Corvallis Environmental Center
A global overview of drought and heat-induced tree mortality reveals emerging climate change risks for forests
2009 · Craig D. Allen, Alison K. Macalady, et al. · Forest Ecology and Management
Indicators for Monitoring Biodiversity: A Hierarchical Approach
1990 · Reed F. Noss · Conservation Biology
Ecoregions of the Conterminous United States
1987 · James M. Omernik · Annals of the Association of American Geographers