Arctic vegetation analyses - methods

To understand how tree stands at the treeline in Siberia respond to climate changes, we assess temporal and spatial tree stand dynamics during summer expeditions. Therefore, we use methods of dendrochronology and forest ecology. These analyses were done on several plots spanning the Russian Far-East from 70° to 160° East and 58° to 72° North.

Additionally, we take needle samples for genetic analyses using nuclear microsatellite primer (SSR) and with recently developed genetic markers, aiming at single nucleotide polymorphism (SNP) on the chloroplast and mitochondrial genome. The results are used to reveal local dispersal patterns, population genetics and to infer the historical biogeography of larches.

Main methods

Vegetation survey of dominant taxa, recording coverages (Larix, Pinus, Salix, Alnus, Vaccinium, Ledum, Dryas, Poaceae, Cyperaceae, mosses and lichens), and further meta data (active layer thickness, micro relief, aspect, slope), on forest plots and in the regions

  • Larch tree plot analysis, recording the exact position of trees, their height, stem diameter at breast and basal height, vitality status and if they are reproductive active
  • Recruitment pattern analysis, by determining the age of the individuals of scanned tree discs of larger trees or thin cuts of smaller individuals, and with genetic markers, to assign parents to recruits and thus the distance of seed and pollen dispersal
  • Population genetics, PCR-based with nuclear microsatellite primer in multiplexes
  • Biogeography, based on nuclear microsatellite primer and SNP