A study looked at how a moss called Polytrichum commune responds to intense light stress in a lab setting. They used different levels of light stress and monitored the moss's chlorophyll levels over time. The results showed that the moss can handle light stress pretty well, with some changes in its chlorophyll levels. Xanthophyll pigments and changes in a part of the moss called PS II help protect it from the stress. The moss also copes better with stress when it's a little dehydrated. These findings suggest that Polytrichum commune is well-adapted to survive in tough alpine environments.