29 March 2026 | 10:00 - 11:45 CEST / UTC+2
Open Session - HYBRID
Room: Per Kirkeby Auditorium
Session Description:
This session explores Arctic land-based systems, from tundra and boreal ecosystems to permafrost landscapes and freshwater environments. It examines vegetation change, biogeochemical cycling, hydrology and disturbance regimes, and how terrestrial processes both respond to and influence Arctic climate change.
Keynote: Dr. Efrén López-Blanco
Oral presentations:
Name: Millicent Harding (Durham University)
Title of Presentation: Climate change impacts on the Arctic tundra-forest ecotone change – past, present and future
Abstract text: The forest-tundra ecotone (FTE) is the transition zone between the northern boreal forest and the Arctic tundra. It has undergone rapid warming, faster than anywhere else on earth, in recent decades due to climate change especially in the Fennoscandian Arctic. In response to this warming, the boreal forest is expected to migrate northwards so tree density, growth, and stand productivity are expected to increase with critical potential feedbacks to the Earth’s climate system. How different tree species respond may have profound implications for Earth’s future energy balance and the magnitude of future warming experienced on earth. The climate of the Fennoscandian Arctic is controlled by an oceanic climate regime that then transitions into a more continental regime which has a large impact on the forest behaviour. However, where forest edge advance might be expected under climate warming this is not always occurring so understanding the role of microclimate in modifying forest behaviour is extremely important to accurately predict change.We urgently need to know the change in status of the FTE over past decades to better predict potential magnitudes of change in the future. This requires detailed information at multiple spatial scales. A novel combination of remote sensing of FTE status and change, microclimate data, combined with cutting edge computational approaches in ecological models is proposed as a key approach in integrating information to predict future change. As carbon storage dynamics change from longer term below ground to shorter term aboveground stocks over the FTE it is key to understand how much may be stored in aboveground biomass using terrestrial laser scanning techniques in the field. The project will draw upon very recent advances in high-resolution satellite imagery, in combination with very recent advances in digital twin computing power and ecological-climate models.
Name: Lena Lancastle (University of Sheffield)
Title of Presentation: Changing Arctic ecosystems: drivers of fine scale vegetation greenness and impacts on soil carbon storage.
Abstract text: The Arctic is warming nearly four times faster than the global average. This is having significant impacts on terrestrial ecosystems, with vegetation increasing in biomass and productivity. This phenomenon is known as “Arctic greening” and can have significant implications for ecosystem change and potential feedback to climate by altering soil carbon stores. However, greening patterns are highly heterogenous across space with the drivers of this variability unclear, especially at small scales . Additionally, the impact of these vegetation changes on soil carbon storage is not fully understood but potential for depletion has been shown in research. This leaves us with significant knowledge gaps surrounding not only the patterns of vegetation change, but also the potential impacts on soil carbon. Our research questions focused on 1. How do small-scale environmental conditions such as topography and soil conditions influence vegetation greenness? And 2. How do these vegetation differences impact soil carbon stocks and stability? These were investigated in Abisko, Sweden (68.3° N, 18.8° E) using an intensive field study consisting of 150 1mx1m plots covering an area of ~10km, with an elevational gradient ranging from 513m a.s.l to 966m. Within each plot, measurements of vegetation structure and species composition were taken. These included average vegetation height, tallest 5 individuals, % vegetation cover, % plant functional type cover, top 5 species by abundance and species richness. Leaf samples of the top 5 species within each plot were taken to determine specific leaf area and leaf CN content. Soil samples were taken for determination of soil organic C stocks and C stability (cPOM and cMAOM), enzyme activity and nutrient concentrations. Our results provide insights into how environmental conditions drive vegetation greenness in an Arctic tundra landscape, additionally they will provide essential knowledge for how these vegetation patterns subsequently impact soil carbon storage.
Name: Scott Sugden (McGill University)
Title of Presentation: Shared patterns of microbial community assembly across distinct taxonomic assemblages in five deglaciating polar ecosystems
Abstract text: Almost 10% of Earth’s land area is covered by glacial ice, but as glaciers continue to melt due to ongoing climate change, more than one-third of this area will be exposed by 2100. Because soils drive terrestrial biogeochemical cycles of carbon, nitrogen, and other nutrients, an understanding of microbial succession and activity in deglaciating ecosystems will be crucial for predicting future biogeochemical dynamics in polar regions. We therefore used a combination of next-generation sequencing, in situ gas flux measurements, and isotope-tracing experiments to evaluate microbial community activity in five glacier forefields in the Arctic and Antarctica, encompassing soil ages spanning from <5 to 200 years. We found that each glacier forefield harbored a taxonomically distinct metacommunity, but despite this variability, the underlying factors driving community turnover were consistent among all five forefields. Young soils were dominated by chemolithoautotrophic taxa derived from subglacial sediments, while photosynthetic and heterotrophic metabolisms became increasingly abundant with soil age and continued to dominate even in >100-year-old soils. These changes were most strongly correlated with decreasing soil moisture content and pH following glacier retreat. Measurements of microbial activity further confirmed a shift from litho- to photo-autotrophic metabolisms over time, as well as prominent roles for trace gas oxidation, methane oxidation, and nitrogen fixation for driving nutrient acquisition in these ecosystems. Overall, our results demonstrate the pathways and processes that drive soil development and biogeochemical activity in one of the most rapidly changing ecosystems on the planet and support predictive efforts to understand the future polar landscape.
Name: Rebecca Paarnannguaq Berg (Statens Serum Institut)
Title of Presentation: Meat-Borne Parasites in Greenland: Emerging Observations and Ongoing Investigations
Abstract text: Parasites are an important part of ecosystems and are widespread in Arctic wildlife. The life cycles of parasites are diverse and meat-borne parasites often need multiple hosts to complete theirs. These parasites may influence both wildlife health and food safety. However, their diversity and occurrence in Greenland remain poorly documented.In recent years, hunters and herders have reported an apparent increase in visible cyst-like lesions in harvested caribou (Rangifer tarandus subspp.). These findings have renewed attention to meat-borne parasites such as Sarcocystis, Taenia, and Trichinella species, which are of relevance for both animal and human health across the Arctic.This ongoing study aims to document and characterize the parasites associated with the reported lesions and to consolidate current knowledge on meat-borne parasites in Greenland caribou and the wider North American Arctic. Sampling collection has been initiated, and laboratory analyses using morphological and molecular methods are underway to determine the parasite species.Slaughterhouse findings and preliminary field observations suggest that Sarcocystis species are the most likely cause of the macroscopic cysts currently reported in caribou. However, comprehensive species identification and analysis are pending and will be presented alongside broader contextual findings. The study will provide valuable baseline information on parasite occurrence and implications for Arctic food systems.By the time of presentation, initial analytical results and perspectives on future surveillance and research priorities will be shared. Strengthened collaboration among hunters, herders, local communities, veterinarians, and researchers is essential to improve diagnostic capacity and ensure safe, sustainable use of traditional food resources under changing Arctic conditions.
Name: Anna Kirchner (Aarhus University)
Title of Presentation: How to model shrubs? Data-availability challenges from a modeller’s perspective
Abstract text: The expansion of shrubs across tundra ecosystems is one of the most prominent climate change responses in Arctic terrestrial ecosystems. Therefore, their inclusion and accurate representation in global earth system models (ESMs) is crucial for simulations of Arctic land cover change and climate feedbacks. However, Arctic shrub ecosystems and mechanisms remain underrepresented in many land surface model components of ESMs. We argue that one of the reasons for this underrepresentation is the challenge of obtaining large-scale synthesized data products of shrub characteristics to use for model calibration and validation. Large-scale modelling needs to translate the observed diversity of shrub growth forms and mechanisms into simplified categories of shrub types that are representative of shrub characteristics, their role in ecosystem functioning, and their response to and interactions with changing environmental conditions on a larger spatial scale. To validate those modelling efforts, modellers rely on synthesized data products upscaling measured shrub characteristics spatially and linking different observed variables. While a large range of field observations of shrubs are available, only few variables are synthesised and linked in a way that makes them accessible for large-scale modelling. Here we present a new data-driven implementation of three plant functional types of Arctic shrubs in the global land surface model ORCHIDEE, and the challenges connected to obtaining suitable calibration and validation data products, including biomass, growth form, carbon fluxes and shrub cover. We aim to showcase how this data-driven shrub implementation significantly improves the simulated high-latitude carbon balance of the model, raise awareness of the existing mismatch between available data and modelling needs, and call for a better collaboration between field ecologists and modellers.