ENERGETICS AND ANIMAL PRODUCTIVITY
97
made was that even though numbers of individuals and biomass varied
in the salt marsh “community” the energy jlow through the population
remained relatively constant.
It is also worth noting the difference between the figures used by
Odum and Smalley (1959) and those used by Smalley (1960). First,
there was a 1.4 kcal/m2/year difference in the figures on gross productivity in the two papers. Secondly, Odum arid Smalley used an assimilation figure of 36%, resulting in an estimate of 77-77 kcal/m2 ingested
annually, while Smalley set the assimilation rate at 27.4 and the ingestion rate at 107 kcal/m2/year. In the first CiiSe, the maximum assimilation rate was used. In the second assimilation was an average rate. Thus,
the first paper compared the average efficiency of the animal, while the
second compared the maximum efficiency.
The salt marsh is not typically a terrestrial community but is rather
an ecotone. The fact that typically marine populations as well as
terrestrial populations can be found at times in the same square meter
plot tends to complicate analysis of this type of habitat. Allowances
must also be made in the analysis for immigration and emigration of
materials and populations, particularly if the inflow and outflow of
energy is not equal.
Teal (1962) attempted an analysis of the energetics of the salt marsh
community. He employed data from several sources in making his estimates. A number of assumptions were used to give estimates where data
were lacking. He stated production equalled 0.25 to 0.3 respiration;
energy degradation was equal under anaerobic and aerobic conditions;
the racoons had an assimilation equal to that of the Clapper rails;
spiders and carnivorous birds took the same proportion of the prey as
did the mud crabs, rails, and racoons which preyed upon detritus algae
feeders. Some of these assumptions were supported by logic or circumstantial evidence; others, such as the last two listed, were not.
The energy flow through the salt marsh system was summarized by
Teal as follows: Input as light 6 x 106 E:cal/m2/year, loss in photosynthesis 563 620 kcal/m2/year, gross production of the producers
36 380 kcal/m2/year, respiration by the producers 28 175 kcal/m2/year,
net production of the producers 8 205 kcal/m2/year, bacterial respiration 3 890 kcal/m2/year, primary consumer respiration 596 kcal/m2/
year, secondary consumer respiration 48 koal/m2/year.
The total energy released by the consumers equaled 4 534 kcal/m2/
year or 55% of the net production of the pi-oducers, leaving 3 671 kcal/
m2/year to be exported by tides and other losses. This “community”
contained a great number of marine and fresh wqter species. If we confined attention to terrestrial animals then his data on the grasshopper,
Orchelimum, the plant bug, Prokelisia, and the nematodes should
97
made was that even though numbers of individuals and biomass varied
in the salt marsh “community” the energy jlow through the population
remained relatively constant.
It is also worth noting the difference between the figures used by
Odum and Smalley (1959) and those used by Smalley (1960). First,
there was a 1.4 kcal/m2/year difference in the figures on gross productivity in the two papers. Secondly, Odum arid Smalley used an assimilation figure of 36%, resulting in an estimate of 77-77 kcal/m2 ingested
annually, while Smalley set the assimilation rate at 27.4 and the ingestion rate at 107 kcal/m2/year. In the first CiiSe, the maximum assimilation rate was used. In the second assimilation was an average rate. Thus,
the first paper compared the average efficiency of the animal, while the
second compared the maximum efficiency.
The salt marsh is not typically a terrestrial community but is rather
an ecotone. The fact that typically marine populations as well as
terrestrial populations can be found at times in the same square meter
plot tends to complicate analysis of this type of habitat. Allowances
must also be made in the analysis for immigration and emigration of
materials and populations, particularly if the inflow and outflow of
energy is not equal.
Teal (1962) attempted an analysis of the energetics of the salt marsh
community. He employed data from several sources in making his estimates. A number of assumptions were used to give estimates where data
were lacking. He stated production equalled 0.25 to 0.3 respiration;
energy degradation was equal under anaerobic and aerobic conditions;
the racoons had an assimilation equal to that of the Clapper rails;
spiders and carnivorous birds took the same proportion of the prey as
did the mud crabs, rails, and racoons which preyed upon detritus algae
feeders. Some of these assumptions were supported by logic or circumstantial evidence; others, such as the last two listed, were not.
The energy flow through the salt marsh system was summarized by
Teal as follows: Input as light 6 x 106 E:cal/m2/year, loss in photosynthesis 563 620 kcal/m2/year, gross production of the producers
36 380 kcal/m2/year, respiration by the producers 28 175 kcal/m2/year,
net production of the producers 8 205 kcal/m2/year, bacterial respiration 3 890 kcal/m2/year, primary consumer respiration 596 kcal/m2/
year, secondary consumer respiration 48 koal/m2/year.
The total energy released by the consumers equaled 4 534 kcal/m2/
year or 55% of the net production of the pi-oducers, leaving 3 671 kcal/
m2/year to be exported by tides and other losses. This “community”
contained a great number of marine and fresh wqter species. If we confined attention to terrestrial animals then his data on the grasshopper,
Orchelimum, the plant bug, Prokelisia, and the nematodes should