Ators of change are NDVI and the active layer thickness. Key phrases Alaska Toolik Climate change Ecological effects Greenland Zackenberg Medium pass filter VegetationINTRODUCTION Climate warming within the Arctic, substantial more than current decades and well-documented in IPCC reports (IPCC 2001, 2013), is reflected in modifications in a wide range of environmental and ecological measures. These illustrate convincingly that the Arctic is undergoing a system-wide response (ACIA 2005; Hinzman et al. 2005). The altering measures range from physical state variables, such as air temperature, permafrost temperature (Romanovsky et al. 2010), or the depth of seasonal thaw (Goulden et al. 1998),to modifications in ecological processes, including plant growth, which can result in alterations inside the state of ecosystem components including plant biomass or adjustments in ecosystem structure (Chapin et al. 2000; Sturm et al. 2001; Epstein et al. 2004). In spite from the massive number of environmental and ecological measurements created over current decades, it has proven difficult to discover statistically substantial trends in these measurements. This difficulty is caused by the higher annual and seasonal variability of warming in the air temperature as well as the complexity of biological interactions. A single remedy for the variability problem is always to carry out long-term research. These research are high priced to carry out in the Arctic with the outcome that quite a few detailed studies happen to be reasonably short-term (e.g., the IBP Arctic projects inside the U.S. and Canada), or have already been long-term projects limited in scope (e.g., the Sub-Arctic Stordalen project in Abisko, Sweden; Jonasson et al. 2012). Presently, you will find but two projects underway which are both long-term and broad in scope: Toolik in the Low Arctic of northern Alaska and Zackenberg in the High Arctic of northeast Greenland (Fig. 1). Right here we use data from these sites to ask which M2I-1 web varieties of measures really yield statistically substantial trends of effects of climate warming Further, are there widespread characteristics of those beneficial measures that minimize variabilitySTUDY Sites The Toolik project (Table 1) is situated at the University of Alaska’s Toolik Field Station (TFS) some 125 km inland from the Arctic Ocean. The Long term Ecological Analysis (LTER)1 and related projects at this website Author(s) 2017. This article is published with open access at www.kva.seenAmbio 2017, 46(Suppl. 1):S160SFig. 1 Location of Toolik, Alaska (68o380 N, 149o430 W) and Zackenberg, Greenland (74o300 N, 21o300 W), long-term arctic study sitesTable 1 Ecological settings for Toolik and Zackenberg analysis web-sites Toolik field station Location Inland, Northern Alaska 68o380 N, 149o430 W, 719 m altitude Physical Rolling foothills, Continuous permafrost (200 m), annual setting temperature -8 , summer time (mid-June to mid-August) 9 , annual precipitation 312 mm Ecology Tussock tundra (sedges, evergreen PubMed ID: and deciduous shrubs, forbs, mosses, and lichens). Low shrubs, birches, and willows develop among tussocks and along water tracks and stream banks. Low Arctic LTER (Long-term Ecological Study), ITEX (International Tundra Experiment), NOAA’s Arctic Plan, CALM (Circumpolar Active Layer Monitoring), and also the TFS environmental monitoring program Zackenberg Coast, Northeast Greenland 74o300 N, 21o300 W, 0 m altitude Mountain valley, Continuous permafrost (estimated 20000 m), annual temperature -8 , summer (three months) 4.five , an.