Timescale of reduction of long-term phosphorus release from sediment in lakes

It is important for lake management and policy to estimate the timescale of recovery from long-term P release sediment after a reduction in external load. To provide scientific basis this, condensed model was elaborated, applied evaluated four lakes. The based on first order kinetics, with an overall rate constant composed diagenesis labile (kd,2) burial (kb) below active layer. Using variation fractions dated cores, kd,2 varied 0.0155 0.383 yr?1, kb 0.0184 0.073 yr?1 0.0230 0.446 yr?1. layer depths, 8 29 cm, values are within ranges found by others. time 75% (t75) 60 years Lough Melvin, 3 Ramor, 33 Sheelin 41 Neagh, although only Ramor Neagh. Combining other estimates (mean 0.0981 median 0.0426; n=14) produces t75 value less than 14 years. A review models indicates one two decades monitoring also decades. desirable directly all lakes if important, but, generally, it should take between three