Responses of Seagrass Amphibolis antarctica Roots to Nutrient Additions Along a Salinity Gradient in Shark Bay, Western Australia

Husen Rifai, Firman Zulpikar, Muhammad Safaat, Jeverson Renyaan, Laode Alifatri, Asep Rasyidin


Seagrass meadows in oligotrophic environments are particularly susceptible to nutrient enrichment, yet morphological and architectural seagrass root responses in these ecosystems are poorly understood. This study aimed to investigate the response of Amphibolis antarctica, one of dominant seagrass species in Shark Bay, roots to nutrient additions along a salinity gradient in the oligotrophic ecosystem of Shark Bay, Western Australia. A fully factorial nutrient additional experiment with four treatments (Control, N, P and N+P) was conducted at each of five sites along a salinity gradient (between ~38ppt in site 1 and ~50ppt in site 5) in Shark Bay across a three-year period (2012-2015). In the laboratory, the roots morphology and architecture A. antarctica were investigated using a software (WinRhizo). Then, a two-way analysis of variance (ANOVA) was performed to investigate if there was a significant change in the morphology and architecture of the roots after the nutrient inputs and along five sites with salinity gradient. There was no significant impact of nutrient addition on the root’s morphology and architecture of A. antarctica species. However, the effect of site factor with salinity gradient was significant to all morphological aspects (total root length, root surface area and root diameter) of A. antarctica roots. These findings highlight the more ecological function of A. antarctica roots being in anchoring of the plant into the seafloor rather than to absorb nutrient from the sediment.

Keywords: Nutrient addition, Oligotrophic habitats, Amphibolis antarctica, Shark Bay

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Arias-Ortiz A, Serrano O, Masque P, Lavery PS, Mueller U, Kendrick GA, Rozaimi M, Esteban A, Fourqurean JW, et al (2018) 'A marine heatwave drives massive losses from the world's largest seagrass carbon stocks', Nature Climate Change, 8:338

Armitage AR, Frankovich TA, Fourqurean JW (2011) 'Long-Term Effects of Adding Nutrients to an Oligotrophic Coastal Environment', Ecosystems, 14:430-444

Atkinson MJ (1987) Low phosphorus sediments in a hypersaline marine bay. Estuarine, Coastal and Shelf Science 24:335–347

Carruthers TJB, Dennison WC, Kendrick GA, Waycott M, Walker DI, Cambridge ML (2007) Seagrasses of southwest Australia: A conceptual synthesis of the world's most diverse and extensive seagrass meadows. J Exp Mar Biol Ecol 350: 21–45

Charlton WA (1996) Lateral root initiation. In: Waisel Y,Eshel A, Kafkafi U (eds) Plant roots: the hidden half. Marcel Dekker, New York, NY, p 149–173

den Hartog C, Kuo J (2006) Taxonomy and biogeography of seagrasses. In : Larkum AWD, Orth RJ, Duarte CM (eds) Seagrasses : biology, ecology and conservation. Springer, The Netherlands, p 1-23

Duarte CM (1991) Seagrass depth limits. Aquat Bot 40: 363–377

Duarte CM, Chiscano CL (1999) Seagrass biomass and production: a reassessment. Aquat. Bot. 65:159–174

Duarte CM, Middelburg JJ, Caraco N (2005) Major role of marine vegetation on the oceanic carbon cycle. Biogeosciences 2:1–8

Easterling DR, Meehl GA, Parmesan C, Changnon SA, Karl TR, Mearns LO (2000) ‘Climate extremes: Observations, modeling, and impacts’, Science, vol. 289, no. 5487, p 2068-2074

Evrard V, Kiswara W, Bouma TJ, Middelburg JJ (2005) Nutrient dynamics of seagrass ecosystems: 15N evidence for the importance of particulate organic matter and root systems. Mar Ecol Prog Ser 295: 49−55

Fitter AH (1991) The ecological significance of root system architecture: an economic approach. In: Atkinson D (ed) Plant root growth: an ecological perspective. Blackwell Scientific Publishers, London, p 229−243

Fitter AH, Stickland TR (1991) Architectural analysis of plant root systems. 2. Influence of nutrient supply on architecture in contrasting plant species. New Phytol 118:383-3889

Fitter AH, Stickland TR, Harvey ML, Wilson GW (1991) Architectural analysis of plant root systems. 1. Architectural correlates of exploitation efficiency. New Phytol 118: 375−382

Fraser MW, Kendrick GA, Grierson PF, Fourqurean JW, Vanderklift MA, Walker DI (2012) 'Nutrient status of seagrasses cannot be inferred from system-scale distribution of phosphorus in Shark Bay, Western Australia', Marine and Freshwater Research, 63:1015-1026

Fraser MW, Kendrick GA, Statton J, Hovey RK, Zavala-Perez A,Walker DI (2014) 'Extreme climate events lower resilience of foundation seagrass at edge of biogeographical range', Journal of Ecology, 102:1528-1536

Fourqurean JW, Duarte CM, Kennedy H, Marba N, Holmer M, Mateo MA, Apostolaki ET, Kendrick GA, Krause-Jensen D, McGlathery K , Serrano O (2012) Global carbon stocks in seagrass ecosystems. Nature Geosciences, 5:505-509

Heck KL Jr, Hays C, Orth RJ (2003) Critical evaluation of the nursery role hypothesis for seagrass meadows. Mar Ecol Prog Ser 253:123–136

Hemminga MA, Duarte CM (2000) Seagrass ecology. Cambridge University Press, UK : 298 pp

Hodge A (2004) The plastic plant: root responses to heterogeneous supplies of nutrients. New Phytol 162: 9−24

Hovey RK, Cambridge ML, Kendrick GA (2011) 'Direct measurements of root growth and productivity in the seagrasses Posidonia australis and P-sinuosa', Limnology and Oceanography, 56:394-402

Hovey RK, Cambridge ML, Kendrick GA (2012) 'Season and sediment nutrient additions affect root architecture in the temperate seagrasses Posidonia australis and P. sinuosa', Marine Ecology Progress Series, 446:23-30.

Jansen C, Van De Steeg HM, De Kroon H (2005) Investigating a trade-off in root morphological responses to a heterogeneous nutrient supply and to flooding. Funct Ecol 19: 952−960

Kendrick GA, Fourqurean JW, Fraser MW, Heithaus MR, Jackson G, Friedman K, Hallac D (2012) 'Science behind management of Shark Bay and Florida Bay, two P-limited subtropical systems with different climatology and human pressures Introduction', Marine and Freshwater Research, 63:941-951

Kenneth AM (2004) Influence of Seagrasses on Water Quality in Shallow Regions of the Lower Chesapeake Bay. Journal of Coastal Research: Special Issue 45: p 162 –178.

Kilminster KL, Walker DI, Thompson PA, Raven JA (2006) Limited nutritional benefit to the seagrass Halophila ovalis, in culture, following sediment organic matter enrichment. Estuar Coast Shelf Sci 68: 675−685

Kiswara W, Behnke N, Van Avesaath P, Huiskes AHL, Erftemeijer PLA, Bouma TJ (2009) 'Root architecture of six tropical seagrass species, growing in three contrasting habitats in Indonesian waters', Aquatic Botany, 90:235-245.

Koch EW, Ackerman JD, Verduin J, van Keulen M (2006) Fluid dynamics in seagrass ecology — from molecules to ecosystems. In: Larkum, A.W.D, Orth, R.J., Duarte, C.M. (Eds.), Seagrass: Biology, Ecology and Conservation. Springer, The Netherlands, p 193–225

Logan BW, Cebulski DE (1970) Sedimentary environments of Shark Bay, Western Australia. In ‘Carbonate Sedimentation and Environments, Shark Bay, Western Australia’. (Ed. B. W. Logan.) p. 1–36. (The American Association of Petroleum.Geologists

Lynch J (1995) Root architecture and plant productivity. Plant Physiol 109: 7–13

Mckenzie LJ, Yoshida RL (2016) Seagrass-watch : Proceeding of a workshop for monitoring seagrass habitats in the Mackay Whitsunday Natural Resource Management Region, QPWS Whitsunday information centre, jubilee pocket, Airlie beach, 16-17 July 2016 (Seagrass-watch HQ, Cairns) 68 pp

Nagelkerken I, Roberts CM, Van der Velde G, Dorenbosch M, Van Riel MC, Cocheret de la Moriniere E, Nienhuis PH (2002) How important are mangroves and seagrass beds for coral-reef fi sh? The nursery hypothesis tested on an island scale. Marine Ecology Progress Series, 244: 299-305

Pierret A, Gonkhamdee S, Jourdan C, Maeght JL (2013) 'IJ_Rhizo: an open-source software to measure scanned images of root samples', Plant and Soil, vol. 373, no. 1-2, pp. 531-539

Robinson D (1994) The responses of plants to non-uniform supplies of nutrients. New Phytol 127: 635−674

Short F, Carruthers T, Dennison W, Waycott M (2007) 'Global seagrass distribution and diversity: A bioregional model', Journal of Experimental Marine Biology and Ecology, vol. 350, no. 1-2, pp. 3-20

Underwood AJ (1997) Experiments in ecology: their ecological design and interpretation using analysis of variance. Cambridge University Press, Cambridge

Walker DI, Kendrick GA, McComb AJ (1988) 'The distribution of seagrass species in Shark Bay, Western-Australia, with notes on their ecology', Aquatic Botany, 30:305-317

Yano K, Kume T (2005) Root morphological plasticity for heterogeneous phosphorus supply in Zea mays. Plant Prod Sci 8:427 – 432


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