Lodenius, Martin; Josefsson, Jussi; Heliövaara, Kari; Tulisalo, Esa; Nummelin, Matti
(Wiley-Blackwell, 2009)
Insect Science
Ash fertilization of forests returns nutrients to forest ecosystems and has a
positive effect on soil pH, but it also may elevate Cd concentrations of forest biota. Cadmium
concentrations of some forest insects (Formica ants, carabids and Coleopteran larvae from
decaying wood) were investigated in southern Finland, where two plots were fertilized with
wood ash, while two other plots represented unfertilized control plots. In ants, mean Cd
concentration was 3.6 ± 1.4 mg/kg, with nest workers having significantly higher concentrations
than workers trapped in pitfall traps. Concentrations at fertilized and unfertilized
plots were similar. In carabid beetles, the average Cd concentration of Carabus glabratus
was 0.44 ± 0.36 mg/kg, with no significant difference between control plots and fertilized
plots. In another carabid beetle, Pterostichus niger, mean Cd concentration was higher at
fertilized plots compared to control plots. We conclude that the variation of Cd concentrations
in the insects studied is more efficiently controlled by species-specific differences than
fertilization history of the forest floor.