Breakdown of introduced and native leaves in two Indian streams

The decomposition of leaves of Ficus benghalensis, Anacandium occidentale, Acacia auriculiformis and Eucalyptus globulus was followed during 16 weeks in two streams in the Western Ghat forest region of Karnataka, India. The concentration of nitrogen increased during decay; the levels of phosphorus, soluble phenolics and calcium decreased. Fungal colonization of the leaves was followed by counting the numbers of conidia released during aeration. Highest conidium production was found on leaves of Ficus benghalensis. Daily exponential decay coefficients k where not significantly different between leaf species or streams and varied between -0.0063 and -0.0090. Correlation analyses between k and initial leaf parameters (N, P, Ca, and phenolics) did not yield any significant values, but there was a significant linear correlation between k values and log (maximum sporulation rate).