Floating plant habitat and method for its production

Abstract

The invention relates to a floating plant habitat (1) for deployment on a body of water, comprising at least one temporary float (3) and a plant composition comprising helophytes (2), which is received by the at least one temporary float (3), wherein the at least one temporary float (3) is formed from a polymer foam material that decomposes over time and contains an organic-plant-based aggregate with a mass fraction of 5% to 30%.

Description

[0001] Floating plant habitat and methods for its production

[0002] The invention relates to a floating plant habitat, which takes the form of a floating island. The invention further relates to a method for producing such a floating plant habitat.

[0003] Floating islands are natural or artificial platforms that drift on the water's surface and are not connected to the bottom. They are typically mats of vegetation that form naturally. Natural floating islands often consist of densely intertwined roots and rhizomes of plants that hold organic material together. Buoyancy is generated both by hollow plant parts and by anaerobic decomposition processes, in which gas produced by bacteria or fungi is trapped within the plant network. Larger fragments of shoreline can also become buoyant, with the vegetation of bushes or trees remaining on them.

[0004] It has been shown that floating islands offer numerous advantages for various aquatic environments. Firstly, floating islands with diverse plant life can contribute to water purification in artificial ponds or rainwater retention basins. Secondly, floating islands can be used to design waterways. In urban areas, plant and animal habitats can be created both above and below the water's surface, contributing to climate improvement and remaining largely unaffected by water level fluctuations. Furthermore, floating islands can be deployed mobilized, allowing them to be transported to desired locations. For example, floating plant habitats can serve as pioneers in the renaturalization of developed riparian zones.

[0005] The formation and growth of natural floating islands depend on various factors. Essentially, the formation of natural floating islands is influenced by the type of plant and its growth rate. For example, certain reed species can grow and reproduce relatively quickly. Once these plants are dense enough to form a cohesive mass, they can float on the water without any buoyancy aid. Another aspect is the accumulation of organic material. Over time, layers of dead plants, soil, and other organic materials form, held together by the growing plants. These layers become thicker and more stable over several growing seasons. Climatic conditions influence plant growth and the decomposition of organic materials.Warm and humid conditions promote rapid plant growth and the formation of floating islands. Overall, the process of forming stable, naturally floating islands is gradual and can take several decades. In particular, the natural formation of the buoyancy layer is a complex process that is time-consuming and requires stable environmental conditions. For commercial use of the benefits of natural floating islands, this natural formation process is too lengthy.

[0006] Therefore, efforts are underway to find ways to create artificial floating islands as plant habitats in a defined form and within a shorter timeframe than the natural process. A major challenge in providing artificial floating islands lies in accelerating the natural processes required to develop lasting buoyancy, in order to produce defined artificial floating islands quickly. The production of buoyancy bodies from natural materials, such as bundled reeds, is already known. An example of a floating reed gabion can be found in DE 10 2015 107 782. These buoyancy bodies are planted with pioneer plants such as reed species or sedges, which are first pre-cultivated on a natural fiber mat for one or more growing seasons.Pre-cultivation creates a plant mat growing from the tissue and living roots and rhizomes of the plants. Following the model of hydroponic systems, this plant mat is applied to the structure forming the floating body, and this assembly is then placed in the water. However, it has been shown that the biological degradation of reed floating bodies occurs too rapidly to simultaneously produce sufficient living plant material for self-sustaining buoyancy. The conditions for the formation of a natural buoyancy body, in which the storage of gases from anaerobic decomposition processes plays a role, could therefore not be met. The excessively rapid biological degradation of the substructure supporting the plants ultimately leads to the premature sinking of the island.

[0007] It is therefore an object of the invention to provide defined floating plant habitats that enable self-sustaining buoyancy. The environmental impact of the components used should be as low as possible. Furthermore, it is an object of the invention to provide a method for producing artificial floating plant habitats.

[0008] The problem is solved by a floating plant habitat with the features according to claim 1 and a method for producing an artificial plant habitat with the features according to claim 14. Advantageous further developments or embodiments are specified in the dependent claims. The invention is based on the idea of ​​providing a floating plant habitat in the form of an artificial island which, due to metabolic processes of plants and bacteria, develops self-sustaining buoyancy in the long term.

[0009] A floating plant habitat for deployment on a water surface is proposed. According to the invention, the floating plant habitat comprises at least one temporary floating body and a plant composition containing helophytes, which is absorbed by the at least one temporary floating body, wherein the at least one temporary floating body is formed from a time-decomposing polymer foam material containing an organic plant additive with a mass fraction of 5% to 30%.

[0010] The buoyancy of the temporary float is achieved by the polymer foam material having a lower density than water. Preferably, the density of the polymer foam material is <0.75 g / cm³. 3 The density is <1000 kg / m³ 3 and is preferably in the range of 100 kg / m³ 3The temporary float has a top side and a water side facing away from the top side, which is at least partially submerged when the temporary float is floating in the water.

[0011] Preferably, the polymer foam material has corresponding open pores and closed pores, wherein the proportion of closed pores is at least 20%.

[0012] The corresponding pores allow water to penetrate and roots to grow through the polymer foam material. According to a preferred embodiment of the temporary float, the pore size of the polymer foam material is at least 150 pm and at most 1000 pm.

[0013] The temporary float, which serves as the initial support for the plant material, is designed to exist only temporarily due to self-degradation. The degradation rate is selected based on the composition of the polymer foam material to allow sufficient time for the plants to develop self-sustaining buoyancy. The composition of the polymer foam material, which influences the degradation rate of the temporary float, takes environmental conditions, particularly climatic conditions at the application site, into account. According to one embodiment, the polymer foam material can comprise a polyurethane foam (PU foam) formed from a polyester polyol and lysine diisocyanate as the isocyanate component, wherein the polyester polyol is based on polylactic acid with an OH number of 65.Furthermore, the polymer foam material can be configured as a polyurethane foam (PU foam) based on a polyester polyol and lysine diisocyanate as the isocyanate component, wherein the polyester polyol is based on adipic acid and bio-based butanediol with an OH number of 56. In another alternative embodiment, the polymer foam material can be configured as a polyurethane foam (PU foam) based on a polyester polyol and lysine diisocyanate as the isocyanate component, wherein the polyester polyol is based on succinic acid and bio-based butanediol with an OH number of 56.

[0014] Furthermore, it may be provided that the temporary float consists of polyurethane foam with an embedded organic-plant additive.

[0015] Regarding the other components of the polymer foam material, it is important to ensure that the degradation products are environmentally compatible. Suitable stabilizers include, for example, polyether-modified polysiloxane (Tegostab_B8409), a silicone-free stabilizer in the form of polyethylene glycol-modified sucrose, or a silicone-free stabilizer in the form of PEG-modified rapeseed acid. Catalysts that can be used include TIBKAT 218, dibutyltin dilaurate from TIB Chemicals, 70% bis(2-dimethylaminoethyl) ether in 30% dipropylene glycol, TIBKAT K25, potassium neodecanoate from TIB Chemicals, Lupragen® N201, an amine catalyst from BASF SE, or Niax A-1, an amine catalyst from Momentive.

[0016] Furthermore, the polymer foam material may be composed of polyurethane foams with different compositions. The composition of the foam material and the proportion of the organic plant-based additive can be varied to achieve a desired degradation rate. Different polyurethane foams can be combined in a layered structure.

[0017] Ground miscanthus, miscanthus fibers, wood fibers, lignin, chitosan, peat, and / or straw can be used as organic plant-based additives. Preferably, the organic plant-based additive is added during the polymer foam synthesis to ensure its embedding within the polymer foam.

[0018] According to one embodiment, the polymer foam material may contain a polyurethane foam (PU foam) based on biopolyols, a polylactic acid foam (PLA foam), and / or a polyhydroxybutyrate foam (PHB foam). The polymer foam material may be formed as a layered material made of the aforementioned polymer foams.

[0019] The degradation period of the temporary floating body is influenced by the polymer foam material and its proportion of organic-plant additive. A higher proportion of organic-plant additive contributes to an increased degradation rate of the polymer foam material, so that the degradation rate of the temporary floating body for a climate region with essentially constant vegetation cycles can be adjusted not only by the polymer foam used, but also by the proportion of organic-plant additive. The composition of the polymer foam material is preferably defined such that the degradation rate is preferably lower than the growth rate of the plants in the composition.In this way, it is ensured that sufficient buoyancy-generating phytomass or aerenchyma tissue of the helophytes is formed within the decomposition or breakdown period of the polymer foam material in order to guarantee self-sustaining buoyancy and the associated buoyancy of the plant habitat even after the complete breakdown of the temporary floating body.

[0020] The use of organic plant material as an additive offers several advantages. Firstly, it provides a breeding ground for microorganisms, thereby influencing the biodegradation process to achieve a predictable degradation rate of the temporary float. Secondly, plant fibers, in particular, contribute to improved stability of the temporary float when used as an organic additive.

[0021] The plant composition may include at least one plant species selected from a group containing Phragmites australis, Carex laciocarpa, Menyanthes trifoliata, Typha latifolia, and Typha angustifolia. The specified plants are intended for use in the floating plant habitat in temperate Central European climates. However, the plant composition can generally be adapted to different climate-region-specific requirements, so it may consist of different plants. For use in tropical regions of Asia, the plant composition may primarily consist of vetiver grass (Vetiveria zizanioides). In North America, maidencane (Panicum hemitomon) may be the preferred component of the plant composition.

[0022] The polymer foam material forming the temporary float can have various geometric shapes. According to a preferred embodiment, the temporary float is plate-shaped, with a rectangular shape being particularly easy to achieve.

[0023] According to one embodiment, the temporary float can have several depressions on its upper surface into which plants of the plant composition are placed. Some of these depressions may be designed as openings. These openings, open to the water side, also serve to hold plants of the plant composition. Roots of plants placed in the openings can spread along the underside of the temporary float without resistance. This is advantageous because the spread of plant roots along the underside of the temporary float promotes the formation of a root network outside the float, thereby creating conditions for self-sustaining buoyancy. According to an advantageous embodiment, the openings may taper in a funnel shape or in steps towards the water side of the temporary float.

[0024] The temporary floating body can be bordered on the top by a rim that extends above the water surface. This is particularly advantageous during the propagation phase, as the rim retains plant material and sediment, thus preventing it from being washed away.

[0025] According to a further embodiment of the invention, several temporary floating bodies can be connected to one another to form a closed surface and placed on a water surface. Advantageously, the area of ​​the floating plant habitat can be varied by the number of temporary floating bodies.

[0026] The invention further relates to a method for producing a floating plant habitat. In this method, a temporary floating body is first provided, consisting of a time-decomposing polymer foam material with an organic-plant additive. The synthesis of a preferably used polyurethane polymer foam material is based on a one-shot process. First, the non-reactive components are introduced. These can be added directly to the foam formulation in powder form or dispersed or dissolved in the biopolyols. Depending on their properties, the individual components are weighed into a reaction vessel and mixed using a stirrer. Finally, isocyanate is added to the reaction solution, after which the rising process begins immediately. Subsequently, the resulting polymer foam is dried and packaged.

[0027] An alternative method for producing polymer foam material is the prepolymer process. In this process, a portion of the starting materials is first converted into oligomeric compounds. Unlike the final product, these oligomeric compounds may still be soluble or meltable. Only with further crosslinking do the prepolymers become a thermosetting final product. One advantage of this method is the greater structural diversity of the final products.

[0028] The polymer foam for the polymer foam matenal can thus be produced in a one-shot process or using a prepolymer process. According to the invention, the polymer foam matenal consists of at least one polymer foam and at least one organic plant additive embedded therein.

[0029] An example of the production of a polyurethane polymer foam material is given below. A polyester-based biopolyol is used as the polyol component, and lysine diisocyanate is used as the isocyanate component. Ground material from giant miscanthus (Miscanthus x giganteus), with a particle size of 63 pm to 200 pm, is used as an organic plant-based additive. The following relative amounts are used in relation to the amount of polyol:

[0030] 43% Lysine diisocyanate

[0031] 2% polyethylene glycol, 3% water

[0032] 4% stabilizer (polyether-modified polysiloxane)

[0033] 0.25% crosslinking catalyst (70% bis(2-dimethylaminoethyl) ether in 30% dipropylene glycol)

[0034] 3% blowing catalyst (dibutyltin dilaurate)

[0035] 30% additive

[0036] The mixture is thoroughly stirred using a stirrer. A physical blowing agent in the form of water is then added, followed by another stir. Finally, the lysine diisocyanate is pipetted into the reaction solution and stirred again. Immediately after stirring ceases, the foaming process begins. Once the foaming process is complete, the resulting polymer foam is dried and processed further.

[0037] Various polyurethane foam (PU foam) variants can be produced as polymer foam materials. One option is to produce a PU foam based on a polyester polyol and a lysine diisocyanate as the isocyanate component, using polylactic acid with an OH number of 65 as the polyester polyol. Another option is to produce a PU foam based on a polyester polyol and a lysine diisocyanate as the isocyanate component, using adipic acid and bio-based butanediol with an OH number of 56 as the polyester polyols. In a further alternative embodiment, a PU foam based on a polyester polyol and a lysine diisocyanate as the isocyanate component can be produced, using succinic acid and bio-based butanediol with an OH number of 56 as the polyester polyols.

[0038] Suitable stabilizers include, for example, polyether-modified polysiloxane (Tegostab_B8409), a silicone-free stabilizer in the form of polyethylene glycol-modified sucrose, or a silicone-free stabilizer in the form of PEG-modified rapeseed acid. Suitable catalysts include TIBKAT 218, dibutyltin dilaurate from TIB Chemicals, 70% bis(2-dimethylaminoethyl) ether in 30% dipropylene glycol; TIBKAT K25, potassium neodecanoate from TIB Chemicals; Lupragen® N201, an amine catalyst from BASF SE; or Niax A-1, an amine catalyst from Momentive.

[0039] The following table shows combinations of suitable polyols, stabilizers and catalysts for the production of a time-degradable and environmentally friendly PU foam as a polymer foam material.

[0040] Polyol Stabilise Catalyst Hydrolysis Degradability Environmental compatibility or stability of degradation products 1, 2 or 3 1 1 and 2 Medium Medium Medium 1, 2 or 3 1 1 and 3 Medium Medium Medium 1, 2 or 3 1 3 and 4 Medium Medium High

[0041] 1, 2 or 3 1 3 and 5 Medium Medium High

[0042] 1, 2 or 3 2 or 3 1 and 2 Medium High Medium 1, 2 or 3 2 or 3 1 and 3 Medium High Medium 1, 2 or 3 2 or 3 3 and 4 Medium High High

[0043]

[0044] 1, 2 or 3 2 or 3 3 and 5 Medium High High

[0045] where the combinations are polyols:

[0046] 1. Polyester polyol based on polylactic acid with an OH number of 65,

[0047] 2. Polyester polyol made from adipic acid and bio-based butanediol with a

[0048] OH number of 56,

[0049] 3. Polyester polyol made from succinic acid and bio-based butanediol with an OH number of 56,

[0050] as a stabilizer:

[0051] 1. Tegostab_B8409 (polyether modified polysiloxane),

[0052] 2. Silicone-free stabilizer (polyethylene glycol-modified sucrose),

[0053] 3. Silicone-free stabilizer (PEG-modified rapeseed acid) and

[0054] as a catalyst:

[0055] 1. TIBKAT 218, dibutyltin dilaurate from TIB Chemicals,

[0056] 2. 70% bis(2-dimethylaminoethyl) ether in 30% dipropylene glycol, 3. TIBKAT K25, potassium neodecanoate, from TIB Chemicals,

[0057] 4. Lupragen® N201, amine catalyst from BASF SE and

[0058] 5. Niax A-1, amine catalyst from Momentive,

[0059] They can be used.

[0060] According to the procedure, a plant composition containing helophytes specific to the climate region is pre-cultivated on an organic substrate or on the temporary floating platform for a period of one growing season. The pre-cultivation step can therefore be carried out separately on an organic substrate, for example a fiber mat, or directly on the temporary floating platform.

[0061] After pre-cultivation, the floating body with the pre-cultivated plant composition is cultivated in a propagation tank for a period of one to three further vegetation periods and finally placed on a water surface.

[0062] The pre-cultivation and subsequent cultivation of the plant composition are carried out under the climatic conditions of the specific climate region of the climate-region-specific helophytes. If cultivating the plant composition in the natural environment of the specific climate region is not possible, the cultivation steps can also be carried out in a greenhouse. Greenhouse cultivation has the advantage of constant climatic conditions, which allows the floating plant habitats to be produced with consistent quality within a predictable timeframe.

[0063] According to one variant of the process, the plants of the plant composition are pre-cultivated on a fiber mat.

[0064] Furthermore, it can be provided that the plants in the plant arrangement are pre-cultivated in separate containers.

[0065] Alternatively or additionally, plants from the planting arrangement can be pre-cultivated in depressions of the temporary floating body.

[0066] For the plant composition, at least one plant species selected from a group of plant species containing Phragmites australis, Carex laciocarpa, Menyanthes trifoliata, Typha latifolia, Typha angustifolia, can be cultivated.

[0067] As an organic plant-based additive, at least one substance selected from a group containing ground miscanthus, miscanthus fibers, wood fibers, lignin, chitosan, peat, and straw can be incorporated during the production of the polymer foam. Preferably, the organic plant-based additive is added to the polymer foam during synthesis in the form of a powder or short fibers.

[0068] The temporary floats can be geometrically dimensioned to allow for handling by a single person. For example, plate-shaped designs with an edge length or diameter not exceeding 1 m are practical. The thickness can be, for instance, 10 cm. The polymer foam can be produced in block form using a foaming machine, with individual plates then cut from this continuous block.

[0069] According to a preferred embodiment, the temporary floating body is square with an edge length of 66 cm and a thickness of 8 cm. Advantageously, several such temporary floating bodies can be joined together to form a continuous surface after cultivation in the water. In this way, the size of the floating plant habitat can be adapted to different requirements.

[0070] The floating plant habitat is produced in a climate-region-specific manner. For the purposes of the invention, a climate region is understood as a geographical area characterized by a specific climate. Climate regions are larger areas with a largely uniform macroclimate. The boundaries between climate regions are defined by temperature and precipitation thresholds. Therefore, the term "climate-region-specific" refers to features, measures, or adaptations that, with regard to the design of the biodegradable temporary floating structure and the selection of the plant composition supporting it, are specifically tailored to the climatic conditions of a particular climate region. This includes designing the floating plant habitat in such a way that it is adapted to the climatic conditions of the region, such as temperature, precipitation, and wind, taking into account the seasons and their changes.The floating plant habitat is thus tailored, in terms of its geometry, the composition of the polymer foam material, and the plant composition, to the specific conditions or characteristics of a particular climate region. For this reason, the floating plant habitat supports climate-region-specific helophytes.

[0071] According to another design variant, several depressions are formed on the top of the temporary floating body to accommodate plants.

[0072] Furthermore, it can be provided that several openings, open to the water side, are formed on the upper surface of the buoyancy body to accommodate plants. For planting, plants from the selected planting scheme are inserted into the openings so that the roots can come into contact with water at the water-side openings.

[0073] Furthermore, it is possible to subsequently introduce additional depressions or openings, which do not have an opening to the water side, into the temporary floating body.

[0074] From the perspective of minimizing environmental impact, the temporary floating structure is designed to decompose completely under normal conditions within three to five years. Accordingly, the selection and cultivation of the plant composition will be designed to ensure that sufficient phytomass, or aerenchyma tissue, of the helophytes is formed during the decomposition period to guarantee the self-sustaining buoyancy of the plant habitat in the water.

[0075] Further details, features, and advantages of embodiments of the invention will become apparent from the following description of exemplary embodiments with reference to the accompanying drawings. These show:

[0076] Fig. 1: a schematic representation of an embodiment of a floating plant habitat to further explain the method for producing the floating plant habitat, Fig. 2: a schematic representation of another embodiment of a floating plant habitat to further explain the method for producing the floating plant habitat, and Fig. 3: a schematic representation of an embodiment of a buoyancy body for the floating plant habitat.

[0077] Figure 1 shows a schematic representation of an embodiment of a floating plant habitat 1 to further illustrate the method for producing the floating plant habitat 1. The method for producing the floating plant habitat 1 essentially concerns two aspects: the provision of the polymer foam material for the temporary floating body 3 and the provision of the plant composition, which consists essentially of helophytes 2. According to one embodiment, the cultivation of the helophytes 2 takes place in two steps: first as a pre-culture in an organic substrate and then in a second cultivation on the temporary floating body 3. The provision of the temporary floating body 3 can be independent of the provision of the plant composition. The temporary floating body 3 is made of a biodegradable porous polymer foam material.The polymer foam matenal, for example, is a polyurethane foam produced using a one-shot process. A polyol component, such as polyester polyol based on polylactic acid with an OH number of 65, is used in the production of the polyurethane foam. Lysine diisocyanate forms the isocyanate component. To define the properties of the polyurethane foam, further components are added during foam synthesis. These components include polyethylene glycol as a chain extender, deionized water, polyether-modified polysiloxane as a stabilizer, 70% bis(2-dimethylaminoethyl) ether in 30% dipropylene glycol as a crosslinking catalyst, and dibutyltin dilaurate as a blowing catalyst. Furthermore, an organic-plant-based additive is embedded in the polymer foam to support the biodegradability of the temporary float 3.In this example, ground material from giant miscanthus (Miscanthus x giganteus) is incorporated as an organic plant additive. This ground material preferably contains only particles with a particle size in the range of 63 pm to 200 pm. Based on the amount of polyol used, the following relative amounts of the components can be employed: 43% isocyanate, 2% polyethylene glycol, 3% deionized water, 4% polyether-modified polysiloxane as a stabilizer, 0.25% of 70% bis(2-dimethylaminoethyl) ether in 30% dipropylene glycol as a crosslinking catalyst, 3% propellant catalyst, and 30% ground material from giant miscanthus (Miscanthus x giganteus).

[0078] For the synthesis of polyurethane foam, the non-reactive components are first added. These include polyester-based polyols, polyethylene glycol, a blowing and crosslinking catalyst, a stabilizer, deionized water, and the organic-plant additive. The individual components are transferred to a reaction vessel. The resulting mixture is stirred. Dichloromethane is then added, followed by another stir. Finally, lysine diisocyanate is pipetted into the reaction solution and stirred again. Immediately after stirring is complete, the foaming process begins. After the foaming process, it is dried and processed further. The resulting polymer foam material has a proportion of corresponding open pores and a proportion of closed pores, with the proportion of closed pores being at least 20%.

[0079] The formed polymer foam material is cut into a sheet shape, resulting in a plate-shaped temporary float 3 measuring 1000 mm by 1000 mm and 80 mm thick. In the example shown, forty-two funnel-shaped openings 5 ​​are made in a top surface 3.1 of the temporary float 3 using a suitable tool, such as a drill. These openings 5 ​​extend from the top surface 3.1 to a water side 3.2. On the water side 3.2, the openings 5 ​​have a diameter ranging from 20 mm to 30 mm. The shape of the openings 5 ​​corresponds to the internal shape of vessels 4, which are shown enlarged in the illustration above for better visualization.

[0080] For pre-cultivation, in the example shown in Figure 1, helophytes 2 of the species Phragmites australis are cultivated as a plant group in several separate containers 4 in an organic substrate. Pre-cultivation takes place under optimal, climate-region-specific conditions over a period of one growing season in the containers 4. To ensure the best possible growing conditions, pre-cultivation can be carried out in a greenhouse.

[0081] After pre-cultivation, the helophytes 2 are removed from the containers 4 and the plant clumps of the helophytes 2 are planted into the funnel-shaped openings 5 ​​of the plate-shaped temporary floating body 3, as indicated by the arrow. The plants have a total fresh weight of approximately 65 g. In Figure 1, the front part of the temporary floating body 3 is shown transparently, allowing a view of a second row of six helophytes 2 inserted into the openings 5.

[0082] The planted temporary floating structure 3 is cultivated in a propagation tank for one to three growing seasons, during which the polymer foam matal is permeated by the roots and rhizomes of the helophytes 2. During this period, the decomposition of the water-floating temporary floating structure 3 begins. After further cultivation, the fully permeated temporary floating structure 3 is released into an environmental body of water as a floating plant habitat 1.

[0083] The degradation of the temporary floating body 3 occurs under ambient conditions in stagnant or slow-flowing freshwater within 2 to 3 years, corresponding to a monthly degradation rate of 3 to 4%. During the degradation process, the number of closed pores in the polymer foam material decreases continuously.

[0084] Over the following years, the plants develop an underground biomass averaging 150g to 200g of fresh mass, depending on location and nutrient availability. The root system density increases due to the growing proportion of fine roots in the plant species Phragmites australis considered in this example, but remains less than 1, allowing the plants to float on the water despite the aboveground biomass. Submersion of the planted temporary floating body 3 into the water is to be expected, but this does not negatively affect its buoyancy. Helophytes are characterized by the fact that they form the vast majority of their total biomass, both aboveground and belowground, underground, that is, below the water's surface. This characteristic is crucial for their self-sustaining buoyancy.In accordance with the invention, helophytes are therefore preferably used for the plant composition in which the ratio of aboveground to belowground biomass is less than 1, preferably less than 0.33.

[0085] Figure 2 shows a schematic representation of another embodiment of a floating plant habitat 1 to further explain the method for producing the floating plant habitat 1. In contrast to the previous example in Figure 1, the pre-cultivation of helophytes 2 on a fiber mat 6 is used for a period of one growing season. The temporary floating body 3 is provided as in the previous example, except that no perforations are formed. After the initial cultivation, the fiber mat 6 with the helophyte growth is transferred to the upper surface 3.1 of the temporary floating body 3. The planted temporary floating body 3 is placed in a cultivation basin so that water can reach the roots of the helophytes 2 located on the upper surface 3.1 through the pores of the temporary floating body 3.The temporary floating body 3 remains in the propagation tank for three growing seasons, during which time decomposition of the temporary floating body 3 begins and the roots of the helophytes 2 grow through it. The helophytes 2 then form a buoyancy-providing root system, which gradually replaces the temporary floating body 3 in terms of its buoyancy properties. Finally, the resulting floating plant habitat 1 is released into a natural body of water.

[0086] Figure 3 shows a schematic representation of an embodiment of a plate-shaped temporary float 3 for the floating plant habitat. The side length is 660 mm and the thickness is 60 mm. Sixteen perforations 5 are formed on the upper surface 3.1, each with an opening on the water side. The diameter of the perforations 5 on the upper surface 3.1 is 40 mm. The distance between each perforation 5 and the edge of the temporary float 3 is 100 mm. [Reference numeral list]

[0087] 1 floating plant habitat 2 helophytes

[0088] 3 temporary floats 3.1 Top side

[0089] 3.2 Waterside

[0090] 4 containers

[0091] 5 breakthroughs

[0092] 6 fiber mat

Claims

Patent claims 1. Floating plant habitat (1) for application to a water surface, comprising at least one temporary floating body (3) and a plant composition comprising helophytes (2) which is absorbed by the at least one temporary floating body (3), wherein the at least one temporary floating body (3) is formed from a time-decomposing polymer foam material which contains an organic plant additive with a mass fraction of 5% to 30%.

2. Floating plant habitat (1) according to claim 1, characterized in that the polymer foam material has corresponding open pores and closed pores, wherein the proportion of closed pores is at least 20%.

3. Floating plant habitat (1 ) according to one of claims 1 or 2, characterized in that the pore size of the pores of the polymer foam material is at least 150 pm and at most 1000 pm.

4. Floating plant habitat (1) according to one of claims 1 to 3, characterized in that the polymer foam material comprises a polyurethane foam (PU foam) which is formed on the basis of a polyester polyol and a lysine diisocyanate as an isocyanate component, wherein the polyester polyol is based on polylactic acid with an OH number of 65, adipic acid and bio-based butanediol with an OH number of 56, or based on succinic acid and bio-based butanediol with an OH number of 56.

5. Floating plant habitat (1) according to one of claims 1 to 4, characterized in that the polymer foam material contains a polyurethane foam (PU foam) based on biopolyols, a polylactide foam (PLA foam) and / or a polyhydroxybutyrate foam (PHB foam).

6. Floating plant habitat (1) according to one of claims 1 to 5, characterized in that the organic plant additive is ground miscanthus, miscanthus fibers, wood fibers, lignin, chitosan, peat and / or straw.

7. Floating plant habitat (1) according to one of claims 1 to 6, characterized in that the plant composition includes at least one plant species selected from a group of plant species containing Phragmites australis, Carex laciocarpa, Menyanthes trifoliata, Typha latifolia, Typha angustifolia.

8. Floating plant habitat (1) according to one of claims 1 to 7, characterized in that the temporary floating body (3) is plate-shaped.

9. Floating plant habitat (1) according to one of claims 1 to 8, characterized in that the temporary floating body (3) has several depressions on an upper surface (3.1) into which plants of the plant composition are received.

10. Floating plant habitat (1) according to one of claims 1 to 9, characterized in that the temporary floating body (3) has several openings (5) open to a water side (3.2) for receiving plants of the plant composition.

11. Floating plant habitat (1) according to claim 10, characterized in that the openings (5) taper in a funnel shape or in steps towards the water side (3.2).

12. Floating plant habitat (1) according to one of claims 1 to 11, characterized in that the temporary floating body (3) is bounded on the upper side (3.1) by a circumferential edge projecting above a water surface.

13. Floating plant habitat (1) according to one of claims 1 to 12, characterized in that several temporary floating bodies (3) are connected to each other to form a closed surface and are applied to a water surface.

14. Method for producing a floating plant habitat (1) in which a temporary floating body (3) made of a time-decomposing polymer foam material with an organic-plant additive is provided, a plant composition comprising climate-region-specific helophytes (2) is pre-cultivated on an organic substrate or on the temporary floating body (3) for a period of one growing season, subsequently the temporary floating body (3) with the pre-cultivated plant composition is cultivated in a propagation basin for a period of one to three further growing seasons and finally is deployed on a water surface.

15. Method according to claim 14, characterized in that the plants of the plant composition are pre-cultivated on a fiber mat (6).

16. Method according to claim 14, characterized in that the plants of the plant composition are pre-cultivated in separate containers (4).

17. Method according to claim 14, characterized in that the plants of the plant composition are pre-cultivated in depressions of the temporary floating body (3).

18. Method according to one of claims 14 to 17, characterized in that at least one plant species selected from a group of plant species containing Phragmites australis, Carex laciocarpa, Menyanthes trifoliata, Typha latifolia, Typha angustifolia is / are cultivated as the plant composition.

19. Method according to one of claims 14 to 18, characterized in that the polymer foam of the polymer foam material is provided in a one-shot process or with a prepolymer process.

20. Method according to one of claims 14 to 19, characterized in that at least one substance selected from a group of substances containing ground miscanthus, miscanthus fibers, wood fibers, lignin, chitosan, peat, and straw is embedded as an organic-plant additive in the provision of the polymer foam or polymer foam material.

21. Method according to one of claims 14 to 20, characterized in that several individual temporary floating bodies (3) are joined together in the water to form a closed surface.

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