Welker IPY snow shrub 2007 flux data, Toolik, Alaska.


This is a study of how different snow regimes effect CO2 exchange in tussock tundra and whether there are shifts in ecosystem C cycling when facets of "drift" effects are isolated. The study is part of the IPY program and is aimed at measuring the state of Arctic tundra.

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Published on EDI/LTER Data Portal


Welker, J., Sullivan, P. 2011. Welker IPY snow shrub 2007 flux data, Toolik, Alaska. Environmental Data Initiative. http://dx.doi.org/10.6073/pasta/288210c11a86847870d9c96577ad0839

Date Range: 

Saturday, June 2, 2007 to Thursday, August 9, 2007

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This is CO2 flux data, NEE and Re, from four locations on the eastern side of the Toolik River where by snow fences were established as part of IPY. We measured CO2 excange during the summer of 2007 multiple times and at 3 locations (3 replicates) with four treatments, control, drift, drift and shoveled and drift, shoveled and watered ( C, D, DS, DSW). The three replicates were called: upper, south, north (U, S, N).

During the snow-free growing season (June-August), ecosystem CO2 fluxes were measured using a clear plexiglass chamber (0.5 x 0.5 x 0.40 cm). Net ecosystem exchange (NEE) and ecosystem respiration (ER) measurements were made at mid-day in tussock and intertussock location. CO2 concentration, temperature and humidity within the chamber were monitored using a LI-6200 portable photosynthesis system (LI-COR Biosciences, Lincoln, NE). The chamber was fitted with two small fans and a sensor to measure photosynthetic photon flux density (PPFD). The chamber was vented to the atmosphere between measurements until [CO2] returned to ambient levels. CO2 exchange rates during the clear and dark chamber measurements were calculated following Hooper et al. (2002). Photosynthesis is presented as a positive flux and respiration as a negative flux in this study. Therefore, gross ecosystem photosynthesis (GEP) was determined by subtracting ER (dark chamber) from NEE (clear chamber).

Version Changes: 

Version 1 : Mar 2011 Received file from Jeff Welker. Updated the metadata sheet and created eml files and web files. JimL
Version 2: added missing code for flux and location name. JimL 5June13
Version 3: Corrected Distrubution URL. It had xlsfiles in the path. Jim L 19Jun14
Version 4: Changed Distrubution URL since the LTER network DAS system is being discontinued. JimL 9Apr2015

Sites sampled.

Full Metadata and data files (either comma delimited (csv) or Excel) - Environmental Data Initiative repository.

Use of the data requires acceptance of the data use policy --> Arctic LTER Data Use Policy