Accelerated nitrogen cycling on Mediterranean seagrass leaves at volcanic CO2 vents

Abstract

Seagrass meadows form highly productive and diverse ecosystems in coastal areas worldwide, where they are increasingly exposed to ocean acidification (OA). Efficient nitrogen (N) cycling and uptake are essential to maintain plant productivity, but the effects of OA on N transformations in these systems are poorly understood. Here we show that complete N cycling occurs on leaves of the Mediterranean seagrass Posidonia oceanica at a volcanic \(CO_{2}\) vent near Ischia Island (Italy), with OA affecting both N gain and loss while the epiphytic microbial community structure remains largely unaffected. Daily leaf-associated N2 fixation contributes to 35% of the plant’s N demand under ambient pH, while it contributes to 45% under OA. Nitrification potential is only detected under OA, and N-loss via \(N_2\) production increases, although the balance remains decisively in favor of enhanced N gain. Our work highlights the role of the N-cycling microbiome in seagrass adaptation to OA, with key N transformations accelerating towards increased N gain.

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Citation

BibTeX citation:

@online{j2024,
  author = {J, Berlinghof and LM, Montilla and F, Peiffer and GM, Quero
    and U, Marzocchi and TB, Meador and F, Margiotta and M, Abagnale and
    C, Wild and C, Cardini},
  title = {Accelerated Nitrogen Cycling on {Mediterranean} Seagrass
    Leaves at Volcanic {CO2} Vents},
  date = {2024-03-19},
  url = {https://www.luismmontilla.com/papers/berlinghof2024/},
  doi = {10.1038/s42003-024-06011-0},
  langid = {en},
  abstract = {Seagrass meadows form highly productive and diverse
    ecosystems in coastal areas worldwide, where they are increasingly
    exposed to ocean acidification (OA). Efficient nitrogen (N) cycling
    and uptake are essential to maintain plant productivity, but the
    effects of OA on N transformations in these systems are poorly
    understood. Here we show that complete N cycling occurs on leaves of
    the Mediterranean seagrass *Posidonia oceanica* at a volcanic
    \$CO\_\{2\}\$ vent near Ischia Island (Italy), with OA affecting
    both N gain and loss while the epiphytic microbial community
    structure remains largely unaffected. Daily leaf-associated N2
    fixation contributes to 35\% of the plant’s N demand under ambient
    pH, while it contributes to 45\% under OA. Nitrification potential
    is only detected under OA, and N-loss via \$N\_2\$ production
    increases, although the balance remains decisively in favor of
    enhanced N gain. Our work highlights the role of the N-cycling
    microbiome in seagrass adaptation to OA, with key N transformations
    accelerating towards increased N gain.}
}

For attribution, please cite this work as:

J, Berlinghof, Montilla LM, Peiffer F, Quero GM, Marzocchi U, Meador TB, Margiotta F, Abagnale M, Wild C, and Cardini C. 2024. “Accelerated Nitrogen Cycling on Mediterranean Seagrass Leaves at Volcanic CO2 Vents.” Communications Biology. March 19, 2024. https://doi.org/10.1038/s42003-024-06011-0.