Neotropical savanna (Colombia)
Mid-Late Miocene - Early Pliocene grass communities of the Central Andean Plateau (CAP)
The Central Andean Plateau was about ~1700 m.a.s.l. in the Middle Miocene and had reached near-modern elevations (~4000 m.a.s.l.) by the Early Pliocene. The paleobotanical record of the Descanso formation, in the Peruvian Altiplano (Cuzco region) was recently investigated by Martinez et al. (2020) who documented a shift from of a montane ecosystem in the Miocene to Puna-like vegetation in the Early Pliocene, this latter representing the earliest evidence of a Puna-like ecosystem. Climate inferences from fossil evidence suggest wetter conditions in the Miocene and modern precipitation levels in the Pliocene.
The processes that lead to the evolution of modern high-elevation Andean ecosystems (Paramo, Puna, austral alpine vegetation) are debated, and wide range of climatic (e.g., hydric gradients), geographic and ecological factors have been hypothesized to have led to floristic differences between these ecosystems.
I am using phytolith assemblages to better characterize the Neogene plant communities of the Descanso formation, and shed further light on the origin of the modern day Puna in the CAP.
I will also extract phytoliths from modern soil surface samples and plant specimens collected in different high elevation Andean ecosystem (e.g. Puna, Paramo) in order to compare them with the Descanso formation phytolith assemblages and increase the accuracy of vegetation reconstructions.