Temporal and inter habitat variations of substratum, vegetation and substratum macroinvertebrates attributes across coastal wetland systems, North East Aegean, Greece

Abstract

1. Using five coastal wetland systems across Kalloni bay, Lesvos Island, NE Aegean, we investigated: (I) the interaction between spatial units (land, wetland, sea) and seasons (spring, autumn) of substratum physicochemical attributes, vegetation composition and aerial cover, and substratum macroinvertebrates distribution and abundance and (II) the relative importance of substratum attributes in explaining temporal and inter habitat variations in vegetation and substratum macroinvertebrates distributions to elucidate the functional role of these coastal wetlands in the landscape.
2. Electrical conductivity, percent organic matter and bulk density of substratum showed the most pronounced differences among spatial units, between seasons, and among spatial units x seasons interaction, respectively. Comparison of C:N and N:P ratios among spatial units and between seasons indicated that, in general, nitrogen and phosphorus appear to be limiting factors at the sea and the land unit, respectively. It is likely that these coastal wetlands function as transformers of chemical elements while P limits primary production.
3. Significant substratum physicochemical attributes explained 23.4 and 14.7% of plants distribution in spring (percent organic matter, total phosphorus concentration, electrical conductivity) and autumn (electrical conductivity, pH), respectively, while significant substratum variables explained 46.1 and 73.3% of macroinvertebrates distribution in spring (percent organic matter) and autumn (total phosphorus concentration, electrical conductivity, percent organic matter), respectively.