[1] Colorado State Univ, Nat Resource Ecol Lab, Ft Collins, CO 80523 USA
[2] Univ Aberdeen, Inst Biol & Environm Sci, Aberdeen, Scotland
[3] Karlsruhe Inst Technol, Inst Meteorol & Climate Res Atmospher Environm Re, D-82467 Garmisch Partenkirchen, Germany
[4] Int Livestock Res Inst ILRI, Mazingira Ctr, POB 30709, Nairobi 00100, Kenya
[5] Queensland Univ Technol, Inst Future Environm, Brisbane, Qld 4000, Australia
[6] AgResearch, Lincoln Res Ctr, Private Bag 4749, Christchurch 8140, New Zealand
[7] Aarhus Univ, Dept Agroecol, 20 Blichers, DK-8830 Tjele, Denmark
[8] AgResearch, Invermay Res Ctr, Private Bag 50034, Mosgiel, New Zealand