IPYsnowshrub2007 Jeff Welker

Ecosystem/Biomedical Lab University of Alaska Anchorage AK 99508 USA

Paddy Sullivan

Ecosystem/Biomedical Lab University of Alaska Anchorage AK 99508 USA

Arctic LTER Program

The Ecosystems Center Marine Biological Lab 7 MBL St Woods Hole MA 02543 USA

(508) 289 7496 arc_im@mbl.edu http://ecosystems.mbl.edu/ARC/ 2011 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. snow fences CO2 flux NEE Re productivity distrubance Acceptance and utilization of LTER data requires that: The Principal Investigator be sent a notice stating reasons for acquiring any data and a description of the publication intentions. The Principal Investigator of the data set be sent a copy of the report or manuscript prior to submission and be adequately cited in any resultant publications A copy of any resultant publications should be sent to: Principal Investigator Ecosystems Center Marine Biological Laboratory Woods Hole, MA 02543 http://ecosystems.mbl.edu/ARC/meta_template.php?FileName=./Welker/IPY_Snow_shrub/2008_CO2_Flux_Welker.html Four locations on the eastern side of the Toolik River where by snow fences were established as part of IPY near Toolik Lake on the North Slope of Alaska -149.5712167 -149.5712167 68.623608 68.623608 2008-06-08 2008-08-14 Version 1 : Mar 2011 Received file from Jeff Welker. Updated the metadata sheet and created eml files and web files. JimL Data Manager

The Ecosystems Center Marine Biological Lab 7 MBL St Woods Hole MA 02543 USA

(508) 289 7496 arc_im@mbl.edu http://ecosystems.mbl.edu/ARC/ ARC LTER

The Ecosystems Center Marine Biological Lab 7 MBL St Woods Hole MA 02543 USA

(508) 289 7496 arc_im@mbl.edu http://ecosystems.mbl.edu/ARC/ 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). pers-1 Jeff Welker

Ecosystem/Biomedical Lab University of Alaska Anchorage AK 99508 USA

afjmw1@uaa.alaska.edu Lead PI Mechanisms and feedback consequences of shrub expansion following long-term increases in winter snow depth in northern Alaska: a legacy for IPY NSF-OPP 0612534 The primary aims of this project have been to understand the mechanisms and feedback consequences of shrub increases in northern Alaska using experimental, observational and expedition research. We have undertaken studies at Toolik Lake, Alaska and across the north slope along the Colville and Noatak rivers and in the Chandalar River drainage. Our studies have implement new snow manipulation experiments and we have utilized a snow experiment that was initiated by NSF OPP in 1994. We implemented the first wind turbine powered research at Toolik Lake that powered our CO2 sensors over winter allowing for winter-long quantification of C losses in areas where shrubs have been increasing and in ambient areas. We conducted vegetation surveys along the major river drainages and have characterized areas with expanding and stagnate shrub growth which appear to be related to disturbance history, subsequent soil properties, plant water and nutrient relations and growth. We have also used 14C measurements to depict the loss of ancient C to the atmosphere as snow accumulates when shrubs become an increasing large component of the landscape. This material is based upon work supported by the National Science Foundation under Grants #NSF-OPP 0612534. Any opinions, findings, conclusions, or recommendations expressed in the material are those of the author(s) and do not necessarily reflect the views of the National Science Foundation. uid=ARC,o=lter,dc=ecoinformatics,dc=org all public read 2008_CO2_Flux_Welker.csv Welker IPY snow shrub 2008 flux data, Toolik, Alaska. 2008_CO2_Flux_Welker.csv 1 column , http://metacat.lternet.edu/das/dataAccessServlet?docid=knb-lter-arc.10111&urlTail=Welker/IPY_Snow_shrub/data/2008_CO2_Flux_Welker.csv Block Block Block-these are the locations of the set of treatments-one block consist of all four snow treatments: upper,south, north Block-these are the locations of the set of treatments-one block consist of all four snow treatments: upper,south, north Treatment Treatment Treatment-these are the four different snow mannipulaiton treatments, control where now fence was put up, a drift treatment which is behind the snow fence (1 m x 15 m), the drift plus shoveling which involved snow removal before melt and drift, plus shoveling plus added water after melt. Treatment-these are the four different snow mannipulaiton treatments, control where now fence was put up, a drift treatment which is behind the snow fence (1 m x 15 m), the drift plus shoveling which involved snow removal before melt and drift, plus shoveling plus added water after melt. date date Date is the calender day of flux measurements dd/mm/yyyy plot plot Plot is the subsamples within a treatment: A, B, C Plot is the subsamples within a treatment: A, B, C type type Type is measurments in between tussocks or on tussocks Type is measurments in between tussocks or on tussocks measurement measurement measurements are: NEE-net ecosystem CO2 exchange and ER = ecosystem respiratiaon measured with covered chamber measurements are: NEE-net ecosystem CO2 exchange and ER = ecosystem respiratiaon measured with covered chamber flux flux flux is the rate of CO2 exchange micromolePerMeterSquaredPerSecond real 2008_CO2_Flux_Welker.xls An excel file that has worksheets with the metadata and data. 2008_CO2_Flux_Welker.xls Microsoft Excel http://metacat.lternet.edu/das/dataAccessServlet?docid=knb-lter-arc.10111&urlTail=Welker/IPY_Snow_shrub/xlsfiles/2008_CO2_Flux_Welker.xls Microsoft Excel file micro Einsteins (1E-06 moles of photons) per square meter per second (radiant flux density)