The International Tundra Experiment is a scientific network of experiments focusing on the impact of climate change on selected plant species in tundra and alpine vegetation. Currently, research teams at more than two dozen circumpolar sites carry out similar, multi-year plant manipulation experiments that allow them to compare annual variation in plant performance with respect to phenological response to climate conditions. To learn more about the ITEX program visit    http://www.geog.ubc.ca/itex/

 
The work I am involved with focuses on understanding patterns of leaf mineral nutrition across a series of tundra sites where long-term warming has taken place.  I am measuring the leaf mineral nutrition and stable carbon ratios of the dominant growth forms during early, peak and late season.  This work is in progress and will provide a pan-arctic insight into the response of plant communities to warming.

 

Site (collaborator)

Location

Alexandra Fiord, Canada

(G. Henry/ J. Hudson)

 

78° 53' N, 75° 45' W

 

 

Atqasuk, AK, USA

(R. Hollister)

 

 

70° 29' N, 157° 25' W

 

 

 

Barrow, AK, USA

(R. Hollister)

 

71° 18' N, 156°44' W

 

Dovre, Norway

(A. Hofgaard)

 

61˚57' N, 8˚ 58' E

 

Finse, Norway

(K. Klunderud)

 

60˚37' N, 7˚ 30' E

 

Kangarloosac, Greenland

(E. Post)

 

67° 7' N, 50° 16' W

Latnjajaure, Sweden

(R. Bjork)

 

68° 21′ N, 18° 29′ E

 

Ny-Alesund, Svalbard

(E. Cooper)

 

79º 56’ N 11º 50’ E

Sornfelli, Faroe Islands

(A. M. Fosaa)

 

62° 00' N, 07° 00' N

Toolik Lake, AK, USA

(J. Welker)

68° 38' N, 149° 38' W

Thule, Greenland

(J. Welker)

 

 

77° 29' N, 69° 21' W

 

 
In addition to the pan-arctic survey  I am carrying out detailed studies of the impacts of long-term warming, snow addition and removal on leaf mineral nutrition, stable isotopes ratios (C13, N15), leaf level photosynthesis and canopy structure at the Toolik Lake LTER. http://www.uaf.edu/toolik/

 

 

 

 

 

Initial results suggest that warming and snow have minimal impacts of leaf level properties but that canopy structure is changing dramatically. 

For example data from 2007 (12 years of warming and snow addition treatment) demonstrate the following:

 

 

 

 

There are clear differences in Leaf Area Index among these treatments associated with these long-term treatments

 

There are also differences in canopy height associated with these long-term treatments