Project: Climate change impacts on Arctic soil and lake microbiomes

Acronym	CLIMARCTIC (Reference Number: 96)
Duration	31/12/2016 - 30/12/2019
Project Topic	Nowhere is climate change more intense than in the Arctic, making it the most appropriate reference region for the detection and understanding of global change and its effects on biodiversity and ecosystem functioning. In fact, the physical and chemical attributes of Arctic soils and lakes are very sensitive to climate change because of their close proximity to tipping points related to the 0°C threshold. The biogeochemical cycles and functioning of these terrestrial Arctic ecosystem are to a large extent controlled by microorganisms from all domains of life. The combined effects of increasing temperatures and changes in the length of the growth season and moisture availability on different processes in the carbon (photosynthesis, respiration, methane production), nitrogen and phosphorus cycles of Arctic terrestrial ecosystems are poorly understood. CLIMARCTIC is aimed at studying the potential effects of climate change on the diversity and genetic functional attributes (nutrient and carbon cycling) of a High Arctic terrestrial microbiome in soils, wetlands and lakes. The combination of paleolimnological, field and experimental studies will provide insights into the response of these ecosystems to climate changes and hence to assess their role as feed-back mechanisms in the climate system under future global changes. Representative samples along environmental and temporal scales (different seasons) will be taken in two lakes and their catchment areas in Svalbard (Ny-Alesund, international platform for Arctic research) for microscopy and sequence-based biodiversity assessments of marker genes, as well as taxonomic profiling using high performance liquid chromatography of the photosynthetic pigments. This information will be combined with laboratory experiment using stable isotopes of N and C as well as 13C-DNA stable isotope probing to study nutrient and carbon cycling in order to develop a conceptual model of the food webs of a dry and wet tundra system in the catchment of the lakes. Metagenomics and metatranscriptomics on a selection of these samples from these tundra systems will be used to study the genetic make-up of these microbiomes and the differential gene expression patterns in field and laboratory experiments in response to climate changes; a particular focus will be put on nutrient and carbon cycling. The field experiment will make use of snow fences and is aimed at assessing the effect of increased winter precipitation on the functioning of the soil ecosystems. In the laboratory experiments we will assess the effect of hydrological changes from altered precipitation patterns, temperature fluctuations including climate warming and altered freeze thaw cycles on gene expression and carbon cycling. We will also quantify the conversion rates between the different forms of N, P and C in field and laboratory experiments. The total nutrient and carbon concentrations and the different chemical forms of N and P will be analysed in the field samples and in different sources, such as glacier ice, snow banks and (mineral) soils. This information will be used to assess the structuring role of environmental factors on the microbial communities. During the three field campaigns - including one during winter - we will measure snow depth and light climate and analyse the photosynthetic efficiency, the respiration and the methane production in a natural wet and dry tundra site and in the plots with altered snow depth. Changes in nutrient, organic carbon content and food web structure over longer timescales will be analysed in radiometric-dated lake sediment cores to assess the responsiveness, resilience and rates of change of the lakes and their catchments during the past 2000 years. This information will allow us to put the predictions of the response of these communities to changes in temperature and moisture observed in the space-for-time substitution in a context of natural variability. The results of our study will be communicated to a variety of stakeholders including the media, national conservation bodies, the general public, and leading international science policy initiatives both at the national and international level, such as the Arctic Council and the IPCC.
Network	BiodivERsA3
Call	BiodivERsA3 Joint Call 2015

Project partner

Number	Name	Role	Country
1	Ghent University	Coordinator	Belgium
2	Arctic University of Norway	Partner	Norway
3	Swiss Federal Institute for Forest, Snow and Landscape Research	Partner	Switzerland
4	Universidad Autónoma de Madrid	Partner	Spain
5	University of Rostock	Partner	Germany