TITLE: Toolik Snowfence Experiment: 1996-2001 Snowfield Cassiope tetragona quantitative data PRINCIPAL INVESTIGATOR: Dr. Marilyn Walker Leader, Boreal Ecology Cooperative Research Unit USFS PNW Research Station and University of Alaska Fairbanks Boreal Ecology Cooperative Research Unit School of Agriculture and Land Resources Management P.O. Box 756780 University of Alaska Fairbanks Fairbanks, AK 99775-6780 Phone: 907-474-2424 Fax: 907-474-6251 E-mail: ffmdw@uaf.edu FUNDING SOURCE: National Science Foundation ARCTIC SYSTEM SCIENCE PROGRAM: Land-Atmosphere-Ice Interactions (LAII) and The International Tundra Experiment (ITEX) GRANT TITLES AND GRANT NUMBERS: 1994 - 1998: OPP-9400083 -- ITEX / Comparative Responses of Moist and Dry Arctic Tundra to Altered Snow and Temperature Regimes 1999 - 2003: OPP-9907127 -- ITEX / Collaborative Research: Species Responses to Changes in Climate Across Arctic Gradients Using the North America ITEX Network (NATEX): Influences On Community and Ecosystem Processes 1999 - 2003: OPP-9996383 -- ITEX / Comparative Responses of Moist and Dry Arctic Tundra to Altered Snow and Temperature Regimes CONDITIONS FOR USE AND CITATION: For permission to use these data, contact the Principal Investigator. Grant numbers must be cited in any manuscripts resulting from these data. In addition, a copy of the manuscript must be sent to the PI. DATA SET OVERVIEW: This file contains Cassiope tetragona quantitative data collected for the Toolik Snowfence Experiment from 1996 to 2001. The Toolik Snowfence Experiment (part of the International Tundra Experiment network) examines the short- and long-term effects of increased snow depth (shortened growing season) and increased summer temperature on arctic tundra vegetation. The goal of this project is to assess potential changes in tundra plant communities in response to global climate change. Time period covered by data: 19960729 to 20010719 Physical location of measurement: Toolik Field Station, Alaska USA (68.62710 N, 149.59322 W) DATA COLLECTION AND PROCESSING: On six tagged plants in each of the ten snowfield plots, we measured current year's annual growth. Data were collected every 10 days over the growing season in 1997, 1998 and 2000. In 1996 and 2001, data were collected only at peak season. In 1999, these data were not collected. The Toolik Snowfence Experiment's design and manipulation are described further in: Walker, M. D., D. A. Walker, J. M. Welker, A. M. Arft, T. Bardsley, P. D. Brooks, J. T. Fahnestock, M. H. Jones, M. Losleben, A. N. Parsons, T. R. Seastedt and P. L. Turner. 1999. Long-term experimental manipulation of winter snow regime and summer temperature in arctic and alpine tundra. Hydrological Processes 13: 2315-2330. DATA FORMAT: File name: USTOOLIK_snwfld_castet96-01.txt SUMMARY OF VARIABLES FOR 1996-2001 DATA 1. SITE: country/site/project title 2. DATE: date of data collection (YYYYMMDD) 3. LOCATION: site; snowfield 4. PLOT: plot number 5. TREATMENT: treatment, either OTC (open topped chamber) or CTL (control) 6. PLANT: plant number (1-6) 7. ANNUAL_GROWTH: length of current year's annual growth (mm) 8. NOTES DESCRIPTION OF SELECT VARIABLES: SITE USTOOLIK: Toolik Field Station, Alaska, USA; Comparative responses of moist and dry arctic tundra to altered snow and temperature regimes LOCATION Research site: Snowfences are erected and grids established at both a moist tussock site (68.62032 N, 149.59931) and a dry heath site (68.62261 N, 149.59589 W). In addition, monitored plots are established where a natural snowdrift occurs. This site is referred to as the snowfield. TREATMENT ITEX temperature manipulation. OTC: Open-topped chamber (warming), CTL: No chamber (control) CODES USED IN DATA SET In all years "-9999" indicates missing data. Questionable data is indicated by "****" in the notes column. DATA REMARKS: Questionable data are annual growth that decreased over time. This is due to differences in measurement accuracy between dates (number of significant digits). LOCATION OF ORIGINAL DATA SHEETS: Boreal Ecology Cooperative Research Unit, University of Alaska, Fairbanks, Alaska, USA DOCUMENTATION AUTHOR: Original: Amy Breen Carroll, 3 January, 2002 Updated by: Amy Breen Carroll, 18 February, 2002 PRINCIPAL FIELD WORKERS: Andrew Borner PRINCIPAL POSTDOCS: Michael H. Jones Anna Arft PUBLICATIONS WHICH INCLUDE THESE DATA: Arft, A. M., M. D. Walker, J. Gurevitch, J. M. Alatalo, M. S. Bret-Harte, M. Dale, M. Diemer, F. Gugerli, G. H. R. Henry, M. H. Jones, R. D. Hollister, I. S. Jonsdottir, K. Laine, E. Levesque, G. M. Marion, U. Molau, P. Molgaard, U. Nordenhall, V. Raszhivin, C. H. Robinson, G. Starr, A. Stenstrom, M. Stenstrom, O. Totland, P. L. Turner, L. J. Walker, P. J. Webber, J. M. Welker and P. A. Wookey. 1999. Responses of tundra plants to experimental warming: Meta-analysis of the International Tundra Experiment Ecological Monographs 69(4): 491-511.