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|"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.