Establishing indicators for biodiversity [2] (multiple letters)

Jurgen Brauer, Brian Czech, David L. Trauger, Joshua Farley, Robert Costanza, Herman E. Daly, Charles A.S. Hall, Reed F. Noss, Lisi Krall, Paul R. Krausman, Andrew P. Dobson, Andrew Balmford, Peter R. Crane, Rhys E. Green, Georgina M. Mace