SPATIAL VARIABILITY OF CHEMICAL-COMPOUNDS RELATED TO S-CYCLING IN 2 MOORLAND POOLS

Underwater sediments of two Dutch moorland pools, Gerritsfles and Klip lo, have been compared statistically with respect to total S and S-rel ated sediment contents. Horizontal and vertical distribution of S in t he two pools are significantly different from each other. Statistical analyses indicate that spatial variation of S in Gerritsfles is probab ly due to variation in inorganic S contents and in Kliplo due to varia tions in organically bound S. As evidenced by this study, a choice for a measurement unit like mass fraction (g g-1) or volumetric Mass (mg cm-3) is crucial for the interpretation of spatial variability. In spa tial studies of sediment constituents, it is essential to express cont ents of these constituents in volumetric mass fractions, since spatial sediment patterns are often obscured by spatial variations in bulk de nsity. Taking spatial variability into account may highly affect the q uantification of S-budgets of pools or lakes.