This data set comes from the research carried out by Sena et al. Study sites We studied riparian forests of low-order streams located inside preserved areas (1st-3rd order reaches; hereafter sites) in three South American biomes: (i) Amazon (2 sites), (ii) Cerrado (3 sites), and (iii) Atlantic Forest (6 sites). Sites in the Amazon were located in nonflooded forests in the central and northern Amazon with equatorial climate, tall trees, and evergreen canopy. Cerrado sites were located in the Brazilian Central Plateau with a tropical wet‒dry climate, where streams drain through dense corridors of evergreen forests known as gallery forests. Atlantic Forest sites were located in inland and coastal areas of Brazil, spanning a large latitudinal gradient in climate (~ 30 degrees of latitude), from subtropical to equatorial, comprising tropical and subtropical rainforests, Araucaria forests and seasonal tropical forests. The dataset analyzed comprises information from litter for 68 plant species collected across 11 riparian forests within preserved areas (reference conditions) of three neotropical biomes within the tropics: the Amazon (Cantá and Manaus), the Cerrado (Patrocínio, Brasília and Palmas) and the Atlantic Forest (Erechim, Florianópolis, Varzedo, Parnamirim, Palotina and Santa Leopoldina). We analyzed seven chemical traits (%C, %N, %P, %Phenols, C:N, C:P, and N:P ratios) and two physical traits of the litter (toughness and specific leaf area). Field sampling protocol The sampling sites consisted of a 100 m stretch of each forest stream with the most extensive vegetation cover and without apparent anthropogenic impact. Litterfall was sampled using suspended litter traps (1 m2, 10 mm mesh) fixed 1.5 m high on both streambanks to optimize the sampling effort. Fallen leaves were collected every 15 days to avoid leaching or decomposition. Recently fallen leaves were sampled during the period of maximum litterfall in the year, which was defined according to recent literature (Tonin et al., 2017) and/or the expertise of local researchers. Litter was transported to the laboratory and oven-dried (60 °C, 72 h) for chemical analyses; litter used to determine specific leaf area (SLA) and toughness was air-dried only. All litter samples from the same site were pooled and homogenized. Then, the litter for the 5-10 most representative tree species in terms of dry mass were separated and identified to the lowest possible taxonomic level. Physica...