Functional Plant Biology Functional Plant Biology Society
Plant function and evolutionary biology
RESEARCH ARTICLE

The anatomical basis of the link between density and mechanical strength in mangrove branches

Nadia S. Santini A , Nele Schmitz B C , Vicki Bennion A and Catherine E. Lovelock A D

A The School of Biological Sciences, The University of Queensland, St Lucia, Qld 4072, Australia.

B Laboratory for Plant Biology and Nature Management, Vrije Universiteit Brussel, Brussels 1050, Belgium.

C Laboratory for Wood Biology and Xylarium, Royal Museum for Central Africa, Leuvensesteenweg 13, 3080 Tervuren, Belgium.

D Corresponding author. Email: c.lovelock@uq.edu.au

Functional Plant Biology 40(4) 400-408 http://dx.doi.org/10.1071/FP12204
Submitted: 9 July 2012  Accepted: 17 November 2012   Published: 11 January 2013

Abstract

Tree branches are important as they support the canopy, which controls photosynthetic carbon gain and determines ecological interactions such as competition with neighbours. Mangrove trees are subject to high wind speeds, strong tidal flows and waves that can damage their branches. The survival and establishment of mangroves partly depend on the structural and mechanical characteristics of their branches. In addition, mangroves are exposed to soils that vary in salinity. Highly saline conditions can increase the tension in the water column, imposing mechanical stresses on the xylem vessels. Here, we investigated how mechanical strength, assessed as the modulus of elasticity (MOE) and the modulus of rupture (MOR), and density relate to the anatomical characteristics of intact mangrove branches from southeast Queensland and whether the mechanical strength of branches varies among mangrove species. Mechanical strength was positively correlated with density of mangrove intact branches. Mechanical strength (MOE) varied among species, with Avicennia marina (Forssk.) Vierh. branches having the highest mechanical strength (2079 ± 176 MPa), and Rhizophora stylosa Griff. and Bruguiera gymnorrhiza (L.) Savigny ex Lam. and Poiret having the lowest mechanical strength (536.8 ± 39.2 MPa in R. stylosa and 554 ± 58.2 MPa in B. gymnorrhiza). High levels of mechanical strength were associated with reductions in xylem vessel lumen area, pith content and bark content, and positively associated with increases in fibre wall thickness. The associations between mechanical strength and anatomical characteristics in mangrove branches suggest trade-offs between mechanical strength and water supply, which are linked to tree growth and survival.

Additional keywords: fibres, intact branches, modulus of elasticity, modulus of rupture, xylem vessels.


References

Augspurger C, Kelly CK (1984) Pathogen mortality of tropical tree seedlings: experimental studies of the effects of dispersal distance, seedling density, and light conditions. Oecologia 61, 211–217.
Pathogen mortality of tropical tree seedlings: experimental studies of the effects of dispersal distance, seedling density, and light conditions.CrossRef | open url image1

Australian Bureau of Meteorology (2012), ‘Australian Bureau of Meteorology home page.’ (Commonwealth of Australia: Canberra). Available at: http://www.bom.gov.au [Verified 22 November 2012]

Baldwin AH, Platt WJ, Gathen KL, Lessmann JM, Rauch TJ (1995) Hurricane damage and regeneration in fringe mangrove forests of Southeast Florida, USA. Journal of Coastal Research 21, 169–183.

Ball MC (1998) Mangrove species richness in relation to salinity and water logging: a case study along the Adelaide River floodplain, Northern Australia. Global Ecology and Biogeography Letters 7, 73–82.
Mangrove species richness in relation to salinity and water logging: a case study along the Adelaide River floodplain, Northern Australia.CrossRef | open url image1

Bardsley KN (1985) The effects of Cyclone Kathy on mangrove vegetation. In ‘Coasts and tidal wetlands of the Australian monsoon region’. (Eds KN Bardsley, JDS Davie, CD Woodroffe) pp. 167–183. (Australian National University North Australia Research Unit: Darwin)

Chave J, Muller-Landau HC, Baker TR, Easdale TA, Steege H, Webb CO (2006) Regional and phylogenetic variation of wood density across 2456 neotropical tree species. Ecological Applications 16, 2356–2367.
Regional and phylogenetic variation of wood density across 2456 neotropical tree species.CrossRef | open url image1

Chave J, Coomes D, Jansen S, Lewis S, Swenson N, Zanne A (2009) Towards a worldwide wood economics spectrum. Ecology Letters 12, 351–366.
Towards a worldwide wood economics spectrum.CrossRef | open url image1

Crawley MJ (2007) ‘The R book’. (John Wiley & Sons: Chichester)

Curran TJ, Gersbach LN, Edwards W, Krockenberger AK (2008) Wood density predicts plant damage and vegetative recovery rates caused by cyclone disturbance in tropical rainforest tree species of north Queensland, Australia. Austral Ecology 33, 442–450.
Wood density predicts plant damage and vegetative recovery rates caused by cyclone disturbance in tropical rainforest tree species of north Queensland, Australia.CrossRef | open url image1

Déjardin A, Laurans F, Arnaud D, Breton C, Pilate G, Leplé JC (2010) Wood formation in angiosperms. Comptes Rendus Biologies 333, 325–334.
Wood formation in angiosperms.CrossRef | open url image1

Enquist B, West G, Charnov E, Brown J (1999) Allometric scaling of production and life-history variation in vascular plants. Nature 401, 907–911.
Allometric scaling of production and life-history variation in vascular plants.CrossRef | 1:CAS:528:DyaK1MXntFyltr8%3D&md5=db87765029bb1d05575438ea844e4f56CAS | open url image1

Gere JM, Goodno BJ (2009) ‘Mechanics of materials.’ (Cengage Learning: Stamford)

Hacke U, Sperry J, Pockman W, Davis S, McCulloh K (2001) Trends in wood density and structure are linked to prevention of xylem implosion by negative pressure. Oecologia 126, 457–461.
Trends in wood density and structure are linked to prevention of xylem implosion by negative pressure.CrossRef | open url image1

Henriksson J (2001) Differential shading of branches or whole trees: survival, growth, and reproduction. Oecologia 126, 482–486.
Differential shading of branches or whole trees: survival, growth, and reproduction.CrossRef | open url image1

Jacobsen AL, Ewers FW, Pratt RB, Paddock WA, Davis SD (2005) Do xylem fibers affect vessel cavitation resistance? Plant Physiology 139, 546–556.
Do xylem fibers affect vessel cavitation resistance?CrossRef | 1:CAS:528:DC%2BD2MXhtVCgurvN&md5=094960f01a57a55274f48f1411d3e375CAS | open url image1

Jacobsen AL, Agenbag L, Esler KJ, Pratt RB, Ewers FW, Davis SD (2007) Xylem density, biomechanics and anatomical traits correlate with water stress in 17 evergreen shrub species of the Mediterranean-type climate region South Africa. Journal of Ecology 95, 171–183.
Xylem density, biomechanics and anatomical traits correlate with water stress in 17 evergreen shrub species of the Mediterranean-type climate region South Africa.CrossRef | open url image1

King DA, Davies SJ, Tan S, Noor NSMD (2006) The role of wood density and stem support costs in the growth and mortality of tropical trees. Journal of Ecology 94, 670–680.
The role of wood density and stem support costs in the growth and mortality of tropical trees.CrossRef | open url image1

Komiyama A, Poungparn S, Kato S (2005) Common allometric equations for estimating the tree weight of mangroves. Journal of Tropical Ecology 21, 471–477.
Common allometric equations for estimating the tree weight of mangroves.CrossRef | open url image1

Lewis A (1992) Measuring the hydraulic diameter of a pore or conduit. American Journal of Botany 79, 1158–1161.
Measuring the hydraulic diameter of a pore or conduit.CrossRef | open url image1

McKee KL, Mendelssohn IA, Hester MW (1988) Reexamination of pore water sulfide concentrations and redox potentials near the aerial roots of Rhizophora mangle and Avicennia germinans. American Journal of Botany 75, 1352–1359.
Reexamination of pore water sulfide concentrations and redox potentials near the aerial roots of Rhizophora mangle and Avicennia germinans.CrossRef | open url image1

Niklas KJ (1999) The mechanical role of bark. American Journal of Botany 86, 465–469.
The mechanical role of bark.CrossRef | 1:STN:280:DC%2BC3MnhtVKjsw%3D%3D&md5=315615984f013b643438a91f56998033CAS | open url image1

Niklas KJ, Spatz H (2010) Worldwide correlations of mechanical properties and green wood density. American Journal of Botany 97, 1587–1594.
Worldwide correlations of mechanical properties and green wood density.CrossRef | open url image1

Onoda Y, Richards AE, Westoby M (2010) The relationship between stem biomechanics and wood density is modified by rainfall in 32 Australian woody plant species. New Phytologist 185, 493–501.
The relationship between stem biomechanics and wood density is modified by rainfall in 32 Australian woody plant species.CrossRef | open url image1

Paling EI, Kobryn HT, Humphreys C (2008) Assessing the extent of mangrove change caused by Cyclone Vance in the eastern Exmouth Gulf, northwestern Australia. Estuarine, Coastal and Shelf Science 77, 603–613.
Assessing the extent of mangrove change caused by Cyclone Vance in the eastern Exmouth Gulf, northwestern Australia.CrossRef | open url image1

Pfanz H, Aschan G (2000) The existence of bark and stem photosynthesis and its significance for the overall carbon gain: an eco-physiological and ecological approach. Progress in Botany 62, 477–510.

Pratt R, Jacobsen A, Ewers F, Davis S (2007) Relationships among xylem transport, biomechanics and storage and roots of nine Rhamnaceae species of the California chaparral. New Phytologist 174, 787–798.
Relationships among xylem transport, biomechanics and storage and roots of nine Rhamnaceae species of the California chaparral.CrossRef | 1:STN:280:DC%2BD2s3ptlOjsQ%3D%3D&md5=8e7be5bb4d804e16c4e6d94410b76f69CAS | open url image1

Preston AK, Cornwell KW, DeNoyer JL (2006) Wood density and vessels traits as distinct correlates of ecological strategy in 51 California coast range angiosperms. New Phytologist 170, 807–818.
Wood density and vessels traits as distinct correlates of ecological strategy in 51 California coast range angiosperms.CrossRef | open url image1

Robert E, Schmitz N, Boeren I, Driessens T, Herremans K, De Mey J, Van de Casteele E, Beeckman H, Koedam N (2011) Successive cambia: a developmental oddity or an adaptive structure? PLoS ONE 6, e16558
Successive cambia: a developmental oddity or an adaptive structure?CrossRef | 1:CAS:528:DC%2BC3MXhvFahtL8%3D&md5=8ce7d5b11fc77bd134d2507f56cdc3bbCAS | open url image1

Santini NS, Schmitz N, Lovelock CE (2012) Variation in wood density and anatomy in a widespread mangrove species. Trees 26, 1555–1563.
Variation in wood density and anatomy in a widespread mangrove species.CrossRef | open url image1

Schweingruber FH, Borner A, Schulze ED (2008) ‘Atlas of woody plant stems. Evolution, structure, and environmental modifications’. (Springer: Jena)

Shi S, Huang Y, Zeng K, Tan F, He H, Huang J, Fu Y (2005) Molecular phylogenetic analysis of mangroves: independent evolutionary origins of vivipary and salt secretion. Molecular Phylogenetics and Evolution 34, 159–166.
Molecular phylogenetic analysis of mangroves: independent evolutionary origins of vivipary and salt secretion.CrossRef | 1:CAS:528:DC%2BD2cXhtVaqsb%2FL&md5=8dc032aa45b9148c608ad480b4aa89c8CAS | open url image1

Sterck FJ, Van Gelder A, Poorter L (2006) Mechanical branch constraints contribute to life-history variation across tree species in a Bolivian forest. Journal of Ecology 94, 1192–1200.
Mechanical branch constraints contribute to life-history variation across tree species in a Bolivian forest.CrossRef | open url image1

Sun Q, Lin P (1997) Wood structure of Aegiceras corniculatum and its ecological adaptations to salinity. Hydrobiologia 352, 61–65.
Wood structure of Aegiceras corniculatum and its ecological adaptations to salinity.CrossRef | open url image1

van Gelder H, Poorter L, Sterck F (2006) Wood mechanics, allometry, and life-history variation in a tropical rain forest tree comunity. New Phytologist 171, 367–378.
Wood mechanics, allometry, and life-history variation in a tropical rain forest tree comunity.CrossRef | 1:STN:280:DC%2BD28vksFansw%3D%3D&md5=c623eb504d4bacfb68531c750043c09dCAS | open url image1

Wagner KR, Ewers FW, Davis SD (1998) Tradeoffs between hydraulic efficiency and mechanical strength in the stems of co-occurring species of chaparral shrubs. Oecologia 117, 53–62.
Tradeoffs between hydraulic efficiency and mechanical strength in the stems of co-occurring species of chaparral shrubs.CrossRef | open url image1

Wainhouse D, Cross DJ, Howell RS (1990) The role of lignin as a defence against the spruce bark beetle Dendroctonus micans: effect on larvae and adults. Oecologia 85, 257–265.
The role of lignin as a defence against the spruce bark beetle Dendroctonus micans: effect on larvae and adults.CrossRef | open url image1

Whigham DF, Olmsted I, Cabrera Cano E, Harmon ME (1991) The impact of Hurricane Gilbert on trees, litterfall and woody debris in a dry tropical forest in the northeastern Yucatan Peninsula. Biotropica 23, 434–441.
The impact of Hurricane Gilbert on trees, litterfall and woody debris in a dry tropical forest in the northeastern Yucatan Peninsula.CrossRef | open url image1

Yáñez-Espinosa L, Angeles G, López-Portillo J, Barrales S (2009) Variación anatómica de la madera de Avicennia germinans en la laguna de La Mancha, Veracruz, México. Boletín de la Sociedad Botánica de México 85, 7–15.



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