TITLE: Toolik Snowfence Experiment: 1995-2001 Snowdrift depth 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 snowdrift depth data collected for the Toolik Snowfence Experiment from 1995 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: 19950504 to 20010626 Physical location of measurement: Toolik Field Station, Alaska (68.62710 N, 149.59322 W) DATA COLLECTION AND PROCESSING: Data were collected from 1995 to 2001, beginning at field site arrival and every two to three days thereafter, until complete snow melt. Drift depth is measured with permanent graduated snow poles arranged in a grid at the moist tussock and dry heath sites. Poles are in rows (parallel to the east-west aligned snowfence) at distances of 5, 10, 20, 30, 40, 50, 60 and 70 m north of the snowfence and 5, 10, 20, 30 and 40 m south of the snowfence (x coordinates). In each row, poles are positioned every 10 m, from 0 m west to 60 m (y coordinates). Additional poles are erected in Zone 0 (moist site only) and at the snowfield. Positive x coordinate values are north of the snowfence (drift side); negative values are south of the fence (windward side). See the data remarks section below for annual variation of this method. 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_driftdepth95-01.txt SUMMARY OF VARIABLES FOR 1995-2001 DATA 1. SITE: country/site/project title 2. DATE: day of data collection (YYYYMMDD) 3. LOCATION: site; moist, dry or snowfield 4. POSITION: north (leeward/drift side) or south (windward side) of the snowfence 5. FROM_SNOWFENCE: distance from snowfence (south to north, m) 6. ON_SNOWFENCE: position in row (east to west, m) 7. DRIFT_DEPTH (cm) 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. CODES USED IN DATA SET In all years "-9999" indicates missing data. Estimated data is indicated by an "EEEE" in the notes column. DATA REMARKS: Drift depth was measured to the nearest 5 cm from 1995 to 1997, and to the nearest 10 cm thereafter. Absence of drift depth values south of the snowfence (1995, 1997, 1999) and at the snowfield (1998) occurs because those areas were snow free prior to arrival at the site. Drift depth was measured with an avalanche probe on 4 May, 1995 by Skip Walker. This data includes additional coordinates and is measured to the nearest 1 cm. Drift depth data collected in 1998 is not included in this dataset. LOCATION OF ORIGINAL DATA SHEETS: Boreal Ecology Cooperative Research Unit, University of Alaska, Fairbanks, Alaska, USA DOCUMENTATION AUTHOR: Original: Amy Breen Carroll, 13 April, 2001 Updated by: Amy Breen Carroll, 20 December, 2001 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: None to date.