Arctic Vegetation Archive - Alaska: Flux Towers-Zona:
Vegetation plots within the Flux Towers-Zona project eddy covariance tower footprints at Barrow: (three towers) including the Barrow Environmental Observatory Flux Tower (BEO), Barrow Biocomplexity Experiment South Tower (BES), and Climate Monitoring and Diagnostics Laboratory Flux Tower (CMDL), at Atqasuk: the Atqasuk Flux Tower (ATQ), and at Ivotuk: Ivotuk Flux Tower (IVO), were described by Scott J. Davidson and Victoria L. Sloan during the summer of 2014. The research was supported by the Division of Polar Programs of the National Science Foundation (NSF) awarded to Donatella Zona (award number 1204263) and Carbon in Arctic Reservoirs Vulnerability Experiment (CARVE) awarded to Walter Oechel, an Earth Ventures (EV-1) investigation, under contract with the National Aeronautics and Space Administration, and Department of Energy (DOE) Grant DE-SC005160, with logistical support funded by the NSF Division of Polar Programs. Scott Davidson also received funding from a NERC PhD studentship, and Victoria Sloan was partly funded by CYCLOPS (Carbon Cycle Linkages of Permafrost Systems) NERC (UK) grant NE/K00025X/1 awarded to Gareth K. Phoenix.
Within each flux tower footprint, five or ten 1 x 1 m quadrats were placed subjectively within widespread habitat or micro-habitat types identified during initial walkover surveys. At the Barrow-BEO site, habitats consist of polygon rims, low centers (ponds), flat centers, high centers and wet troughs (50 quadrats). At the Barrow-BES site, quadrats were placed close to a boardwalk crossing a drained lake basin (10 quadrats). At the Barrow-CMDL site, habitats were polygon high centers and troughs, and a relatively flat homogenous area unaffected by thaw lake processes (20 quadrats). At Atqasuk-ATQ site, habitats included polygon low centers and ridges on sandy soils (30 quadrats). Ivotuk-IVO habitats comprise a stable plateau, wet meadows on the margin of a watercourse, and a north-west facing slope (30 quadrats). CMDL plots were not included in the analyses by Scott Davidson, but are included in the Flux Towers-Zona dataset.
Differential GPS coordinates were obtained for each plot on the date of survey. Species cover data and environmental, soils and spectral data (active layer thaw depth, moss layer depth, organic horizon layer depth, standing water depth, soil moisture status, vegetation height, LAI (Ivotuk)) were collected in the field. A field spectroscopy measurement was also taken at each plot using a DC UniSpec hand held spectrometer.
The vegetation and spectral data were used to model the relationships between gross primary productivity, dissolved organic carbon, and CH4 fluxes which resulted in the finding that vegetation types are an important consideration when modeling CH4 emissions (Davidson et al. 2016). Additional work suggests that plot-level spectroscopy with hand-held sensors may, with difficulty, be scaled to patch level using spectroscopy data rescaled to match specific wavelengths, but is a demanding process due to vegetation heterogeneity.
References
Davidson, S.J., V. L. Sloan, G. K. Phoenix, R. Wagner, J. P. Fisher, W. Oechel and D. Zona. 2016a. Vegetation type dominates the spatial variability in CH4 Emissions across multiple arctic tundra landscapes. Ecosystems 19:1116-1132. doi:10.1007/s10021-016-9991-0.
Davidson, S. J., M. J. Santos, V. Sloan, J. D. Watts, W. C. Oechel, and D. Zona. 2016b. Mapping Arctic Tundra Vegetation Communities Using Field Spectroscopy and Multispectral Satellite Data in North Alaska, U.S.A. Remote Sensing. 8(12):978; dos:10.3390/rs8120978.
