Characterizing fragmentation in temperate South America grasslands

In the last century, the grasslands of southern South America were rapidly converted to croplands, starting a fragmentation process that is still ongoing. Almost no information is available on the spatial patterns and environmental controls of these processes. Our objective was to characterize the degree of fragmentation and to analyze the environmental controls of landscape composition of the Río de la Plata grasslands, in southern South America. We classified land cover types using three Landsat TM scenes and we analyzed landscape structure using six metrics. Grassland is still the predominant land cover type in the Pampas, occupying 65.5% of the analyzed area. The abundance of the original land cover varied regionally, being higher in the south east (Flooding Pampa) and lower in the northern part of the area studied (Rolling Pampa). Landscape fragmentation was determined by crop production, therefore, was highest in the Rolling Pampa and lowest in the Flooding Pampa. The fragmentation patterns were associated to both climatic and edaphic factors. Fragmentation of native vegetation was mainly regulated by soil drainage, as in poorly drained soils, crop production is almost unfeasible.