title: Transitions in high-Arctic vegetation growth patterns and ecosystem productivity tracked with automated cameras from 2000 to 2013.
abstract: Climate-induced changes in vegetation phenology at northern latitudes are still poorly understood. Continued monitoring and research are therefore needed to improve the understanding of abiotic drivers. Here we used 14 years of time lapse imagery and climate data from high-Arctic Northeast Greenland to assess the seasonal response of a dwarf shrub heath, grassland, and fen, to inter-annual variation in snow-cover, soil moisture, and air and soil temperatures. A late snow melt and start of growing season is counterbalanced by a fast greenup and a tendency to higher peak greenness values. Snow water equivalents and soil moisture explained up to 77 % of growing season duration and senescence phase, highlighting that water availability is a prominent driver in the heath site, rather than temperatures. We found a significant advance in the start of spring by 10 days and in the end of fall by 11 days, resulting in an unchanged growing season length. Vegetation greenness, derived from the imagery, was correlated to primary productivity, showing that the imagery holds valuable information on vegetation productivity.
authors.affiliation: Department of Geosciences and Natural Resource Management, University of Copenhagen, Oestervoldgade 10, 1350, Copenhagen, Denmark. awn@ign.ku.dk.|Center for Permafrost (CENPERM), University of Copenhagen, Oestervoldgade 10, 1350, Copenhagen, Denmark. awn@ign.ku.dk.
authors.forename: Andreas
authors.initials: A
authors.lastname: Westergaard-Nielsen
authors.affiliation: Department for Bioscience, Arctic Research Centre, Aarhus University, Frederiksborgvej 399, 4000, Roskilde, Denmark.
authors.forename: Magnus
authors.initials: M
authors.lastname: Lund
authors.affiliation: Department for Bioscience, Arctic Research Centre, Aarhus University, Frederiksborgvej 399, 4000, Roskilde, Denmark.
authors.forename: Stine Højlund
authors.initials: SH
authors.lastname: Pedersen
authors.affiliation: Department for Bioscience, Arctic Research Centre, Aarhus University, Frederiksborgvej 399, 4000, Roskilde, Denmark.
authors.forename: Niels Martin
authors.initials: NM
authors.lastname: Schmidt
authors.affiliation: Department of Organismic and Evolutionary Biology, Harvard University, Cambridge, MA, 02138, USA.
authors.forename: Stephen
authors.initials: S
authors.lastname: Klosterman
authors.affiliation: Greenland Survey, Asiaq, Svend Jungep Aqqutaa 8, 3900, Nuuk, Greenland.
authors.forename: Jakob
authors.initials: J
authors.lastname: Abermann
authors.affiliation: Department of Geosciences and Natural Resource Management, University of Copenhagen, Oestervoldgade 10, 1350, Copenhagen, Denmark.|Center for Permafrost (CENPERM), University of Copenhagen, Oestervoldgade 10, 1350, Copenhagen, Denmark.
authors.forename: Birger Ulf
authors.initials: BU
authors.lastname: Hansen
mesh_terms: D001110:Arctic Regions; D002980:Climate; D064308:Ecological Parameter Monitoring / Q000379:methods*; D065948:Grassland; D006116:Greenland; D063245:Plant Development; D012621:Seasons; D012914:Snow; D013696:Temperature; D059008:Time-Lapse Imaging
keywords: High-Arctic; Photography; Primary productivity; Time lapse; Vegetation phenology