ITEX DATABASE TOOLIK LAKE FIELD STATION, ALASKA, USA 2000 DATA ***** For permission to use these data, please contact the appropriate principal investigator(s) (listed below). ***** ITEX POINT-QUADRAT DATA DOCUMENTATION Documentation file: README_USTOOL1_2000archive.txt Data file: USTOOL1ptframe2000_archive.txt BRIEF DESCRIPTION OF DATA FILE: Vegetative community dataset collected during the 2000 field season using a fixed, 75 cm square point frame, with 100 measurements spaced 7 cm apart. At each of 100 points per plot, the following information was recorded in a spatially explicit format: species hit, condition, woodiness and repeatability. Plot manipulations include 1) temperature: warming (open top chamber) and control (no chamber) and 2) altered snowpack: plots are established in a grid on the leeward side of a snowfence which divides each site into 6 parallel zones that differ in distance from the snowfence, and therefore, also in snow drift depth. The experiment is established at both a moist tussock and dry tundra site. The experimental design and manipulation are described further in: Walker, M. D. et al. (1999), Long-term experimental manipulation of winter snow regime and summer temperature in arctic and alpine tundra: an integrated ecosystem approach, Hydrological Processes, 13: 2315-2330. Henry, G. H. R. and U. Molau (1997), Tundra plants and climate change: the international tundra experiment (ITEX), Global Change Biology, 3: 1-9. SUMMARY OF VARIABLES 1.SITE: country/site/experiment (see below) 2.DATE: date of data collection; yyyymmdd 3.PLOT: unique plot number 4.WARMING: main ITEX treatment (see below) 5.LOCATION: site; moist or dry 6.ZONE: 0 - 6 (see below) 7.CODE: hit; 6-8 character species or ground condition code (see below) 8.HEIGHT: distance from frame to species or ground (cm) 9.XCOORD: X coordinate of point frame grid (cm) 10.YCOORD: Y coordinate of point frame grid (cm) 11.CONDITION: condition of hit (see below) 12.WOODY:location of hit (see below) 13.QUANTITY: number of hits DESCRIPTION OF SELECT VARIABLES 1. SITE Alaska, USA; Toolik Lake Field Station; Comparative responses of moist and dry arctic tundra to altered snow and temperature regimes 4. WARMING ITEX temperature manipulation. OTC: Open-topped chamber, CTL: No chamber (control) 6. ZONE Snow manipulation. A 60 m snowfence is aligned on an east-west axis at both the moist and dry sites. Both snowfences are perpendicular to the predominant winter winds from the Brooks Range to the south, effectively creating a leeward drift 50-60 m long on the north side of the fence. An established grid on the north side of the fence divides the drift into 6 parallel zones (60 m x 10 m). Zone number increases from 1 to 6, as distance from the snowfence increases. Zones 1, 2 and 3 accumulate the most snow (2-3 m), while zones 4, 5 and 6 accumulate the least snow (0.5-2 m). Zone 0 (the control) is located adjacent to the snowfence grid and does not receive supplemental snow. 7. CODE See associated species file (USTOOL1_specieslist.txt) for species code and ground condition definitions. 11. CONDITION Condition of hit. L: live, D: dead (specimen is dead but attached to substrate), S: standing dead (hit is a non-green portion of a living plant), O: other (hit is a non-living ground condition) 12. WOODY Location of hit for a woody plant. Y: yes (hit woody), N: no (hit not woody or hit not a woody plant), O: other (hit non-living ground condition) 13. QUANTITY Hit quantity for a species at a single x, y coordinate. Height was not recorded for quantity hits. NOTES AND COMMENTS: Hit quantity was recorded for select plots (101, 106, 107, 108, 111, 155, 156, 160, 162, 163, 165, 304) only. No repeatability data was recorded in 2000. Plot 304 was not sampled in preceding years. Missing registration markers were either displaced or lost. LOG OF CHANGES TO DATA FILE: None to date. LOCATION OF ORIGINAL DATA SHEETS: Boreal Ecology Cooperative Research Unit, University of Alaska, Fairbanks, Alaska, USA DOCUMENTATION: Amy Breen Carroll, 8 January, 2001 PRINCIPAL FIELD WORKERS: Katie Hamilton, Research Technician Kimberley Maher, Research Technician Adam Wilson, Research Technician PRINCIPAL POSTDOCS: Michael H. Jones Anna Arft PRINCIPAL INVESTIGATORS: Marilyn Walker (mwalker@lter.uaf.edu) Boreal Ecology Cooperative Research Unit P. O. Box 756780 University of Alaska-Fairbanks Fairbanks, Alaska 99775-6780 USA PUBLICATIONS WHICH INCLUDE THESE DATA: None to date.