TITLE:

Toolik Snowfence Experiment: 1997-2000 Flower: fruit ratio 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 flower: fruit ratio data collected for the Toolik Snowfence 
Experiment from 1997 to 2000.  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: 19970604 to 20000904
Physical location of measurement: Toolik Field Station, Alaska USA 
(68.62710 N, 149.59322 W)


DATA COLLECTION AND PROCESSING:

To assess fecundity of the most common ITEX plant species, we counted the total 
number of flowers and fruits per plot at the moist tussock (Vaccinium vitis-idaea 
and Eriophorum vaginatum), dry heath (Vaccinium vitis-idaea, Dryas octopetala and 
Arctostaphylos alpina) and snowfield (Vaccinium vitis-idaea and Cassiope tetragona) 
sites.  Data were collected at peak season in 1997, 1998 and 2000.  

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_ffratio97-00.txt

SUMMARY OF VARIABLES FOR 1997-2000 DATA

1. SITE: country/site/project title
2. DATE: date of data collection (YYYYMMDD)
3. LOCATION: site; moist, dry or snowfield
4. ZONE: 0 - 6
4. PLOT: plot number
5. TREATMENT: treatment, either OTC (open topped chamber) or CTL (control)
6. VACVIT_FLOWERS: number of Vaccinium vitis-idaea flowers/plot
7. VACVIT_FRUITS: number of Vaccinium vitis-idaea fruits/plot
8. CASTET_FLOWERS: number of Cassiope tetragona flowers/plot
9. CASTET_FRUITS: number of Cassiope tetragona fruits/plot
10. ERIVAG_FLOWERS: number of Eriophorum vaginatum inflorescences in flower/plot
11. ERIVAG_FRUITS: number of Eriophorum vaginatum inflorescences in fruit/plot
12. DRYOCT_FLOWERS: number of Dryas octopetala inflorescences in flower/plot
13. DRYOCT_FRUITS: number of Dryas octopetala inflorescences in fruit/plot
14. ARCALP_FLOWERS: number of Arctostaphylos alpina flowers/plot
15. ARCALP_FRUITS: number of Arctostaphylos alpina fruits/plot

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.

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.

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 or empty cells. 


DATA REMARKS:

Additional flower and fruit data is available within the Dryas octopetala 
quantitative and Eriophorum vaginatum pedicel data sets.

The species monitored in the flower: fruit ratio data set varies annually.  
Eriophorum vaginatum (moist site) and Dryas octopetala (dry site) data was 
collected only in 1997.  Arctostaphylos alpina (dry site) data was not collected 
in 2000.


LOCATION OF ORIGINAL DATA SHEETS:

Boreal Ecology Cooperative Research Unit, University of Alaska, Fairbanks, 
Alaska, USA


DOCUMENTATION AUTHOR: 

Original: Amy Breen Carroll, 11 February, 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.