PARENT SESSION
Poster Session #13: Salt Marshes.
Monday, August 5. Presentation from 5:00 PM to 6:30 PM. Exhibit Hall B & C, TCC

A multivariate approach to the analysis of detritus decomposition rate in the lake Alimini Grande (Southern Italy).

Sangiorgio, Franca^*,1, Vadrucci, Mariarosaria², Pinna, Maurizio³, Basset, Alberto⁴, ¹ Dipartimento di Scienze e Tecnologie Biologiche ed Ambientali - Università degli studi di Lecce, lecce, Italia, Italia² Dipartimento di Scienze e Tecnologie Biologiche ed Ambientali - Università degli studi di Lecce, lecce, Italia, Italia³ Dipartimento di Scienze e Tecnologie Biologiche ed Ambientali - Università degli studi di Lecce, lecce, Italia, Italia⁴

ABSTRACT- Detritus decomposition has a major role in salt marsh ecosystems, contributing to energy flow, nutrient dynamics and sediment accretion. Therefore, functional descriptors of plant detritus decomposition processes are likely to be informative indicators of the ecosystem health. The aim of this study was to highlight the most important sources of variation of the decomposition processes in Alimini Grande, using a statistical multivariate approach. Lake Alimini Grande is a 120-ha brackish lake, connected with a freshwater lake in the South, Lake Alimini Piccolo, fed by groundwater, and with the Adriatic Sea in the East. In the lake we studied reed decomposition on leaf packs of Phragmites australis (Cav) Trin ex Steud. detritus since in the Mediterranean Ecoregion a large proportion of the coarse plant detritus originates from littoral and submerged macrophytes. The study was made at 32 field stations, with a distance from 50m to 500m among stations. At each sampling time a number of physico-chemical characteristics of the water column and of the sediments, which could potentially affect the biotic agents of reed detritus decomposition were also determined. They included water temperature and salinity, D.O., DIP and DIN, freshwater and nutrient inputs, organic matter content and phosphorus content in the sediments. Data will be analysed with the Multivariate Analysis of Variance (MANOVA) and with statistical techniques of ordination as Principal Component Analysis (PCA) and Canonical Correspondence Analysis (CCA).

KEY WORDS: brackish lake, detritus decomposition, multivariate analysis