The LTER moist acidic tussock (MAT) site was set up in 1989.  The experimental design is four blocks of 5 x 20 meter plots with randomly assigned treatments within each block. Treatments include control (CT), nitrogen (N), phosphorus (P) and nitrogen plus phosphorus (NP). Fertilizer is added annually following snowmelt in June as 10 g/m2 nitrogen (as NH4NO3) and 5 g/m2 phosphorous (as triple superphosphate). Exclosure plots were set up at the MAT site in July 1996 on extra 5 x 20 meter plots within the four-block design of the 1989 LTER acidic tussock experimental plots.  On each plot a 5 x 10 meter section was fenced with large mesh (4-inch square mesh) and within this fence a 5x5-meter plot was fenced with a small mesh (1/2-inch square mesh). In each block two fenced plots were setup: a plot with no fertilizer and a plot with annual fertilization treatments as described above. Thus the treatments created are no fence, no fertilizer (NFCT); small mesh fence, no fertilizer (SFCT); large mesh fence, no fertilizer (LFCT); no fence, N plus P (NFNP); small mesh fence, N plus P (SFNP); and large mesh fence, N plus P (LFNP). Only CT, N, P,  NP censused in 2013.

 In 1997 experimental plots were established in three block at the LTER moist non-acidic tussock (MNT) site with the same methods as those used at MAT. CT, N, P and NP treatments were censused in 2013.

Calculations: All percent cover values were summed within each plot, and then each value was divided by the total to generate a percent cover value standardized to 100%.

Sampling Description.

Permanent monitoring areas were established in all treatment plots in 1998. Eight 1 m2 plots are sampled in each treatment in each block each year at the end of July. A 1 m2 quadrat is aligned 0.2 m inside of the plot at the site of a flag marking the first measurement. Within this quadrat, aerial percent cover of all vascular plants are noted by species as is all other ground cover. Categories include moss (all species lumped), lichen (all species lumped), litter, and standing dead Betula nana. Bare ground, frost boil, and water are also recorded. As an indicator of vole activity, the percent cover of the plot comprised of vole burrow holes, vole trails, and vole litter (small pieces of dead plant material) are also recorded. To standardize cover among plots, all percent cover values were summed within each plot, and then each value was divided by the total to generate a percent cover value standardized to 100%. 

Species codes (MAT) are as follows:

And pol - Andromeda polifolia

Arc alp - Arctostaphylos alpina

Bet nan - Betula nana

Cal lap - Calamagrostis lapponica

Car big - Carex bigelowii

Cas tet - Cassiope tetragona

Emp nig - Empetrum nigrum

Eri vag - Eriophorum vaginatum

Led pal - Ledum palustre

Ped lap - Pedicularis lapponica

Pol bis - Polygonum bistorta

Rub cha - Rubus chamaemorus

Sal pul - Salix pulchra

Vac uli - Vaccinium uliginosum

Vac vit - Vaccinium vitis-idaea

Tofieldia - Tofieldia coccinea

Car mic - Carex microchaeta

St. D. Bet. - Standing Dead Betula nana

St. D. Sal pul - Standing Dead Salix pulchra

Species codes (MNT) are as follows:

And pol - Andromeda polifolia

Arc alp - Arctostaphylos alpina

Arn sp. - Arnica sp.

Ast umb - Astragalus umbellatus

Bet nan - Betula nana

Car big - Carex bigelowii

Cas tet - Cassiope tetragona

Cla box - Claytonia bostockii

Draba sp. - Draba sp.

Dry int - Dryas integrifolia

Equ arv - Equisetum arvense

Eri ang - Eriophorum angustifolium

Eri vag - Eriophorum vaginatum

Arc lat - Arctagrostis latifolia

Poa arc - Poa arctica

Led pal - Ledum palustre

Min arc - Minuartia arctica

Pap sp - Papaver sp.

Ped cap - Pedicularis capitata

Ped kan - Pedicularis kanei

Ped oed - Pedicularis oederi

Ped sp.  - Pedicularis sp.

Ped sud - Pedicularis sudetica

Pol bis - Polygonum bistorta

Pol viv - Polygonum viviparum

Pot sp. - Potentilla sp.

Pyr gra - Pyrola grandiflora

Pyr Sec - Pyrola secunda

Ran sp - Ranunculus sp.

Rho lap - Rhododendron lapponicum

Sal arc - Salix arctica

Sal gla - Salix glauca

Sal pul - Salix pulchra

Sal ret - Salix reticulata

Sau ang - Saussurea angustifolia

Sax dav - Saxifraga davurica

Sax pun - Saxifraga punctata

Sen res - Senecio resedifolius

Ste edw - Stellaria edwardii

Tof coc - Tofieldia coccinea

Vac uli - Vaccinium uliginosum

Vac vit - Vaccinium vitis-idaea

Car rot - Carex rotundata

Epi ang - Epilobium angustifolium