Modern pollen spectra from bat guano deposits in southeastern Amazonia

The rich diversity of bat-feeding habits leads to ecological interactions potentially archived in guano deposits. However, the lack of studies on the pollen signal from guano deposits in the Amazon region prevents us from understanding the processes that influence the origin, transport, and taphonomy of pollen grains preserved within caves. To assess the potential of pollen spectra from caves for vegetation reconstruction, we compared the modern pollen-rain records of surface bat guano from five caves with modern pollen records from three lake sediments, in the Carajas region, southeastern Amazonia. The results show high pollen abundance and richness of arboreal elements in bat guano samples, with a dominance of chiropterophiles/entomophilous taxa. Bats are the main means of transporting pollen into the caves, with a minor contribution of airborne and waterborne transport. The greater diversity of forest taxa found in bat guano compared to lake sediments reveals that the former is an excellent natural trap for recording the composition and structure of local vegetation and should be used integrated with other natural traps to provide additional information on environmental and vegetation changes in southeastern Amazonia.

Automated summary

This study compared the modern pollen records from bat guano and lake sediments and found that the guano samples exhibited high abundance and richness of pollen, primarily transported into caves by bats with minor contributions from airborne and waterborne transport. Compared to lake sediments, bat guano is a better natural trap for recording the composition and structure of local vegetation changes.