LAKE INFILL AND ITS EFFECTS ON WATER RESOURCES AND LAKE TERRESTRIALIZATION IN THE SOUTH AMERICAN LOWLANDS

Recent satellite images suggest a potentially important environmental transition occurring in the Pantanal: the terrestrialization of lakes and swamps. This transformation of lentic ecosystems into terra firma in the Pantanal has not been comprehensively studied. However, existing ²¹⁰Pb_xs and ¹⁴C age-depth models are available for a number of end-member lakes including open lakes, either connected or disconnected from the trunk river, and hydrologically closed soda lakes. Minimum estimates for infill rates can be calculated when the age-depth models are coupled with bathymetry and lake volume measurements in each lake. Preliminary data show that sediment accumulation is higher for hydrologically open lakes in the Pantanal such as Lake Gaíva and lower in soda lakes such as Salina da Ponta. The longevity and infill rates of diverse floodplain lakes are key indicators of environmental processes that can be interpreted and applied towards sustaining ecosystem services linked to standing water.