Impacts of pesticides and natural stressors on leaf litter decomposition in agricultural streams Original Research Article

Agricultural pesticides are known to significantly impact the composition of communities in stream ecosystems. Moreover, agricultural streams are often characterised by loss of physical habitat diversity which may impose additional stress resulting from suboptimal environmental conditions. We surveyed pesticide contamination and rates of leaf litter decomposition in 14 1st and 2nd order Danish streams using litter bags with coarse and fine mesh sizes. Two sites differing in physical habitat complexity were sampled in each stream, and we used this approach to differentiate the effects of pesticides between sites with uniform (silt and sand) and more heterogeneous physical properties.