Abstract: From the walden.org website: "On July 6, 2019, one-hundred taxonomic specialists joined over 150 members of the general public to celebrate Professor E.O. Wilson’s 90th birthday and the legacy of Henry David Thoreau in a one-day BioBlitz of Walden Woods. Collectively, we reported 2,242 species over the 24 hours (plus a little). A number of state-listed rare species were found, along with some unexpected organisms new to the area. The 2019 Great Walden BioBlitz was the third decennial event, raising the total number of species observed in a 5-mile radius around Walden Pond to to over 3,690!"
Unlike previous BioBlitzes in this location, in 2019, the BioBlitz boundary was announced as "a 5-mile radius around Walden Pond". Also, unlike previous years, the general public was invited to contribute observations via iNaturalist. These changes could explain the large number of different/new lichen taxa reported, compared to previous Walden Woods BioBlitzes.