Ators of modify are NDVI along with the active layer thickness. Search phrases Alaska Toolik Climate change Ecological effects Greenland Zackenberg Medium pass filter VegetationINTRODUCTION Climate warming within the Arctic, substantial over recent decades and well-documented in IPCC reports (IPCC 2001, 2013), is reflected in changes 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 outcome in changes within the state of ecosystem elements including plant biomass or changes in ecosystem structure (Chapin et al. 2000; Sturm et al. 2001; Epstein et al. 2004). In spite of the massive variety of environmental and ecological measurements created more than current decades, it has verified hard to learn statistically significant trends in these measurements. This difficulty is brought on by the high annual and seasonal variability of warming inside the air temperature along with the complexity of biological interactions. One particular resolution to the variability difficulty would be to carry out long-term studies. These research are high priced to carry out in the Arctic with all the outcome that many detailed studies happen to be somewhat short-term (e.g., the IBP Arctic projects within the U.S. and Canada), or happen to be long-term projects restricted in scope (e.g., the Sub-Arctic Stordalen project in Abisko, Sweden; Jonasson et al. 2012). Presently, you will find but two projects underway that happen to be both long-term and broad in scope: Toolik inside the Low Arctic of northern Alaska and Zackenberg within the Higher Arctic of northeast Greenland (Fig. 1). Here we use information from these web pages to ask which sorts of measures actually yield statistically significant trends of effects of climate warming Further, are there popular traits of these useful measures that minimize variabilitySTUDY Web-sites The Toolik project (Table 1) is positioned at the University of Alaska’s Toolik Field Station (TFS) some 125 km inland from the Arctic Ocean. The Long term Ecological Investigation (LTER)1 and associated projects at this website havehttp:arc-lter.ecosystems.mbl.edu.The Author(s) 2017. This article is published with open access at Springerlink.com 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 Place 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:http://www.ncbi.nlm.nih.gov/pubmed/21301389 and deciduous shrubs, forbs, mosses, and lichens). Low shrubs, 
birches, and willows MK-8745 web develop between tussocks and along water tracks and stream banks. Low Arctic LTER (Long term Ecological Research), ITEX (International Tundra Experiment), NOAA’s Arctic Program, CALM (Circumpolar Active Layer Monitoring), along with the TFS environmental monitoring system Zackenberg Coast, Northeast Greenland 74o300 N, 21o300 W, 0 m altitude Mountain valley, Continuous permafrost (estimated 20000 m), annual temperature -8 , summer season (3 months) four.five , an.
