Litter accumulation in woodlands contaminated by Pb, Zn, Cd and Cu

Abstract

Close to a primary lead-zinc-cadmium smelter the standing crop of litter in woodlands was found to be elevated relative to more distant sites. The total litter accumulation is similar to that from contaminated sites reported by other authors but in this case the concentrations of heavy metals are considerably lower than those reported for other sites. Evidence is provided to support the hypothesis that within the woodlands studied, litter accumulation is not closely pH dependent, but is clearly related to both cadmium and zinc concentrations in litter. Litter accumulation occurs in certain particle size ranges and fractionation shows that the weight of accumulated litter in these size ranges is highly correlated to cadmium concentrations. These results are discussed in relation to the reported possible long term effects of metal contamination on decomposition processes and the possibility of adaptation to these adverse effects.

Effect of heavy metals on soil respiration during decomposition of sugarcane (Saccharum officinarum L.) trash in different soils

“…1995, Dumat et al 2006. Early studies on the effects of heavy metals on soil respiration show the inhibitory effects of Pb, Zn, Cd or Cu (Williams et al 1977, Coughtrey et al 1979. Our data indicate Table 3.…”

Decomposition of Organic Matter with Previous Cadmium Adsorption in Soils

“…However, heavy metals adsorbed onto organic matter in soil are assumed to play an important role in the suppression of organic matter decomposition. It has been reported that soil respiration and enzymatic activities decreased as the concentration of total heavy metals increased in the soil around a brass foundry (Tyler 1974;Ebregt and Boldewijn 1977), and that litter accumulation is clearly related to both Cd and Zn concentrations in litter (Coughtrey et al 1979). The inhibition of organic matter decomposition in soil strongly contaminated with heavy metals may be due to the adsorption of heavy metals onto organic matter.…”

Humus forms in terrestrial ecosystems: a framework to biodiversity

“…All sudden environmental changes are amenable to the local extinction of species and, thus, above some given threshold of tolerance, of functions (Barros et al, 2001). Local changes in humus forms and important soil functional processes have been repeatedly described under the influence of pesticide and fertilizer use (Barratt, 1967;Topoliantz et al, 2000), heavy metal deposition (Coughtrey et al, 1979;Gillet and Ponge, 2002), plantation (Nihlgård, 1971;Muys and Lust, 1993), fire (Majer, 1984;Zackrisson et al, 1996) and liming (Deleporte and Tillier, 1999), among others. Some of these changes are irreversible, i.e.…”