A team of researchers from the Smithsonian Tropical Research Institute (STRI) is digitizing images of pollen from more than 18,000 plant species from the tropics. These images are being used to train a machine-learning model to identify pollen grains, a job that usually takes hundreds of hours of microscopy work by pollen experts. The images also will make a wide range of new pollen analyses possible. The resulting database, called PollenGEO, will be free online.
Previously, specialists identified pollen grains one by one under a microscope using illustrated handbooks as a reference. That process is very time consuming and can be particularly challenging in the tropics where there are thousands of plant species, many of them not yet identified. It is also challenging to identify pollen in ancient layers of rock because many of the plant species that produced the pollen are now extinct.
To resolve these challenges, more than 30 researchers and students at STRI led by staff palynologist, Carlos Jaramillo, are digitizing the entire Smithsonian palynological collection; the team are uploading more than 40 million photos of pollen grains from known plant species to create a database.
Croton capitatus, one of more than 40 million recently digitized images of pollen from the Smithsonian collections.
Most samples derive from the Graham Palynological Collection, donated to STRI in 2008, which holds about 18,000 species of mostly tropical pollen on more than 23,000 microscope slides, each accompanied by an index card that describes the sample. About 100 volunteers working through the Smithsonian Transcription Center helped enter the information from the cards into the database.
The collection also includes the Joan Nowicke collection, the Barro Colorado Island collection by Dave Roubik and Enrique Moreno, the Amazon collection made by Paul Collinvaux, and the Sian Ka’an collection, which contains 650 species from southeastern Mexico. In addition, approximately 1,000 fossil pollen samples have been scanned from museum collections at the National Museum of Natural History.
From an STRI press release.