New Insights Into Legacy Phosphorus From Fractionation of Streambed Sediment

Sammanfattning

Streambed and lake sediment was studied in Savjaan, a eutrophic mesoscale catchment (722 km(2)) in central Sweden. Triplicate sediment cores from five lakes and nine streams, ranging from headwater to fourth order, were sampled. The sediment was analyzed with a sequential extraction method, where six different phosphorus (P) fractions were measured. The results showed that streambed sediments store considerable amounts of P and in some cases have comparable P contents (g/kg DW) to lake sediment. Land use, soil type, and drainage area (location in the catchment) had a significant effect on the different P fractions found in surficial sediments. Sediment from lakes and forested headwater streams generally had high proportions of organic P and iron bound P. In larger streams located in agricultural areas on clay soils closer to the catchment outlet, with dense sediment and a relatively low proportion of organic matter, P was to a larger extent bound to calcium. Streambed sediment may be an important catchment scale P store and should be considered when modeling catchment P dynamics. The large stores of streambed legacy P should also be considered when performing ditch maintenance to avoid unnecessary mobilization of bioavailable P.

Nyckelord

catchment study; streambed sediment; phosphorus fractionation; internal loading; legacy phosphorus; ditch maintenance

Publicerad i

Journal of Geophysical Research: Biogeosciences
2020, volym: 125, nummer: 9, artikelnummer: e2020JG005763
Utgivare: AMER GEOPHYSICAL UNION

SLU författare

• Lannergård, Emma

  • Institutionen för vatten och miljö, Sveriges lantbruksuniversitet
    

• Agstam-Norlin, Oskar

  • Institutionen för vatten och miljö, Sveriges lantbruksuniversitet
    

• Huser, Brian

  • Institutionen för vatten och miljö, Sveriges lantbruksuniversitet
    

• Sandström, Sara

  • Institutionen för vatten och miljö, Sveriges lantbruksuniversitet
    

• Rakovic, Jelena

  • Institutionen för vatten och miljö, Sveriges lantbruksuniversitet
    

• Futter, Martyn

  • Institutionen för vatten och miljö, Sveriges lantbruksuniversitet
    

Globala målen (SDG)

SDG6 Rent vatten och sanitet för alla

UKÄ forskningsämne

Oceanografi, hydrologi, vattenresurser
Markvetenskap

Publikationens identifierare

• DOI: https://doi.org/10.1029/2020JG005763

Permanent länk till denna sida (URI)

https://res.slu.se/id/publ/108294