A Dynamic State of Closed Ecosystem and Generation of the Earth's Environment
Shigeru Moriyama, Mitsuko Takahara and Gakuji Nomoto*
College of Industrial Technology, Nihon University, Narashino, Chiba 275
*Department of Agriculture, Tokyo University, Tokyo 113
abstract
The earth forms a living-system and is one of huge closed
ecosystems (CES). We are performing various experiments to study the living-system
and the nature of microcosmic type CES. In this paper, we show some interesting
experimental results of behaviors of CES mainly at a changeover process from a
semi-open state to a perfectly closed state. And we report very noteworthy
phenomena on instability of CES which may be included inherently in CES. From
the above experiments, we suggest that CES possesses some important properties
to elucidate the nature of the actual earth as a living-system, and that
climatic changes, such as oceanic anoxia events and the accompanying changes
emerged on the ancient earth, could be brought, not by any substantial and
special cause but by a slight disturbance to CES.
1. Introduction
The earth forms one of huge closed ecosystems. Closed ecosystem
(CES) is characterized by materially closed but energetically open system. CES
is categorized into two kinds of type in their characteristics. One is CES of a
space station type, and another is of microcosmic type. The actual earth is
never the CES of a space station type which is controlled and supported for the
human survival, by man, mechanical and electric powers. The actual earth's
ecosystem has been developing in autonomous and holistic order. So, CES of
microcosmic type is quite suitable for a model of the earth.
Until now we have made three experimental apparatus of microcosmic
type CES named CES#1-#3. Each container with about 40 - 60 cm diameter is
filled halfway with water, and the upper part in the container has an
atmosphere. In the container, at first there were water plants, aquatic and
semi-aquatic animals such as beeshrimps and snails, and pebbles. The container
is placed within a water-bath to maintain a constant temperature of 25C.
The system is lighted with an artificial sun-light: the study given in this
paper was made by 24 hours-lightening. Various measuring tools are connected to
the apparatus. We are measuring in real time O2 and CO2
concentrations in the atmosphere and dissolved O2 concentration in
the hydrosphere. ATP measurements are made to obtain the numbers of living and
dead bacteria in water, and chemical measurements are also performed to
research water qualities.
We have performed various experiments for a few years, using the
above three apparatus of the microcosmic type CES developed by us (CES#1 is not
running now, and CES#3 is operating to collect data in the state of the 'open').
In this paper, we will show interesting results of behaviors of CES#2 mainly in
a switchover process from a 'open' system
to a 'closed'
system. Here, the word 'open' means
a state of CES which has been exposed to the open air by opening the top part
of the container in about 5 cm-width.
At first, we have carried out some experiments with CES#2 about
one year by using the 'open'
system. Waiting for a suitable time, then we have closed the container
perfectly to make 'closed'
state. We compare the behaviors of these two systems and investigate dynamic
states of these systems.
2. Characteristics of CES
Intuition seems to tell us that CES is pretty polluted since green
algae (Rhizoclonium sp.) are surpassing other water plants and grow
thickly. But it is wrong. Regardless of 'closed'
or 'open',
water qualities in these ecosystems are rather pure than not. The numbers of
living and dead bacteria in CES, for instance, are nearly equal to those in the
water collected from natural spring water to drink. The reason why the numbers
of bacteria in CES fall below expectations is brought about from the fact that
lives in CES are not free to display all of their abilities, because lives are
trying to live together in mutual prosperity by holding down demonstration of
their abilities.
The pH of the hydrosphere in CES is high. In general the value is
over 8.5, regardless of 'closed' or 'open'.
And CES in the state of perfectly 'closed' has
the value over 9.0 of pH. These high values of pH are due to the release of
ammonia ejected finally from animals in case of decomposition of protein.
Although nitrifying bacteria oxidize ammonia aerobically into nitrite(by
nitrite bacteria) and nitrate(by nitrate bacteria), the closed and narrow space
in CES would contribute to rise the value of pH up.
But the value of pH seems to keep near constant as long as the
ecosystem is lasting. The data of concentrations of NH3(`0
mg/l), NO2 (0.005 mg/l) and NO3 (`0
mg/l) ions in the hydrosphere of CES definitely indicate activation of the
nitrifying bacteria in CES. Purifying the hydrosphere in CES by oxidizing
ammonia, they act to retain a stable state of the system. This is the reason
CES sustains near constancy of pH against release of harmful ammonia into the
hydrosphere, and is one of regulations of 'living
system'.
3. About 'open' system
Input to 'open' system
is light and CO2 for photosynthesis from the open air. Since the 'open'
system is exposed to the infinite amount of air, it is possible in theory for
organic bodies to propagate as much as they like. But, a high increase in
organism is a characteristic only in the developing stage seen at the early
stages of the system, and in the period of maturity a constant amount of
organisms is maintained to sustain the ecosystem stably. Supported by infinite
amount of resources, the 'open' system
works stably consuming the resources moderately.
The numbers of living and dead bacteria are comparable at the
early stages of the system, and they had repeated to increase and to decrease
out of phase each other. This is a regulating behavior to stabilize the young
system. In the developing stage, the number of bacteria is 10 times or more
larger than that in the maturity period. In the period of maturity, regardless
of 'open'
or 'closed'(CES#"),
the number of living bacteria is always much larger than that of dead ones
except the times of some changes. These are phenomena common to CES#2 and #3.
In summary, 'open' system
is working photosynthesis by consumption of CO2 from an open air
which has an infinite amount of resources, and, keeping more amount of organism
than in 'closed'
system, it is ejecting waste matter largely. A chain of these processes is
continuing stably in case of 'open'
system.
And the systems of, for instance, rumen and hyponica
also fall under the category of this 'open'
system.
4. Behavior in transition from 'open' to 'closed' system
The behavior of CES just after perfectly closing is very
stimulative.
First, dissolved O2 concentration in the hydrosphere
had dropped abruptly. Near the bottom of the container (30 cm in depth from the
water surface) it decreased rapidly from 12 ppm to 0 - 0.8 ppm in only 4 days.
And it restored the concentration at a slower speed and became 10 ppm in a
month. Here, it should be noted that an anoxic state can be made comparatively
easily in the hydrosphere of CES by some disturbance.
Second, O2 gas concentration in the atmosphere of CES
also decreased sharply in about 1 %, but got back again in 3 days. CO2
gas concentration in the atmosphere decreased rapidly, together with decrease
in O2 concentration, from 0.02 % to near 0 % (lower limit of the
measuring instrument). This shows that all the CO2 released into
closed space is used immediately for photosynthesis and thus circulating.
The regulating behavior to the abrupt disturbance is also recorded
clearly in variations of oscillating periods of atmospheric O2 and
CO2 concentration. The most prominent oscillation period in 'open'
system was 0.5 - 1.5 days. After closing, it shifted quickly to shorter periods
of 6 - 7 hours and of 1.5 hours.
These are regulating responses of the system to a disturbance of
an abrupt closing of CES.
5. Instability of CES
It deserves special mention that the CES we are observing might
actually possess instability. The following two cases (a) and (b) support the
suggestion.
(a): We had supposed that the temporary opening of the 'closed'
system could not damage the system so much, because the 'closed'
system had been maintaining a near constant status for 46 days after the
closing and especially keeping the atmospheric O2 concentration near
constancy of 21% which is almost the same condition as an open air. So, even if
a temporary opening is imposed upon the system, the circumstances around the
CES are supposed to be unchanged as long as no other disturbances are assigned
to the system. In fact, we imposed no other disturbances than a temporary
opening of the top of the container.
But, no sooner had we opened the CES#2 temporarily for only one
hour than the O2 concentrations both in the atmosphere and dissolved
in the hydrosphere began to drop down suddenly. The O2 concentration
in the atmosphere dropped down from around 21% to about 15% in 40 days.
Photosynthetic mechanism of the system seems to have been out of order as a
whole; although at the present we cannot give a detailed explanation on the
mechanism, it would not be so simple. The green algae which covered vigorously
with the water surface decreased sharply. This is thought to induce the sharp
drop of the atmospheric O2 concentration of the CES.
The dissolved O2 in the hydrosphere of the CES showed a
little different behavior from one of the atmospheric O2. Although,
showing ups and downs, the dissolved O2 concentration also decreased
rapidly from around 10 ppm to about 6.5 ppm in only 10 days, it had restored
again toward 9 ppm in two weeks after the temporary opening. Green algae became
again very fresh in the hydrosphere except at the surface, covering the bottom
of the container with vigor, and thus reformation of the damaged system is
likely to be made persistently.
(b): Another abrupt unexpected changes of the state of the CES#2
had happened after three months of the case (a), when a light was turned off
for one days. The stable state of the system of long standing had been
destroyed in an almost instant. O2 concentration in the atmosphere
had decreased from about 19% to 12% in 10 days, and on the contrary CO2
concentration had increased from about 0% to 1.7% in 12 days. Furthermore, more
shocking movement was observed at the dissolved O2 concentration in
the hydrosphere; in almost one day, it had dropped sharply in only one day from
some 25% toward mere 4% (Fig.1). The green algae which had been covering
vividly with the hydrosphere (and also snails) were damaged badly, remaining
some small patches of green algae in the bottom of the hydrosphere. The number
of living bacteria have become ten times as large as that before the
destruction, while the number of dead ones remains unchanged. The value of pH
had also shown a dramatic change from 9.5 to 7.5.
The result of (b) demonstrates that influence of the
photosynthetic living things has been waning abruptly by the darkening, and as
a result the nature of the system had transferred to another one. We think that
the leading figures supporting the system had been rearranged completely; both
methane bacteria and methane-oxidizing bacteria may have become influential and
emit CO2, decomposing organic matters.
And furthermore, the result of (b) gives one important suggestion
for mechanism of climatic changes: (i) first of all, a change of anoxia event
would break out suddenly in the hydrosphere and then it will appear slowly in
the atmosphere; (ii) the system without photosynthetic living things would have
an environment enriched with CO2 gas as proposed by the Lovelock's
gaia theory.
The fact that similar phenomena, as in (a) and (b), had happened
twice in CES deserves attention and would suggest universality of this
phenomenon. The events happened in (a) and (b) tell us that CES which looks
like stable at a glance might actually be very unstable, and even by a slight
disturbance it would be transferred toward another unexpected state. However,
on the other hand, as shown in (a) CES certainly has a latent regulating
ability against damages. Thus, CES has the same characteristics as 'chaos',
while, different from chaos, CES has an autonomous latent ability to regulate
persistently.
AS also indicated above, this nature peculiar to CES seems to be
very important to the mechanism of climatic changes of the earth. By a slight
disturbance, the earth which is composed of a huge CES could change its state
drastically, as our experiments showed. For instance, the anoxic state in the
ocean could be emerged easily not by an external forcing but by the inherent
nature of CES-itself. Historical oceanic anoxia events which had emerged on the
earth, e.g., 250 million years ago, have been explained until now by
changes of oceanic currents and of biotic activities linked with super
continental formation. These proposed mechanisms, however, request further
problem to solve; that is, why then had the changes of oceanic currents or
super continental formation happened? All of these explanations are based upon
the point at issue on mechanical responses of the earth system for the given
external and powerful perturbations; namely, these theories need a substantial
and special cause for emergence of oceanic anoxia events.
But, the earth as a CES may not need such an external, special and
mechanical cause, e.g., changes of ocean currents, for an appearance of
anoxic ocean, because CES can induce an anoxic state easily in the hydrosphere
by the inherent instability of CES-itself. As our experiments indicate, only a
slight and any disturbance for the earth as a CES may be enough to bring an
anoxic event into the ocean and then large impact into the atmosphere.
The above matters need further study. We are now planning further
confirmation of these very interesting phenomena by using CES#3.
6. Concluding remarks
Concerning the characteristics of CES, the following are
noteworthy:
i) CES takes dynamic action for creation and regulation of the
circumstance and the system-itself. This means that life and its environment in
the earth which is a huge CES construct a cooperative system, and they are
never separated from each other.
ii) CES is operating with its own oscillation. This is very
important to the mechanism on appearance of climatic variation on the earth in
the point that, without any external forcing, the earth as a living-system can
vary its state.
iii) CES has a possibility for a sudden turn of state of the
system by a slight perturbation, but on the other hand it has a persistently
restoring ability. Abrupt anoxia events occurring in the hydrosphere should be
noted most. This indicates that there exists instability in CES despite of a
stable state in appearance, and gives an important suggestion different from
the current theories for the mechanism of climatic changes.
We think that it is very important to investigate behaviors of
CES, as a living system, in order to grasp the nature of the actual earth
system which most obviously is a huge CES.