Phosphorus in interstitial water: methods and dynamics

Interstitial (pore) water is important for phosphorus dynamics in limnic ecosystems. This review summarizes the most important processes influencing the generation and transport of pore-water P from, to and within the sediment. Sampling methodology is discussed thoroughly in combination with what little information is available on various P species in the pore water.Pore water P concentrations in various trophic systems and the spatial and temporal distributions are also described. The last sections of the article deal with diffusive P flux calculations and comparison with measured P fluxes. Factors influencing P fluxes, such as adsorption, possible precipitation mechanisms, advection and bioturbation, are discussed.The general conclusion drawn from this review is that pore-water P investigations (concentrations and gradients) are an underestimated ecological tool in studying and describing trophic status, redox conditions, spatial and temporal distribution of P-sediment release, potential precipitation mechanisms on a long-term basis and ground-water inflow areas, as well as lake-water seepage.