@inbook {1307, title = {Polar Systems}, booktitle = {Millennium Ecosystem Assessment. Current State and Trends: Findings of the Condition and Trends Working Group}, year = {2005}, pages = {717-743}, publisher = {Island Press}, organization = {Island Press}, keywords = {LTER-MCM}, doi = {LTER}, author = {F. S. Chapin and McGuire, A and Nuttall, M and Ross A. Virginia and Young, O and Zimov, S and Christensen, T and Godduhn, A and Murphy, E and Diana H. Wall and Zockler, C and Berman, M and Callaghan, T and Peter Convey and A. S. Crepin and Danell, K and Hugh W. Ducklow and Forbes, B and Kofinas, G}, editor = {R. Hassan and R. Scholes and N. Ash} }