Concentration and pools of heavy metals in organic soils in post-fire areas used as forests and meadows
Wydanie: 4 / 2011
Kategorie: Horticulture and forestry , Pollution and environment
High concentration of heavy metals in organic soils may be the result of intensive, deep-seated fires causing high temperatures. This research has been carried in four post-fire areas, located in forests or on meadows in Lower Silesia. The aim has been to deter- mine the impact of some parameters on the content of heavy metals in soils under post-fire meadows and forests. The concentration and pool of the analyzed heavy metals were determined in soils against the background of such parameters as the depth in a horizon, organic matter content, soil colour and soil reaction. Twenty Histosol soil profiles (85 soil samples) were analyzed, representing peat-muck, muck (Mtllc1, Mtlllc1) and mineral-muc- ky (Me11) and on-muck soils (according to the Polish taxonomy of soils). The soils were strongly desiccated. Some physicochemical and chemical properties of pyrogenic soils were analyzed in dry samples collected into plastic bags with an lnstorfu auger. Heavy metals (Zn, Cu, Pb, Ni, Cr) were determined in HCl + HNO3. Pools of heavy metals were recalculated into g m-2 in 0-20 cm layers of soils and compared among forest and meadow soils. Due to intensive fires, the reaction of pyrogenic soils was slightly acid, neutral or alkaline. As a consequence of the high temperatures, a broad spectrum of soil colours was noticed. The results showed increased concentrations of heavy metals in the topmost and muddy soil horizons. The alkaline soil reaction favoured accumulation of heavy metals. Pools of heavy metals in soils were significantly lower in forest than in meadow areas, which could be attributed to different time periods which elapsed since the fires. The Hue tint of the colour of soil horizons containing ashes indicated the presence of oxidized iron forms and a low content of organic carbon. The accumulation of heavy metals in post-fire sites in Lower Silesia was negatively correlated with the soil's strongly acid reaction. The determined concentrations of heavy metals did not exceed the threshold values set for unpolluted soils.
Bogacz A., Woźniczka P., Łabaz B. 2011. Concentration and pools of heavy metals in organic soils in post-fire areas used as forests and meadows. J. Elem. 16(4): 515-524.
Słowa kluczowe:soil, peat, fire, heavy metals, valley areas, dewatering process.