WWF's Terrestrial Ecoregions

Data on ecoregions is taken from the World Wildlife Fund's Terrestrial Ecoregions of the World version 2.0 from 2004. Ecoregion borders have been simplified using the modified Visvalingam algorithm implemented in mapshaper, to allow for better rendering performance.

Olson, D.M., E. Dinerstein, E.D. Wikramanayake, N.D. Burgess, G.V.N. Powell, E.C. Underwood, J.A. D'Amico, I. Itoua, H.E. Strand, J.C. Morrison, C.J. Loucks, T.F. Allnutt, T.H. Ricketts, Y. Kura, J.F. Lamoreux, W.W. Wettengel, P. Hedao, and K.R. Kassem. Terrestrial Ecoregions of the World: A New Map of Life on Earth (PDF, 1.1M) BioScience 51:933-938.