DOI: 10.5061/dryad.pn63g
title: Data from: Vegetation patterns in small boreal streams relate to ice and winter floods

description: 1. In-stream and riparian vegetation is species-rich, productive and
 dynamic. Its patterns in small boreal streams are largely driven by
 seasonal flow regimes. Traditionally, flow-related processes during the
 growing season, particularly the spring flood, have been seen as the most
 important, whereas vegetation has been viewed as being dormant and ‘less
 affected’ during winter. 2. Riparian and in-stream vegetation was
 inventoried during the summers 2011‒2013 in eight reaches of northern
 Swedish streams. Along each reach the ice formation was surveyed during
 winter by visual inspections and with permanently placed cameras. We then
 evaluated the potential effects of ice regimes and winter flooding on
 riparian and in-stream vegetation during 3 years by relating the abundance
 of winter floods caused by anchor-ice to the cover, composition and
 biomass of vegetation. 3. We found that the numbers of winter floods were
 higher along reaches with anchor-ice formation than in reaches without. We
 also found that species diversity of riparian vegetation was higher in the
 reaches with anchor-ice. This resulted from a lower cover of riparian
 dwarf shrubs and a higher cover of graminoids and forbs along reaches with
 anchor-ice. We also found a lower cover of in-stream algae but a higher
 cover of bryophytes in anchor-ice reaches. These patterns were consistent
 throughout the study period although there were interannual differences in
 temperature, water levels and ice cover. 4. During our study period, we
 encountered an average of 20 shifts per winter between freezing and
 thawing, while there was an average of 10 shifts per winter during
 1960‒1990. This indicates a warming climate in high latitudes. Higher
 temperatures and more shifts between freezing and thawing may initially
 increase ice dynamics. However, with further increases in mean temperature
 ice production should eventually decrease. 5. Synthesis. Ice and winter
 floods caused by anchor-ice appear to be important disturbance agents that
 allow less competitive species to establish along small boreal streams. If
 ice dynamics is reduced, the composition and production of riparian and
 in-stream vegetation may be changed, with possible consequences for the
 entire stream ecosystem.
description: Biomass of riparian
 vegetationBiomass of functional
 groups (forbs, shrubs and grasses) of riparian vegetation. Data were
 sampled for three years. Included is also pysical data for the different
 stream reaches.Biomass.csvInstream vegetation coverInstream bryophyte and algae cover from eight stream reaches. Physical data such as substrate, depth and discharge of the stream reaches is also included in the data set. Information of sampling can be found in the paper.Instream_bryophytes_phys.csvCover of riparian bryophytesPercent cover of riparian bryophytes along eight stream reaches at different elevations from the channel. Physical data and presence of anchor ice is also included.Riparian_bryophytes.csvTemperature and water levelsData from temperature and pressure loggers, both air and water. From eight stream reaches 2011-2013.Water_Air_temp_levels.csvIce inventory dataPercent cover of surface, suspended and anchor ice along eight stream reaches, 2011-2013.Icedata.csvCover of vascular plants 2011Percent cover of vascular plant species in the riparian zone and three different elevations from the stream channel. Data from 2011.Riparian_vascular_2011.csvCover of vascular plants 2012Percent cover of vascular plant species in the riparian zone at three different elevations from the stream channel. Data from 2012.Riparian_vascular_2012.csvCover of vascular plants 2013Percent cover of vascular plant species in the riparian zone at three different elevations from the stream channel. Data from 2013.Riparian_vascular_2013.csvR-scriptR-script for analysis of biomass of different functional groups, riparian bryophyte cover and in-stream cover of algae and bryophytes.Rscript.txt