Ators of change are NDVI and also the active layer thickness. Keyword phrases Alaska Toolik Climate transform Ecological effects Greenland Zackenberg Medium pass filter VegetationINTRODUCTION Climate warming in the Arctic, substantial over recent decades and well-documented in IPCC reports (IPCC 2001, 2013), is reflected in alterations inside a wide variety 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 alterations in ecological processes, like plant growth, which can outcome in changes within the state of ecosystem components such as plant biomass or alterations in ecosystem structure (Chapin et al. 2000; Sturm et al. 2001; Epstein et al. 2004). In spite with the huge quantity of environmental and ecological measurements created over current decades, it has confirmed tough to discover statistically substantial trends in these measurements. This difficulty is caused by the high annual and seasonal variability of warming inside the air temperature and also the complexity of biological interactions. One resolution towards the variability dilemma is usually to carry out long-term research. These research are expensive to carry out in the Arctic with all the outcome that quite a few detailed studies have already been comparatively short-term (e.g., the IBP Arctic projects inside the U.S. and Canada), or happen to be long-term projects limited in scope (e.g., the Sub-Arctic Stordalen project in Abisko, Sweden; Jonasson et al. 2012). At the moment, there are but two projects underway that happen to be both long-term and broad in scope: Toolik in the Low Arctic of northern Alaska and Zackenberg within the High Arctic of northeast Greenland (Fig. 1). Here we use data from these web pages to ask which types of measures essentially yield statistically significant trends of effects of climate warming Additional, are there typical characteristics of these useful measures that lower variabilitySTUDY Websites The Toolik project (Table 1) is positioned in 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 associated projects at this website Author(s) 2017. This short article is published with open access at www.kva.seenAmbio 2017, 46(Suppl. 1):S160SFig. 1 Place 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 study 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 season (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 grow involving tussocks and along water tracks and stream banks. Low Arctic LTER (Long term Ecological Study), ITEX (International Tundra Experiment), NOAA’s Arctic System, CALM (Circumpolar Active Layer Monitoring), and also the TFS environmental monitoring TAK-220 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) 4.5 , an.