Tiny pools in the sertão

Aechmea bromeliad: pollen reservoir in the Caatinga

ALEX POPOVKIN / BAHIA / BRASILAechmea bromeliad: pollen reservoir in the CaatingaALEX POPOVKIN / BAHIA / BRASIL

The hot, dry Caatinga environment of the state of Bahia is not well-suited to the preservation of pollen, which can be used to sample past and present plant diversity in a given region. But biologist Jéssica Gomes seems to have found a solution during her master’s studies at the State University of Bahia: the pools of water retained in the leaf rosettes of bromeliads from the genus Aechmea are natural pollen traps that capture these minuscule reproductive grains (Acta Botanica Brasilica, April/June 2014). In the reservoirs of 10 adult bromeliads observed at Canudos Biological Station, in Northeast Bahia, Gomes found 149 different types of pollen. She was able to partially or fully identify 88 of them, most of them to species level, enough to conclude that bromeliads store up a good sample of the local vegetation. She also identified the 10 most representative plant species in the Caatinga. But the information cannot be interpreted as a be-all and end-all: two of the species found in the bromeliads do not exist at the study site, indicating that animals or the wind must have transported the pollen from neighboring regions. In addition, some flowering plants that exist in the area were not necessarily represented in the sample. Even so, collecting pollen from these mini-pools could help characterize the flora of the Caatinga biome.