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Ecology Quotations 

"Succession . . . must be regarded as the development or life-history of the climax formation. . . . Succession is preeminently a process the progress of which is expressed in certain initial and intermediate structures or stages, but is finally recorded in the structure of the climax formation." Frederic Clements, Plant Succession: An Analysis of the Development of Vegetation. Washington, D.C.: Carnegie Institution of Washington, 1916.
"The vegetation of an area is merely the resultant of two factors, the fluctuating and fortuitous immigration of plants and an equally fluctuating and variable environment. As a result, there is no inherent reason why any two areas of the earth's surface should bear precisely the same vegetation. . . . Every species of plant is a law unto itself, the distribution of which in space depends upon its individual peculiarities of migration and environmental requirements. . . . The species disappears from areas where the environment is not longer endurable. It grows in company with any other species of similar environmental requirements, irrespective of their normal associational affiliations." Henry A. Gleason, "The Individualistic Concept of the Plant Association," Bulletin of the Torrey Botanical Club, 53 (1926), pp. 7-16, 23-26.
"All ethics so far evolved rest upon a single premise: that the individual is a member of a community of interdependent parts. . . . The land ethic simply enlarges the boundaries of the community to include soils, waters, plants, and animals, or collectively: the land." Aldo Leopold, "The Land Ethic," in A Sand County Almanac: and Sketches Here and There (New York: Oxford University Press, 1949), pp. 201-4, 221-5.
"The principles of ecological succession bear importantly on the relationships between man and nature. The framework of successional theory needs to be examined as a basis for resolving man's present environmental crisis. . . . Ecological succession may be defined in terms of the following three parameters. (i) It is an orderly process of community development that is reasonably directional and, therefore predictable. (ii) It results from modification of the physical environment by the community; that is succession is community-controlled even though the physical environment determines the pattern, the rate of change, and often sets limits as to how far development can go. (iii) It culminates in a stabilized ecosystem in which maximum biomass (or high information content) and symbiotic function between organisms are maintained per unit of available energy flow." Eugene P. Odum, "The Strategy of Ecosystem Development," Science, 164 (1969): 262-70.
"Ecologists have always been aware of the importance of natural dynamics in ecosystems, but historically, the focus has been on successional development of equilibrium communities. While this approach has generated appreciable understanding of the composition and functioning of ecosystems, recently many workers have turned their attention to processes of disturbance themselves and to the evolutionary significance of such events. . . . We use the phrase "patch dynamics" to describe their common focus. . . . Equilibrium landscapes would . . . seem to be the exception, rather than the rule. . . Preservation of natural systems necessarily involves a paradox: we seek to preserve systems that change. Success in a conservation effort thus requires an understanding of landscape patch structure and dynamics." S.T.A. Pickett and P.S. White, The Ecology of Natural Disturbance and Patch Dynamics (Orlando, Fla: Academic Press, 1985), pp. xiii, 5, 12.