South Atlantic tourist resorts: predictors for changes induced by afforestation

FAGGI, A. PEREPELIZIN P., J. DADON

Urban Biodiversity and Design

Blackwell

Año: 2008;

In Argentina coastal resorts, are located on dunes, originally covered by herbaceous native vegetation. Primary occupation remained in fishing and stock rising until the area became important for tourism. Up to that date, there was a law obligation to forest the dunes before land was divided into lots for settlement. Since then, exotic afforestations have been increased to stabilize blowing sands. We investigated the effect of exotic afforestation on extant dune vegetation and bird diversity. We conducted pair wise plant and bird inventories in forested and undisturbed dunes in the Buenos Aires province. We considered plant and bird richness as well as plant cover and similarity indexes. As the structure of vegetation changed from an open canopy to a relatively closed one, the habitat quality for natural vegetation decreased and the most vulnerable species disappeared. Afforested plots showed a clear decline of shade intolerant species that are characteristic of dunes and of native species indicating moist environmental conditions. Grassy dunes had significant higher bird richness than forested dunes and were characterized by grasslands and rural birds, predominantly insectivores. Under forest the bird assemblages changed and the community became dominated by granivores and urban adapted species. A decrease of plants and birds indicating wetness could be explained by higher evapotranspiration rates of trees, which made the wooded habitat dryer. The functional groups: “dune obligate” and “humid soils” plants as well as “insectivore” and ¨granivore” birds showed to be good predictors for changes induced by afforestation and can be proposed as bioindicators.