A research team from the Aerospace Information Research Institute of the Chinese Academy of Sciences (AIRCAS), in collaboration with Argentina's Center for Advanced Studies in Earth Sciences and Biodiversity (CADIC-CONICET), has identified critical blind spots in current Antarctic vegetation mapping caused by the poor detectability of dark-colored lichens.

Recently published in The Innovation, their findings demonstrate that conventional optical remote sensing methods systematically underestimate vegetation coverage across Antarctica, with the issue being particularly pronounced in regions dominated by dark-colored lichens.

Specifically, in the lower-latitude South Shetland Islands, vegetation coverage is underestimated by approximately 31.5%, and dark-colored lichens account for 73% of this discrepancy.

In the higher-latitude northeastern Antarctic Peninsula, lichens make up as much as 90% of total vegetation coverage. Even so, spectral indices frequently classify these areas as "non-vegetated." Additionally, the study reveals that the higher the proportion of dark-colored lichens, the more severe the underestimation—pointing to a systematic bias in existing Antarctic vegetation mapping frameworks.

Furthermore, the researchers integrated observations with a recently released lichen geospatial dataset to quantitatively assess how "invisible vegetation" drives mapping errors. Their results show that dark-colored lichens constitute an average of 54% of Antarctic lichen communities: in lower-latitude regions, this proportion exceeds 40%, while in higher latitudes, it reaches nearly 80%. This uneven distribution creates spatially biased underestimation, which distorts cross-regional vegetation analyses and impedes accurate evaluations of both vegetation distribution and ecosystem dynamics.

The study highlights that future Antarctic vegetation remote sensing should focus on high-latitude lichen hotspots through long-term monitoring and model optimization, the researchers noted.

Dark-colored lichens on the Antarctica. (Image by AIRCAS)