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Marine Environmental Research 87-88 (2013) 96e102

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Marine Environmental Research

journal homepage: www.elsevier.com/locate/marenvrev

Effect of different substrata on rhizome growth, leaf biometry and
shoot density of Posidonia oceanica

G. Di Maida a, A. Tomasello a,*, M. Sciandra b, M. Pirrotta a, M. Milazzo a, S. Calvo a

a Dipartimento di Scienze della Terra e del Mare (DiSTeM), Università degli Studi di Palermo, Viale delle Scienze Ed. 16, 90128, Palermo, Italy
b Dipartimento di Scienze Economiche, Aziendali e Statistiche (SEAS), Università degli Studi di Palermo, Viale delle Scienze Ed. 13, 90128, Palermo, Italy

article info abstract

Article history: The effects of different substratum typologies on Posidonia oceanica growth and morphology were
Received 30 January 2013 estimated in four Sicilian meadows using Generalized and Linear Mixed Models combined with retro-
Received in revised form dating and biometric analyses. Substratum exerted a multiple effect, resulting in different biometric
29 March 2013 features for P. oceanica shoots settled on rock from those growing on sand and matte. On rock, values for
Accepted 2 April 2013 growth rate, leaf length and shoot surface were lower than those on other substrata, with 42%, 23% and
32% the highest degree of difference respectively. The present study may have interesting methodo-
Keywords: logical consequences for the comprehensive understanding of the causative variables potentially
Biomonitoring affecting meadows features and their health status. The importance of substratum in the prediction of
Benthic ecology likely biometry changes in P. oceanica meadows, means that knowledge of substratum type should
Seagrass receive due attention in the future to derive reliable estimates of meadow status.
Posidonia oceanica
Substratum Ó 2013 Elsevier Ltd. All rights reserved.
Lepidochronology
Leaf biometry
Shoot age
GLMM
LMM

1. Introduction crevices (Bellan-Santini et al., 1994; Hemminga and Duarte, 2000;
Mazzella et al., 1993). P. oceanica meadows can also develop on
The seagrass Posidonia oceanica (L.) Delile forms the most matte, a typical terraced formation built up by itself, consisting of
common and widespread meadows of the Mediterranean Sea intertwined rhizomes, roots and sediment (Boudouresque and
(Mazzella et al., 1993) likely representing the marine ecosystem Meinesz, 1982). Several studies have highlighted the importance
with the highest levels of biodiversity and productivity (Bell and of substratum features on the distribution and colonization of
Harmelin-Vivien, 1982; Bellan-Santini et al., 1994; Boudouresque, P. oceanica, as well as on its morphology and growth dynamics (De
2004; Boudouresque and Meinesz, 1982; Hemminga and Duarte, Falco et al., 2008; Di Carlo et al., 2005, 2006, 2007; Marbà and
2000; Mazzella et al., 1992). The development of these meadows Duarte, 1997).
requires stable environmental conditions (Gobert et al., 2006) and
their distribution is strictly related to a complex interaction of bi- Leaf compartment and biomass allocation have been examined
otic and abiotic factors (Hemminga and Duarte, 2000). Indeed, by comparing P. oceanica plants growing on matte and on artificial
substratum types and features are key factors for settlement and substratum (rubble mounds) (Di Carlo et al., 2006, 2007). Significant
growth of seagrasses worldwide (Boeger, 1992; Koch, 2001; differences in the morphology of leaves were detected. Leaf area and
Livingston et al., 1998; Marbà and Duarte, 1998). Within the Med- length of both adult and juvenile leaves were lower on plants
iterranean, P. oceanica is able to grow on different types of sub- growing on rubble substratum than on matte; biomass allocation on
strata, ranging from sand, which is easily penetrable by the roots, to rubble mounds was skewed toward the roots, whilst a balance be-
rock, in which the very sturdy roots are able to enter through tween leaves and roots was detected on matte. Only one paper
focused on the comparison between P. oceanica shoots growing on
* Corresponding author. Tel.: þ39 091 23862852; fax: þ39 091 6230219. the three prevalent growth substrata (sand, rock, matte), analyzing
E-mail address: agostino.tomasello@unipa.it (A. Tomasello). parameters at different levels of ecological complexity (individual,
population and community) (Giovannetti et al., 2008). The results
0141-1136/$ e see front matter Ó 2013 Elsevier Ltd. All rights reserved. showed that, at the individual level, the leaf surface of orthotropic
http://dx.doi.org/10.1016/j.marenvres.2013.04.001