Mediterranean seagrasses as carbon sinks: Methodological and regional differences

Abstract

Abstract. The increasing rates of CO2 due to anthropogenic activities are causing important potential climate threats for the Mediterranean Sea: ocean acidification and warming. In this region, two seagrass species, Posidonia oceanica and Cymodocea nodosa can play a crucial role in climate change mitigation. Through their metabolic activity, they can act as carbon sinks; buffer lowering pH values during the day and store carbon in the sediment underneath their meadows. In this study we analyse the metabolism synthesized from published data on seagrass community metabolism and from own results to evaluate trends through time of these two species comparing two methodologies: benthic chambers and multiparametric sensors. Furthermore, we analysed seasonal trends of both seagrass species´ metabolic rates and their variation between the Eastern and Western Mediterranean basins, with no significant results despite the clear visual trends. Our analysis revealed that there are significant differences between methodologies, with multiparametric sensors estimating higher rates, but unable to differentiate between habitats and useful to assess seagrass metabolism at a community level whereas benthic chambers are capable to evaluate rates at a seagrass species level. We found significant differences between the two Mediterranean regions for both methodologies, with highest rates of Net Community Production found in the Easter basin. At a species level, we found that Posidonia was more productive compared to Cymodocea. Furthermore, 86.7 % of the metabolic values reflected that the meadows were acting as carbon sinks in the Western basin.

Urban Land Carbon Emission and Carbon Emission Intensity Prediction Based on Patch-Generating Land Use Simulation Model and Grid with Multiple Scenarios in Tianjin

“…This method allows for an assessment of how different land use types affect carbon cycling. Previous research has shown that forests, grasslands, water bodies, and unused land have a significant capacity for carbon absorption [34], while cultivated land and construction contribute to carbon emissions. Given the direct impact of changes in land types, such as arable land, forest land, grasslands, water bodies, and unused land, on regional carbon emissions, the carbon emissions of these land types can be estimated using the carbon emission coefficient method.…”

How Does Ocean Acidification Affect the Early Life History of Zostera marina? A Series of Experiments Find Parental Carryover Can Benefit Viability or Germination

“…Increased sugar production increases palatability to herbivores (Arnold et al, 2012;Hernán et al, 2016). Additionally, although there is a clear correlation between seagrass metabolism and temperature (Escolano-Molto et al, 2021), an emerging body of evidence suggests that seedlings are not as robust as adults and are therefore more vulnerable to heat stress (Guerrero-Meseguer et al, 2017;Zimmerman et al, 2017).…”