RÍ (Rúna) Magnússon MSc

RÍ (Rúna) Magnússon MSc

Promovendus, PhD candidate

Current Activities - You can follow my research through the following channels:

 

I am in the Dutch national committee of Association for Polar Early Career Scientists. Keep an eye on the website for projects and events of interest to early career polar researchers in the Netherlands. 

For an impression of fieldwork in the Siberian Arctic, have a look at this fieldwork video

Project outline - I study permafrost-shrub interactions on the Siberian lowland tundra. My overarching aim is to determine (1) whether lowland tundra ecosystems show a net decline or expanse of shrub vegetation, (2) how this is related to abrupt permafrost thaw and (3) to what extent this is caused by extreme summer precipitation.

Global warming in high-latitude regions is significantly stronger than the global average. During the past decade, numerous researchers have reported trends of shrub expansion under warmer conditions. However, this Arctic greening trend seems to have halted during the past years, the causes of which are unknown. Simultaneously, increasing mention is made of abrupt permafrost thaw throughout the Arctic region, creating thaw ponds in which vegetation drowns. We propose that this provides a likely cause for this shift away from Arctic greening. Moreover, we hypothesize that extreme summer precipitation may trigger abrupt permafrost thaw due to increased heat transport to the permafrost. Combining satellite image analysis, dendrochronological analysis, field manipulation experiments and field monitoring will help us assess coupled dynamics of vegetation and permafrost thaw and elucidate its drivers in lowland tundra ecosystems. Using time-series of satellite imagery we will assess the spatio-temporal dynamics of shrub decline/expansion on a landscape scale, aided by ground point observations and monitoring. To assess to what extent climatic conditions affect shrub decline and/or expansion we will use dendrochronological analysis on dwarf shrubs. Lastly, we will determine experimentally whether extreme summer precipitation triggers permafrost thaw using an irrigation set-up. A mechanistic understanding of shrub dynamics and permafrost degradation is vital for assessing future development of this ecosystem under global change and its implications for greenhouse gas balance. We expect that this research project in an understudied Arctic region will shed a new light on Arctic landscapes.