title: Biogeography of photoautotrophs in the high polar biome.
abstract: The global latitudinal gradient in biodiversity weakens in the high polar biome and so an alternative explanation for distribution of Arctic and Antarctic photoautotrophs is required. Here we identify how temporal, microclimate and evolutionary drivers of biogeography are important, rather than the macroclimate features that drive plant diversity patterns elsewhere. High polar ecosystems are biologically unique, with a more central role for bryophytes, lichens and microbial photoautotrophs over that of vascular plants. Constraints on vascular plants arise mainly due to stature and ontogenetic barriers. Conversely non-vascular plant and microbial photoautotroph distribution is correlated with favorable microclimates and the capacity for poikilohydric dormancy. Contemporary distribution also depends on evolutionary history, with adaptive and dispersal traits as well as legacy influencing biogeography. We highlight the relevance of these findings to predicting future impacts on diversity of polar photoautotrophs and to the current status of plants in Arctic and Antarctic conservation policy frameworks.
authors.affiliation: Institute for Applied Ecology New Zealand, School of Applied Sciences, Auckland University of Technology , Auckland, New Zealand.
authors.forename: Stephen B
authors.initials: SB
authors.lastname: Pointing
authors.affiliation: Department of Biology, University of Kaiserslautern , Kaiserslautern, Germany.
authors.lastname: Burkhard Büdel
authors.affiliation: British Antarctic Survey, NERC , Cambridge, UK ; National Antarctic Research Centre, University of Malaya , Kuala Lumpur, Malaysia.
authors.forename: Peter
authors.initials: P
authors.lastname: Convey
authors.affiliation: Institute for Applied Ecology New Zealand, School of Applied Sciences, Auckland University of Technology , Auckland, New Zealand.
authors.forename: Len N
authors.initials: LN
authors.lastname: Gillman
authors.affiliation: Institute of Botany, University of Basel , Basel, Switzerland.
authors.forename: Christian
authors.initials: C
authors.lastname: Körner
authors.affiliation: Institute for Applied Ecology New Zealand, School of Applied Sciences, Auckland University of Technology , Auckland, New Zealand.
authors.forename: Sebastian
authors.initials: S
authors.lastname: Leuzinger
authors.affiliation: Centre d'\Études Nordiques and Département de Biologie, Université Laval , Québec, QC, Canada.
authors.forename: Warwick F
authors.initials: WF
authors.lastname: Vincent
keywords: antarctic; arctic; bryophytes; cryptogams; cyanobacteria; lichen; plant biogeography