Both sites were in typical moist acidic sedge tussock tundra in which E. vaginatum was the dominant graminoid and C. bigelowii was subdominant. The comparison of control and fertilized plots was part of the same experiment described by Chapin and Shaver (1985). The fertilizer treatment consisted of annual application of 10 g per m2 of N (as NH4NO3) and 5 g per m2 P (as triple superphosphate), beginning in 1982. The microenvironmental comparison was done at Imanavait Creek, about 10 km NE of Toolik Lake. At Imnavait Creek we compared leaf growth in "non-track" tussock tundra and in "water tracks", which are areas of above-average surface and subsurface water flow.

Notes: Only tillers that did not flower are included in this file. When measurements stopped due to tiller death or herbivory a #N/A is recorded.. Where there are no values or the tiller senescent zeros are used. In cases where the total leaf length was unknown because of broken leaf tips the longest previous leaf length was used. In most cases these leaves had stopped growing.

Reference Citations: Chapin,FS,III; Shaver,GR (1985): Individualistic growth response of tundra plant species to manipulation of light, temperature and nutrients in a field experiment. Ecology 66, 564-576
Shaver,GR and JA Laundre(In prep.) Leaf exsertion, leaf elongation,
and leaf senescence in Eriophorum vaginatum and Carex bigelowii
in northern Alaska.

Sampling Description.

Measurements of leaf growth were made throughout the 1985 and 1986 growing seasons at approximately 10-day intervals. The tillers were selected haphazardly, with the restriction that they had to be near the edges of the study plots so that they could be measured without excessive trampling in the plot. The tillers were tagged and labeled, with individuals numbered 1-20. The older leaves that had no visible green tissue were clipped at the base to equal lengths. The clipped leaves were used as the 0 point to measure the total length and green length of all of the remaining leaves.