| Summary: | The data presented were collected on the second summer of the experiment, in 2000, during summers of 2007 or 2008, 2012, and 2017 for 48 plots (24 experiment open-top chamber plots and 24 control plots) at four sites (Atqasuk Wet Meadow, Atqasuk Dry Heath, Barrow Wet Meadow, and Barrow Dry Heath) and 2014 for 8 plots (4 control and 4 experimental) at two sites (Barrow Dry Heath and Atqasuk Dry Heath). The data were gathered by placing a Point Frame over each plot and recording the top and bottom species at each location in years prior to 2007 and every contact after then. The height of the top species was recorded relative to the ground at that location. The grids were spaced 7 cm apart and started at 3.5 cm from the edge of the square 70 cm frame. The species was recorded at each location along with its height relative to the ground surface. Occasionally it was difficult to distinguish which species was on the ground because there were several intertwined individuals, therefore preference was given to vascular plants, then lichens, and then mosses. Due to the limitations of field identification many species were lumped into larger taxa. The taxa provide are relatively robust, however even with the species lumping presented there may have been some difficulty with bryophytes and lichens. Prior to 2007 the sampling only involved the top and bottom hits. In 2007 or 2008, 2012, and 2017 all hits were recorded. The height of each hit was estimated for the first sampling (1995-1997). In 2014 only 8 plots from each dry site were sampled as soil samples were taken from these plots.
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