The Arctic is underlain by vast areas of permafrost, holding tremendous amounts of greenhouse gases trapped in the soil beneath the active layer (the part of permafrost soils that thaw and refreeze over the summer season). In times of climate change and steadily rising temperatures, these gases will be released into the atmosphere. At the same time, plant growth and soil life are enhanced in a warmer Arctic with longer growing seasons. Could this layer of plants, mosses, organic soil and other life on the surface function as a “cooling blanket” and protect the permafrost from warm temperatures?
We know that plants can insulate the frozen ground to a certain extent, but these studies have concentrated on aboveground plant parts, ignoring the belowground root system and enigmatic microbial world. For instance, there is a distinct increase of shrubs in the Arctic regions, referred to as ‘Arctic Greening’ but still it is unknown whether this may counteract the thawing of the Arctic permafrost. Most of our knowledge is based on the Low Arctic, while drivers in Low- and High Arctic sites, such as Svalbard, may well be different.
INSULATE aims to study the effects of climate change, both biotic (vegetation, microbiota) and abiotic factors (e.g. temperature) on permafrost insulation on a year-round basis in the High Arctic. During this project we will monitor Arctic biota (for instance, plants, mosses and microbes) at established borehole infrastructures in the High Arctic tundra of Svalbard. These boreholes are drilled several meters deep, with known soil temperatures and sediment or bedrock composition. We will combine a range of new field and lab techniques and state-of-the-art chemical and DNA-based measurements in order to distinguish between contributions of aboveground and belowground life forms and climatic factors in insulating permafrost. The outcome will be to identify tipping points in ecological protection by Arctic biota and predict future insulation by Arctic biota in a warming Arctic.
In 2025, measurements continued around the 10 boreholes that were chosen in Longyearbyen, including a wide range of vegetation types. At each borehole, soil temperature and moisture, thaw depth, surface properties such as albedo, as well as gas fluxes were assessed throughout the summer. These measurements will help us understand the effect of vegetation properties and related insulation potential on the carbon budget.
We further developed a standardized protocol for pan-Arctic measurements of vegetation and soil components to determine whether (a)biotic drivers differ between Low and High Arctic environments. We made use of a large network of sites using boreholes and/or CALM sites on Svalbard, in Alaska and Abisko, Sweden (Global Terrestrial Network for Permafrost; GTN-P). 20 surveys around boreholes and CALM grids were conducted in Longyearbyen and Ny Ålesund. Vegetation was recorded and soil parameters such as moisture and organic layer thickness was assessed.
We also established a moss transplant experiment in both dry and wet sites in the vicinity of Longyearbyen. There, we investigated whether different mosses affect ground temperatures and thaw depth to a different extent when hydrological conditions change. In addition, moss patches were sampled for a laboratory experiment which will investigate which vegetation characteristics, i.e. their “traits” are responsible for insulating the soil. To this end, a laboratory setup was developed where frozen sand cores are overlain by mosses and thaw depth is measured over time. Moss traits that may influence thaw depth, such as surface roughness, were investigated. We furthermore sampled soil cores for a similar laboratory setup with the aim to investigate the belowground soil structure and microbiome, and how these parameters influence insulative properties under dry and wet conditions. Both experiments together will enable us to gauge above-and belowground contributions to insulation. As a further step to disentangle the belowground contribution of plants to insulation, we studied the root system of common Arctic plants, investigating, e.g., root biomass, rooting depth and branching architecture.
Permafrost is thawing at unprecedented rates with rising temperatures in the Arctic, releasing large amount of greenhouse gases into the atmosphere. Currently, there is a large knowledge gap on the insulative effects of Arctic biota on the frozen ground.
There is also a great urgency to understand whether drivers of permafrost insulation differ between High and Low Arctic environments, and whether Arctic greening might counteract the thawing of the Arctic.
INSULATE aims to study the interactive effects of climate change and (a)biotic factors on permafrost insulation in both warm and cold seasons in the High Arctic.
We will monitor Arctic biota at established borehole infrastructures in the High Arctic tundra of Svalbard. Combining new field and lab techniques and state-of-the-art chemical and DNA-based measurements, INSULATE will (1) disentangle the contribution of above versus belowground components and climatic factors to insulation of permafrost. It will investigate how they affect (2) soil temperatures and active layer thickness, (3) by including Low Arctic sites, identify tipping points in ecological protection by Arctic biota, and (4) predict future insulation by Arctic biota in a warming Arctic.
Our project faces challenges linked to the planned interdisciplinary studies, and the complexity of year-round field work in the Arctic. The success of the project is guaranteed by the involvement of an interdisciplinary team of world-leading Arctic researchers who are part of world-wide research networks, the excellence of the research facilities, field logistic and infrastructure available to the team, and the high quality of the project organization.
INSULATE will significantly increase our understanding of insulation properties and buffering potential of thawing permafrost under the largest threats to High Arctic ecosystems. The results will be of a global importance and relevant to the scientific community, stakeholders and to the public.
