Spatial patterns of arctic tundra vegetation properties on different soils along the Eurasia Arctic Transect, and insights for a changing Arctic

Howard E. Epstein, Donald A. Walker, Gerald V. Frost, Martha K. Raynolds, Uma S. Bhatt, Ronald Daanen, Bruce C. Forbes, Jozsef Geml, Elina Kaarlejärvi, O. V. Khitun, Artem V. Khomutov, Patrick Kuss, M. O. Leibman, G. V. Matyshak, Natalya G. Moskalenko, Pavel T. Orekhov, Vladimir E. Romanovsky, Ina Timling

Research output: Contribution to journalArticleScientificpeer-review

Abstract

Vegetation properties of arctic tundra vary dramatically across its full latitudinal extent, yet few studies have quantified tundra ecosystem properties across latitudinal gradients with field-based observations that can be related to remotely sensed proxies. Here we present data from field sampling of six locations along the Eurasia Arctic Transect in northwestern Siberia. We collected data on the aboveground vegetation biomass, the normalized difference vegetation index (NDVI), and the leaf area index (LAI) for both sandy and loamy soil types, and analyzed their spatial patterns. Aboveground biomass, NDVI, and LAI all increased with increasing summer warmth index (SWI—sum of monthly mean temperatures > 0 °C), although functions differed, as did sandy vs. loamy sites. Shrub biomass increased non-linearly with SWI, although shrub type biomass diverged with soil texture in the southernmost locations, with greater evergreen shrub biomass on sandy sites, and greater deciduous shrub biomass on loamy sites. Moss biomass peaked in the center of the gradient, whereas lichen biomass generally increased with SWI. Total aboveground biomass varied by two orders of magnitude, and shrubs increased from 0 g m−2 at the northernmost sites to >500 g m−2 at the forest-tundra ecotone. Current observations and estimates of increases in total aboveground and shrub biomass with climate warming in the Arctic fall short of what would represent a 'subzonal shift' based on our spatial data. Non-vascular (moss and lichen) biomass is a dominant component (>90% of the photosynthetic biomass) of the vegetation across the full extent of arctic tundra, and should continue to be recognized as crucial for Earth system modeling. This study is one of only a few that present data on tundra vegetation across the temperature extent of the biome, providing (a) key links to satellite-based vegetation indices, (b) baseline field-data for ecosystem change studies, and (c) context for the ongoing changes in arctic tundra vegetation.
Original languageEnglish
Article number014008
JournalEnvironmental research letters
Volume16
Issue number1
Early online date18 Dec 2020
DOIs
Publication statusPublished - 2021
MoEC publication typeA1 Journal article-refereed

Keywords

  • LAI
  • NDVI
  • Siberia
  • arctic tundra biome
  • latitudinal gradient
  • tundra vegetation
  • vegetation biomass

Field of science

  • Environmental sciences

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