One brief discussion of the models of plant community succession proposed
Clements and Gleason is at:
http://www.physicalgeography.net/fundamentals/9i.html (or see below...the
web page seems to be off-line currently)
As an environmental planner, and assuming that you're trying to give the
participants a sense of the history behind theories of successional change in
natural complex systems, I would definitely include Eugene Odum's article, "The
Strategy of Ecosystem Development," Science, v164 (18 Apr. 1969): 262-270, as
well as Crawford Holling's 1986 "The Resilience of Terrestrial Ecosystems:
Local Surprise and Global Change," 292-317 in William C. Clark & R.E. Munn
(eds.), Sustainable Development of the Biosphere, Cambridge, UK: Cambridge
University Press.
I'd also suggest Stewart Pickett's 1976 "Succession: An Evolutionary
Interpretation," in The American Naturalist, v110n971. (Jan. - Feb., 1976):
107-119.
You might find material as well in:
Golley, Frank B. (ed.). 1977. Ecological Succession. Benchmark Papers in
Ecology, v5 (1977). Stroudsburg, PA: Dowden, Hutchinson & Ross, Inc.
and may want to look at:
Freudenburg, William R. 1985. "Succession and Success: A New Look at an Old
Concept," Sociological Spectrum, v5n3 (1985): 269-289.
and perhaps William A. Niering's 1987 "Vegetation Dynamics (Succession and
Climax) in Relation to Plant Community Management," Conservation Biology 1 (4),
287-295.
I also just came across a set of three articles by John Phillips (1934-35),
which I've not yet read, in The Journal of Ecology, titled "Succession,
Development, the Climax, and the Complex Organism: An Analysis of Concepts."
(These are available off JSTOR.)
I've myself looked at the influence of these models of change on urban
planning, a la the Chicago School of Sociology, in the early years of the 20th
Century, which has a number of additional citations as well:
Vasishth, Ashwani & David C. Sloane. "Returning to Ecology: An Ecosystem
Approach to Understanding the City," pp343-366 in Michael Dear (ed.), 2002,
From Chicago to LA: Making Sense of Urban Theory, Thousand Oaks, CA: Sage
Publications.
A pdf of this is available directly at:
http://www-rcf.usc.edu/~vasishth/Vasishth+Returning_To_Ecology.pdf
I have digital copies of at least some of these, and I would really appreciate
a compilation of any responses you might get off-list,
Cheers,
-
Ashwani
Vasishth [EMAIL PROTECTED] (818) 677-6137
Assistant Professor
Department of Urban Studies and Planning, ST 206
California State University, Northridge
http://www-rcf.usc.edu/~vasishth
http://www.physicalgeography.net/fundamentals/9i.html
[]
In the first quarter of this century there was considerable debate about the
nature of the community. F.E. Clements (1916) conceived of the community as a
sort of superorganism whose member species were tightly bound together both now
and in their common evolutionary history. Thus, individuals, populations, and
communities have a relationship to each other that resembles the associations
found between cells, tissues, and organs.
Clements' theories on communities were also linked to succession. His
successional concept suggested that communities of organisms are subject to
special laws in which the action of the whole is greater than the sum of the
parts, and that this action results in a directional change in the species
composition of the community to a climax state controlled primarily by climate.
The main processes acting to produce the various successional stages of species
dominance, and finally climax, are competition and plant modification of the
abiotic environment. Environmental modification, however, is detrimental to the
plants doing the modifying. Modification changes the environment allowing the
establishment of new colonists, and then results in the subsequent competitive
exclusion of the former inhabitants by these colonists. This facilitative
process stops when the climax community is reached.
Clements presented a deterministic unidirectional view of succession where the
present pattern is governed by the past pattern. The philosophical structure of
Clements' holistic approach is quite similar to advances in other sciences of
that time. In geology and geomorphology theorists presented views that
contained various stages of maturity, and compared landscape evolution
metaphorically to a developing organism. The parallel in theoretical approach
of these sciences with the work of Clements may be the result of attitudes
prevalent in science as a whole at that time.
In 1926, H. Gleason (1926) devised a new theory to explain the nature of
communities. Gleason's individualistic concept saw the relationship between
coexisting species as simply the result of similarities in their requirements
and tolerances (and partly the result of chance). Taking this view, community
boundaries need not be sharp, and associations of species would be much less
predictable than one would expect from the superorganism concept.
Gleason argued that the holistic view point of Clements was inadequate in
explaining the mechanism of succession. For example, Gleason suggested that
Clementsian concepts could not properly explain the occurrence of such
phenomena as retrogressive successions. In reference to his view of succession,
Gleason stated that ".... 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". Thus, associations of plants, or
communities, were not highly organized, but aggregations of independent plant
species, each specialized to survive on habitats they were adapted for.
Retrogressive successions were possible in Gleason's model if environmental
variables deteriorated with time, changing the pattern of establishment, growth
and reproduction of plants in a habitat. Clements' model, however, assumed long
term climatic stability, and this assumption does not allow for short term !
retrogressive community change.
Clements and Gleason presented two diametrically opposed opinions on community
organization and structure. Further investigation in this discussion will show
that these views are still present in the hypotheses of later theorists, but in
a somewhat modified form. Many of these modified hypotheses involve a synthesis
of the early ideas of Clements and Gleason. This synthesis is the result of the
addition of new ecological information or the re-analysis of old information on
how ecosystems function over time. The synthetic evolution of successional
hypotheses must be expected, as investigation finds new mechanisms responsible
for temporal vegetation change in a relatively unexplored world. The early
presence of simple diametrically opposed successional hypotheses in the early
years is probably the result of the immature state of understanding of turn of
the century ecology.
Central to Gleason's succession model is the notion of abiotic and biotic
heterogeneity in space and time. This concept is a characteristic view of much
of modern ecology. Recently, several scientists have examined the role of
disturbance on community structure. These researchers suggest that disturbance
is a common process in most communities that shapes the nature and structure of
biotic interactions and processes. These ideas follow directly from Gleason's
early observations of pattern and process in the plant community.
The individualistic concept of succession outlined by Gleason was ignored by
the scientific community for some twenty to thirty years. Important papers and
books citing this work did not appear until the late 1940s and early 1950s. It
was the ideas of Clements that dominated ecological thought in one way or
another up to this period.
Our current view on the nature of community structure is close to the
individualistic concept. Results of many studies indicate that a given
location, by virtue mainly of its physical characteristics, possesses a
reasonable predictable association of species. However, a given species that
occurs in one predictable association is also quite likely to occur with
another group of species under different conditions elsewhere.
* * *
>Good afternoon,
>
> I am writing with an inquiry about the seminal plant ecology
>papers by Clements (Nature and Structure of the Climax) and Gleason (The
>Individualistic Concept of the Plant Association). Are you aware of a
>publication that summarizes these two articles and their importance to
>subsequent thinking and research on plant ecology and succession?
>
> I am coordinating for forest land managers a short course on
>silviculture and ecological classification
>(http://www.cnr.umn.edu/sfec/materials_mod5.html ), for which we have
>assigned readings for one of the modules. The readings include these two
>papers. Our trainees struggled with reading and digesting the writing,
>and asked if I could locate a summary for them.
>
> This isn't typical reading for foresters, and my resources only
>contain the actual papers. After working on this request a bit, it
>occurred to me that a group such as Ecological Society of America
>members, and others, would likely know immediately if such a summary
>existed.
>
> If I should be in contact with someone other than yourselves,
>please let me know who that is. I appreciate your help.
>
>Thank you.
>Sincerely,
> Louise Levy
>
>~`~`~`~`~`~`~`~`~`~`~`~`~`~`~`~`~`~`~`~`~`~`~`~`~`~`~`~`~`~`~`~`~`~`~`~`~`
>Louise Levy, Coordinator
>Sustainable Forests Education Cooperative
>Cloquet Forestry Center
>175 University Road
>Cloquet, MN 55720
>
>tel: 218-726-6404
>fax: 218-879-0855
>
>www.cnr.umn.edu/sfec/
>
>What we plant in the soil of contemplation, we reap in the harvest of action.
>Meister Eckhart
>
>~`~`~`~`~`~`~`~`~`~`~`~`~`~`~`~`~`~`~`~`~`~`~`~`~`~`~`~`~`~`~`~`~`~`~`~`~`
