Spruce and Peatland ResponsesUnder Changing Environments
This data set consists of phenological transition dates, as derived from direct observations of vegetative and reproductive phenology recorded by a human observer, from the SPRUCE experiment during 2018, the third full year of whole-ecosystem warming (Hanson et al. 2017). Both spring and autumn phenological events are included.
Since April 2016, human observers have been directly tracking the phenology of both woody and herbaceous species on a weekly schedule within the SPRUCE experimental chambers. The observed date report here is the first survey date on which an event/phenophase was definitively observed.
This dataset consists of PhenoCam data from the SPRUCE experiment from the beginning of whole ecosystem warming (Hanson et al. 2017) in August 2015 through March-31 of 2019, with start- and end-of-season phenological transition dates derived through the end of autumn 2018.
Digital cameras, or phenocams, installed in each SPRUCE enclosure track seasonal variation in vegetation “greenness”, a proxy for vegetation phenology and associated physiological activity. Three separate regions of interest (ROIs) were defined for each camera field of view, corresponding to different vegetation types and demarcating: Picea trees (vegetation type EN, for evergreen needleleaf); Larix trees (vegetation type DN, for deciduous needleleaf); and the mixed shrub layer (vegetation type SH).
This data set consists of reflectance observations from hyperspectral remote sensing of the vegetation communities in SPRUCE experimental study plots located in the S1-Bog. Community vegetation plots in ten chambered treatment plots (6, 19, 11, 20, 4, 13, 8, 16, 10, 17) and 3 unchambered ambient plots (7, 14, 21) were scanned. Spectral data were collected on 22 September 2016 under clear sky conditions beginning at 1:00 p.m. local time. Although it was past peak growing season, senescence had only just begun at the site, and experimentally warmed plots were still near peak growing conditions.
This data set reports the tritium concentrations in (1) porewater from selected SPRUCE experimental plots located in the S1 bog and in (2) groundwater, streamwater, and precipitation in the S1 bog watershed, and (3) in porewater from the S2 bog, S3 fen, and Bog Lake fen. All sites are located at the USDA Forest Service, Marcell Experimental Forest (MEF) near Grand Rapids, MN. Samples were collected between June of 2014 and August of 2016.
These data include samples collected pre- and post- belowground warming treatments associated with the SPRUCE Experiment. There are 10 experimental plots in SPRUCE: 5 temperature treatments (+0, +2.25, +4.5, +6.75, +9°C) at ambient CO2, and the same 5 temperature treatments at elevated CO2 (+500 ppm).
Porewater samples in this dataset were collected from three of the warming treatment plots (+0, +4.5, +9°C) at ambient CO2.
