Projects
International Tundra EXperiment (ITEX)
Primary Investigator: Robert D. Hollister
Brief Description:
This study seeks to quantify and improve the understanding of short-term and long-term responses of tundra vegetation to annual variation of and increase in temperature. This project provides data for improved prediction of the response of the tundra to climate change.
To accomplish this the project will continue and expand a tundra warming experiment at Barrow and Atqasuk, Alaska. This experiment, which has been in place in the Barrow since 1994 and at Atqasuk since 1996, has provided new insights on flower and growth responses to warming. This research is a contribution to the US NSF Arctic Observatory Network (AON) Program and the 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. The chambers raise the daily temperature of the tundra plant canopy by 1.5 to 2.0 ºC which is in the range predicted by global climate simulations.
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 moisture, from wet meadow to dry heath tundra types.
Barrow |
Atqasuk |
||
Dry Heath
|
Wet Meadow
|
Dry Heath
|
Wet Meadow
|
| Alopercurus alpinus | Alopecurus alpinus | Antennaria friesiana | Betula nana |
| Arctagrostis latifolia | Arctophila fulva | Arctagrostis latifolia | Calamagrostis spp. |
| Carex stans | Calamagrostis holmii | Armeria sibirica | Carex aquatilis |
| Cassiope tetragona | Cardamine pratensis | Artemesia artica | Carex rariflora |
| Draba lactea | Carex stans | Artemesia borealis | Carex rotundata |
| Draba micropetala | Carex subspathacea | Carex bigelowii | Dupontia psilosantha |
| Festuca brachyphylla | Ceratium beeringianum | Carex saxatilis | Eriophorum angustifolium |
| Juncus biglumis | Cochlearia officinalis | Cassiope tertragona | Eriophorum russeolum |
| Luzula arctica | Draba lactea | Diapensia lapponica | Eriophorum scheuchzeri |
| Luzula confusa | Draba micropetala | Hierachloe alipina | Luzula arctica |
| Oxyria digynia | Dupontia fisheri | Ledum palustre | Luzula wahlenbergii |
| Papaver hultenii | Eriophorum russeolum | Luzula arctica | Pedicularis sudetica |
| Papaver lapponicum | Eriophorum scheuchzeri | Luzula confusa | Polygonum viviparum |
| Pedikalaris kanei | Eriophorum triste | Luzula wahlenbergii | Salix polaris |
| Poa arctica | Hierochloe pauciflora | Minuartia obtusiloba | Salix pulchra |
| Poa malacantha | Juncus biglumis | Polygonum bistorta | |
| Potentilla hyparctica | Luzula arctica | Salix phlebophylla | |
| Salix rotundifolia | Luzula confusa | Trisetum spicatum | |
| Saxifraga caespitosa | Melandrum apetalum | Vaccinium vitis-idaea | |
| Saxifraga cernua | Petasites frigidus | ||
| Saxifraga flagellate | Poa arctica | ||
| Saxifraga foliolosa | Ranunculus nivalis | ||
| Saxifraga nivalis | Ranunculus pygmaeus | ||
| Saxifraga punctata | Salix pulchra | ||
| Senecio atropurpureus | Salix rotundifolia | ||
| Stellaria laeta | Saxifraga caespitosa | ||
| Vaccinium vitis-idaea | 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
Acknowledgements:
Funding for this research is provided by the Arctic Sciences Division of the Office of Polar Programs (OPP) of the National Science Foundation (NSF) (Award # OPP-) with logistics provided by the Barrow Arctic Research Consortium (BASC).