Vegetation Survery in the Taiga-Tundra Ecotone

To understand how tree populations in the taiga-tundra ecotone (TTE) – that is, the northern boreal zone, including the northern treeline and alpine treelines – respond to climate change, we collect a wide range of data during our summer expeditions that captures the spatial and temporal dynamics of these forests.

Our methods include detailed forest inventories that record the exact position of trees, their height, stem diameter at breast height and at the base, vitality status, and whether they are reproductively active. We analyse recruitment patterns by determining the age of individuals from scanned tree increment cores, stem discs of larger trees or thin sections of smaller ones and by using genetic markers to assign recruits to their parents, which allows us to estimate seed and pollen dispersal distances. In addition, we collect needle samples for genetic analyses using nuclear microsatellite primers (SSR) and newly developed genetic markers targeting single nucleotide polymorphisms (SNPs) in the chloroplast and mitochondrial genomes. The results are used to reveal local dispersal patterns, population genetics, and the historical biogeography of these tree populations.

We establish long-term monitoring along environmental gradients by instrumenting vegetation plots (e.g. TOMST sensors for surface and soil temperature and moisture, and TOMST tree dendrometers for monitoring tree growth).