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--- Golley F.B. In trodu ction . Wh at is th e relation sh ip between produ ction of agricu ltu ral an d n on - agricu ltu ral vegetation ?. Workshop agroecology. Paris : CIHEAM, 1984. p. 1-5 (Options Méditerranéennes : Série Etudes; n. 1984-I)
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Words:'Production, Ecosystem, Agroecology, Planning.
Frank B. Golley University Georgia, Athens, Georgia, USA.
of
of in of
1984. was by the
Association
Ecology was to exa-
of vegetation
questions by
of of
be the
of net of
site? And
second, is a
able depending upon the levels of inputs, if one of
the will
be less the
asking these ques-
tions was if
establish base lines of expected levels
a be used .as goals as
be applied in the post the
n
- 1. -
is of
ecosystems and has a of definitions.
example, the fixation of
of photosynthesis and the subsequent of
elements menta¡ basis
is called the Gross vegetation at a site composed of a of
in space and time. The plant tissues uti- lize some of the
these metabolic costs is that available
the plant and is called .
the or
in the is in plant of the plant species
of these is
of
OF
viewed in the con-
text of a of
leaf is
is ,
of photosynthesis which
basis of level
and the leaf and
a of nested systems such
all of which should Each system level behaves
and by 1978; Odum, 1983), as well
. of these systems
duction. is a system output of
which
and how much is given place
of these inputs can
it less and
of
of misma- which ulti- yield. The in
of scale depends
and and
of net
of is
700 g
is about 40 mt ha-'.
Lieth will
of which depend on the
of
is
of
& Whit- 1975) the levels of
ed as and of
of
of of
way by of
types of
if we of
1) we find
a complex which be .
a mode at about 8 mt ha-'. and a
about 2 mt ha-'. Y i ' . A
a less
~.
vide l
Thinking within this concept of a-nested set of
systems, we can Visualize a hypo- 0 example, would that state that
thetical scale of is a maximum of due to
which to 'Ome maximum' The fixes about 3.5 g c
about 400 mg m-3; these conditions
is set duction would then be g C day 5000 g
by of tons ha-!
R
IAMZ-841 Il
18
T O N S HA-’.YR-’
Figure Frequency distribution of net primary above-ground production of natural vegetation, in tons per hectare per year. The distribution is based on 264 cases representing tundra, desert, grass-
land, and & Bazilevitch (1965), Singh et al. (1980), and Canne11 (1982).
suggest to me a way to scale be
development of
* of to place
the leaves
climatic condi- division of
is
so that the of i,s
R IAM2-84/
kinds of vegetation unless conditions The key
ed an optimum quantity of most of the incident light, is
of and
limiting to photosynthesis.
is of
net of vegetation fall well below
the suggested above.
even begin maximum. suspect that this
within an ecosys- tem as
of the and
by
of is
way with inputs of and full
of tion equal to that of
is of
of will be
of the envi- is possible (as in a glass house
of may exceed
vide. And tlius the
is we need to
vegetation and the output of so that
we efficiency of
in any kind of ecosystem.
by by coevolution of plants,
site.
yield
system can be subsidized (so that inputs exceed this is
of phosphate). Thus, the evaluation of of
within the context of a
of
of the system.
of toxic chemicals and depopulation of villages) be subsidiz-
ed by of
lity of life
is diminished.
and of these
subsidies and the consequences of mismanage- ment but as yet we do not have adequate hie-
of inputs and benefits of
be used to de- level but levels in the hie- not included.
Thus, it is we do not have adequate
of systems to second
well stood so that we
We
of scale.
of ecologists, biologists, economists and social
scientists and these sciences seldom
funding even
view, these following conclusions:
1) is by in-
2) of values of
of
K IAMZ-841 I
3) of adequate mechanistic
explanation of levels,
we of
its all levels of a to global with analyses of all system levels it will be
possible level sys-
level systems and it also
will be possible to develop mechanistic expla- nations, including models of
level to the plant leaf;
5 ) to of
duction it to at
levels so that the quality of explanation
CANNEL, G. 1982. NY. 480 pp.
E. 1975. of vegetation units of 203-215. Lieth and
& 1975. of the Studies 14.
J. G. 1978. Living Systems. N'Y.
T. 1983. Systems Ecology, Wiley & Sons, NY.
L. E., & N. 1965. cycling by G. E.
Fogg. & London.
J. S., J. E. & J. 1980.
59-200. A. & G. (eds.). Systems Analysis and Vol. 19.
Univ.
of the New
NY.
R IAMZ-841 I
