed into heartwood (HW) is irregular both radially and longitudinally in trunks of Maritime pine ( Pinus pinaster Ait.), it has been suggested that HW formation is a developmental process, regulated internally within the tree. In trees where stem growth is eccentric due to stem lean or wind action, the number of annual growth rings of SW transformed into HW is greater on the compressed side of the tree. To determine the contribution to bending stiffness, if any, of this prematurely formed HW, four point bending tests were carried out on fresh HW and SW samples taken from the same growth ring, or neighbouring growth rings, at different cross-sectional positions at a height of 2 m from six 52-year-old Maritime pines. The mean (±s.e.) modulus of elasticity ( E ) was 7.6 ± 0.3 GPa (longitudinal direction) for all samples. No significant differences in E were found between HW and SW; thus HW does not play a significant mechanical role in bending stiffness. To test a second hypothesis that early HW formation on the compressed side of trees may maintain a constant, optimal volume of SW around the tree, the Pipe Model Theory was applied to 12 52-year-old leaning Maritime pines (angle of lean varied from 0–22°). The surface area ( S ) of the SW was determined at different heights up the trunk and correlated with crown surface area ( S crown ). Regressions between S SW and S crown were highly significant, thereby supporting the theory that HW formation and extension is controlled internally in Maritime pine. HW formation in Maritime pine then serves to maintain an optimal proportion of functional SW which is an important criterion for survival in a species often subjected to severe drought for long periods. Keywords Heartwood, sapwood, bending test, Pipe Model Theory, Pinus pinaster References LITERATURE CITED 1 RK Bamber Heartwood, its function and formation Wood Science and Technology 10 1976 1 8 2 I Beritognolo C Breton J-P Charpentier P Burtin P Label N Noël E Magel A Stokes C Jay-Allemand Activation of flavonoid metabolism in living sapwood cells is partly responsible for wood colour and durability: towards an original concept of heartwood extension in trees Proceedings of the 3 rd International Conference: The Tree, Montreal 2000 3 P Castèra Propriétés et usages du Pin maritime 1999 Editions ARBORA Bordeaux 4 J-F Dumail Propriétés du bois juvénile de Pin maritime P Castéra Propriétés et usages du Pin maritime 1999 Editions ARBORA Bordeaux 103 111 5 T Fourcaud Défauts de forme et structure interne du Pin maritime P Castéra Propriétés et usages du Pin maritime 1999 Editions ARBORA Bordeaux 77 84 6 C Gachet A Stokes F Salin C Jay-Allemand J-P Charpentier The role of ethylene and polyphenols in the formation of heartwood H-C Spatz T Speck Plant biomechanics 2000 2000 Georg Thieme Verlag New York 423 424 7 BL Gartner Structural stability and architecture of vines vs . shrubs of poison oak, Toxicodendron diversilobum Ecology 72 1991 2005 2015 8 WE Hillis Heartwood and tree exudates. Springer series in wood science 1987 Springer-Verlag Berlin, Heidelberg, New York 9 R Keller JC Mosnier Influence de l'écart à la verticalité des arbres sur pied sur la qualité du bois du pin maritime: observations sur la répartition du bois de compression et sur la place occupée par le duramen Actes du 2ème Colloque, Sciences et Industries du Bois 1987 Editions ARBOLA Nancy p. 225–231 10 AD Kokutse S Berthier A Stokes Formation et développement du bois de coeur P Castéra Propriétés et usages du Pin maritime 1999 Editions ARBORA Bordeaux 287 290 11 B Lemoine A Sartolou Les éclaircies dans les peuplements de Pin maritime d'age moyen Technique et Forêt 28 1976 447 457 12 PJ Marchand Sapwood area as estimator of biomass and projected leaf area for Abies balsamea and Picea rubens Canadian Journal of Forest Research 14 1983 85 87 13 J-P Maugé Le Pin maritime: premier résineux de France 1987 Editions IDF Paris 14 M Mencuccini J Grace M Fioravanti Biomechanical and hydraulic determinants of tree structure in Scots pine: anatomical characteristics Tree Physiology 17 1997 105 113 15 R Morataya G Galloway F Berninger M Kanninen Foliage biomass–sapwood (area and volume) relationships of Tectona grandis L.F. and Gmelina arborea Roxb.: silvicultural implications Forest Ecology and Management 113 1999 231 239 16 KJ Niklas Mechanical properties of Black locust ( Robinia pseudoacacia L.) wood. Size- and age-dependent variations in sap- and heartwood Annals of Botany 79 1997 265 272 17 KJ Niklas Size- and age-dependent variation in the properties of sap- and heartwood in Black locust ( Robinia pseudoacacia L.) Annals of Botany 79 1997 473 478 18 J Pardé J Bouchon Dendrométrie 1987 ENGREF Nancy p. 423–424 19 H Polge G Illy Observations sur l'anisotropie du Pin maritime des landes Annales des Sciences Forestières 24 1967 205 231 21 K Shinozaki K Yoda K Hozumi T Kira A quantitative analysis of plant form—The pipe model theory. Basic analyses Japanese Journal of Ecology 14 1964 97 105 22 K Shinozaki K Yoda K Hozumi T Kira A quantitative analysis of plant form—The pipe model theory. Further evidence of the theory and its application in forest ecology Japanese Journal of Ecology 14 1964 133 139 23 JS Sperry AH Perry J EM Sullivan Pit membrane degradation and air-embolism formation in ageing xylem vessels of Populus tremuloides Michx Journal of Experimental Botany 42 1991 1399 1406 24 R Spicer L Gartner Hydraulic properties of Douglas-fir ( Pseudotsuga menziesii ) branches and branch halves with reference to compression wood Tree Physiology 18 1998 777 784 25 A Stokes S Berthier Irregular heartwood formation in leaning stems of Maritime pine ( Pinus pinaster Ait.) is related to eccentric, radial stem growth Forest Ecology and Management 135 2000 115 121 26 A Stokes S Berthier N Nadhezdhina J Cermak D Loustau Sap flow in trees is influenced by stem movement H-C Spatz T Speck Plant biomechanics 2000 2000 Georg Thieme Verlag New York 272 277 32 FW Telewski Growth, wood density and ethylene production in response to mechanical perturbation in Pinus taeda Canadian Journal of Forest Research 20 1990 1277 1282 27 TE Timell Compression wood in gymnosperms. Springer series in wood science 1987 Springer-Verlag Berlin, Heidelberg, New York 28 SP Timoshenko Résistance des materiaux 1968 Dunod Paris 29 D Whitehead W RN Edwards PG Jarvis Conducting sapwood area, foliage area, and permeability in mature trees of Picea sitchensis and Pinus contorta Canadian Journal of Forest Research 14 1984 940 947 30 RH Waring PE Schroeder R Oren Application of pipe model theory to predict canopy leaf area Canadian Journal of Forest Research 12 1982 556 560 31 H Ziegler Biological aspects of heartwood formation Holz als Roh- und Werkstoff 26 1968 61 68

Irregular Heartwood Formation in Maritime Pine (Pinus pinaster Ait):Consequences for Biomechanical and Hydraulic Tree Functioning