1 Introduction -- Part I: Forest and woodland biomes -- 2 White sand ecosystems in the Amazon basin: geographic distribution, distinctive features, and ecology. An overview -- 3 The forests of the Rio Negro basin in the north-western Amazon: a phytosociological classification -- 4 Amazon caatinga complex: sclerophyllous vegetation on nutrient-poor white sand soils -- Part II: Meadow biomes -- 5 Mapping white-sand ecosystems by integrating Global PALSAR-2 and SENTINEL-1 with NDVI (LANDSAT data) -- 6 The study areas: landscapes and soils -- 7 Soil properties, formation, distribution, and classification -- 8 Origin and sources of sand: from highlands to lowlands -- 9 Sand dynamics and distribution: a geo-sedimentological approach -- 10 Features and trends of meadow landscape evolution -- 11 Meadow phytodiversity: flora, endemism, vegetation types, and geographic distribution patterns -- 12 Synthesis: white-sand and meadow-vegetation relationships.