Common Concern for the Arctic Conference, Ilulissat 2008 Session: Terrestrial Living Resources Arctic Terrestrial Ecosystem Responses to a Warming Climate Jesper Madsen National Environmental Research Institute University of Aarhus, Denmark

National Environmental Research Institute University of Aarhus, Denmark Zackenberg: A High Arctic Integrated Observatory, Terrestrial Ecosystem Responses to a Warming Climate Funding: Danish Government & Greenland Home Rule New station: Nuuk started 2007

National Environmental Research Institute University of Aarhus, Denmark Zackenberg: A High Arctic Ecosystem Under Scrutiny Terrestrial Ecosystem Responses to a Warming Climate

National Environmental Research Institute University of Aarhus, Denmark Terrestrial Ecosystem Responses to a Warming Climate Zackenberg Field Station, March 2008; International Polar Year Project” IsiCab” Zackenberg: Synthesis of the first 10 years of integrated research and monitoring - input to IPY

National Environmental Research Institute University of Aarhus, Denmark A Decade of Warming ( ): Ambient temperatures July June Terrestrial Ecosystem Responses to a Warming Climate Annual mean temperature increase of 2.25 o C

National Environmental Research Institute University of Aarhus, Denmark A Decade of Warming ( ): Terrestrial snow cover melt Terrestrial Ecosystem Responses to a Warming Climate % snow cover, 10 June Date of snow melt has advanced by nearly 1 month

National Environmental Research Institute University of Aarhus, Denmark Ecological Responses: Timing of Reproduction 14.5 days/decade Høye et al Terrestrial Ecosystem Responses to a Warming Climate

National Environmental Research Institute University of Aarhus, Denmark Ecological Responses: Trophic mismatch Example from West Greenland plant-reindeer interactions Post et al Terrestrial Ecosystem Responses to a Warming Climate Warmer climate Earlier spring Higher plant growth synchrony Reduced food quality for reindeer Lower calf production

National Environmental Research Institute University of Aarhus, Denmark Ecological Responses: Trophic cascades Example of fading vole and predator cycles in North Scandinavia Hörnfeldt et al Terrestrial Ecosystem Responses to a Warming Climate

National Environmental Research Institute University of Aarhus, Denmark Summary: short term (1-2 decades) INCREASED air and lake temperature! EARLIER snow and ice melt! LONGER growth season! Climate EXTREME ADVANCE of phenology (reproduction); highly variable; no increase in biomass SYSTEM responses: direct and across trophic climatic effects; interaction between function of ecosystem and effect of climate Ecological Responses SPECIES responses highly plastic; there will be winners and losers Terrestrial Ecosystem Responses to a Warming Climate

National Environmental Research Institute University of Aarhus, Denmark Summary: longer-term (2+ decades) FURTHER ADVANCEMENT of phenology (reproduction) and growth conditions; increasing biomasses SYSTEM responses: how far can the system be “twisted”? Ecological Responses SPECIES successions; high-Arctic species will be “squeezed” between northward moving tree-line and Arctic Ocean; low-Arctic species will spread; higher degree of extreme events will affect long term resilience of populations Terrestrial Ecosystem Responses to a Warming Climate

National Environmental Research Institute University of Aarhus, Denmark Implications for research/monitoring and adaptation CONTINUOUS, YEAR-ROUND integrated monitoring programmes IMPROVED station networks EVALUATE cumulative effects of climate and physical development on living resources FEED-BACK to society to make adaptive policies and sound management of living resources Terrestrial Ecosystem Responses to a Warming Climate

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