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).

北极生态系统正随北极变暖发生改变，北极变暖的速率是全球平均水平的两倍有余。国际冻原实验计划（International Tundra Experiment, ITEX）于20世纪90年代初启动，旨在探究增温与环境变异性对冻原植被特征及生态系统功能的影响。该计划在覆盖北极主要生态系统的诸多研究站点中，为检测冻原植物与生态系统对实验性增温及背景气候变化的响应变化提供了极为宝贵的研究载体。

本数据集以逗号分隔值（CSV）格式存储了来自乌特恰维克（旧名巴罗）与阿塔苏克的ITEX样地群落组成与结构数据。本次公开的采集数据涵盖多批次：2000年（实验开展的第二个夏季）、2007或2008年夏季、2012年及2017年，共覆盖48个样地（24个开放式增温箱实验样地与24个对照样地），涉及4个站点（阿塔苏克湿草甸、阿塔苏克干石楠荒原、乌特恰维克湿草甸、乌特恰维克干石楠荒原）；2014年，覆盖8个样地（4个对照样地与4个实验样地），涉及2个站点（乌特恰维克干石楠荒原、阿塔苏克干石楠荒原）；2019年，覆盖10个样地（5个对照样地与5个实验样地），涉及4个站点（阿塔苏克湿草甸、阿塔苏克干石楠荒原、乌特恰维克湿草甸、乌特恰维克干石楠荒原）；2021年，覆盖10个样地（5个对照样地与5个实验样地），涉及2个站点（乌特恰维克湿草甸、乌特恰维克干石楠荒原）。