Article open access publication

Seagrass-Mediated Phosphorus and Iron Solubilization in Tropical Sediments.

Environmental Science and Technology, American Chemical Society (ACS), ISSN 1520-5851

Volume 51, 24, 2017

DOI:10.1021/acs.est.7b03878, Dimensions: pub.1092754587, PMC: PMC5738630, PMID: 29149570,

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  1. (1) University of Copenhagen, grid.5254.6, KU
  2. (2) University of Technology Sydney, grid.117476.2
  3. (3) University of Natural Resources and Life Sciences, grid.5173.0

Description

Tropical seagrasses are nutrient-limited owing to the strong phosphorus fixation capacity of carbonate-rich sediments, yet they form densely vegetated, multispecies meadows in oligotrophic tropical waters. Using a novel combination of high-resolution, two-dimensional chemical imaging of O2, pH, iron, sulfide, calcium, and phosphorus, we found that tropical seagrasses are able to mobilize the essential nutrients iron and phosphorus in their rhizosphere via multiple biogeochemical pathways. We show that tropical seagrasses mobilize phosphorus and iron within their rhizosphere via plant-induced local acidification, leading to dissolution of carbonates and release of phosphate, and via local stimulation of microbial sulfide production, causing reduction of insoluble Fe(III) oxyhydroxides to dissolved Fe(II) with concomitant phosphate release into the rhizosphere porewater. These nutrient mobilization mechanisms have a direct link to seagrass-derived radial O2 loss and secretion of dissolved organic carbon from the below-ground tissue into the rhizosphere. Our demonstration of seagrass-derived rhizospheric phosphorus and iron mobilization explains why seagrasses are widely distributed in oligotrophic tropical waters.

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University of Copenhagen

Danish Open Access Indicator

2017: Realized

Research area: Science & Technology

Danish Bibliometrics Indicator

2017: Level 2

Research area: Science & Technology

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Times Cited: 24

Field Citation Ratio (FCR): 6.29

Relative Citation ratio (RCR): 1.25

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