JP4803421B2 - Regeneration and restoration methods of submerged plants in shallow lakes - Google Patents

Description

  The present invention relates to a method for regenerating / restoring a submerged plant capable of preserving an ecosystem unique to the lake and improving water quality in a shallow lake.

  In recent years, in shallow ponds, swamps, and lakes (hereinafter referred to as “shallow lakes”), there have been cases where the water quality has not been improved despite the improvement in water quality of river systems flowing into this shallow lake. This is because of the pollution of shallow lakes, once a submerged plant community declines or disappears, self-healing of this submerged plant community is very difficult, so the water quality improvement effect of the submerged plant community cannot be restored, This is thought to be because the once-developed pollution is not resolved.

  For example, the inflow of pollutants before the quality of the inflowing river water improved, and the shallow lakes were polluted and the submerged plant community disappeared all at once. That is, when the transparency of shallow lakes is reduced by this water pollution, even if the submerged plant is located at the bottom of the shallow water, it will at least decline due to insufficient solar radiation in addition to the influence of water pollution. And once a submerged plant community declines or disappears in this way, the influence of wind waves on the water surface directly reaches the bottom mud deposited on the bottom of the water, and the phenomenon of rolling up the bottom mud occurs. For this reason, bottom mud diffuses in water, and elution of nutrients such as nitrogen and phosphorus is activated from the bottom mud. As a result, eutrophication of the lake progresses, phytoplankton grows significantly, and the amount of phytoplankton in the water increases.

  In this way, both the concentration of bottom mud particles in water due to the phenomenon of rolling up the bottom mud and the concentration of phytoplankton in water due to eutrophication increase, so the transparency of the lake is greatly reduced. Therefore, the amount of solar radiation reaching this bottom even at shallow depths decreases to an extent that is not suitable for the self-healing and inhabiting of submerged plants. For this reason, even if the water quality of the inflowing river is improved, the submerged plant communities are not regenerated or restored, and the shallow lakes continue to be polluted.

  Therefore, various proposals have been made to purify such polluted water areas. For example, along the coast of a stagnant water area such as a lake or pond, and forming a revetment with water permeability by securing an appropriate gap distance from this shore, a shallow water depth zone is formed between this revetment and the shore. Form and plant aquatic plants in this shallow water depth zone, install a biological water treatment device along the outside of the revetment, and force this water treatment device to circulate water in the water area A water quality conservation system for a stagnant water area such as a lake or pond having the above structure has been proposed and has already been granted a patent (Patent Document 1). In addition, this water quality conservation system has a shallow water depth zone with a depth of about 30 cm, and as water plants newly planted in this shallow water depth zone, for example, reeds, reeds, makomo, gama, futoi, etc. It is said that it is preferable to use a combination of water-extracted plants such as water-drawn plants, water poppies, watercress and seri and submerged plants such as tanukimo and sugimo. Therefore, according to this water quality conservation system, BOD components such as organic substances, nitrogen and phosphorus are removed from the water area by the water treatment device, and DO (Dissolved Oxygen: dissolved oxygen amount) is generated by the sex plant group in the shallow water zone. By supplying amplifying the purification function inherent in nature, the water quality of the stagnant water area exposed to the increasing pollution load and the stagnant water area where the contamination has already progressed It is said that it is possible to efficiently maintain, restore, and maintain water quality while maintaining harmony with nature.

  In addition, in the deep layers of polluted water areas and dark water areas where light does not pass through the bottom of the water, the water area is made up of draped and filmed bodies, and the water in the water area is made more transparent, and this water is used as a medium. A large amount of dissolved oxygen in the deep layer and the bottom of the water, allowing a large amount of sunlight to penetrate the deep layer and the bottom of the polluted water temperature and the bottom of the water, enabling tourism and entertainment, as well as activating photosynthesis in the deep layer and the bottom of the water. A method for improving the bottom sediment and deep environment using sun light holes using the “water area depression” configured to purify the ecological environment and sludge in the bottom of the water has been proposed and has already been granted a patent (Patent Literature) 2). Moreover, in this improvement method, in order to increase the transparency of the “water area”, specifically, 1) increase the transparency of the water in the “water area” using a known purification device, or 2) Either by putting water with high transparency into the “water area”, 3) forcibly discharging the muddy water in the “water area”, or 4) by introducing a purifier into the “water area” Purify polluted water, or use them in combination as appropriate. According to this improvement method, running costs are low, and ecological environment conservation and sediment environment conservation effects are large. .

  Furthermore, the water stop area where water is constantly stored, the water level fluctuation area provided around this water stop area, and the non-flooding water area provided around this water level fluctuation area, either the regulating pond or the recreational pond. Or an artificial greening area with a configuration provided on both sides, and divided into a plurality of areas according to a predetermined inundation frequency from the water stop area to the water level fluctuation area, and these multiple areas have inundation resistance according to the inundation frequency. There is known an artificial greening method in which a plant transition zone is formed by planting a plant having the plant so that the vegetation can be seen (for example, Patent Document 3). In this artificial revegetation method, the multiple areas are divided into a constantly flooded area, a frequently flooded area and a rare flooded area, and either a floating plant or a submerged plant is included in the constantly flooded area. Planting, frequent submerged areas are planted with either or both submerged plants and wet plants, and the vegetation moves in stages, so a more natural arrangement can be achieved and the seeds settled. It is said that it is easy to promote long-term stable ecosystem composition. In addition, because the plant transition zone is provided in this way, small animals that are strongly influenced by vegetation arrangement are promoted to segregate, and as a result, a highly stable flora and fauna are formed, which excels in diverse ecosystems. A biotope can be created.

  In addition, a shallow pond is continuously provided in the lake body, and a large number of aquatic plants are arranged in the pond, and water is passed between the lake body and the pond, but a partition that blocks passage of water plants is installed. A lake purification device is known (for example, Patent Document 4). In this purification device, it is desirable to arrange a large number of aquatic plants such as water lilies, rhombuses, cormorants, red sea breams, floating grasses in the pond underwater and on the shore. A windmill-driven pump is installed. Therefore, according to this purification device, the water in the lake is purified by utilizing the natural power of water plant water purification, so there is no need for large-scale devices, energy such as electricity and special chemicals for this device. It is said that there is no concern about causing environmental destruction and the cost is low.

Japanese Patent No. 2849020 Japanese Patent No. 3644523 JP 2001-224243 A JP 2003-19493 A

  However, in the above configuration and method, even if an aquatic plant group is formed, the submerged plants unique to the water area have not been clearly regenerated and restored, so that it is not necessarily possible to preserve the lake ecosystem. Problems arise.

  That is, in the above water quality conservation system, a new group of aqueous plants is planted in the newly formed shallow water depth zone, and in the above-mentioned method for improving the bottom quality and deep environment, There is no clear description of the aquatic plant group at least when the photosynthetic action is activated, and the above-mentioned artificial tree planting method uses a plant transition zone where vegetation changes regularly in order to stabilize the ecosystem for a long period of time. It is formed by artificial terrain creation and planting arrangement, and in the above lake purification device, a new pond is attached to the lake body, and aquatic plants are newly formed in this pond as well. Yes. In any case, the submerged plants inherent in the water area are not actively regenerated or restored.

  Moreover, in the said conventional structure and method, the pollution state resulting from the winding-up phenomenon of the bottom mud which arises in a shallow lake with the decline or disappearance of the above-mentioned submerged plant is not fundamentally eliminated. That is, even if it can be expected that the polluted lake water is purified by symptomatic treatment with aquatic plants, there is a lack of the viewpoint of suppressing the rolling up of the bottom mud that causes this pollution. For this reason, in the above-described conventional example, the so-called so-called polluting power resulting from the rolling up of the bottom mud needs to have a greater purification power by aquatic plants, and this power relationship needs to be maintained. Therefore, the improvement of water pollution is expected to be slow and prolonged.

  Accordingly, the present invention provides a method for regenerating / restoring a submerged plant in a shallow lake that solves the problems of the prior art, regenerates or restores a submerged plant that has declined or disappeared inherent to a water region, and improves the water quality of the water region. The purpose is to provide.

In order to solve the above-mentioned problem, the invention according to claim 1 is characterized in that the water pollution of the water area progresses due to the pollutant flowing from the outside, and at least the submerged plant community peculiar to the water area declines or disappears. the even inflow of contaminants is reduced, in shallow lakes pollution condition persists, reduce water turbidity by suppressing winding mud caused by wind waves of the body of water, the transmitted light in the sea bed of the body of water The turbidity lowering means is formed so as to regenerate or restore the inherent submerged plant community in the water area where the submerged plant community has declined or disappeared, and the regenerated or restored submerged plant community covers the bottom of the water. The effect of suppressing the rolling up of the bottom mud is enhanced, the regeneration or restoration of submerged plant communities is further promoted, and the water quality of the water area is improved.

  According to a second aspect of the present invention, in the first aspect, the turbidity reducing means is formed by distributing floating leaf plants in a predetermined manner.

  According to a third aspect of the present invention, in the first aspect, the turbidity reducing means is formed by covering the water bottom with a mat.

  According to a fourth aspect of the present invention, in the first aspect, the turbidity reducing means is formed by surrounding the bottom of the water with a floating frame in which a sheet-like member is suspended.

According to a fifth aspect of the present invention, in any one of the first to fourth aspects, an isolation member that prevents at least an existing floating leaf plant from entering a portion where the submerged plant community is regenerated or restored is provided.

The invention according to claim 6 is a pollutant substance flowing in from the outside, so that water pollution in the water area progresses, at least the submerged plant community inherent in the water area disappears, and the inflow of the pollutant substance decreases. However, in shallow lakes where the pollution state cannot be resolved, the buried seeds of the submerged plants that formed the lost submerged plant communities were collected from within the water area, and the submerged seeds inherent to the water area were collected by the collected buried seeds. In addition to restoring the plant community, the restored submerged plant community covers the bottom of the water and suppresses the rolling up of the bottom mud in the body of water, allowing transmitted light to reach the bottom of the body of water and further promoting the restoration of the submerged plant community. , Improve the water quality of the water area.

  A seventh aspect of the present invention is the method according to the sixth aspect, wherein the regenerated strain obtained by allowing the collected buried seeds to germinate and growing to a predetermined extent is cultured in a large amount, and a location suitable for the growth of the regenerated strain is defined in the water area. The turbidity reducing means is provided to allow the transmitted light to reach the bottom of the water at the selected location, and a predetermined number of regenerated strains are transplanted and fixed on the bottom of the water where the transmitted light is secured to grow as a submerged plant community. .

The invention according to claim 8 is the invention according to claim 7 , wherein the regenerated strain is accommodated in a predetermined container and installed on the bottom of the water, and the bottom of the container is formed to be porous. .

A ninth aspect of the present invention is the method according to any one of the sixth to eighth aspects, wherein the flow model for quantitatively evaluating the bottom mud disturbance and the flow velocity distribution in the bottom of the water based on the topography, hydrology, and weather conditions of the water area is created. Then, the collection point of the buried seed is selected using the flow model.

A tenth aspect of the present invention is the method according to any one of the seventh or eighth aspects, wherein the flow model for quantitatively evaluating the bottom mud disturbance and the flow velocity distribution in the bottom of the water based on the topography, hydrology and weather conditions of the water area is created. Then, using the flow model, a location suitable for the growth of the regenerated strain is selected.

  Since the present invention is configured as described above, it is possible to improve and maintain the water quality of shallow lakes and marine ecosystems including various aquatic organisms that have decreased or disappeared due to the decline or disappearance of submerged plant communities. It is possible to increase the possibility of reviving and reproducing. In other words, once a submerged plant is recovered and restored and settled, the submerged plant community suppresses the rolling up of the bottom mud caused by the wind wave, and the underwater mud particles and underwater plankton underwater Turbidity can be reduced. For this reason, it becomes possible to recover shallow lakes with improved water quality. In particular, since the increase in transparency and the increase in the biological activity of the submerged plant are promoted in cooperation with each other, it is possible to promote the tendency to improve water quality. On the other hand, since the habitat environment that the submerged plant has provided in the past can be recovered, it is possible to preferentially return aquatic organisms that have used the environment.

  FIG. 1 shows a first embodiment using the method for regenerating / restoring a submerged plant of the present invention, and (a) is a schematic diagram showing a state in which a submerged plant has declined and a floating leaf plant has grown. b) is a schematic diagram showing a state in which a floating leaf plant has been cut in order to recover a submerged plant, (c) is a schematic diagram showing a state in which recovery of a submerged plant is started or in the middle of recovery, and (d) It is the schematic which shows the state reproduced | regenerated as a submerged plant.

  In this first embodiment, because of pollutants flowing in from the outside, even if at least the submerged plant communities inherent in the water area decline and the inflow of pollutants from the outside decreases, the water pollution is not eliminated It is a method for regenerating and restoring submerged plants that has coped with lakes and marshes, and it is assumed that floating leaf plants are flourishing throughout the water area or at a specific part.

  That is, as shown in FIG. 1 (a), when a floating leaf plant B is prosperous at a predetermined place P in the water area, for example, a leaf such as a horsetail floats on the surface of the water and settles on the bottom of the lake with its underwater roots. In the case where the floating leaf plant B is prosperous, the wind wave is suppressed in such a place, and the rolling up of the bottom mud is already suppressed. However, since the leaves covering the water surface hinder the supply of light and oxygen, in this first embodiment, only a part of these floating leaf plants B is cut in a predetermined manner, leaving the wave-dissipating effect, and light. A point P that reaches the bottom of the lake is created in a predetermined manner. In addition, as this location P, at least a location having a water depth suitable for the inhabiting of submerged plants is selected.

  That is, when the floating plant B is prospering in this way, the leaves of these floating plant B prevent the transmitted light and oxygen from the water surface from reaching the bottom of the proliferating portion P. For this reason, even if the submerged plant A remains on the bottom of the water, the growth remains undeveloped, and the seed may germinate even if the seed of the submerged plant A remains on the bottom of the water. Is extremely low. Therefore, the submerged plant A inherent to the water area has declined, and even if the place becomes a dominant species suitable for the growth of the submerged plant A, it will not recover and regenerate as a submerged plant community AA. become.

  Therefore, in the first embodiment, as shown in FIG. 1 (b), a number of floating leaf plants B themselves are thinned out to a predetermined degree from a prosperous floating leaf plant B without being limited to removal of floating leaves. In this way, a water bottom portion having a predetermined area where the submerged plant A can recover is formed between the floating leaf plants B left without being cut. In other words, the existing overgrown floating plant B, which has been proven to have some degree of resistance to the deterioration of the water quality of the lake, has excessive light transmission from the water surface to the bottom of the overgrowth place. The floating leaf plant B distributed in this way is used as the turbidity lowering means 1.

  Therefore, a bottom portion exposed in water is formed between the remaining floating leaf plants B, and this bottom portion is a straight path free from obstructions from the bottom portion to the water surface. Therefore, the amount of transmitted light and oxygen supplied from the water surface can be sufficiently secured. For this reason, the submerged submerged plant A remaining in the bottom of the water can grow into a smooth adult. On the other hand, the seed of the submerged plant A remaining in the bottom of the water is given an opportunity to germinate and grow. That is, depending on the prosperity of the floating leaf plant B, when most of the solar radiation is blocked, a certain amount of solar radiation reaches the bottom of the water, so that it can be expected to increase to illuminance that satisfies the germination condition.

  In addition, even if a part of the proliferating floating leaf plant B is cut so as to secure solar radiation at the bottom of the water, the floating leaf plant B remaining in the surrounding area may re-enter the cut portion P. is expected. Therefore, the re-entry prevention means 5 is installed in the cut portion P to prevent the new floating plant B from entering. That is, in the same manner as the oil fence, the cutting portion P is arranged by suspending the sheet 6 that is isolated from the surroundings from the floating body 7 so as to prevent re-entry of the floating plant B.

  This re-entry prevention means 5 is mainly composed of a floating body 7 and a sheet 6 which is a separating member suspended from the floating body 7, and a cutting plant P and a floating leaf plant B remaining around the cutting plant P It is installed over an appropriate range on the boundary line dividing the space. That is, the sheet 6 is stretched between the two P and B in a screen shape to separate the two P and B.

  The floating body 7 is formed in a predetermined shape similar to a buoy or the like, and is mainly composed of a foam or a hollow body. Sufficient buoyancy is secured to suspend the sheet 6 and stay on the water surface. When the seat 6 is suspended from the floating body 7 and installed at a predetermined location P, the lower end of the seat 6 has a length in the hanging direction so that the bottom can be settled.

  Therefore, the re-entry preventing means 5 prevents the floating leaf plant B and the like from entering the cut portion P and growing over by the sheet 6 installed in a predetermined manner. That is, when the re-entry prevention means 5 is installed at a predetermined location P, the floating body 7 is fixed by burying the lower end of the suspended sheet 6 in the bottom of the water, or is moored in a predetermined manner with a wire (not shown), Maintain its installed position. For this reason, in the same manner as the oil fence, the predetermined portion P is isolated from the surroundings, and the floating plant B remaining in the surroundings is prevented from re-entering.

  The re-entry prevention means 5 does not have to surround the entire periphery of the predetermined place P, and is necessary by appropriately taking into account the prosperity of the floating leaf plant B remaining around the predetermined place P and the topography of the water bottom. It shall be installed at the location. Further, the re-entry preventing means 5 may be provided in a double wall shape as shown in FIG. 1 (b), thereby further enhancing the prevention effect.

  Therefore, when recovery of the submerged plant A is started in this manner, positive feedback that accelerates and accelerates the change in the direction of reducing the turbidity in water is obtained. That is, with the growth of the submerged plant A, the turbidity in water, which is an inhibition factor for this growth, is reduced, so that the growth can be activated and the change tendency to reduce the turbidity in water in conjunction with this is further increased. it can.

  More specifically, the submerged plant A that grows so as to cover the surface of the bottom mud mitigates and suppresses the rolling up of the bottom mud by wind waves. Therefore, elution of nutrient salts such as nitrogen and phosphorus from the bottom mud into water is suppressed. Therefore, the concentration of nutrients dissolved in the water is reduced. For this reason, the biological activity of the phytoplankton in the water that has absorbed the nutrients is reduced. As a result, the amount of the underwater phytoplankton decreases, and at the same time, the amount of the bottom mud particles that are wound up and float in the water continues to decrease.

  In this way, an increase in transparency due to a decrease in phytoplankton and a decrease in turbidity due to a decrease in the amount of rolled up bottom mud can occur at the same time, so that the turbidity in water can be greatly reduced in the vicinity of the submerged plant A. That is, the concentration of phytoplankton and the concentration of bottom mud particles located in the vicinity of the submerged plant A can be decreased simultaneously.

  And since turbidity falls in this way and the transmitted light amount which reaches | attains the water bottom in which the submerged plant A was located increases, the growth activity and breeding activity of the submerged plant A which received this transmitted light become active. That is, the submerged plant A transplanted to the predetermined location P has the necessary transmitted light secured to the germinated branches and leaves, and the roots of the submerged plant A are nutrients such as nitrogen and phosphorus from the bottom mud of the predetermined location P. Can be taken directly, so it can grow and settle sufficiently stably.

  In this way, the submerged plant A suppresses the rolling of mud caused by wind waves, reduces the amount of mud particles generated, and reduces the generation factor of phytoplankton, thereby reducing the turbidity in water, The amount of transmitted light to A is increased, the growth of the submerged plant A is promoted, the suppression effect by the submerged plant A is increased, and a positive feedback action that the tendency to decrease the turbidity in water increases can be obtained.

  Therefore, as a result of the above, as shown in FIG. 1 (c), the submerged plant community AA inherent to the lake is gradually recovered and the submerged plant zone is regenerated in a form coexisting with the floating leaf plant B. can do.

  That is, as shown in FIG. 1 (c), when the submerged plant A has become a community and has secured a certain number of individuals and a stable growth state, this submerged plant community AA is: Since the invasion of the floating plant B from the surroundings can be prevented, the re-entry prevention means 5 is removed. Therefore, it is not necessary to leave an artifact in the water area. For this reason, it does not affect living organisms other than the plant body, and it becomes a favorable environment for the restoration of the ecosystem.

  Then, as shown in FIG. 1D, when the submerged plant A has settled and has grown to such an extent that it can grow stably and continuously, the floating plant B is appropriately removed. For example, first, the floating leaf plant B left without being cut is removed and removed from between the grown submerged plants A. For this reason, it can be developed into a community consisting only of the submerged plant A. That is, the number of submerged plants A that have become adults can be steadily increased, and the vegetation density including the juveniles can be increased. For this reason, the effect | action which prevents the bottom mud rolling by the submerged plant community AA can be strengthened. As a result, the submerged plant community AA can live stably.

  In this way, a plurality of submerged plant communities AA can be recovered and regenerated in a self-sustaining manner, the vegetation range of these communities can be expanded by the growth action of these submerged plant communities AA, and contacted with each other. It can be regenerated as a continuous submerged plant zone. That is, it is expected that the submerged plant community AA that has been regenerated in this way and has secured stable growth can be expanded to its surrounding area by its reproductive action.

  As another example of the first embodiment, because of pollutants flowing in from the outside, not only the submerged plant communities inherent in the water area have declined, but the floating leaf plants have declined or disappeared, and external pollution has occurred. If the water pollution is not eliminated even if the inflow of the substance is reduced, the floating leaf plant may be restored first, and then the submerged plant community may be restored in the same manner as described above.

  That is, in this other example, although not shown in particular, the above-mentioned plant where both plants have declined or disappeared as described above, and where the submerged plant community is to be restored, has grown in other parts of the water area. Either transplanting an adult floating leaf plant with guaranteed resistance, or introducing a floating leaf plant having a certain level of resistance to the current water pollution environment of the water area from the outside of the water area, or transplanting, or The turbidity lowering means with a configuration in which floating leaf plants are distributed is provided by combining both of these as appropriate to suppress wind waves on the water surface at the planned location and not to excessively reduce the transmitted light to the bottom of the water. Next, the above-mentioned re-entry prevention means is appropriately provided to start the recovery cycle of the aquatic plant community that has obtained the positive feedback action as described above, so that the aquatic plant zone is finally obtained.

  Therefore, according to this other example, the place where the submerged plant community is restored need not be restricted to the place in the water area where the floating leaf plant is prosperous, so the selection range is expanded. For this reason, the location suitable for the growth of the submerged plant A can be selected, and the submerged plant community can be recovered earlier. On the other hand, if a place where a lot of bottom mud roll-up phenomenon is seen and a submerged plant community is recovered at this place, it is possible to improve water pollution earlier, that is, to improve water quality earlier. Become.

  As described above, according to the method for regenerating / restoring a submerged plant of the first embodiment, recovery and water quality improvement of a submerged submerged plant are caused to occur at the same time and proceed in parallel. Can be expected to recover as a community and expand the community in an expanded manner.

  That is, according to this method for regenerating and recovering a submerged plant, it is possible to shift from a state in which water pollution is maintained to a state in which the water quality is changed, and this change state is accompanied by the natural and spontaneous growth of the plant body. Thus, it is possible to obtain a positive feedback action that changes the water quality in the direction of improvement, and to improve the water quality in a sustainable and expanding manner without requiring any maintenance and maintenance costs. Thus, not only can the positive feedback loop cycle continue to improve water quality, but also the change in this positive feedback direction can be accelerated.

  Also, as a submerged plant suitable for restraining the rolling up of the bottom mud, and a kind of submerged plant for preventing the rolling up of the bottom mud, especially if the axle algae can be recovered, the axle algae will have its fine branches covering the bottom mud. If these are sufficiently grown and prosperous, an effect of sufficiently and reliably suppressing the rolling up of the bottom mud can be obtained. Therefore, if the type of submerged plant to be recovered in this manner is suitable for preventing the bottom mud from rolling up, other types of submerged plants that are not suitable for restraining the bottom mud from starting from the recovery of this type of submerged plant. Can also be recovered.

  On the other hand, in order to prepare a habitat for regenerating submerged plants, existing floating leaf plants are distributed in a predetermined manner and used as turbidity lowering means, and at least as the submerged plant community regenerates, the floating leaf plants used as this turbidity lowering means Since this is gradually reduced, aquatic plants are maintained in this regenerated area even if they are of different species. In other words, a unique submerged plant community is being regenerated by gradually replacing the existing floating plant community. For this reason, the ecosystem in the water area before and after the regeneration can be shifted to a state where the unique submerged plant community has been regenerated while ensuring continuity without disrupting or greatly disturbing the ecosystem.

  As a result, it is expected to contribute to the conservation of biodiversity in lakes and marshes as well as improving water quality. In this way, it is possible to recover the declined submerged plant community and conserve it in a self-contained manner, and it is possible to reproduce an ecosystem including aquatic organisms unique to the lake other than aquatic plants. In other words, the recovered submerged plant community can prepare a habitat suitable for aquatic organisms unique to the lake, so that it is not just a return of aquatic organisms, but aquatic organisms unique to the lake can be preferentially inhabited. . On the other hand, for example, if a point in the water area close to land, that is, a waterfront area, can be selected as a place to recover a submerged plant community, the waterfront area as a habitat for more species can be regenerated. It can contribute to the conservation of biodiversity. The aquatic organisms include organisms that temporarily use submerged plant communities.

  In this way, if the aquatic plant communities peculiar to the lake can be restored, it will contribute to the regeneration and activation of the entire ecosystem including the water area of this lake and social culture including water culture. I can expect that.

  Next explained is the second embodiment of the invention. In addition, the same code | symbol is attached | subjected to the member of the same structure as above-mentioned 1st Embodiment, and description is abbreviate | omitted or simplified. That is, the description will focus on the differences from the first embodiment, and the configuration not described in the second embodiment, the method such as the work procedure, and the action obtained by these will be described in the first embodiment. It is the same as the embodiment.

  The regeneration / restoration method of the second embodiment is a pollutant that has flowed from the outside, so even if at least the submerged plant community inherent in the water area disappears and the inflow of pollutants from the outside decreases, It is a method for regenerating and restoring submerged plants that deal with shallow lakes where pollution is not resolved, and assumes that seeds of lost submerged plants are buried somewhere in the water. That is, even if the submerged plant zone disappears, it is highly likely that the seeds are buried in the bottom mud and are in a dormant state.

  Therefore, in this regeneration / restoration method, seeds embedded in a germinable state (hereinafter referred to as buried seeds) are collected from within the water area, and a large amount of the regenerated strain is cultured from the buried seeds and selected as desired. The turbidity reducing means is provided in the water area, and a predetermined number of regenerated strains having a predetermined population size are transplanted to restore a submerged plant community unique to the water area.

The above-mentioned buried seeds are considered to be distributed planarly and vertically in the bottom mud. That is, depending on the length of time (years) from the disappearance of the submerged plant to the present time, the buried seeds are spread more widely or deeply embedded away from the location where the community existed Conceivable.
Therefore, first of all, we will grasp the distribution situation of buried seeds in lake bottom mud and develop an efficient harvesting technique as seeds for restoring unique submerged plants.
Secondly, a technique is developed for germinating the collected buried seeds and culturing them in large quantities as a regenerated strain for restoration.
Thirdly, we will develop a technique for transplanting the regenerated strains cultured in large quantities to restore the submerged plant communities.

  In more detail, the collection method includes the development of a three-dimensional flow / seed diffusion model, the understanding of the bottom mud properties by point characteristics by the bottom mud columnar sample survey at multiple points, and the germination of buried seeds contained in the bottom mud at the sampling point Experiment and analysis of germinated plants, provisional selection of buried seed collection points based on the results of this analysis, understanding of the relationship between the amount of bottom mud collected at this collection point, the amount of germinated seeds, and the number of species, the determination of the collection point, These stages are being developed in sequence.

  In other words, in order to reproduce the state of seed diffusion and to quantify the sedimentation tendency of the bottom mud, it is possible to quantitatively evaluate the bottom mud disturbance and flow velocity distribution due to wind waves on the lake bottom based on the local topography, hydrology, and weather conditions. A dimensional flow simulation model and a seed diffusion model (hereinafter referred to as a flow model) are created. This flow model is a mathematical virtual model created based on topography, hydrology, and meteorological data measured and observed in actual waters, and this model was used on a computer to reflect environmental conditions. If various parameters are set and the simulation program is executed, predetermined estimation data or prediction data can be obtained as the simulation result.

  Therefore, the created flow model can be used for selecting sampling points for grasping the bottom mud properties by point characteristics. That is, for example, a point where the characteristics of bottom mud property and sedimentation tendency of the bottom mud clearly appear can be predicted and selected in advance. Furthermore, this flow model can also be used as a seed diffusion model. That is, it can be estimated from the past distribution of submerged plant communities where seeds and follicular spores are likely to accumulate. Specifically, in a computer simulation using a flow model, how the seeds and follicles of the submerged plant diffuse from the location of the submerged plant community that existed in the past, and accumulate in many present locations. I can guess.

  The seed settling velocity parameter used in the flow model as the seed diffusion model is set based on the actually measured value. In other words, a real experiment is performed in a room or the like, and the sedimentation characteristics of seeds are measured in advance.

  Next, in order to grasp the bottom mud properties and sedimentation tendency of the bottom mud, the bottom mud properties by site characteristics are investigated. That is, the bottom mud properties and sedimentation tendency are affected by topographical differences such as water depth and distance from the lake shore, and characteristics such as the presence or absence of surrounding rivers. For this reason, a method for obtaining and analyzing bottom mud columnar samples at several local sites has been selected as the survey method. In addition, these locations are selected using the flow model, taking into account the seeds of submerged plants and the locations where the follicles are buried, and the optimum locations for grasping the bottom mud properties and sedimentation tendency.

  Specifically, as shown in FIG. 2 (a), undisturbed columnar samples Sa1 and Sa2 of lake bottom mud are collected at several points St1 and St2, and these columnar samples Sa1 and Sa2 are collected as shown in FIG. 2 (b). As shown in the left figure, the columnar sample Sa1 is sliced in the depth direction of the bottom mud and analyzed. That is, the part corresponding to each layer of the bottom mud in the longitudinal direction of the columnar sample Sa1 is cut into a flat plate shape, and these cut samples Sa11, Sa12, Sa13 are analyzed. In addition, as this analysis, indicators, such as a moisture content, oxidation-reduction potential, and ignition loss, are measured for every layer, for example.

  Moreover, the samples Sa11 to Sa13 of the residual analysis are provided for germination and culture tests. At this time, the bottom mud samples Sa11 to Sa13 of each layer are partly stored, and for the sample Sa12 containing a lot of germinated seeds, the dating is performed to elucidate the past era when the buried seeds were deposited. Used for that. That is, the distribution situation of buried seeds for each age is grasped.

  The measured values of various characteristics obtained from the analysis of the columnar samples Sa1 and Sa2 collected at each of these points verify the accuracy of the simulation results by the flow model, correct the flow model itself, and correct each parameter. Used to do.

  Next, germination and culture experiments of buried seeds are performed. In this germination experiment, using an incubator that can set any environmental conditions, the collected bottom mud is used as a medium in this incubator, and the buried seeds washed out in this medium are installed. This is done by setting various conditions. That is, as shown in the left diagram in FIG. 2B, the mud columnar sample Sa12 collected at a certain sampling point is sliced for each layer at the sampling point. And as shown to the right figure in FIG.2 (b), the mud of this each layer was used as the culture medium, this culture medium and the buried seed isolate | separated from the mud were accommodated in the container, and various environmental conditions were set with the incubator. Perform germination experiments.

  That is, even though the buried seed remains in the bottom mud, it cannot grow as a submerged plant in the current lakes. This is probably due to one of the reasons that it cannot grow. That is, for the latter reason, the buried seeds that germinated when the germination conditions are satisfied cannot be further grown due to lack of solar radiation due to the nutrients in the seeds, and eventually die. It is done.

  Therefore, in this germination experiment, it is possible to exclude the factors that hinder the lack of solar radiation due to the effect of hoisting mud in the field, but it is necessary to examine various conditions such as temperature, light, moisture conditions, etc. . Therefore, germination conditions (or dormancy release conditions) are clarified by changing environmental conditions such as light, moisture, water temperature, and oxygen concentration.

  For germinated seeds, elucidate their growth conditions. In particular, the axle algae are effective in improving underwater transparency because the branched alga bodies cover the bottom mud surface. Therefore, the species is identified from the germinated plants by paying attention to the axle algae.

  And about the plant species germinated under a certain condition, the taxonomic research is performed, a species is identified, and suitable growth conditions are determined for every identified species.

  By combining the above analysis results, it is possible to elucidate the distribution in the planar and depth directions where it is considered that there are many germinated buried seeds. Therefore, it is possible to grasp the situation of buried seeds and to select a point where buried seeds suitable for restoration of the community are buried based on the situation. In other words, there are not only many seeds that are well-preserved, that is, germinable, but also seeds belonging to different lines of the same species so that genetic diversity can be ensured in the community. Can be selected.

  Specifically, the properties of the bottom mud and the distribution of storage conditions of the buried seeds are organized using a GIS (Geographic Information System) (not shown). Generally, this GIS is a system that manages the position and shape (map) of features and attributes (tables) in association with each other, and performs spatial analysis, layer (different map) overlay processing, and attributes (tables). ) Search / aggregate functions, etc., and combining these functions enables various analysis and statistical processing.

  In this GIS, the property data obtained by analyzing the bottom mud collected from each point and the data related to the buried seed obtained by the germination and culture test of the buried seed in the bottom mud are input. Based on this organized information, a method for efficiently collecting a large number of types of buried seeds, such as selecting the collection point, while quantitatively grasping the buried seeds remaining in the bottom mud ,decide.

  In this way, as shown in FIG. 2 (c), not only the current location of buried seeds is estimated from the distribution of past submerged plant communities, but also the above factors are taken into consideration. Select a point where the best buried seed can be collected efficiently.

  Then, the relationship between the amount of collected bottom mud, the amount of germinated seeds and the number of species is grasped. That is, at the point where the stored state of the buried seeds found as described above is good, a large number of bottom mud columnar samples are collected, and a sufficient amount of bottom mud is collected to grasp the above relationship. To do. And using this bottom mud, said germination test is performed and the said relationship is calculated | required quantitatively.

  Therefore, if the result shows that the amount of germinated seeds and the number of seeds is larger than the amount of collected bottom mud per unit at the selected point, the temporarily selected sampling point should be Confirm as

  Next, a mass culture method is developed. This mass culture method is a technique for obtaining a regenerated strain from the collected buried seed and mass-cultivating it, and is developed in parallel with the selection of the restoration site by the flow model.

  That is, a technique for mass-cultivating a regenerated strain obtained by selectively sorting out buried seeds contained in a specific layer in the bottom mud at the collection point and growing from the selected buried seeds is developed. For example, a method of cultivating a regenerated strain a1. Develop.

  Next, we will develop a reproducible transplant / restore technique. That is, the seeds of germination are germinated and propagated for each distribution location based on the results of distribution obtained by grasping the situation of the seeds of the above-mentioned soil and developing an efficient sampling method. At the same time, we will investigate the breeding pattern such as whether the plant body obtained from the buried seeds is hermaphroditic or heterozygous, and in combination with the above, develop a method of transplanting and restoring so that it can be reproduced locally.

  Moreover, it is considered that the following two conditions must be satisfied in order to restore the submerged plant community in the actual and current lakes, that is, in the field. In other words, the first condition is to select a place that can be established as a submerged plant community in consideration of the local topography, hydrology, weather, and water quality, and the second condition is to reproduce at that place. It is possible to introduce a submerged plant while ensuring an initial population size of a certain size or more.

Therefore, we will conduct a demonstration experiment to restore submerged plants. That is, as shown in FIG. 4 (a), a place where the regenerated strain a1 of the submerged plant A obtained by culturing from the buried seed is thought to be physically established is selected by computer simulation using a flow model. This place is set as the experimental area P0. Then, a preliminary local vegetation regeneration test is performed in advance by introducing the regenerated strain a1 cultured in large quantities into the experimental area P0 in this actual lake.
In this case, since the floating leaf plant B is prosperous in the experimental area P0, the floating leaf plant B is thinned to a predetermined thickness in the same manner as in the first embodiment, and the floating leaf plant B is distributed in a predetermined manner to eliminate the wave. The turbidity lowering means 1 having a configuration that secures the property and light transmittance is provided in the experimental area P0.

In this verification experiment, we evaluate the degree of colonization by the initial population size and the interaction with other organisms. That is, for example, the regenerated strains a1 having individual populations having different population sizes are installed in predetermined areas in the experimental area P0. Then, the relationship between the size of the introduced initial population size and the degree of establishment is obtained, or the influence of the submerged plant A growing from the introduced regenerated strain a1 and the existing aquatic organisms on each other is observed. .
Furthermore, seed diffusion is predicted using a flow model, and in the field introduction experiment, seed diffusion from the place of introduction is also predicted.

  Therefore, by this introduction experiment, the size of the initial population size can be determined as a plant population generated and established by the regenerated strain a1 transplanted in the field.

  Thus, when the above-mentioned various studies, developments, and demonstration experiments are completed, the restoration of a practical submerged plant community AA is started locally. In other words, if the wind model is low and measures are taken to reduce turbidity by the flow model, sunlight will reach the bottom of the lake, and the bottom will be selected as a highly recoverable place P suitable for the growth of submerged plants. . Then, as shown in FIG. 5 (a), in the case where the predetermined place P selected for practical use is in addition to the disappearance of the submerged plant group, the floating leaf plant has disappeared and is almost bare, this floating leaf plant. Instead, as shown in FIG. 5 (b), turbidity lowering means 11 comprising inanimate means is provided. This turbidity lowering means 11 has a structure in which a floating frame 13 with a sheet-like member 12 hung down is arranged in a predetermined manner, like an oil fence, and the wave attenuation inside the floating frame 13 is reduced. I try to figure it out.

  That is, the floating body frame 13 is configured such that several floating bodies 13a and 13a are connected to each other at predetermined ends and floated on the water surface, and an arbitrary range is enclosed in a frame shape. These floating bodies 13a and 13a are formed in a long shape having a predetermined length, and are mainly composed of a foam or a hollow body, and a predetermined buoyancy is ensured. That is, each floating body 13a, 13a has not only buoyancy to the extent that each floats on the water surface, but also extra buoyancy is ensured by the amount corresponding to the suspended sheet-like member 12. When the sheet-like member 12 is suspended from the floating bodies 13a and 13a and installed at a predetermined location, the length in the hanging direction can attenuate the influence of underwater waves from the outside of the area surrounded by the floating body frame 13. The length and the length that the lower end of the bottom can be secured are secured. Therefore, for example, if a range of small sections divided at a predetermined point P is set so as to be surrounded by a floating frame 13 in which the sheet-like member 12 is suspended, the magnitude of the wind wave within this range can be limited. Waves transmitted from outside the range can be attenuated.

  In addition, as shown in FIG. 4 (b), the regenerated strain a1 is accommodated in a predetermined container 15, transported to a predetermined location while being accommodated in the container 15, and placed at the water bottom of the location. .

  That is, after the buried seeds germinate and root to become the regenerated strain a1 that has been grown to a predetermined extent, the regenerated strain a1 is transferred to a predetermined container 15 having a flat plate shape, and each container containing the regenerated strain a1. 15 are arranged in a predetermined arrangement at the bottom of the predetermined number of places P selected as described above, and piles 16 are driven into the installed container 15 as shown in FIG. 4 (c). The container 15 is fixed at the place where it is installed.

  The container 15 is formed in a flat dish shape that opens upward, has a bottom area that can be stably placed, and has a generally flat shape so that the entire shape is not swept away by the water flow through the predetermined portion P. It has a shape. Moreover, this container 15 accommodates the sand-like culture medium which supports the lower part of the reproduction | regeneration stock | strain a1, and the bottom face is formed in the porous at least. That is, the container 15 is modified by a predetermined processing so that the bottom surface portion thereof is multi-hard. And in this container 15, the gravel which is a sand-like culture medium is accommodated by the quantity which ensured the predetermined depth as a support body which hold | maintains the reproduction | regeneration stock | stump | stock a1 in the substantially upright posture, and the reproduction | regeneration stock | stump is contained in this gravel. The root of a1 is buried. Therefore, the container 15 prevents the sand-like medium from flowing out from the bottom surface, and allows the root of the regenerated strain a1 to pass in the thickness direction of the bottom surface and extend outside the container 15. On the other hand, since the bottom surface of the container 15 is formed in a porous shape, the pile 16 formed in the shape of a short rod having a predetermined diameter can penetrate the bottom surface without damaging the bottom surface and thereby penetrate the bottom of the water. 15 can be fixed to the bottom of the water.

  The container 15 may be entirely formed of a single porous material and the entire surface thereof may be porous. In this configuration, the configuration is simple and the cost can be reduced. At the same time, it is not necessary to restrict the extending direction of the roots grown from the regenerated strain a1 to only the bottom surface, and the regenerated strain a1 is more easily grown.

  Therefore, when installing the regenerated strain a1, a predetermined number of containers 15 containing the regenerated strain a1 are arranged on the water bottom of the predetermined location P, and each container 15 is fixed and installed with a pile 16. Compared with the case where the root of the regenerated strain a1 is manually embedded in the bottom of the water, the work is greatly facilitated, and the opportunity for damage to the regenerated strain a1 can be reduced. Therefore, a large number of regenerated strains a1 can be installed quickly and accurately. As a result, the regenerated strain a1 can be transplanted so that the initial population size can be ensured easily and reliably and can be grown smoothly.

  In this way, the regenerated strain a1 accommodated in the container 15 and placed on the bottom of the water receives the transmitted light and grows toward the adult, and the root grows along with the growth, and the stretched root becomes porous. It passes through the bottom of the qualitative container 15 and enters the bottom mud at a predetermined location P, and the regenerated strain a1 is settled on the water bottom. That is, the regenerated strain a1 takes in nutrients from the bottom mud at a predetermined location P, and synthesizes it with transmitted light secured in a predetermined manner and grows. As a result, the submerged plant A grown from the regenerated strain a1 settles on the bottom of the water and grows naturally.

  Therefore, the submerged plant A grows steadily, recovery of the submerged plant community AA and improvement of water quality are started, and a positive feedback action is obtained in the same manner as in the first embodiment. You can proceed to. In particular, in this case, the submerged plant A is not mixed with such a floating leaf plant as compared with the first embodiment in which the floating leaf plant vegetated adjacent to the submerged plant A is used as the turbidity reducing means 1. Since it grows alone, it can be expected to grow more smoothly. As a result, as shown in FIG. 5C, the submerged plant community AA unique to the lake can be restored, and the submerged plant zone can be restored.

  As described above, according to the regeneration / restoration method of the second embodiment, the same effects as those of the first embodiment can be obtained, and the restoration of the submerged plant and the improvement of water quality are caused simultaneously. In addition to proceeding in parallel, it can be expected that the submerged plants unique to the water area will be restored as a community and that this community will expand and develop spontaneously.

  In particular, in the regeneration / restoration method of the second embodiment, there is a possibility that the extraction plant that is relatively easy to restore in a shallow lake in a cloudy state or the bottom layer becomes anaerobic by covering the water surface when it grows in large quantities. Since a submerged plant that has once disappeared is restored as an adult rather than a floating leaf plant, the restored submerged plant can suppress the rolling up of the bottom mud and improve the habitat of benthic organisms. That is, at least, the anaerobic bottom layer and insufficient solar radiation can be solved.

  Furthermore, with local operation in mind, a series of procedures to regenerate submerged plant communities, including examining the possibility of physical establishment in advance and conducting specific field verification tests to establish it, that is, Since it is included in the restoration plan, it is sufficiently practical and high realizability can be obtained.

  On the other hand, compared to conventional methods that aim to improve the lake environment including water quality by working directly and strongly on the ecosystem, such as biomanipulation that changes the ecosystem structure by removing fish of a certain nutrition level, This regeneration / restoration method can be said to be so-called environmental conservation through the use of soft ecosystems. At the same time, we aim to improve water quality by regenerating and restoring submerged plants inherent to endangered lakes. Therefore, it is not necessary to give an extra load to the ecosystem in the water area. In other words, water quality improves with the growth of submerged plants, so it is possible to make continuous and continuous changes to the water quality environment before pollution without suddenly changing or disrupting the ecosystem structure. it can.

  That is, not only can the positive feedback loop cycle described above be continued, but this cycle can be promoted to accelerate the change in the positive feedback direction. Also, if the restored submerged plant is a species suitable for improving water quality, that is, especially if the axle algae can be restored, the axle algae will grow well and grow because their fine branches cover the bottom mud. When it does, the effect which suppresses winding up of bottom mud sufficiently and reliably will be acquired.

  Therefore, it can be expected to improve water quality and contribute to the conservation of lake biodiversity. In this way, submerged plant communities as habitats of many species called aquatic organisms can be regenerated and self-contained and sustainably preserved, including aquatic organisms unique to the lake other than aquatic plants. Reproducible ecosystems. That is, since a habitat suitable for aquatic organisms unique to the lake can be prepared, it is possible to preferentially inhabit aquatic organisms unique to the lake rather than simply return of aquatic organisms. The unique aquatic organisms include organisms that temporarily use the waterfront area for predation and evacuation.

  Thus, if the aquatic plant community peculiar to the lake can be restored, it can be expected to contribute more to the regeneration of the ecosystem and social culture of the entire region including the water area of this lake.

  Next explained is the third embodiment of the invention. In addition, the same code | symbol is attached | subjected to the member of the same structure as above-mentioned 2nd Embodiment, and description is abbreviate | omitted or simplified. That is, the description will focus on the differences from the second embodiment, and the configuration not described in the third embodiment, the method such as the work procedure, and the actions obtained by these will be described in the second embodiment. It is the same as the embodiment.

  In this third embodiment, as shown in FIG. 6 (a), when the predetermined location selected for the above restoration is almost completely bare with the submerged plant group and the floating leaf plant group disappearing. The turbidity lowering means 21 comprising inanimate means that directly covers the bottom of the bare place P is provided to suppress the rolling up of the bottom mud. That is, in this third embodiment, a mat 22 made of a fiber made of biodegradable plastic as the turbidity lowering means 21 is driven into a predetermined place with a pile 23 to suppress the rolling up of the bottom mud.

  The mat 22 is made of a thin fiber using a biodegradable material such as a plant-derived biodegradable plastic, and this fiber is secured to a large number of gaps between the fibers in the same manner as steel wool. The planar members are tangled with each other and have a predetermined thickness. Therefore, the mat 22 is formed with a predetermined thickness with a predetermined gap between the fibers. Therefore, the mat 22 can be flexibly deformed and deformed according to the shape of the water bottom where the mat 22 is installed. And can reliably cover the bottom of the water. For this reason, it is not necessary to transmit the influence of underwater disturbance to the bottom of the water. On the other hand, at least the roots from the plant body located on the mat 22 can be penetrated in the thickness direction of the mat 22 to reach the bottom of the water with its growth. The mat 22 has a predetermined material selected, or a fiber diameter, a thickness, etc., are secured to predetermined dimensions. At least the mat 22 is installed in water and then the disassembly is completed naturally. The time required to do so is set to be longer than the time required for the regenerated strain a1 installed at the same time to grow into a plant that can suppress the phenomenon of rolling up the bottom mud.

  And as shown in FIG.6 (b), as for the said selected location P, the water bottom of this location P is covered with the mat 22, The predetermined location of this mat 22 is penetrated, respectively, and the pile 23 However, it has been driven to the bottom of the water. For this reason, the mat 22 is fixed by these piles 23 so as not to move from the installed water bottom and to cover the water bottom, regardless of underwater disturbance caused by wind waves.

  Therefore, most of the influence of underwater disturbance caused by wind waves is blocked or alleviated by the mat 22 and does not substantially reach the bottom of the water. For this reason, rolling up of the bottom mud from the water bottom covered with the mat 22 is suppressed. For this reason, the raise of the turbidity by winding up of the bottom mud in this water bottom is suppressed. As a result, the amount of transmitted light is secured at the bottom of the water so that the submerged plant can be grown.

  Then, in the water bottom where the amount of transmitted light is secured in this manner, the regenerated submerged plant a1 of the submerged plant is transplanted in a predetermined number of units almost simultaneously as in the second embodiment. As shown in (c), the regenerated strain a1 grows on the bottom of the water, the inherent submerged plant A is restored as a submerged plant community AA, and the water purification that has obtained the positive feedback action described above proceeds in parallel. .

  That is, the regenerated strain a1 accommodated in the container 15 and installed on the bottom of the water receives the transmitted light and grows toward the living body, and the root of the regenerated strain a1 comes into contact with the bottom of the container 15 and the bottom. It penetrates the mat 22 and enters the bottom mud of the bottom of the water, and settles on the bottom of the water as a submerged plant.

  On the other hand, the mat 22 is naturally biodegraded, but remains at least until the regenerated strain a1 is activated and grows, and is completely decomposed after becoming a submerged plant community that can suppress the raising of the bottom mud to some extent. Disappear. Therefore, the work of removing the mat 22 can be made unnecessary and labor saving can be achieved. In particular, it is possible to avoid the occurrence of human error such as forgetting to remove, and the management after installation can be simplified. In this way, it is not necessary to leave the man-made product after being naturally decomposed, which is preferable as a habitat environment for the regenerated and restored submerged plant community.

  As described above, according to the reproduction / restoration method of the third embodiment, in addition to obtaining the effects of the second embodiment, the mat is selected as the turbidity reducing means. It was installed so as to cover the bottom of the water, and the rolling up of the bottom mud from the bottom of the water was suppressed, so that the mat can be prevented from becoming an obstruction in the surface of the water and in the water. For this reason, it is not necessary to obstruct various activities and water traffic on the surface of the water like observation of transplanted submerged plants.

  Since the mat is installed so as to cover the bottom of the water in this way, it is difficult to receive water flow resistance, so that the mat can be installed at a place where a water flow of a certain speed exists. For example, the mat can be stably installed at a place where water flow always exists, other than underwater disturbance due to wind waves, such as in the vicinity of a lake inflow or outflow estuary. Therefore, the selection range of the installation location in the water area is expanded. For this reason, the application range of this reproduction / restoration method can be expanded.

  On the other hand, using a biodegradable material, a mat with a predetermined time required for natural decomposition is used, so at least mat removal work after restoring submerged plant communities is unnecessary, and labor saving can be achieved. Costs for community restoration can be reduced. In addition, the mat as an artifact can be completely eliminated without leaving a part of the mat, so that it does not affect the ecosystem.

  In order to regenerate a submerged submerged plant community or to restore a lost submerged plant community, any one of the turbidity lowering means described in the first to third embodiments described above is used. You may select suitably or may be used in combination as appropriate. That is, the turbidity lowering means of each embodiment described above are not mutually exclusive, so depending on the actual local situation, several turbidity lowering means may be combined as appropriate to further reduce the turbidity. You may enhance the effect. In addition, for example, when a small-sized floating plant community grows densely at a predetermined location, that is, when a floating plant community occupies a part of the planned area for regenerating and recovering a submerged plant community. In order to distribute this floating leaf plant community without removing it and use it as a turbidity lowering means that takes charge of a part of the planned area, The turbidity lowering means of the third embodiment may be provided. A shallow lake is not only a lake with a shallow water depth but also a shallow water area with an area that affects water pollution. Including lakes.

  Furthermore, in each of the above-described embodiments, an example in which the present invention is applied to a shallow lake in an inland area has been described. However, the present invention is not limited to this. It includes sea areas such as the inner part of the sea, and in accordance with these, the decline or disappearance of each area is the target of regeneration or recovery.

1st Embodiment as an example to which the regeneration / restoration method of this invention is applied is shown, (a) is a schematic diagram showing a state in which a floating leaf plant is prospering at a predetermined location, and (b) is prospering. Schematic showing a state in which the floating plant is distributed as a turbidity lowering means, (c) is a schematic diagram showing a state where a submerged plant has settled and has grown naturally, and (d) is a regenerated submerged plant community. It is the schematic which shows a state. It is the schematic which shows 2nd Embodiment as an example of application of the reproduction | regeneration / restoration | reconstruction method of this invention, and shows column-shaped sample collection of bottom mud in several places. It is the schematic which shows this 2nd Embodiment and shows the collection of analytical data and the germination test of the collected columnar sample. It is the schematic which shows 2nd Embodiment and shows the outline | summary which selects the collection point of a buried seed. It is the schematic which showed 2nd Embodiment and showed the outline | summary of the mass culture of the reproduction | regeneration strain | stump | stock. It is the schematic which shows 2nd Embodiment and shows the experimental area set to the local lake. It is a schematic sectional drawing which shows 2nd Embodiment and shows the container which accommodated the reproduction | regeneration stock | strain. It is a schematic sectional drawing which shows the state which showed 2nd Embodiment and fixedly installed the container which accommodated the reproduction | regeneration stock | stump in the water bottom. This 2nd Embodiment is shown, (a) is the schematic which shows the state where the predetermined location is bare, (b) is the schematic which shows the state which installed the turbidity reduction means, (c) is It is the schematic which shows the state which the submerged plant community restored | restored. 3rd Embodiment is shown as an example of application of the reproduction | regeneration / restoration method of this invention, (a) is the schematic which shows the state where the predetermined location is bare, and (b) installs a turbidity reduction means The schematic which shows the state which carried out, (c) is the schematic which shows the state which the submerged plant community restored | restored.

Explanation of symbols

1,11,21 Turbidity reduction means 5 Re-entry prevention means 6 Sheet (separation member) 7 Floating body 12 Sheet (sheet-like member) 13 Floating body frame 13a Floating body 15 Container 16 Pile (for container fixation) 22 Mat 23 Pile (mat fixation) for)
A Submerged plant a1 Regenerated strain AA Submerged plant community B Floating leaf plant P Regeneration / restoration site of submerged plant community Sa1, Sa2 Undisturbed columnar sample of lake bottom mud St1, St2 Sample of columnar sample of bottom mud

Claims (10)

Due to pollutants flowing in from the outside, water pollution progresses in the water area, at least the submerged plant communities inherent in the water area decline or disappear, and even if the inflow of the pollutant decreases, the pollution state is not resolved In a shallow lake,
Reduce the water turbidity by suppressing winding mud caused by wind waves of the waters, waters forming the turbidity reduction means to reach a transmitted light sea bed of the body of water, the submerged plant communities is declined or disappeared To regenerate or restore the unique submerged plant community,
Shallows characterized in that the submerged plant communities regenerated or restored cover the bottom of the water, thereby enhancing the suppression effect of rolling up the bottom mud, further promoting the regeneration or restoration of submerged plant communities, and improving the water quality of the water area. How to regenerate and restore submerged plants in lakes.   The method for regenerating / restoring a submerged plant in a shallow lake according to claim 1, wherein the turbidity reducing means is formed by predetermined distribution of floating leaf plants.   The method for regenerating / restoring a submerged plant in a shallow lake body according to claim 1, wherein the turbidity reducing means is formed by covering the water bottom with a mat.   The method for regenerating / restoring a submerged plant in a shallow lake according to claim 1, wherein the turbidity lowering unit is formed by surrounding the bottom of the water with a floating frame in which a sheet-like member is suspended. The submergence in a shallow lake according to any one of claims 1 to 4, wherein an isolation member for preventing an existing floating leaf plant from entering is provided at a location where the submerged plant community is regenerated or restored. Plant regeneration and restoration methods. Because of pollutants flowing in from the outside, water pollution in the water area will progress, at least the submerged plant communities inherent to the water area will disappear, and even if the inflow of the pollutant substance decreases, the shallow lake where the pollution state will not be resolved In
The buried seeds of the submerged plant that formed the disappeared submerged plant community were collected from within the water area, and the collected buried seeds restored the submerged plant community inherent to the water area,
The restored submerged plant community covers the bottom of the water to suppress the rolling up of the bottom mud, and the transmitted light reaches the bottom of the water area to further promote the restoration of the submerged plant community , improving the water quality of the water area. A method for regenerating and restoring submerged plants in shallow lakes. Germinating the collected buried seeds, cultivating a large amount of the regenerated strain that has been grown to a predetermined extent,
Select a location suitable for the growth of this regenerated strain from the water area,
Provide turbidity lowering means to allow the transmitted light to reach the water bottom of the selected location,
The method for regenerating / restoring a submerged plant in a shallow lake according to claim 6, wherein a predetermined number of regenerated strains are transplanted and fixed on the bottom of the water where the transmitted light is secured to grow as a submerged plant community. 8. The shallow lake according to claim 7 , wherein the regenerated strain is housed in a predetermined container and installed at the bottom of the water, and the container is formed with a porous bottom at least. How to regenerate and restore submerged plants. Create a flow model that quantitatively evaluates the bottom mud disturbance and flow velocity distribution on the bottom of the water based on the topography, hydrology, and weather conditions of the water area, and uses the flow model to select the landfill seed collection point A method for regenerating and restoring a submerged plant in a shallow lake according to any one of claims 6 to 8 . Create a flow model that quantitatively evaluates bottom mud disturbance and flow velocity distribution at the bottom of the water based on the topography, hydrology, and weather conditions of the water area, and uses the flow model to select locations that are suitable for the growth of the regenerated strain The method for regenerating and restoring a submerged plant in a shallow lake according to claim 7 or 8 .