| Abstract: | The effects of an organotin pesticide, fentin hydroxide (triphenyltin (IV) hydroxide; TPTH) , on the soil fauna mediated decomposition of poplar leaf litter were examined. The responses of micro-ecosystems (MES) containing soil animals were compared to MES without fauna. The isopod Porcellio scaber Latr. was chosen as a representative saprotrophic soil fauna species. TPTH was added in four concentrations, ranging from 0.1 to 100 μg (g dry litter)?1. MES respiration was used as a measure of decomposition rate. To measure the nitrogen mineralisation by microflora and isopods, ammonium and nitrate concentrations in the litter were determined. Analyses of the litter showed that TPTH was not degraded during the experiment. TPTH had a short-term effect on microbial respiration, which diminished after two days. Ammonium production by isopods within the system was the most sensitive parameter for the effects of TPTH . The No Observed Effect Concentration (NOEC) was 10 μg g?1. It was concluded that, while TPTH is a fungicide, it does not seem to be very toxic to microbial respiration and ammonification as measured within the micro-ecosystem; isopod activities are more sensitive. |
