Spatial delineation of a new fog-driven ecosystem in the tropical lowlands

A recent review about diversities of epiphytes in tropical forests of the Neotropics revealed an unexpected high diversity at lower elevations in an area in French Guiana where the formation of nocturnal radiation fog, intensified by katabatic drainage flows from the surrounding terrain fosters epiphytic growth. Consequently, the new diversity hotspot has been termed ’Tropical Lowland Cloud Forest‘ (TLCF) in analogy to the well-known Tropical Montane Cloud Forests. In this new project funded by the German Research Foundation, we test the hypothesis that the new forest type is widespread in the Tropics if the local terrain allows the formation of nocturnal radiation fog. The presented study is based on satellite data because no operational fog measurements from natural rain forests are available. Since fog in TLCFs is a nocturnal / early morning phenomenon, we use all overflights by the MODIS Aqua platform with 1 km resolution. Fog / low stratus clouds are derived by using a machine learning approach which is trained by MODIS and CALIPSO data. Potential lowland forest areas will be derived from ASTER Global Digital Elevation Model  and Landsat Vegetation Continous Fields