Latitudinal Patterns in European Seagrass Carbon Reserves: Influence of Seasonal Fluctuations versus Short-Term Stress and Disturbance Events
|Author(s)||Soissons Laura M.1, Haanstra Eeke P.1, Van Katwijk Marieke M.2, Asmus Ragnhild3, Auby Isabelle4, Barille Laurent5, Brun Fernando G.6, Cardoso Patricia G.7, Desroy Nicolas8, Fournier Jerome9, Ganthy Florian4, Garmendia Joxe-Mikel10, Godet Laurent11, Grilo Tiago F.12, Kadel Petra3, Ondiviela Barbara13, Peralta Gloria6, Puente Araceli13, Recio Maria13, Rigouin Loic4, Valle Mireia10, 14, Herman Peter M. J.1, 2, 15, Bouma Tjeerd J.1|
|Affiliation(s)||1 : Univ Utrecht, NIOZ Royal Netherlands Inst Sea Res, Dept Estuarine & Delta Syst, Yerseke, Netherlands.
2 : Radboud Univ Nijmegen, Inst Water & Wetland Res, Dept Environm Sci, Nijmegen, Netherlands.
3 : Helmholtz Zentrum Polar & Meeresforsch, Alfred Wegener Inst, Bremerhaven, Germany.
4 : Inst Francais Rech Exploitat Mer, Lab Environm Ressources Arcachon, Arcachon, France.
5 : Univ Nantes, Fac Sci & Tech, EA 2160, Equipe Mer Mol Sante, Nantes, France.
6 : Univ Cadiz, Fac Ciencias Mar & Ambientales, Area Ecol, Dept Biol, Cadiz, Spain.
7 : Univ Coimbra, Marine & Environm Res Ctr, Dept Life Sci, Coimbra, Portugal.
8 : Inst Francais Rech Exploitat Mer, Lab Environm & Ressources, Dinard, France.
9 : CNRS, UMR Biol Organismes & Ecosyst Aquat 7208, Paris, France.
10 : Ctr Tecnol Experto Innovac Marina & Alimentaria T, Marine Res Div, Pasaia, Spain.
11 : Univ Nantes, CNRS, UMR Littoral Environm Teledetect Geomat Nantes Ge, Nantes, France.
12 : Univ Lisbon, Fac Ciencias, Lab Maritimo Guia, Marine & Environm Sci Ctr, Cascais, Portugal.
13 : Univ Cantabria, Environm Hydraul Inst IH Cantabria, Santander, Spain.
14 : Pontificia Univ Catolica Ecuador, Sede Esmeraldas PUCESE, Escuela Gest Ambiental, Esmeraldas, Ecuador.
15 : Deltares, Delft, Netherlands.
|Source||Frontiers In Plant Science (1664-462X) (Frontiers Media Sa), 2018-02 , Vol. 9 , N. 88 , P. 1-12|
|WOS© Times Cited||1|
|Note||Specialty section: This article was submitted to Functional Plant Ecology, a section of the journal Frontiers in Plant Science|
|Keyword(s)||carbon reserves, European Atlantic coast, latitude, resilience, Zostera noltei, climate setting, stress events|
Seagrass meadows form highly productive and valuable ecosystems in the marine environment. Throughout the year, seagrass meadows are exposed to abiotic and biotic variations linked to (i) seasonal fluctuations, (ii) short-term stress events such as, e.g., local nutrient enrichment, and (iii) small-scale disturbances such as, e.g., biomass removal by grazing. We hypothesized that short-term stress events and small-scale disturbances may affect seagrass chance for survival in temperate latitudes. To test this hypothesis we focused on seagrass carbon reserves in the form of starch stored seasonally in rhizomes, as these have been defined as a good indicator for winter survival. Twelve Zostera noltei meadows were monitored along a latitudinal gradient in Western Europe to firstly assess the seasonal change of their rhizomal starch content. Secondly, we tested the effects of nutrient enrichment and/or biomass removal on the corresponding starch content by using a short-term manipulative field experiment at a single latitude in the Netherlands. At the end of the growing season, we observed a weak but significant linear increase of starch content along the latitudinal gradient from south to north. This agrees with the contention that such reserves are essential for regrowth after winter, which is more severe in the north. In addition, we also observed a weak but significant positive relationship between starch content at the beginning of the growing season and past winter temperatures. This implies a lower regrowth potential after severe winters, due to diminished starch content at the beginning of the growing season. Short-term stress and disturbances may intensify these patterns, because our manipulative experiments show that when nutrient enrichment and biomass loss co-occurred at the end of the growing season, Z. noltei starch content declined. In temperate zones, the capacity of seagrasses to accumulate carbon reserves is expected to determine carbon-based regrowth after winter. Therefore, processes affecting those reserves might affect seagrass resilience. With increasing human pressure on coastal systems, short- and small-scale stress events are expected to become more frequent, threatening the resilience of seagrass ecosystems, particularly at higher latitudes, where populations tend to have an annual cycle highly dependent on their storage capacity.