Abstract
Seagrasses form one of the most productive and threatened ecosystems worldwide because of global change and anthropogenic pressures. The frequency of extreme climatic events, such as heat waves, are expected to increase and may drive even more adverse effects than gradual warming. This study explores for the first time the effects of a sudden and temporary increase of temperature in situ on carbon metabolism and dissolved organic carbon (DOC) fluxes in a community dominated by a seagrass (Cymodocea nodosa) during two contrasting seasons (winter and summer). Results showed a positive correlation between temperature and seagrass production between seasons, while the experimental sudden and temporary increase in water temperature did not produce significant differences in carbon community metabolism and DOC fluxes in winter. In contrast, high temperature conditions in summer enhanced significantly the net community production and affected positively to DOC fluxes. Hence, this study indicates that a sudden and temporary increase in water temperature, which characterize marine heat waves, in temperate areas may enhance the autotrophic metabolism of seagrass communities and can yield an increase in the DOC released, in contrast to previous researches suggesting solely negative effects on seagrasses.
Highlights
Global warming is emerging as a major threat to ecosystems worldwide [1, 2]
There were no significant differences in the carbon community metabolism and dissolved organic carbon (DOC) fluxes mediated by temperature increase during the winter trial
There were no significant differences in the carbon community metabolism and DOC fluxes between treatments during the winter trial
Summary
Global warming is emerging as a major threat to ecosystems worldwide [1, 2]. Mean global sea–surface temperatures have increased by 0.8 ̊C over the last century [3] and, by the end of this century, is projected to increase by 3–4 ̊C [4]. Besides mean sea–surface temperature alteration as a consequence of global change, the frequency and magnitude of extreme climatic events such as sudden and temporary increase of temperature–which characterizes the heat waves–across the globe are expected [4,5,6] Climate change research is generally concerned with the variation in ecosystems structure and functions associated with gradually increasing mean temperatures [7]. Extreme climatic events such as heat waves will dictate. In Situ temperature increase on metabolism and dissolved organic carbon in Cymodocea nodosa analysis, decision to publish, or preparation of the manuscript
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Free) 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call
