Open AccessRapid responses of permafrost and vegetation to experimentally increased snow cover in sub-arctic Sweden
Author(s) -
Margareta Johansson,
Terry V. Callaghan,
Julia Bosiö,
H. Jonas Åkerman,
Marcin Jackowicz-Korczyński,
Torben R. Christensen
Publication year - 2013
Publication title -
environmental research letters
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 2.37
H-Index - 124
ISSN - 1748-9326
DOI - 10.1088/1748-9326/8/3/035025
Subject(s) - permafrost , snow , environmental science , graminoid , vegetation (pathology) , physical geography , arctic , plateau (mathematics) , peat , arctic vegetation , precipitation , snow cover , subsidence , climatology , atmospheric sciences , hydrology (agriculture) , geology , ecology , tundra , ecological succession , plant community , geomorphology , geography , structural basin , oceanography , meteorology , medicine , mathematical analysis , mathematics , geotechnical engineering , pathology , biology
Increased snow depth already observed, and that predicted for the future are of critical importance to many geophysical and biological processes as well as human activities. The future characteristics of sub-arctic landscapes where permafrost is particularly vulnerable will depend on complex interactions between snow cover, vegetation and permafrost. An experimental manipulation was, therefore, set up on a lowland peat plateau with permafrost, in northernmost Sweden, to simulate projected future increases in winter precipitation and to study their effects on permafrost and vegetation. After seven years of treatment, statistically significant differences between manipulated and control plots were found in mean winter ground temperatures, which were 1.5 degrees C higher in manipulated plots. During the winter, a difference in minimum temperatures of up to 9 degrees C higher could be found in individual manipulated plots compared with control plots. Active layer thicknesses increased at the manipulated plots by almost 20% compared with the control plots and a mean surface subsidence of 24 cm was recorded in the manipulated plots compared to 5 cm in the control plots. The graminoid Eriophorum vaginatum has expanded in the manipulated plots and the vegetation remained green longer in the season