78
M A N F R E D D. E N O E L M A N N
subjectively determined, dominant, characteristic, influential, conspicuous, and rare species categories can be given a more objective
basis using energetics criteria. A species with a large number of slow
metabolizing individuals may be less important to the community than
another species with fewer metabolically or reproductively active individuals. Finally, the Lindeman model depends heavily upon natural
history observations, life tables, metabolic data, phenology, physiology,
and, in short, the majority of the factual information accumulated from
natural communities over the years. This model, though imperfect, can
give a new dimension to the old concepts in ecology. There are, of course,
other models in the ecological literature which are designed to define
and characterize elements of certain ecological concepts (e.g. MacArthur,
1960; Hairston, 1959; Hairston et al., 1960; Patten, 1959; et cetera). All
of these are of value in our present stage of knowledge. Some models
may eventually have greater significance than do those based on energetics. Others may contribute much to the Lindeman model. Of course
all of them are subject to a great deal of debate, and the resolution of
the debate will come from a conclusive experiment or observation. As
has been pointed out by Slobodkin (1962) and will be underlined again
in this paper - the paucity of the data in the field of energetics at this
time emphasizes the need for research rather than discourse.
111. HISTORICAL CONSIDERATIONS
At first glance there is a parallel between the spread of the study of
energetics in ecology and the evolution of the vertebrates. Both had
their origins in fresh water and then spread to the sea, but only with
reluctance did they clamber to the land. It required 20 years from the
beginning of the productivity studies t o the enunciation of the guiding
principles of those studies and it required another 20 years for those
studies to spread to terrestrial situations.
Although the work of Birge and Juday laid down the beginnings of
productivity studies in 1922 and the trophic dynamic approach was
proposed by Lindeman in 1942, the first major work on terrestrial
systems did not appear in the literature until 1960 when Golley published a Microtus food chain analysis in the Lindeman tradition. The
limnologists and oceanographers during the forties and fifties produced
numerous works on freshwater and marine habitats.
The terrestrial biologists were not completely inactive during this
period, for Bornebusch (1930) did his classical study on beech forests in
Denmark. He paid attention not only to the number of individuals in
each species but also to their weights and respiratory rates. It was
apparent to Bornebusch that the different rates of metabolism of the
M A N F R E D D. E N O E L M A N N
subjectively determined, dominant, characteristic, influential, conspicuous, and rare species categories can be given a more objective
basis using energetics criteria. A species with a large number of slow
metabolizing individuals may be less important to the community than
another species with fewer metabolically or reproductively active individuals. Finally, the Lindeman model depends heavily upon natural
history observations, life tables, metabolic data, phenology, physiology,
and, in short, the majority of the factual information accumulated from
natural communities over the years. This model, though imperfect, can
give a new dimension to the old concepts in ecology. There are, of course,
other models in the ecological literature which are designed to define
and characterize elements of certain ecological concepts (e.g. MacArthur,
1960; Hairston, 1959; Hairston et al., 1960; Patten, 1959; et cetera). All
of these are of value in our present stage of knowledge. Some models
may eventually have greater significance than do those based on energetics. Others may contribute much to the Lindeman model. Of course
all of them are subject to a great deal of debate, and the resolution of
the debate will come from a conclusive experiment or observation. As
has been pointed out by Slobodkin (1962) and will be underlined again
in this paper - the paucity of the data in the field of energetics at this
time emphasizes the need for research rather than discourse.
111. HISTORICAL CONSIDERATIONS
At first glance there is a parallel between the spread of the study of
energetics in ecology and the evolution of the vertebrates. Both had
their origins in fresh water and then spread to the sea, but only with
reluctance did they clamber to the land. It required 20 years from the
beginning of the productivity studies t o the enunciation of the guiding
principles of those studies and it required another 20 years for those
studies to spread to terrestrial situations.
Although the work of Birge and Juday laid down the beginnings of
productivity studies in 1922 and the trophic dynamic approach was
proposed by Lindeman in 1942, the first major work on terrestrial
systems did not appear in the literature until 1960 when Golley published a Microtus food chain analysis in the Lindeman tradition. The
limnologists and oceanographers during the forties and fifties produced
numerous works on freshwater and marine habitats.
The terrestrial biologists were not completely inactive during this
period, for Bornebusch (1930) did his classical study on beech forests in
Denmark. He paid attention not only to the number of individuals in
each species but also to their weights and respiratory rates. It was
apparent to Bornebusch that the different rates of metabolism of the