Refining pedotransfer functions for estimating peat bulk density

Several previous studies have demonstrated the close relationship between peat dry bulk density and gravimetric moisture content. However, the basis for including peat ash (mineral) content or variation in the specific gravity of peat solids has not been covered. Here we present a theoretical basis for estimating peat dry bulk density for saturated peats from values of moisture content and, where available, ash content. The theory is evaluated using datasets obtained from Scotland, Ireland and Indonesia where both dry bulk density and peat moisture content have been measured. Deviations from theory are discussed in terms of peat gas volume and possible errors in the determination of peat dry bulk density.