100 Influential Papers - page 13

15
Botkin, D.B., Janak, J.F. & Wallis, J.R. (1972)
Some ecological consequences of a computer model
of forest growth.
Journal of Ecology, 60, 849-872.
Botkin, Janak and Wallis were pioneers in the application of
simulation modelling to understanding successional processes in
forests. The paper engenders the sort of excitement that arises
when you stumble upon an old camera and cherished childhood
photos. You stop everything you’re doing for a few moments to
admire them, opening up the camera’s back and fiddling with the
delicate lever which controls the aperture and gently pressing
that all-or-nothing shutter; you feel you understand completely
how it works and admire its simple beauty. The white-bordered
photos are small and grainy with exaggerated colour, but they
too have a remarkable quality to them. So it is with this particular
study. The algorithm is straight forward, captured completely in
a few simple equations and capable of running on any computer
with at least 50 kbytes of available memory, yet it contains
the major building blocks found in all later forest simulators:
subroutines describing tree growth, recruitment and mortality
with modifiers for site conditions. The presented outputs are
little more than a few hand-drawn curves, yet they capture the
essence of forest succession remarkably well, and herald an era
when simulation models are used routinely as tools to integrate
ecological knowledge and test hypotheses that cannot be
explored by conventional experimentation.
David Coomes
16
Crocker, R.L. & Major, J. (1955)
Soil development in relation to vegetation and
surface age at Glacier Bay, Alaska.
Journal of
Ecology, 43, 427-448.
The study employed the chronosequence approach, whereby
soils were sampled on terrain of increasing age since glacial
retreat. Glacier Bay was ideally suited to the study because
of the detailed history of deglaciation at the site, which
allowed soils to be aged, and the rich knowledge of vegetation
succession. Crocker and Major’s most striking finding was the
rapid rate of soil nitrogen accumulation, which was strongly
related to vegetation distribution and development; during early
succession, soil nitrogen was found to increase dramatically
under plants believed to fix nitrogen, especially
Alnus
, and then
decline in late succession following the replacement of
Alnus by
Picea
. Such patterns of nitrogen accumulation during succession
are now well documented and understood. However, this study
firmly established the need to consider both plants and soils, and
their intimate interactions, to fully understand how ecosystems
develop and function. The paper is also an enjoyable read.
Crocker and Major write in an engaging and very descriptive way
about their experiences of sampling soils at Glacier Bay and the
problems that they encountered; such writing is now lost from
ecological literature.
Richard Bardgett
17
COMMUN I TY AND ECOSYS T EM DYNAM I C S
13
Watt, A.S. (1947)
Pattern and process in the plant community.
Journal of Ecology, 35, 1-22.
Although based on his extensive studies of grasslands in Breckland (eastern England), beech woods
in the Chiltern Hills and heathlands on Scottish mountains, Alex Watt’s paper highlights two essential
aspects of the science of ecology. First, ecology is an observational science; people have attempted
to identify patterns in what is observed. Second, ecology is an experimental science; by deducing the
processes which created those patterns, hypotheses can be formulated and tested by experimentation.
The dynamic nature of plant communities is a core consideration, with competition and stress,
caused by disease or depletion of nutrients, being both explicitly and implicitly associated with ‘cyclic
change’. Perhaps for a botanist, it is surprising to find Watt’s disappointment in the lack of literature
demonstrating the “intimacy and integration between plants and animals” and “the life histories and
food habits of microorganisms”. How many times in the last decade or two have papers in the
Journal
of Ecology
referred to plant-animal interactions, or to above-ground/below ground relationships? Half a
century earlier, Watt was suggesting that these topics needed more investigation, but his thesis is that
“problems in nature are problems of the ecosystem rather than of soil, animals or plants” (page 22), a
strong pointer to the need for a systems approach in ecology.
Michael B. Usher
2
AS Watt
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