Late spring decomposition rates in a second order stream: assessing relationships among breakdown rates, decomposer diversity and substrate morphology.

Ecological processes are inluenced both by biotic and abiotic factors. Leaf litter breakdown in freshwater does not except this rule. Substrate morphology and characteristics may inluence benthic decomposers abundances and distribution. In fact, both substrate and macroinvertebrates follow a patchy distribution along stream’s ecological gradients. Abundances and diversity of decomposers directly affect leaf litter processing and decomposition rates linking biotic and abiotic factors to the ecological process of decomposition. Fractal dimension of substrates can give a measure of surfaces complexity and may be related both to water turbulence and macroinvertebrates clinging. In this study we have investigated the functional relationships between macroinvertebrates diversity and abundances, chemical and physical parameters, rocks, pebbles and stones numbers and dimension and fractal dimension of substrate.