Plant community composition in the International Tundra Experiment (ITEX) plots at Utqiaġvik and Atqasuk, Alaska

Arctic ecosystems are changing in response to arctic warming, which is proceeding more than twice as fast as the global average. The International Tundra Experiment (ITEX) was established in the early 1990s to understand the effects of warming and environmental variability on tundra vegetation properties and ecosystem function. The ITEX program has been extremely valuable for detection of changes in tundra plant and ecosystem responses to experimental warming and to background climate change across sites that span the major ecosystems of the Arctic. These files contain data representing the community composition and structure of ITEX plots at Utqiaġvik (formerly Barrow) and Atqasuk in a csv file format. The data presented were collected on the second summer of the experiment, in 2000, during summers of 2007 or 2008, 2012, and 2017 for 48 plots (24 experiment open-top chamber plots and 24 control plots) at four sites (Atqasuk Wet Meadow, Atqasuk Dry Heath, Utqiaġvik Wet Meadow, and Utqiaġvik Dry Heath), in 2014 for 8 plots (4 control and 4 experimental) at two sites (Utqiaġvik Dry Heath and Atqasuk Dry Heath), in 2019 for 10 plots (5 control and 5 experimental) at four sites (Atqasuk Wet Meadow, Atqasuk Dry Heath, Utqiaġvik Wet Meadow, and Utqiaġvik Dry Heath), and in 2021 for 10 plots (5 control and 5 experimental) at two sites (Utqiaġvik Wet Meadow and Utqiaġvik Dry Heath).