Monitoring of alien aquatic plants in the inland waters of Sicily (Italy)

From Firenze University Press Journal: Journal of Plant Taxonomy and Geography (Webbia)

Angelo Troia, Dipartimento STEBICEF (Scienze e Tecnologie Biologiche, Chimiche e Farmaceutiche), Università degli Studi di Palermo, Palermo, Italy

Vincenzo Ilardi, Dipartimento DISTEM (Scienze della Terra e del Mare), Università degli Studi di Palermo, Palermo, Italy

Elisabetta Oddo, Dipartimento STEBICEF (Scienze e Tecnologie Biologiche, Chimiche e Farmaceutiche), Università degli Studi di Palermo, Palermo, Italy

Azolla filiculoides

Updated and reliable data on the presence and distribution of alien aquatic plant species in Sicily are lacking, and there is a need to fill this gap for a proper and efficient management of freshwater ecosystems and biodiversity. This paper reviews the available knowledge about alien aquatic vascular plants in the inland waters of Sicily (Italy).

The aim is to provide an updated checklist, as a first step in the study of the impact of those plants on the native species and ecosystems of this Mediterranean island.

The paper focuses on the strictly aquatic species (hydrophytes), excluding emergent macrophytes. Four species were listed, all of them free-floating and with American origin. Most of them occur within protected areas, and their introduction in the island appears to be anthropogenic.

A set of functional traits of the alien species, such as relative growth rate, leaf mass per area, nitrogen and carbon content, were screened. These traits are useful for assessing the species invasive potential compared to native ones.

Invasive alien species pose a major global threat to the conservation of biodiversity, causing the extinction of native species and modifying ecosystem functions: this is true also for aquatic habitats, particularly susceptible to invasion due to usually high disturbance regimes affecting these habitats and the easy dispersal of water plant propagules. In addition, aquatic environments are also difficult to monitor, and an early detection of introduction of a submerged species is seldom possible (Brundu 2015).

Mediterranean islands are particularly appreciated model systems for studying invasions due to the diversity of alien taxa, long history of species introductions and (usually) detailed floristic records (Hulme 2004; Lloret et al. 2005; Bjarnason et al. 2017; Chiarucci et al. 2017; Pasta et al. 2017).The island of Sicily is one of the main hotspots of plant biodiversity, in the center of the Mediterranean basin (Médail and Diadema 2009), housing more than 3,000 wild plant species (Pignatti et al. 2017–2019) and being an ideal stage for research in ecology and evolution (e.g. Geraci et al. 2009, 2019; Minissale and Sciandrello 2016); it hosts different types of fresh-water habitats, both lentic (coastal wetlands, temporary ponds, lakes, reservoirs) and lotic (springs, streams, permanent and seasonal watercourses) (Gianguzzi et al. 2016), with many endemic or endangered species occur-ring in aquatic habitats (cf. Bonanno and Veneziano 2011; Troia et al. 2012; Troia and Lansdown 2016; Scian-drello et al. 2016; Minissale et al. 2017).

In the last years new aquatic alien species, such as Lemna minuta Kunth (Marrone and Naselli-Flores 2011), and new populations of already reported ones, such as Eichhornia crassipes (Mart.) Solms (Ferro 2013), have been reported. Nevertheless, no recent and updated synthesis on the ecology and the distribution of the Sicilian alien aquatic flora is currently available.Thus, the aims of this work were i) to compile data on the distribution of alien vascular plant species with special reference to their occurrence in protected areas, as a first step in the analysis of the effects of the alien species on the aquatic habitats of the island; ii) to compile data on some functional traits (such as relative growth rate, leaf area, leaf mass per area, nitrogen and carbon content) of the alien species, in order to allow predictions about their potential invasiveness of natural wetlands.

DOI: https://doi.org/10.36253/jopt-8414

Read Full Text: https://oaj.fupress.net/index.php/webbia/article/view/8414