Microbial-driven impact on aquatic phosphate fluxes in a coastal peatland

Polyphosphate-accumulating microbial mats can influence PO 4 3- concentration in the benthic zone. To investigate role of P cycling, short peat cores including supernatant water from a coastal fen NE Germany (southern Baltic Sea) were incubated winter, summer and fall under 3 conditions: situ , elevated temperature oxygen-depletion. Bottom concentrations decreased treatments where mat had formed (summer winter) but not mat-deficient treatment. The densely populated with polyphosphate-rich Lyngbya sp. filaments. On last day incubation, oxygen-depleted bottom lower winter (70×) (44×) than treatment, demonstrating significant effect on fluxes, even conditions. Mean polyphosphate-P content upper 1 cm layer 8 freshly collected was 2.23 µmol g -1 (5% total P), comprising noticeable percentage reservoir. Low sediment Fe:P molar ratios among (5.9-6.3) indicated that P-adsorption sites Fe-P compounds fairly saturated limited efficiency precipitating additional . Using known temperature-dependent coefficients for biological systems, we estimate temperature-elevated reduced by 96% presence mat. We propose take up large amount dissolved inorganic P, highlighting its regulatory peatland fluxes varying environmental