Temperature tolerance and survival of intertidal populations of the seagrass Zostera noltii (Hornemann) in Southern Europe (Ria Formosa, Portugal)

摘要: The dwarf seagrass Zostera noltii is an important primary producer in Atlantic coastal ecosystems from Mauritania to southern Norway and the Mediterranean Sea. Sessile intertidal organisms existing at interface between marine terrestrial environments may be particularly vulnerable environmental change. In this study, we asked how near thermal tolerance limits natural populations of Z. are Ria Formosa lagoon system Portugal. We recorded maximum temperatures during 2007 summer, conducted experiments determine sub-lethal temperature shoots sampled two sites located different tidal heights. Mortality rates photosynthetic performance were within a range heat shock 35 41°C. Survival was ≤37°C, while higher led sudden drop capacity followed by mortality (shoot loss) that occurred more rapidly with increasing temperatures. At 39°C above, rate shoot both close 100%, occurring 5 13 days after shock. ca. 95 90% 37°C, respectively. From these results for estimated approximately 38°C noltii, 36°C summer 2007. Considering predicted trajectories coming decades, raise concern as future viability southernmost edge their distribution.