Phytoliths in modern plants from amazonia and the neotropics at large Implications for vegetation history reconstruction

Phytolith analysis is increasingly being applied in studies of Neotropical forest history and associated pre-Columbian human influences, especially in the Amazon Basin. In order to enlarge modern reference collections that are integral to these efforts, we analyzed phytoliths from 360 species of mainly eudicotyledons from 80 different families and 10 Arecaceae species. Many are native to Amazonia and have not been studied previously. Production and morphological characteristics of the phytoliths were assessed along with their survivability in ancient soils and sediments. Our analysis affirmed the validity of family- and genus-level diagnostic phytoliths from arboreal and other woody growth taxa uncovered in previous research. It also revealed new diagnostic phytoliths from both well- and little-studied families of importance in the Amazonian forest, and affirmed the utility of other types such as spheroids and sclereids for documenting arboreal/woody growth more generally in paleoecological research. Although where pollen is recovered it will continue to document a greater number of arboreal/woody species, phytoliths can identify a diversity of those taxa in the Amazonian and Neotropical forest at large–including when pollen does not– with family, genus, and possibly even species-level diagnostics.