Tolong jelaskan mengenai Amerika Utara dari Kawasan ekologi

Abell, R.A. et al. (2000). Freshwater Ecoregions of North America: A Conservation Assessment Washington, DC: Island Press, .

Ricketts, T.H. et al. 1999. Terrestrial Ecoregions of North America: A Conservation Assessment. Washington (DC): Island Press, .

Krever, V., Dinerstein, E., Olson, D. and Williams, L. 1994. Conserving Russia's Biological Diversity: an analytical framework and initial investment portfolio. WWF, Switzerland.

Wikramanayake, E., E. Dinerstein, C. J. Loucks, D. M. Olson, J. Morrison, J. L. Lamoreux, M. McKnight, and P. Hedao. 2002. Terrestrial ecoregions of the Indo-Pacific: a conservation assessment. Island Press, Washington, DC, USA, .