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Angermeier, P. L. and J. R. Karr (1994). Biological integrity versus biological diversity as policy directives. BioScience. 44:690-697.

The authors argue that resource policy would be most effective if the goal were the protection of biological integrity. Biological integrity is defined as biological diversity plus the processes that support that diversity. Thus, it is a truer systems approach to resource management than just managing for the greatest different types of organisms. In their argument, the authors stress the importance of understanding organizational heirarchies in ecosystem management. Objective recognition and assessment of changes in integrity are critical for the concept's use in resource policy. Thus, appropriate benchmarks need to be established against which future system states can be compared and contrasted. Variation in elements attributable to natural processes does not represent a variation in integrity, but variation caused by humans does. The authors argue further that evolotionary history should provide the primary basis for assessing biological integrity. A keystone concept in their argument is that ecological processes are buffered from perturbation by redundancy among ecosystem elements and processes. Anthropogenic influences often simplify systems, reducing their redundancy, and thus negatively impair system integrity. In essence, the goals of biological conservation and restoration should focus on protecting integrity, especially the organizational processes that generate and maintain all elements, rather than focusing on the presence or absence of particular elements.