Plant density measurements in International Tundra Experiment (ITEX) and Arctic System Science Program (ARCSS) 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 plant cover and counts of individuals in 5, 10” by 10” square subplots at Utqiaġvik (formerly Barrow) and Atqasuk in a text comma delimited format. The 5 subplots were established in existing plots. These include 96 ITEX plots and a subset of 30 ARCSS grid plots in Utqiaġvik and 96 ITEX plots and a subset of 30 ARCSS grid plots in Atqasuk. The data presented were collected from 2011-2019 at both Utqiaġvik and Atqasuk, and during 2021 at Utqiaġvik only.