Wetlands distribution in the agricultural-livestock core of the South American temperate pampas landscape. Approach from soil cartography

Expansion and intensification of agriculture are among the main factors of degradation and systematic loss of wetlands throughout the twentieth century. We analyze the potential occurrence of wetlands in the core area of the temperate Pampas region of South America, recognized for the quality of its pastures and the suitability of its soils for grain production. We mapped the spatial distribution of wetlands in the Province of Buenos Aires based on the analysis and classification of the local soil database at a scale of 1:50,000. Thus, 399 soil series were classified as hydric/non-hydric according to the scope of methods and criteria reviewed. Then we used this information to classify 2211 map units into five categories based on the percentage of hydric and non-hydric soil series: 1—hydric (100% hydric series); 2—predominantly hydric (66–99% hydric series); 3—partially hydric (33–65% hydric series); 4—predominantly non-hydric (1–32% hydric series); and 5—non-hydric (0% hydric series). We estimated wetlands cover about 35% of the province. Wetlands distribution is not uniform, we identified three main landscapes: terrestrial matrix with wetlands, mosaic of wetlands and non-wetlands, and mosaic dominated by wetland patches. Our results provide tools for land management in terms of strategies for a wise use of wetlands and their conservation. Our map shows high values of consistency with the occurrence of wetlands visually identified in high-resolution imagery (Google Earth platform). In such a highly agriculturized landscape, our results indicate a much larger wetland area compared to estimates made with optical remote sensing data classifications.