Realm: Terrestrial
Climate: Polar
Biome: Tundra
Central latitude: 68.629636
Central longitude: -149.575656
Duration: 6 years, from 1982 to 2000

14003 records

40 distinct species

Across the time series Ledum palustre is the most frequently occurring species

Methods

Plots were setup in June 1981 with annual fertilization treatments of 10 g/m2 Nitrogen (as NH4NO3) and 5 g/m2 Phosphorous (as triple superphosphate) were applied. Greenhouses and shade houses were annually set up in late May or early June and removed in the end of August or early September. Greenhouses and shade houses were discontinued in 1989. There are 4 replicate blocks each containing 1 replicate of each of the following treatments. Control (CT)Fertilized (NP)Greenhouse (GH)SAMPLING TECHNIQUES: Biomass quadrats size 20x20 cm were taken from Toolik tussock site. Five quadrats were taken from each of four blocks. All aboveground biomass plus belowground stems and rhizomes were clipped in 20x20 cm quadrats. Normally 4 or 5 quadrats were randomly located along line transects in each of four replicate blocks for each treatment. Aboveground biomass is considered within the quadrat if it is associated with a meristem that is within the quadrat. Quadrats were sorted within 24 hours into species and then into tissue type. Depending on the harvest tissue types can be broad categories i.e. above and below or more detailed i.e. inflorescences new growth old growth etc. They were then dried at 50-70 degrees Celsius in a drying oven. After several days in the oven samples were weighed to nearest milligram. Finally the samples from all quadrats from a transect were combined according to tissue type. For some harvest samples were returned to Marine Biological Lab Woods Hole MA for nutrient analysis. Details are given in Shaver and Chapin (Ecological Monographs 61(1) 1991 pg. 1.) Leaf area was measured in 1995 and 2000 harvest with a LiCor LI-3000A area meter. Leaf areas for graminoids deciduous and forbs were measured immediately after plucking and before drying. Leaf areas for Evergreen species (except Ledum) were measured after drying for 2-4 days. Leaf areas for Ledum were measured after final dry weights were done. Cassiope leaf areas were measured on the unseparated leaves and stems. Greenhouse fertilized (GHNP)Shade (SH) Normally 4 or 5 quadrats were randomly located along line transects in each of four replicate blocks for each treatment Unit of abundance = NA, Unit of biomass = Weight

Citation(s)

Mack, M. C., Schuur, E. A. G., Bret-Harte, M. S., Shaver, G. R. & Chapin, F. S. (2004) Ecosystem carbon storage in arctic tundra reduced by long-term nutrient fertilization. Nature, 431, 440–443.
Shaver, G. (2015) “Above ground plant biomass a moist acidic tussock tundra experimental site, 1984, Artic LTER, Toolik Lake, Alaska”. Available at: http://dx.doi.org/10.6073/pasta/08a91cb2697f7cdc82d654e82b53c5c5, accessed 2016.
Shaver, G. R. & Chapin, F. S. (1991) Production: biomass relationships and element cycling in contrasting arctic vegetation types. Ecological Monographs, 61(1), 1–31.