Assessing the spatial complexity in a coastal wetland site (Southern Italy) according to different habitat and land cover classification schemes

Aim: Object of this work was to compare different habitat and land cover classification schemes, applied to a specific coastal wetland landscape, with a defined thematic resolution level. Location and Methods: Study area is the SCI IT9110005, one of the most extensive wetlands of the Italian peninsula and one of the largest components of the Mediterranean wetland system, located in the Northeastern part of the Puglia Region (Southern Italy). The natural vegetation is represented mostly by halophytic scrub, reed thickets and by annual pioneer salt marsh communities. Natural and semi-natural landscape elements were described as phytosociological units and represented on a vegetation map at a 1:5,000 scale. Vegetation units were then reclassified in habitat types according to Annex I of the EEC 92/43 Directive and EUNIS habitat classification schemes and in land cover types according to different land cover schemes. For each scheme a thematic map was produced and, for each map, various landscape metrics were calculated. Results and Conclusions: The selection of a specific class scheme affects the spatial pattern of the derived landscapes and consequently the landscape metrics, especially at class level. The presence of various vegetation types and mosaics increases the complexity of the spatial pattern, which varies greatly according to the classification system considered, based on how the different types are aggregated. Our results confirm that the choice of specific classification schemes produces important effects on the spatial composition of the derived patch-mosaic landscape, and therefore can significantly affect the derived landscape metrics values.