Inter- and intra-habitat variability of plant detritus decomposition in a transitional environment (Lake Alimini, Adriatic Sea)

Abstract

A comparative analysis of inter- and intra-habitat variations of detritus decay rates across ecosystem types was carried out in the Lake Alimini complex (Italy) to assess the relevance of major structural ecosystem features on detritus processing rates. Reed (Phragmites australis) detritus decomposition was studied in a stream, a freshwater lake and a salt marsh on a seasonal basis at a total of 20 sampling stations using the leaf pack technique. Overall, the spatial variability of leaf decomposition rates was more pronounced than the temporal variability, decomposition rates in the stream being 3.6 and 5.2 times faster than in the freshwater lake and salt marsh, respectively. The intra-habitat spatial variability of leaf decay rates in the stream was also higher than in the other systems. Environmental features were relevant factors affecting intra- and inter-habitat variation of reed decay rates, and their relevance to leaf detritus decomposition showed a strong seasonal variation.

Keywords:

• Decomposition
• Phragmites australis
• Intra-habitat heterogeneity
• Inter-habitat heterogeneity
• Niche

Acknowledgements

The study was funded by the INTERREG Italia-Grecia project ‘Conservation of a fragile salt-marsh ecosystem with works to environmental protection of Alimini Lakes (Otranto)’ and by the COFIN project ‘Community organization and plant decomposition processes: field patterns of variation and underlying mechanisms related to individual body size’. F. Sangiorgio was supported by an INTERREG II fellows grant. The authors thank A. De Rinaldis and P. Pintozzi, for technical assistance in fieldwork, and L. Sabetta, for statistical advice. The authors thank Mr George Metcalf of the University of Lecce, for his valuable assistance in checking the manuscript.