The Arctic Plant Aboveground Biomass Synthesis Dataset

Abstract

Plant biomass is a fundamental ecosystem attribute that is sensitive to rapid climatic changes occurring in the Arctic. Nevertheless, measuring plant biomass in the Arctic is logistically challenging and resource intensive. Lack of accessible field data hinders efforts to understand the amount, composition, distribution, and changes in plant biomass in these northern ecosystems. Here, we present The Arctic plant aboveground biomass synthesis dataset, which includes field measurements of lichen, bryophyte, herb, shrub, and/or tree aboveground biomass (g m^-2) on 2,327 sample plots from 636 field sites in seven countries. We created the synthesis dataset by assembling and harmonizing 32 individual datasets. Aboveground biomass was primarily quantified by harvesting sample plots during mid- to late-summer, though tree and often tall shrub biomass were quantified using surveys and allometric models. Each biomass measurement is associated with metadata including sample date, location, method, data source, and other information. This unique dataset can be leveraged to monitor, map, and model plant biomass across the rapidly warming Arctic.

Fig. 1

Synthesis dataset field site locations in (a) geographic and (b) climatic spaces. The synthesis dataset includes field sites from the sparsely vegetated High Arctic, moderately vegetated Low Arctic, mountainous Oroarctic, and forested Subarctic. (a) Bioclimatic zones were derived from several datasets^– and clipped to north of 55°N. (b) Climatologies are for the period 1981 to 2010 based on the CHELSA dataset gridded at 1 km² resolution (version 2.1)^,. Growing degree days represent the heat sum above 0 °C. To improve clarity, panel (b) excludes the Subarctic, the warmest and wettest 2.5^th percentiles, and climate spaces (i.e., unique growing degree day and precipitation combinations) that covered less than 500 km².

Fig. 2

Frequency distributions of where and when sample plots were measured. Specifically, the (a) bioclimatic zone, (b) country, (c) year, and (d) day of year in which sample plots were measured. (b,c,d) Histogram bars are subdivided and color-coded by bioclimatic zones.

Fig. 3

Workflow diagram depicting the process for creating The Arctic plant aboveground biomass synthesis dataset from existing datasets. Harmonization of metadata and biomass data included reformatting sample dates and spatial coordinates into common formats, as well as summarizing aboveground biomass by a common set of plant functional types.

Fig. 4

Frequency distribution of plant aboveground biomass (g m⁻²) by functional type for sample plots in The Arctic plant aboveground biomass synthesis dataset. To improve clarity, (1) the x-axis is limited to 95% of the maximum range in aboveground biomass for each plant functional type, and (2) sample plots are not shown if there was no biomass (i.e., 0 g m⁻²) for the plant functional type. The total number of sample plots and field sites with biomass measurements is provided for each plant functional type.