Theme 1
Project 1042

Feedbacks between hydrological and nutritional changes as induced by permafrost melting, and ecosystem functioning
Project leader: Prof. dr. M.A.P.A. Aerts
Researcher(s): Dr. F. Keuper
Starting date: 1-feb-07

Global warming is most manifest at high-latitude ecosystems such as (sub-)arctic tundra. One of the direct consequences is permafrost melting, releasing ‘fossil’ water. Elevated temperatures may lead to higher water and nitrogen availability. This project investigates if elevated temperatures in northern tundra ecosystems affect water and nitrogen availability and the species composition and Plant Functional Type dominance of the vegetation and how this in turn leads to changes in Net Primary Production (NPP) and local hydrology (cf. project I). The research focus is on northern Sweden where water and snow addition experiments will be performed. Additional measurements on the effects of water addition on vegetation characteristics will be performed in Siberia. This will be the first study in which deuterium and 18O isotopic signatures will be used in a field setting to investigate how permafrost melting influences water availability to the vegetation and how this feeds back on plant species composition and NPP. These vegetation characteristics feed back on the land surface energy budget because of the different regulating hydrological properties of plants. These data serve as input date for projects I and III at small spatial scales.

Keuper, F., Dorrepaal, E., Van Bodegom, P.M., Aerts, R., Van Logtestijn, R.S.P., Callaghan, T.V., Cornelissen, J.H.C. (2011). A Race for Space? How Sphagnum fuscum stabilizes vegetation composition during long-term climate manipulations . Global Change BiologyVolume 17, Issue 6: 2162-2171.
Darwin Center authors: Aerts M.A.P.A., Keuper F.

Callaghan, T.V., Tweedie, C.E., Åkerman, J., Andrews, C., Bergstedt, J., Butler, M.G., Christensen, T.R., Cooley, D., Dahlberg, U., Danby, R.K., Daniëls, F.J.A., De Molenaar, J.G., Dick, J.d , Mortensen, C.E., Ebert-May, D., Emanuelsson, U., Eriksson, H., Hedenås, H. , Henry, G.H.R., Hik, D.S., Hobbie, J.E., Jantze, E.J., Jaspers, C., Johansson, C., Johansson, M., Johnson, D.R., Johnstone, J.F. , Jonasson, C., Kennedy, C., Kenney, A.J. , Keuper, F., Koh, S., Krebs, C.J., Lantuit, H., Lara, M.J., Lin, D., Lougheed, V.L., Madsen, J., Matveyeva, N., Mcewen, D.C. , Myers-Smith, I.H., Narozhniy, Y.K. , Olsson, H., Pohjola, V.A., Price, L.W., Rigét, F., Rundqvist, S., Sandström, A., Tamstorf, M., Bogaert, R.V., Villarreal, S., Webber, P.J. , Zemtsov, V.A. (2011). Multi-decadal changes in tundra environments and ecosystems: Synthesis of the international Polar year-back to the future project (IPY-BTF) . AmbioVolume 40, Issue 6: 705-716.
Darwin Center authors: Keuper F.

Johansson, M., Åkerman, J., Keuper, F., Christensen, T.R., Lantuit, H., Callaghan, T.V. (2011). Past and Present Permafrost Temperatures in the Abisko Area: Redrilling of Boreholes . AmbioVolume 40, Issue 6: 558-565.
Darwin Center authors: Keuper F.

Keuper, F., van Bodegom, P.M., Dorrepaal, E., Weedon, J., van Hal, J., van Logtestijn, R.S.P., Aerts, R. (2012). A Frozen Feast: Thawing permafrost increases plant-available nitrogen in subarctic peatlands.. Global Change Biology18: 1998-2007.
Darwin Center authors: Aerts M.A.P.A., Keuper F.

Keuper, F., Parmentier, F.J.W., Blok, D., van Bodegom, P.M., Dorrepaal, E., van Hal, J., van Logtestijn, R.S.P., Aerts, R. (2012). Tundra in the rain: differential vegetation responses to three years of experimentally doubled summer-precipitation in Siberian shrub and Swedish bog tundra.. Ambio41: 269-280.
Darwin Center authors: Aerts M.A.P.A., Blok D., Keuper F., Parmentier F. J. W.

Darwin Center authors: Keuper F.