A second principle about ecosystems that is important to Corps actions is scale. This can be described by components and interactions at the genetic, species, population, community, or landscape scale. Most managers are able to concentrate on just one or two scales, but for full ecosystem management, all are required.
An illustrated introduction to scale and relevant terms is found here. This section was prepared by Dr. Bertie Weddell, Draba Consulting, Pullman, WA. Trained in wildlife biology and zoology, Dr. Weddell has 11 years of experience in applied ecology problems in wetlands and grasslands. Her work on issues such as the historical ecology of wetlands and the disturbance dynamics and restoration potential of intermountain steppe communities, has led her to search for ways of managing natural resources in ways that integrate the needs of people and non-human species.
She is the author of "Managing for Products, Preserves, or Processes: Conserving Living Natural Resources in the Context of a Changing World," which will be published by Cambridge University Press in the fall of 2001.