These communities must have reached Mount Melbourne from far away. Transport was probably by wind as there is no flowing water in the region. Mount Melbourne was recently active, located south of the Antarctic Circle thus has a polar night lasting 13 weeks, the soils contain toxic elements such as mercury, the volcano is distant from ecosystems that could be the source of colonization events and away from the westerlies, which may explain why the vegetation is species-poor. Pohlia nutans may have arrived only recently on Mount Melbourne, or this volcano is not as favourable for its growth as Mount Rittmann where this moss is more common. Its colonies are less vigorous colonies on Mount Melbourne than Campylopus pyriformis.