Publication Date:
2023-07-07
Description:
Rising atmospheric CO2 causes ocean acidification that represents one of the major ecological threats for marine biota. We tested the hypothesis that long-term exposure to increased CO2 level and acidification in a natural CO2 vent system alters carbon (C) and nitrogen (N) metabolism in Posidonia oceanica L. (Delile), affecting its resilience, or capability to restore the physiological homeostasis, and the nutritional quality of organic matter available for grazers. Seawater acidification decreased the C to N ratio in P. oceanica tissues and increased grazing rate, shoot density, leaf proteins and asparagine accumulation in rhizomes, while the maximum photochemical efficiency of photosystem II was unaffected. The 13C-dilution in both structural and non-structural C metabolites in the acidified site indicated quali-quantitative changes of C source and/or increased isotopic fractionation during C uptake and carboxylation associated with the higher CO2 level. The decreased C:N ratio in the acidified site suggests an increased N availability, leading to a greater storage of 15N-enriched compounds in rhizomes. The amount of the more dynamic C storage form, sucrose, decreased in rhizomes of the acidified site in response to the enhanced energy demand due to higher shoot recruitment and N compound synthesis, without affecting starch reserves. The ability to modulate the balance between stable and dynamic C reserves could represent a key ecophysiological mechanism for P. oceanica resilience under environmental perturbation. Finally, alteration in C and N dynamics promoted a positive contribution of this seagrass to the local food web.
Keywords:
Alkalinity, total; Alkalinity, total, standard deviation; Asparagine per dry mass; Asparagine per dry mass, standard error; Benthos; Biomass/Abundance/Elemental composition; Carbohydrates, non structural; Carbohydrates, non structural, standard error; Carbon; Carbon, standard error; Carbon/Nitrogen ratio; Carbon/Nitrogen ratio, standard error; CO2 vent; Coast and continental shelf; EXP; Experiment; Field observation; Glutamic acid, standard error; Glutamic acid per dry mass; Glutamine per dry mass; Glutamine per dry mass, standard error; Holocellulose, standard error; Holocellulose per dry mass; Ischia_OA; Lignin, standar error; Lignin per dry mass; Location; Mediterranean Sea; Nitrogen, per dry mass; Nitrogen, standard error; Nitrogen, total; Nitrogen content per dry mass, standard error; OA-ICC; Ocean Acidification International Coordination Centre; Partial pressure of carbon dioxide, standard deviation; Partial pressure of carbon dioxide (water) at sea surface temperature (wet air); pH; pH, standard deviation; Plantae; Posidonia oceanica; Proteins, soluble; Proteins, soluble, standard error; Proteins, total; Proteins, total, standard error; Registration number of species; Replicate; Seagrass; Shoot density; Shoot density, standard error; Single species; Species; Starch; Starch, standard error; Sucrose, standard error; Sucrose per dry mass; Temperate; Tracheophyta; Treatment; Type; Uniform resource locator/link to reference; δ13C; δ13C, standard error; δ15N; δ15N, standard error
Type:
Dataset
Format:
text/tab-separated-values, 414 data points
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