The effects of thermal conditions and canopy density on Posidonia oceanica seedlings: implications for future seagrass restoration

Seagrass restoration have been significantly increased worldwide and the use of seedlings have been encouraged. To successfully use seedlings in restoration, understanding the factors that affect their growth has become pivotal. This study aimed at evaluating the development of the Mediterranean seagrass Posidonia oceanica seedlings in different thermal environments by cross-transplantation between the eastern and western coast of Sardinia (Italy), and in several P. oceanica canopy densities. The thermal conditions of receiving and donor sites did not affect the development of P. oceanica seedlings, since seedlings from the same origin developed consistently in both sites, highlighting a good acclimation. Furthermore, seedlings germinated in dead matte or low canopy density generally showed a higher development, providing good insights for future restoration actions.