after the addition of polypeptone, and the protozoan, Cyclidium glaucoma, multiplied afterward. Then, the chlorophyceans, Chlorella sp. and Scenedesmus
quadricauda, and the rotifers, Lecane sp. and Philodina erythrophthalma, multiplied
in a more moderate fashion. In the 10x addition system, bacteria multiplied promptly
after addition, and Cyclidium glaucoma multiplied but then suddenly decreased and
perished afterward. Additionally, Chlorella sp., Scenedesmus quadricauda, Lecane
sp., and Philodina erythrophthalma multiplied.
From the behaviors of the constituent organisms in the microcosm, it was observed
that bacteria multiplied when organic matter was added and Cyclidium glaucoma
multiplied as it preyed upon the bait. However, when organic matter was overloaded,
because Cyclidium glaucoma disappeared after an increase in the concentration of
organic matter, it was thought that the primary consumers (protozoans) were damaged
(i.e., disappeared from the system) by too high of an addition concentration of the
substrate. Chlorella sp. multiplied well, as evaluated by the comparison with the
population (N 30 ) of the stable stage, but Cyclidium glaucoma perished at concentrations of greater than 250 mg/L. Organisms were shown to multiply in proportion to the
increase in the concentration of polypeptone, except for the protozoan, Cyclidium
glaucoma, and it became clear that the sensitivity of primary consumers (protozoans)
to organic matter was extremely high. The rotifer, Lecane sp., followed by the
protozoan, Cyclidium glaucoma, reacted sensitively based on a comparison of the
population sizes before and after the addition (B 16–30 ) of polypeptone, and the
possibility that Lecane sp., a bacterivore, participated as a buffer was demonstrated.
7.8.2 Acetone
When acetone is used as a solvent for a pesticide that is added to the microcosm,
more than three times the respiration and production amounts are measured in the
acetone addition system than are measured in the control system. Treated statistically
(via ANOVA), there was an observed difference in the amounts of respiration and
production between the control system and the solvent addition system on each
measurement day. In the case of acetone addition, significantly higher values relative
to the control system were shown for the respiration amount on the 9th day after
addition and the production amount on the 7–9th days after addition. In this way,
because the pesticide had very low solubility in water, it was necessary to dissolve it
in organic solvents, such as acetone, but it became clear that the organic solvent itself
caused an increase in the amounts of production and respiration.
7.8.3 Ethanol
When ethanol is used as a solvent for a pesticide that is added to the microcosm,
more than three times the respiration and production amounts are measured in the
acetone addition system than are measured in the control system. Treated statistically
7 Example Assessments of the Microcosm N-System
111
quadricauda, and the rotifers, Lecane sp. and Philodina erythrophthalma, multiplied
in a more moderate fashion. In the 10x addition system, bacteria multiplied promptly
after addition, and Cyclidium glaucoma multiplied but then suddenly decreased and
perished afterward. Additionally, Chlorella sp., Scenedesmus quadricauda, Lecane
sp., and Philodina erythrophthalma multiplied.
From the behaviors of the constituent organisms in the microcosm, it was observed
that bacteria multiplied when organic matter was added and Cyclidium glaucoma
multiplied as it preyed upon the bait. However, when organic matter was overloaded,
because Cyclidium glaucoma disappeared after an increase in the concentration of
organic matter, it was thought that the primary consumers (protozoans) were damaged
(i.e., disappeared from the system) by too high of an addition concentration of the
substrate. Chlorella sp. multiplied well, as evaluated by the comparison with the
population (N 30 ) of the stable stage, but Cyclidium glaucoma perished at concentrations of greater than 250 mg/L. Organisms were shown to multiply in proportion to the
increase in the concentration of polypeptone, except for the protozoan, Cyclidium
glaucoma, and it became clear that the sensitivity of primary consumers (protozoans)
to organic matter was extremely high. The rotifer, Lecane sp., followed by the
protozoan, Cyclidium glaucoma, reacted sensitively based on a comparison of the
population sizes before and after the addition (B 16–30 ) of polypeptone, and the
possibility that Lecane sp., a bacterivore, participated as a buffer was demonstrated.
7.8.2 Acetone
When acetone is used as a solvent for a pesticide that is added to the microcosm,
more than three times the respiration and production amounts are measured in the
acetone addition system than are measured in the control system. Treated statistically
(via ANOVA), there was an observed difference in the amounts of respiration and
production between the control system and the solvent addition system on each
measurement day. In the case of acetone addition, significantly higher values relative
to the control system were shown for the respiration amount on the 9th day after
addition and the production amount on the 7–9th days after addition. In this way,
because the pesticide had very low solubility in water, it was necessary to dissolve it
in organic solvents, such as acetone, but it became clear that the organic solvent itself
caused an increase in the amounts of production and respiration.
7.8.3 Ethanol
When ethanol is used as a solvent for a pesticide that is added to the microcosm,
more than three times the respiration and production amounts are measured in the
acetone addition system than are measured in the control system. Treated statistically
7 Example Assessments of the Microcosm N-System
111