Study of plant traits, soil features and plant invasion in sandy beach of Grado and Marano lagoon (northern Adriatic Sea)

Biotic invasions are altering the world's natural communities and their ecological characters at an unprecedented rate. If we fail to implement effective strategies to curb the most damaging impacts of invaders, we risk impoverishing and homogenizing the ecosystems on which we rely to sustain ecosystem services given by biodiversity with irreplaceable natural services. As other extreme environments, sandy beaches are undergoing severe changes due to global changes. Climate changes are drastically shifting the most important ecological drivers affecting their plant communities (e.g., sand salinity, sand deposition, wind, marine aerosol and water table). These modifications can trigger rapid changes in species composition and abundance of a naturally highly dynamic ecosystem, often favoring invasive alien plants. The aim of this study is to evaluate which are the ecological drivers that cause alien species plant invasion, analyzing plant response from cellular to community level, through a laboratory-field approach, measuring plants traits and evaluating the species composition of the whole plant community. The study sites are barrier islands of the Marano and Grado lagoon (45°40’40’’ N 13°03’50’’ E to 45°46’30’’ N 13°27’20’’ E). It is located in the north part of the Adriatic Sea. The lagoon is morphologically classified as a leaky lagoon, with strong tidal influence. The experimental design includes a gradient study (from water edge to dune’s back side) of alien species on native species occurring in diverse plant communities evaluating plant traits and species composition in relation to the most important soil features (e.g. soil salinity, grain size). Plants traits can be divided in physiological (e. g. Non-Structural Carbohydrates, osmolites, secondary metabolites) and morphological (e. g. Specific Leaf Area, biomass, height, number and dimension of leaves) while plant communities can be evaluated with taxonomical and functional diversity and plant – plant interactions. Particular attention is given to Ambrosia psilostachya DC., Cyperus esculentus L., and Sporobolus pumilus (Roth) P.M. Peterson & Saarela. We expect to clarify the role of soil proprieties on biological invasion, focusing on salt tolerance strategies, which might be a key driver for future scenarios of rainfall reduction and consequent increase of soil sand content.