We are seeking a research fellow that will join a cross-disciplinary team (ecology, palaeoecology, genetics, archaeology, geology, niche modelling) working in two geographical regions (Norway and the Alps). We will expand our knowledge on past vascular plant and animal diversity and abundance at a taxonomic depth that has not been possible until now due to methodological limitations. We expect to disentangle the effects of past human land-use (hunting, husbandry, burning, agriculture), climate change, and biota on species and ecosystem changes and thereby be able to answer questions central to our understanding of our biological resources, such as the level of persistence of species and resilience of ecosystems to environmental drivers, the extinction risk of species, and the capacity of mountain landscape to buffer against these changes. By identifying drivers of shifts in ecosystem services through time, we may inform future management.
The successful candidate will work on development of improved technology. The most recent applications of ancient plant DNA analyses are largely developed by our team (Taberlet et al. 2007, Sønstebø et al. 2010, Yoccoz et al. 2012, Willerslev et al. 2014). For vascular plants, the 50-100 base pair long P6 loop region of the chloroplast trnL (UAA) intron is used in a PCR based method (Taberlet et al. 2007), which allows identification of all plant families, most genera (>75%), and one third of the species (Sønstebø et al. 2010). When applied to modern lake sediments, half of the species present within 2 m of lakes were detected (Alsos et al. In prep.). Our recent study of an 8500 year old core from Svalbard show that the method detect all except two genera identified in a macrofossil study from the same lake (Alsos et al. 2015). Overall, 1.2 times more taxa of vascular plants were identified with ancient DNA than macrofossils, and the number of taxa identified per sample was 2.7 times higher for the former. Thus, DNA analyses of Holocene lake sediment can reveal the presence of rare taxa and thereby allow for a better estimation of species persistence. Further, the method is now resource-efficient and repeatable, and it can be extended to any group of organisms, given that a DNA reference library and adequate primers are developed . It also allows for semi-quantitative interpretations based on the number of PCR repeats where taxa are identified (Pansu et al. 2015). We will do minor optimization of these applications and analyse all samples for vascular plants and key herbivores.
Contact : Prof. Inger Greve Alsos
Tromsø University Museum
Email: inger.g.alsos at uit.no