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FORHOT (Natural Soil Warming in Natural Grasslands and a Sitka Spruce Forest in Iceland)



In the FORHOT research project we study how changes in soil temperature affect various ecosystem processes in both natural grasslands and a planted 45-year old Sitka spruce forest in S Iceland. Background: On May 29, 2008, there was an earthquake in S-Iceland that measured 6.3 on the Richter scale. One of its many implications was that geothermal systems close to its epicentre were disturbed. At Reykir, one of the campuses of the Agricultural University of Iceland, one such geothermal system moved from its previous location, to a new and previously “cold” area. The new belowground geothermal channels resulted in soil temperature to increase in the new area that is ca. 4 ha in size. The soil temperature increase varies with depth down to the geothermal channels, and ranges from +0 °C to +52 °C where the channels are closest to the surface. The heated area is covered by two ecosystem types: a) a planted 45 year old Sitka spruce (Picea sitchensis) forest and b) a natural treeless grassland dominated by Festuca sp., Agrostis sp. and moss. This created a natural soil warming experiment that now (2014) has lasted for six years. This natural experiment gives a unique opportunity for ecologists to study how various ecosystem processes are affected by temperature. The large range in temperature elevations at the ForHot site both offer conditions similar to the predicted climate change during the next century and more extreme temperatures that can give new insights into stress physiology.


Natural warming experiment in Iceland.


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