ITEX DATABASE
TOOLIK LAKE FIELD STATION, ALASKA, USA
1996 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_1996archive.txt Data file:
USTOOL1ptframe1996_archive.txt

BRIEF DESCRIPTION OF DATA FILE:

Vegetative community dataset collected during the 1996 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.REPEAT: repeatability (see below)


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. REPEAT

Subjective assessment of whether the species, growth form, or ground
condition is likely to be encountered on the next sampling date; e.g.
leaf-tip of a grass: N; center of rock: Y.


NOTES AND COMMENTS:

None to date.


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:

Bill Gould, Research Technician Canuche Terranella, 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.