88
MANFRED D . ENOELMANN
populations and adheres to the Bornebusch pattern in that oxygen
consumption was estimated, but, the values were not converted to
caloric equivalents. Nielsen obtained data on respiration rate of
enchytraeid worms via Cartesian diver in the laboratory. Using field
information, he calculated respiratory+ values for field populations of
both enchytraeids and nematodes. He took into consideration (1) environmental temperature, (2) activity, (3) oxygen tension, (4) drought
or moisture content of the soil, and (5) mean body weight, in making
the field estimate (see Table 11). If we make the assumption that the
RQ of the animals is 0.85 (an average RQ for a mixed diet), then each
litre of oxygen will yield 4.8 kcal of heat.
TABLE I1
The Numbers of Individuals and Calories Respired by the Enchytraeid
and Nematode Worms in a Permanent Pasture in Denmark. Data
from Nielsen, 1961
Calories Released
No. of
Respiration
Yearly via
Individuals
Total Litres
Respiration
Taxon
Station
x 10a/ma
of Oa/ma/yr
kcal/ma/yrt
Enchytraeidae
1
44
7
33.6
4
30
10
48-0
18
74
32
153.6
Nematoda
1
i x 104
43-63
2064-302-4
4
5 x 103
3 1-46
148+3-220.8
18
1 x 104
71
340-8
t Calculated by the present author using 4.8 kca1:L conversion factor.
Using the respiration figures and making some assumptions about the
nature of assimilated food of the nematodes, Nielsen estimated that
these animals required 800 kg of bacteria (live weight) and 320 kg of
plant root cells (live weight) to satisfy the respiratory requirements indicated by his calculations. The diet of enchytraeids was assumed to be
bacteria and the amount requireg to maintain the enchytraeids was
estimated at 300-400 kg (live weight). Nielsen pointed out succinctly
that knowledge of numbers of individuals alone is not sufficient to allow
judgement of population. Data on the enchytraeids indicated that the
site with the smallest numbers of individuals per meter square did not
have the lowest respiratory metabolism. Presumably, then, the animals
at “station 4” had a greater impact upon the environment than did
those at “station 1”. However, the consumption of energy for body
MANFRED D . ENOELMANN
populations and adheres to the Bornebusch pattern in that oxygen
consumption was estimated, but, the values were not converted to
caloric equivalents. Nielsen obtained data on respiration rate of
enchytraeid worms via Cartesian diver in the laboratory. Using field
information, he calculated respiratory+ values for field populations of
both enchytraeids and nematodes. He took into consideration (1) environmental temperature, (2) activity, (3) oxygen tension, (4) drought
or moisture content of the soil, and (5) mean body weight, in making
the field estimate (see Table 11). If we make the assumption that the
RQ of the animals is 0.85 (an average RQ for a mixed diet), then each
litre of oxygen will yield 4.8 kcal of heat.
TABLE I1
The Numbers of Individuals and Calories Respired by the Enchytraeid
and Nematode Worms in a Permanent Pasture in Denmark. Data
from Nielsen, 1961
Calories Released
No. of
Respiration
Yearly via
Individuals
Total Litres
Respiration
Taxon
Station
x 10a/ma
of Oa/ma/yr
kcal/ma/yrt
Enchytraeidae
1
44
7
33.6
4
30
10
48-0
18
74
32
153.6
Nematoda
1
i x 104
43-63
2064-302-4
4
5 x 103
3 1-46
148+3-220.8
18
1 x 104
71
340-8
t Calculated by the present author using 4.8 kca1:L conversion factor.
Using the respiration figures and making some assumptions about the
nature of assimilated food of the nematodes, Nielsen estimated that
these animals required 800 kg of bacteria (live weight) and 320 kg of
plant root cells (live weight) to satisfy the respiratory requirements indicated by his calculations. The diet of enchytraeids was assumed to be
bacteria and the amount requireg to maintain the enchytraeids was
estimated at 300-400 kg (live weight). Nielsen pointed out succinctly
that knowledge of numbers of individuals alone is not sufficient to allow
judgement of population. Data on the enchytraeids indicated that the
site with the smallest numbers of individuals per meter square did not
have the lowest respiratory metabolism. Presumably, then, the animals
at “station 4” had a greater impact upon the environment than did
those at “station 1”. However, the consumption of energy for body