Acknowledgments and Sources | Conservation Map of the U.S

We thank the many groups who provided data and assistance for this map, especially Colorado State University, Conservation Biology Institute, IHS Inc., the Land Trust Alliance, The Trust for Public Land, The Nature Conservancy, U.S. Forest Service, and U.S. Geological Survey. Thanks also to ESRI for its support in printing this map.

We also are deeply grateful to the many individuals who assisted in the development and production of this map through provision of data, analyses, and other information, including:  Rob Aldrich, Pat Comer, Tom FitzHugh, Curtis Flather, Pilar Hernandez, Catherine Jarnevich, Lynn Kutner, James Melonas, Andrew du Moulin, Tom Stohlgren, Rickie White, H. Dean Williams, and Matt Zieper. Thanks as well to the following partners for reviewing editorial content: Tim Glidden, Rich Knox, Bill Poole, Breece Robertson, Jonathan Likeke Scheuer, Matt Shaffer, and David Slater.

Map Design and Production Team

Design: Allen Carroll Project director: Frank Biasi Project managers: Dierdre Bevington-Attardi, Lori Scott Text: Rob Riordan, Bruce Stein, Kyle Copas GIS: Frank Biasi, Demian Rybock, Ashley Adams, Derek Azar, Jon Hak, Ted Sickley. Production: Glen Callouet, James McClelland, Jr. Photo editor: Miriam Stein Text Editor: David Miller

Sources: Natural States of America Map  

Main Map (center)

Protected areas data compiled from various sources, primarily: Protected Areas Database (v. 4.5), Conservation Biology Institute, and The Nature Conservancy. Additional statewide data from The Nature Conservancy and others for the following states: CO, CT, DE, FL, MA, MD, ME, NH, NJ, NY, PA, RI, VA, VT, WA.

Detailed review and refinement of data structure provided by:

Ecological division boundaries adapted from Figure 2 in: Comer, P., D. Faber-Langendoen, R. Evans, S. Gawler, C. Josse, G. Kittel, S. Menard, M. Pyne, M. Reid, K. Schulz, K. Snow, and J. Teague. 2003. Ecological Systems of the United States: A Working Classification of U.S. Terrestrial Systems. NatureServe, Arlington, Virginia. See also: Figure 2 in P.J. Comer and K.A. Schulz. 2007. Standardized Ecological Classification for Mesoscale Mapping in the Southwestern United States. Rangeland Ecology & Management 60:324–335.

Comer et al. (2003) describes these ecological division boundaries as follows: “Ecological Divisions are sub-continental landscapes reflecting both climate and biogeographic history, modified from Bailey [US Forest Service](1995 and 1998) at the Division scale. Continent-scaled climatic variation, reflecting variable humidity and seasonality (e.g. Mediterranean vs. dry continental vs. humid oceanic) are reflected in these units, as are broad patterns in phytogeography (e.g. Takhtajan 1986). The division lines were modified by using ecoregions established by The Nature Conservancy (Groves et al. 2002) and World Wildlife Fund (Olson et al. 2001) throughout the Western Hemisphere.”

Land Protection Graph (lower left)

Number of land trusts from: Land Trust Alliance. 2006. The 2005 National Land Trust Census Report.

Acres protected through private action data collated from various sources, including: The Trust for Public Lands, The Conservation Fund, and The Nature Conservancy (June 2008).

Imperiled Species Hotspots (top right)

Rarity-weighted species richness analysis conducted by NatureServe based on 2008 U.S. natural heritage program element occurrence data. Hotspots analysis based on approximately 64,000 occurrences of critically imperiled (G1) and imperiled (G2) species of vertebrate animals, invertebrates, and plants. For discussion of Rarity-Weighted Richness Analyses, see Stein, B.S., L.S. Kutner, and J.S. Adams. 2000. Precious Heritage: The Status of Biodiversity in the United States. Oxford University Press, New York,  pp.171-173.

Vertebrate Species Diversity (upper right)

Terrestrial vertebrate species richness analysis conducted by NatureServe based on NatureServe digital distribution maps of ca. 1,900 species of birds, mammals, amphibians, and reptiles. [Individual range maps available at NatureServe Explorer and downloadable from NatureServe.]

Land Protection Investments (lower right)

Annual per capita spending by states from: The Trust for Public Land's Conservation Almanac 1998-2005

State and local ballot initiatives passed between 1998 and 2008 from: The Trust For Public Land's LandVote® Database, 2008.

Land Trust Activity (bottom right)

Land trust location and acreage protected data from: Land Trust Alliance. 2006. The 2005 National Land Trust Census Report.

Sources: Open Space at Risk Map

Main Map (center)

Cropland land cover data from: National Land Cover Data Set 2001, produced by the Multi-Resolution Land Characteristics Consortium (MRLC), a federal consortium including the Environmental Protection Agency, United States Geologic Survey, National Oceanic and Atmospheric Administration, United States Forest Service, National Aeronautic and Space Administration, Bureau of Land Management, LANDFIRE, Natural Resources Conservation Service, National Park Service, US Fish and Wildlife Service, Office of Surface Mining.

Housing density data from: Spatially Explicit Regional Growth Model (SERGoM) developed by David M. Theobald, Colorado State University and based on the U.S. Census Bureau’s block-group and block data for 2000. For discussion of SERGoM, see D. M. Theobald. 2005. Landscape patterns of exurban growth in the USA from 1980 to 2020. Ecology and Society 10(1): 32. 

Active oil and gas wells data from: IHS Inc. Well data includes all states with significant oil and gas production except Pennsylvania. Data not available for the following states: CT, DE, DC, GA, HI, ID, IA, ME, MD, MA, MN, MS, NH, NH, NJ, NC, PA, RI, SC, TN, VT, and WI. “IHS Inc. is a leading global source of critical information and insight for customers in a broad range of industries. Our customer product and service solutions span four major areas of information: energy, product lifecycle management, environmental and security. IHS has been in business since 1959 and employs more than 3,000 people in 35 locations around the world.”

Development Pressures (top right)

Housing density conversion analysis conducted by David M. Theobald, Colorado State University, based on the Spatially Explicit Regional Growth Model (SERGoM) (see above), which uses Woods & Poole decadal county-level population projections to drive the growth model, and a variety of ancillary datasets to refine allocation of housing units. Density categories used in this conversion analysis are: urban (<0.1 ha per unit); suburban (0.1 – 0.68 ha per unit); exurban (0.68 – 16.18 ha per unit); and rural (>16.18 ha per unit).

Climate Change (upper right)

Climate change stress index developed by Linda Joyce, Curtis Flather, and Marni Koopman of the U.S. Forest Service Rocky Mountain Research Station with funding from the Wildlife Habitat Policy Research Program.

Altered River Flows (lower right)

Ratio of dam storage to runoff analysis conducted by The Nature Conservancy Global Freshwater Team based on flow data from the U.S. Geological Survey and dam storage data from the U.S. Army Corps of Engineers. Map includes rivers with watersheds greater than 1,000 square kilometers.

Invasive Species (bottom right)

Zebra mussel (Dreissena polymorpha) sightings distribution data from: Benson, A. J., U.S. Geological Survey, Non-Indigenous Aquatic Species Program. Data retrieved June 2008.

Tamarisk (Tamarix ramosissima) distribution data compiled from various sources by: U.S. Geological Survey, National Institute of Invasive Species Science.

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