Connectivity of the American Agricultural Landscape: Assessing the National Risk of Crop Pest and Disease Spread

• Published in: Bioscience Vol. 59; no. 2; pp. 141 - 151
• Main Authors: Margosian, Margaret L, Garrett, Karen A, Shawn Hutchinson, J. M, With, Kimberly A
• Format: Journal Article
• Language: English
• Published: Circulation, AIBS, 1313 Dolley Madison Blvd., Suite 402, McLean, VA 22101. USA University of California Press 01.02.2009; American Institute of Biological Sciences; Oxford University Press
• Subjects: 21st Century Directions in Biology; Agricultural land; Agricultural Production; agricultural statistics; Animal and Plant Health Inspection Service; Causes of; Cereal crops; Climate change; Colleges & universities; Company business management; Company distribution practices; Connectivity; Control; Corn; Cotton; Counties; crop acreage; Crop density; Crop diseases; Crop production; Crops; Disease; disease outbreaks; Disease spread; disease transmission; Distribution; Environmental economics; Food supply; Genetic diversity; Geographic information system; Geographic information systems; geospatial technology; Graph theory; Heterogeneity; invasive species; Land Use; landscape connectivity; Landscapes; literature reviews; Management; Methods; Networks; OVERVIEW ARTICLES; Pathogens; Pest control; Pest outbreaks; Pesticides; Pests; Plant diseases; plant diseases and disorders; plant pests; Protection and preservation; Risk assessment; Soybeans; Triticum aestivum; Wheat; Zea mays; United States; geographic information systems; networks; graph theory; landscape connectivity; invasive species
• ISSN: 0006-3568; 1525-3244
• DOI: 10.1525/bio.2009.59.2.7

More than two-thirds of cropland in the United States is devoted to the production of just four crop species—maize, wheat, soybeans, and cotton—raising concerns that homogenization of the American agricultural landscape could facilitate widespread disease and pest outbreaks, compromising the national food supply. As a new component in national agricultural risk assessment, we employed a graph-theoretic approach to examine the connectivity of these crops across the United States. We used county crop acreage to evaluate the landscape resistance to transmission—the degree to which host availability limits spread in any given region—for pests or pathogens dependent on each crop. For organisms that can disperse under conditions of lower host availability, maize and soybean are highly connected at a national scale, compared with the more discrete regions of wheat and cotton production. Determining the scales at which connectivity becomes disrupted for organisms with different dispersal abilities may help target rapid-response regions and the development of strategic policies to enhance agricultural landscape heterogeneity.