In situ monitoring of microclimate and metabolic activity in lichens from Antarctic extremes: a comparison between South Shetland Islands and the McMurdo Dry Valleys

摘要: Lichens are the dominant organisms in terrestrial Antarctic ecosystems and show a decline species number, coverage, growth rate from maritime (62°S) to McMurdo Dry Valleys (78°S). While Livingston Island (maritime Antarctica) is hot spot for lichen biodiversity, (continental known as one of most extreme environments life. Previous studies suggest biodiversity gradient be linked water availability acting through length active period, but no activity data available Valleys. The work presented here compares metabolic lichens at 4½ months continuous monitoring that involves concurrent measurements chlorophyll fluorescence microclimate. latitudinal comparison two contrasting habitats plant physiological Two foliose genus Umbilicaria were monitored both regions plus sample crustose Caloplaca results showed very large difference duration over this supports different abundance, rates already reported between regions. Despite activity, habitat conditions, analysis behaviour shows interesting common features, while had additional strategies improve hydration. This offers explanation abundance inside Valleys, indicating better adaptation polar desert.