Sticta species with cyanobacteria as photobionts can fix nitrogen from the atmosphere, and due to their relative abundance and high turnover, they contribute appreciably to the rainforest ecosystem.

[4] Photobiont partners of Sticta species include members of the green algae genera Chloroidium, Coccomyxa, Elliptochloris, Heveochlorella, and Symbiochloris.

[4] Phylogenetic analysis of small and large ribosomal RNA subunits has confirmed that the genus Sticta is monophyletic.

[9][10] Some epiphytic lichen species may be used as "ancient woodland indicators"; they can used to quantitatively assess the degree to which a forest has had a long history of canopy continuity.

[11] The presence of these species is a reliable indicator that the forest has existed back to early medieval times, without being clear-cut and regrown.