0000000000203406
AUTHOR
M Pirrotta
Descriptors of Posidonia oceanica meadows: Use and application
This work benefited partly from the financial support of the European program ΓNTERREG IIIA Corsica, Sardinia. Tuscany
Reference growth charts for assessing growth performance of Posidonia oceanica (L.) Delile
Posidonia oceanica is considered a key species due to its different roles as primary producer, substrate for many species, shoreline erosion protector and long-term carbon store (1).The importance of P. oceanicahas stimulated several studies aimed at quantifying its status. In particular growth performance of rhizomes has become among the most used descriptors for monitoring changes of P. oceanicameadows induced by human or naturalexogenous factors (2). However, ability to detect any change of growth in space or in time is often confounded by natural age-induced variations, which involves serious interpretation problems (3). A general approach adopted to overcome this problem is to build gr…
Osservazioni sugli endofiti fungini in Posidonia oceanica
La presenza di funghi endofiti in rizomi radici e foglie di Posidonia oceanica (L.) Delille è stata valutata nell’ambito di uno studio morfologico ed ecologico condotto in differenti ambienti mediterranei. In particolare, su individui prelevati in 5 diversi siti costieri siciliani, sono state effettuate osservazioni mirate alla visualizzazione di strutture miceliari nei tessuti dell’ospite, all’isolamento di colonie fungine su substrati artificiali agarizzati e alla loro identificazione su basi morfologiche e molecolari. Le indagini, sebbene tuttora in corso, rilevano la costante presenza di microrganismi fungini endofiti negli organi saggiati sia pure con differenti valori di frequenza d’i…
Study on Posidonia oceanica (L.) Delile roots growing on different substrata by isto-anatomical and micro-morphological analysis
Posidonia oceanica (L.) Delile grows on different substratum types, ranging from sand, which is easily penetrable by the roots, to rock, in which they are able to enter through crevices (1). In this study a survey was carried out on roots of plagiotropic rhizomes growing on sand (matte), and rock (dolonstone and calcarenite), to assess difference in morphological and anatomical features. In particular, for each substratum, nine rhizomes were randomly sampled by scuba diver at 10 meters of depth. In each rhizome histological and morphometric data (2, 3) were recorded on roots up to the second lateral order. Roots on rock were isolated from their substratum by chemical dissolution. Data analy…
References growth charts: a new practical tool for comparing Posidonia oceanic growth patterns accounting for age and depth
Over the past three decades an increasing amount of dating records dealing with Posidonia oceanica growth performance was incorporated into a variety of studies, from which a dualistic nature of the factors influencing seagrass growth arose. A large amount of literature focused on the role of exogenous factors in explaining rhizome growth variations, while only few studies invoked the importance of endogenous factors in driving growth. A particular attention was paid on the confounding role of shoot age, as endogenous factor, when the effect of exogenous variables on growth performance is analyzed. Shoot age confounding implies serious interpretation problems, since it is difficult to disti…