Shifts in sediment microbial activities driven by the expansion of Spartina versicolor: implications for the ecosystem services

Abstract

Spartina versicolor (Ait.) Muhl. (Poaceae) is a perennial rhizomatous grass that grows in a wide range of coastal habitats being endemic from North America, where it as been identified as Spartina patens. There are some doubts on how this specie has entered in the Mediterranean space. It is probable that the plant was introduced first to various ports around the Mediterranean, as it was used as packing material in ships boxes and crates. Being a strong rhizomatous invasive species, the presence of S. patens in NW Iberian salt marshes could represent a considerable impact on the native plant communities. Recent data, showed a large expansion of this specie coverage area along almost all estuarine ecosystems on the western coast of Portugal, invading the habitats of more sensible autochthonous species, such as Spartina maritima. In the present work a seasonal monitoring of both endemic and alien species rhizosediment microbial activities will be presented in order to understand the impact of this specie on the organic matter cycling along a seasonal cycle. This will allow to understand the impact of this invasor on the sediment functions while ecosystem service provider while cycling the incoming organic matter.