PI: Jeffrey Welker, Department of Biological Sciences, University of Alaska, Anchorage, AK 99508; 907-271-2701; afjmw1@uaa.alaska.edu

DATA CONTACT: Patrick Sullivan, Department of Biological Sciences, University of Alaska, Anchorage, AK 99508; 907-522-4828; paddy@uaa.alaska.edu

FUNDING SOURCE: NSF-0221606/0508408

DATASET OVERVIEW:
Dataset includes measurements of Dryas integrifolia and Salix arctica leaf gas exchange made under conditions of saturating light, ambient CO2 and optimum temperature. Also included are leaf C and N concentrations and leaf d15N and d13C. Measurements were made at 5 sites near Thule (Pituffik), Greenland: 3 sites along a south-facing hill slope, the site of a warming x watering experiment and the site of a fertilization experiment. At the experimental sites, measurements were made in control plots, in plots that received the higher of two levels of infrared warming and in plots that were fertilized with 5 g N m-2 yr-1 applied as granular NH4NO3 and 2.5 g P m-2 yr-1 as granular P2O5 beginning in 2004. Site and treatment descriptions can be found in the references listed below. Coverage is from 20050708- 20050801.

INSTRUMENT DESCRIPTION:
LI-6400
Costech 4010 EA
Thermo-Finnigan Delta Plus XP Stable Isotope Ratio Mass Spectrometer

DATA COLLECTION AND PROCESSING:
Gas exchange data are expressed on a projected leaf area basis

DATA FORMAT:
Tab-delimited text

DATA REMARKS:
None

REFERENCES:

Warming x watering experiment:
Sullivan, P.F., Welker, J.M., Steltzer, H., Sletten, R.S., Hagedorn, B., Arens, S.J.T. and Horwath, J. (2008) Energy and water additions give rise to simple responses in plant canopy and soil microclimates of a high arctic ecosystem. Journal of Geophysical Research, 113, G03S08.

South-facing hill slope:
Sullivan, P.F. and Welker, J.M. (2007) Variation in leaf physiology of Salix arctica within and across ecosystems in the High Arctic: test of a dual isotope conceptual model. Oecologia, 151, 372-386.

Ferilization experiment:
Arens, S.J.T., Sullivan, P.F. and Welker, J.M. (2008) Nonlinear responses to nitrogen and strong interactions with nitrogen and phosphorus additions drastically alter the structure and function of a high arctic ecosystem. Journal of Geophysical Research, 113, G03S09.