[5] A 1989 study near Casey Station, Antarctica found that U. sphacelata showed potential for photosynthetic activity even under challenging environmental conditions.

[6] Other research conducted near Casey Station revealed that U. sphacelata exists in two forms: a blackish pigmented light-form found in exposed sites and a yellowish shade-form in sheltered habitats.

The lichen shows signs of photoinhibition (decreased photosynthetic rate) when exposed to light levels above 600 μmol m⁻² s⁻¹ PAR, particularly at lower temperatures, suggesting that it photosynthesises most efficiently during overcast conditions.

During the studied austral summer period, the lichen was only physiologically active for about 27% of the time, primarily when moistened by snow, producing approximately 3.44 g carbon per square meter.

This productivity is significantly lower than laboratory studies had suggested, highlighting the challenges of survival in the Antarctic environment.