Global Tundra Vegetation Change - 30 years of plant abundance data from unmanipulated and experimentally-warmed plots

We amassed plot-based data on vegetation abundance (cover, point-frame hits, biomass, subplot frequency, stem-counts) from permanently marked plots, transects, and study areas throughout the tundra biome, and in and out of warming experiments. Criteria for inclusion in the warming treatment analysis were measures of plant abundance in warmed and control plots in at least one year. For the long-term change project, criteria for inclusion were repeat-measurements of plant abundance in unmanipulated vegetation using the same techniques in 2+ study years at least 5 years apart in time. We also collected air and soil temperature data (where available) from the study site locations.我们收集了来自苔原生物群区（tundra biome）全境永久标记样地（permanently marked plots）、样带（transects）及研究区域的样方级植被丰度数据，涵盖盖度（cover）、点框取样击中数（point-frame hits）、生物量（biomass）、小样方频率（subplot frequency）及茎秆计数（stem-counts），数据覆盖增温实验内外的样地。纳入增温处理分析的标准为：至少在1个年份内获取了增温样地（warmed plots）与对照样地（control plots）的植物丰度测定数据。针对长期变化项目，纳入标准为：采用相同的采样技术，在至少间隔5年的2个及以上研究年份中，对未受人工干扰的植被开展植物丰度重复测定。此外，我们还从研究样地收集了空气与土壤温度数据（若可获取）。