Mapping and quantifying habitat fragmentation in small coastal areas: a case study of three protected wetlands in Apulia (Italy)

Abstract

In the Mediterranean Region, habitat loss and fragmentation severely affect coastal wetlands, due to the rapid expansion of anthropogenic activities that has occurred in the last decades. Landscape metrics are commonly used to define landscape patterns and to evaluate fragmentation processes. This investigation focuses on the performance of a set of landscape pattern indices within landscapes characterized by coastal environments and extent below 1,000 ha. The aim is to assess the degree of habitat fragmentation for the monitoring of protected areas and to learn whether values of landscape metrics can characterize fine-resolution landscape patterns. The study areas are three coastal wetlands belonging to the Natura 2000 network and sited on the Adriatic side of Apulia (Southern Italy). The Habitat Maps were derived from the Vegetation Maps generated integrating phytosociological relevés and Earth Observation data. In the three sites, a total of 16 habitat types were detected. A selected set of landscape metrics was applied in order to investigate their performance in assessing fragmentation and spatial patterns of habitats. The final results showed that the most significant landscape patterns are related to highly specialized habitat types closely linked to coastal environments. In interpreting the landscape patterns of these highly specialized habitats, some specific ecological factors were taken into account. The shape indices were the most useful in assessing the degree of fragmentation of habitat types that usually have elongated morphology along the shoreline or the coastal lagoons. In all the cases, to be meaningful, data obtained from the application of the selected indices were jointly assessed, especially at the class level.

Coastal salt-marshes plant communities of the Salicornietea fruticosae class in Apulia (Italy)

“…In the study area, due to the intensive agricultural activities and the presence of a network of infrastructures linked to specific production sites, these habitat types have undergone reduction and fragmentation of their distribution area. So, in most cases, they do not form well-structured vegetation belts, but rather a mosaic of fragmented patches (Tomaselli et al 2012). The most threatened communities of the class are: Agropyro scirpei-Inuletum crithmoidis, LimonioArtemisietum coerulescentis and Halimiono-Suaedetum verae, normally spreading in the upper part of the salt marshes and therefore subjected to more intensive anthropogenic pressures.…”

Multi-modal knowledge base generation from very high resolution satellite imagery for habitat mapping

“…Le Cesine Nature Reserve is 380 hectares in size and it provides resting and breeding sites for many species of birds. This site is a coastal area, whose structure is mainly comprised of ponds, marshes and wet meadows, with a very high diversity in habitats and vegetation types [Tomaselli et al, 2011;Adamo et al, 2014]. On the basis of ground truth data by the National Research Council in Italy (CNR), and according to the Typology of Ecosystems proposed by Maes et al (2013) as basic units for ecosystem mapping at European scale, there are two types of terrestrial ecosystems in the area of interest.…”

Conservation status of habitats (Directive 92/43 EEC) of coastal and low hill belts in a Mediterranean biodiversity hot spot (Gargano – Italy)

“…Monitoring of habitat extension, fragmentation, and spatial con nectivity through the use of specific landscape metrics (Tomaselli et al 2012). The following indicators such as the total number of species (floristic richness) and number of species of conservation interest/total species are suggested.…”

“…The increasing human pressures is causing habitat reduction, loss, and fragmentation along the coastline (Levin et al 2009;Tomaselli et al 2012), often combined with a likewise fast process of homogeniz ation, denudation, and destabilization of the uplands (Géhu et al 1984;Géhu & Biondi 1994;Naveh 1998;Acosta et al 2003). The Gargano extending into the Adriatic Sea (Figure 1), for its geographical position and geologic history (Bosellini & Ferioli 1988;Bosellini et al 1993), is a biodiversity hot spot at global level, including a high diversity of plant communities of a significance far exceeding their relatively small covered area.…”