International Tundra Experiment (ITEX) Temperature Manipulation
Principal Investigator: Dr. Patrick J. WebberProject Manager: Robert D. Hollister
Project Abstract:
This study seeks to quantify and improve the understanding of short-term and long-term responses of tundra plants, growth forms and vegetation to annual variation of and increase in temperature. This project will provide data for improved prediction of the response of the arctic flora and vegetation, including some important plant resources of the Alaskan Arctic Coastal Plain, to climate warming.
To accomplish this the project will continue and expand a tundra warming experiment at Barrow and Atqasuk, Alaska; use permanent plots established at these sites 25 and 27 years ago to determine if changes are a result of the observed climatic warming; initiate an investigation of the effect of temperature increase on the soil-plant nutrient system; and identify species assemblages which could be used as a basis for modeling the response of Arctic vegetation to climate warming.
This research is a contribution to the US NSF Arctic System Science (ARCSS) Program and the UNESCO Man and the Biosphere (MAB) International Tundra Experiment (ITEX). ITEX sites are located at 37 locations in 13 countries including all the Arctic Nations. ITEX uses small, passive, clear-plastic, open-top chambers to warm the tundra and extend the growing season. The chambers raise the daily temperature of the tundra plant canopy by 1.5 to 2.0 °C which is in the range predicted by global climate simulations. This experiment which has been in place in the Barrow Environmental Observatory for three years and one year at Atqasuk has already provided new insights on flower and growth responses to warming. This proposal requests funding to continue the project for an additional five years.
Research Design:
There are 24 chambers and 24 control plots at each of the four sites studied. This high amount of replication allows for detection of change in spite of the noise of the system. The sites span gradients of temperature, from cooler Barrow to warmer Atqasuk, and moister, from wet meadow to dry heath tundra types.
| Atqasuk | Barrow | ||
|
Dry Heath
Antennaria friesiana
Arctagrostis latifolia Artemisia borealis Carex bigelowii Cassiope tetragona Diapensia lapponica Hierochloe alpina Ledum palustre Luzula arctica Luzula confusa Minuartia obtusiloba Pedicularis lapponica Polygonum bistorta Salix phlebophylla Trisetum spicatum Vaccinium vitis-idaea |
Wet Meadow
Betula nana
Calamagrostis sp. Carex aquatilis Carex rariflora Carex rotundata Dupontia fisheri/psilosantha Eriophorum angustifolium Eriophorum russeolum Juncus biglumis Luzula wahlenbergii Pedicularis sudetica Polygonum viviparum Salix polaris Salix pulchra Saxifraga foliolosa |
Dry Heath
Alopecurus alpinus
Arctagrostis latifolia Carex aquatilis/stans Cassiope tetragona Draba lactea Draba micropetala Festuca brachyphylla Juncus biglumis Luzula arctica Luzula confusa Oxyria digyna Papaver hultenii Papaver lapponicum Pedicularis kanei Poa arctica Poa malacantha Potentilla hyparctica Ranunculus nivalis Ranunculus pygmaeus Salix rotundifolia Saxifraga caespitosa Saxifraga cernua Saxifraga flagellaris Saxifraga foliolosa Saxifraga nivalis Saxifraga punctata Senecio atropurpureus Stellaria laeta Vaccinium vitis-idaea |
Wet Meadow
Alopecurus alpinus
Arctophila fulva Calamagrostis holmii Cardamine pratensis Carex aquatilis/stans Carex subspathacea Cerastium beeringianum Chrysosplenium tetrandrum Cochlearia officinalis Draba lactea Draba micropetala Dupontia fisheri Eriophorum angustifolium/triste Eriophorum russeolum Eriophorum scheuchzeri Hierochloe pauciflora Juncus biglumis Luzula arctica Luzula confusa Melandrium apetalum Pedicularis kanei Petasites frigidus Poa arctica Ranunculus nivalis Ranunculus pygmaeus Salix pulchra Salix rotundifolia Saxifraga caespitosa Saxifraga cernua Saxifraga foliolosa Saxifraga hieracifolia Saxifraga hirculus Stellaria humifusa Stellaria laeta |
Measures Collected at all Sites:
- Plant Phenology and Growth
- Species Composition and Abundance
- Screen Height Temperature
- Canopy Temperature
- Soil Temperature
- Precipitation
- Canopy Relative Humidity
- Soil Moisture
- Light Intensity
- Wind Speed Near the Ground
Funding for this research was provided by the Arctic Systems Science Division of the Office of Polar Programs (OPP) of the National Science Foundation (NSF) (Award # OPP-9714103) with logistics provided by BASC.