Season to provide an annual estimate. Keller et al. (2010) measured strontium isotope ratios (87Sr86Sr), which decrease with depth in soils at the Arctic LTER, to estimate the increasing depth of water flow within the soil. Utilizing the point-frame system described by Walker (1996), Gould and Mercado-Diaz (in Shaver et al. 2014) monitored the response of plant communities to ambient climate in 155 permanent plots. Measurements were produced at 5- to 7-year intervals due to the fact 1989 in two 1 km2 grids setTable two Environmental and ecological variables measured more than the long-term at Toolik and Zackenberg web pages Website Toolik Web-site Climate Thaw depth Biology Kuparuk River Climate, physics Biology Climatic norms for river basin (1989010) and discharge and temperature (1972010) are in Bowden et al. (2014) Principal production and respiration (1984998), epilithic chlorophyll (1983010), bryophyte cover (1992006), benthic insect taxa (1984998), and grayling development (1985005) data are in Bowden et al. (2014) Epilimnion temperature (July, 1985007) and summer season alkalinity (1975011) information are in Luecke et al. (2014) Chlorophyll (July, 1985010) information are in Luecke et al. (2014) Temperature, 1991005, wind direction and speed (1985005), and precipitation, purchase NBI-98854 1997005, are offered in Hansen et al. (2008). Information are out there at Greenland Ecosystem Monitoring (http:www.information.g-e-m.dk) The summer thaw depth progression from June 1 to September 7 at ZEROCALM-2, 1996005, is offered in Christiansen et al. (2008) Plant communities had been analyzed (1997, 2008) in relation to summer time temperature and spring snow cover. 5 replicate plots in eight plant communities were sampled (Schmidt et al. 2012). NDVI measures (Tagesson et al. 2012) gave gross primary production at the peak with the growing season from 1992 to 2008 Precipitation, temperature, and snow depth measured hourly (1996010). Abundance of 6 plant species, 6 taxa of arthropods, 4 species of birds, and 3 mammals measured weekly and seasonally (Mortensen et al. 2014). At 2 lakes, temperature, ice cover, and nutrients have been measured (1997005) as well as volume of phytoplankton and abundance of zooplankton (Christoffersen et al. 2008) Air temperature, precipitation, wind speed and path, and developing season dates for 1989010 are in Cherry et al. (2014) Summer depths of thaw for July and August within the Tussock Watershed, 1989010, are in Kling et 
al. (2014) Net principal production aboveground for moist acidic tundra from 6 harvests 1989000 and point-frame data (four harvests 1989008) are in Shaver et al. (2014) Environmental and ecological variablesToolik Lake Physics and chemistry Biology Zackenberg Physics Thaw depth Plant communities and production Variations and trends in biotic and abiotic PubMed ID:http://www.ncbi.nlm.nih.gov/pubmed/21300681 ecosystem compartmentsThe Author(s) 2017. This short article is published with open access at Springerlink.com www.kva.seenAmbio 2017, 46(Suppl. 1):S160SFig. 2 Annual mean Barrow SAT (surface air temperature, closed circles) for 1950014, annual mean Toolik SAT (x’s) for 1989-2014, and Zackenberg SAT (open squares) for 1996014. Also shown will be the linear regressions for Barrow 1950014 (dashed dot line), Barrow 1996014 (short-dashed line), Toolik 1996014 (long-dashed line), and Zackenberg 1996014 (dotted line). Regression lines and coefficients are ordered from prime to bottom as Toolik, Zackenberg, Barrow (1996014), and Barrow (1950014). Only the Barrow 1950014 and Zackenberg 1996014 linear regressions are important (p \ 0.01). Information from Alaska Climate Study Ce.