Global change: biogeographical and geomorphological perspectives

Human-induced climate change, habitat fragmentation and loss as well as land use changes are global threats that are changing the atmosphere, climate, hydrology, biodiversity and even earth surface processes and ultimately landscapes. High-latitudes are experiencing rapid and significant change associated with climate warming. This places global change research at the centre of the international scientific agenda.

A key aim of the global change research of the Physical Geography Research Groups is to improve understanding and forecast the nature of change in the biogeographical and geomorphological systems, particularly at high-latitudes.

Possible changes in the structure and position of treeline ecotone and changes in species occurrence and patterns of biodiversity in space and time can be studied using species distribution modelling. When predicting changes in treeline ecotone we cannot simply use the changing temperature patterns alone, but we need to consider the complex interactions between biotic and abiotic factors. Hence, we need to build more complex and ecologically realistic models.

The novel modelling approaches (e.g. consideration of functional traits) and higher quality of data will significantly advance species distributions modelling. This will improve the understanding of sensitivity of subarctic tree-line to climate change.

Determination of the environmental factors controlling earth surface processes and landform patterns in cold regions is one of the central themes in periglacial geomorphology. Recently, novel statistical techniques and modelling methods have gained more attention in the field of periglacial geomorphology. Especially in the context of global change, spatial models are essential tools for assessing the impacts of changing environmental conditions on geodiversity and geomorphological processes.

Main objectives

  • To investigate the impacts of climate change on the high-latitude treeline ecotone and periglacial processes (e.g. permafrost)
  • To explore the spatial and temporal changes in high-latitude biodiversity patterns
  • To evaluate the accuracy, utility and feasibility of statistically-based spatial models in examining treeline ecotone and periglacial processes

Staff

  • Professor Jan Hjort
  • Dr. Janne Alahuhta
  • Researcher Henna Sormunen

Main collaborators

  • Professor Miska Luoto, Department of Geosciences and Geography, University of Helsinki, Finland
  • Professor Bernd Etzelmüller, Department of Geosciences, University of Oslo, Norway
  • Professor Hanne H. Christiansen, Geology Department, The University Centre on Svalbard (UNIS), Norway
  • Dr. Risto Virtanen, Senior Curator, Department of Biology, Botanical Museum, University of Oulu, Finland
  • Dr. Jani Heino, Natural Environment Centre, Finnish Environment Institute & Department of Biology, University of Oulu, Finland

Projects

  • Perma-Nordnet Read more
  • Macroecological approaches to understanding macrophyte diversity Read more

Main publications

  • Hjort, J., Ujanen, J., Parviainen, M., Tolgensbakk, J. & B. Etzelmüller (2014). Transferability of geomorphological distribution models: evaluation using solifluction features in subarctic and Arctic regions. Geomorphology 204, 165-176.
  • Hjort, J. & M. Luoto. (2013). Statistical methods for geomorphic distribution modeling. In: Shroder, J., Jr., Baas, A.C.W. (Eds.). Treatise on Geomorphology. Academic Press, San Diego, 59–73.
  • Alahuhta, J., Heino, J. & M. Luoto (2011). Climate change and the future distributions of aquatic macrophytes across boreal catchments. Journal of Biogeography 38: 383-393.
  • Alahuhta, J., Vuori, K.-M. & M. Luoto (2011). Land use, geomorphology and climate as environmental determinants of emergent aquatic macrophytes in boreal catchments.  Boreal Environment Research 16, 185–202.
  • Hjort, J. & M. Luoto (2011). Novel theoretical insights into geomorphic process-environment relationships using simulated response curves. Earth Surface Processes and Landforms 36, 363–371.
  • Sormunen, H., Virtanen, R. & M. Luoto (2011). Inclusion of local environmental conditions alters high-latitude vegetation change predictions based on bioclimatic models. Polar Biology 34, 883–897.
  • Hjort, J., Etzelmüller, B. & J. Tolgensbakk (2010). Effects of scale and data source in periglacial distribution modelling in a High Arctic environment, western Svalbard. Permafrost and Periglacial Processes 21, 345–354.
  • Christiansen, H.H., Etzelmüller, B., Isaksen, K., Juliussen, H., Farbrot, H., Humlum, O., Johansson, M., Ingeman-Nielsen, T., Kristensen, L., Hjort, J., Holmlund, P., Sannel, A.B.K., Sigsgaard, C., Åkerman, H.J., Foged, N., Blirka, L.H., Pernosky, M.A. & R. Ødegård (2010). The Thermal State of Permafrost in the Nordic area during IPY 2007-2009. Permafrost and Periglacial Processes 21, 156–181.
  • Luoto, M., Marmion, M. & J. Hjort (2010). Assessing the spatial uncertainty in predictive geomorphological mapping: a multi-modelling approach. Computers and Geosciences 36, 355–361.
  • Virtanen, R., Luoto, M., Rämä, T., Mikkola, K., Hjort, J., Grytnes, J.-A. & J. Birks (2010). Recent vegetation changes in the high latitude tree line ecotone are controlled by geomorphologic disturbance, productivity and diversity. Global Ecology and Biogeography 19, 810–821.

Last updated: 16/1/2014