Ultra-fine vegetation root preparation method capable of simulating the influence of transpiration

Abstract

The present invention belongs to the field of ecological slope restoration, and relates to a method for preparing an ultra-fine vegetation root system capable of simulating the influence of transpiration, comprising: 1) selecting angiosperm shrubs that are sown and grow well, removing the soil on the surface of the root system after digging the whole plant, and cleaning the root system; 2) calculating the total surface area of ​​the main root and lateral root of the root system of the angiosperm shrub; 3) using a scanning electron microscope to obtain the aperture and distribution characteristics of the duct in the main root and lateral root section; 4) simplifying the duct with dense distribution of the main root and lateral root, and simplifying the real root system of the angiosperm shrub dug on site; 5) modeling the simplified root system of the angiosperm shrub and the duct obtained in the simplified main root and lateral root section; 6) importing into a 3D printer for printing. The present invention provides a method for preparing an ultra-fine vegetation root system capable of simulating the influence of transpiration, which is low in cost and has good consistency in simulation style.

Description

Technical Field

[0001] The invention belongs to the field of ecological slope restoration, and relates to a method for preparing an ultra-fine vegetation root system capable of simulating the influence of transpiration, and in particular to a method for preparing an ultra-fine vegetation root system capable of finely simulating root ducts and used for studying vegetation transpiration. Background Art

[0002] During the construction of infrastructure such as roads and water conservancy projects, excavation and backfilling are usually carried out, resulting in a large number of road cutting slopes, which will destroy the ecological balance of the original vegetation system, expose the surface, reduce the soil's ability to resist erosion, and even cause disasters such as mudslides and landslides. Not only does it cause damage to the ecological environment, it also threatens people's lives and property. In recent years, the concept of vegetation slope protection has attracted increasing attention at home and abroad. Compared with traditional slope protection methods, plant slope protection has the characteristics of low investment and convenient maintenance, and can protect the environment and beautify the ecological environment.

[0003] Plants can not only enhance the stability of shallow soil slopes through the mechanical properties of their roots, but also absorb soil moisture through transpiration, generate suction in the soil, and thus change the engineering properties of the soil. Under the combined action of matrix suction and osmotic suction in the soil and plant bodies, the transpiration of plants transfers soil moisture to the leaves through the roots and wood of the plants. The soil suction generated by transpiration can not only enhance the shear strength of the soil, but also improve the shear dilatancy of the soil, further enhancing the shear strength of the soil. Enhancing the shear strength of the soil can effectively control surface hydraulic erosion and enhance slope stability.

[0004] Trachea are important pipe structures for transporting water and inorganic salts in the xylem of woody plants and are commonly found in most angiosperms. They are tubular structures formed by many long tubular cells connected in a tip-to-tip manner. The entire trachea is a long tubular structure with a length of up to 0.001–10m, which is 100–1000 times the diameter of the trachea.

[0005] Although the existing methods of 3D scanning and model reconstruction of vegetation roots can model the vegetation roots well, in the process of modeling the vegetation roots, only the macroscopic model of the entire vegetation root system is reconstructed, thereby ignoring the pore structure of the cross section of the vegetation root system and the influence of transpiration. The existing root simulation methods can only consider either the root reinforcement effect or the transpiration effect, and cannot reflect the joint influence of the root reinforcement effect and transpiration at the same time. The prepared ultra-fine vegetation root system can be used to simulate the influence of transpiration on the mechanical properties and permeability characteristics of the soil. Summary of the invention

[0006] In order to solve the above-mentioned technical problems existing in the background technology, the purpose of the present invention is to provide a method for preparing ultra-fine vegetation roots with low cost, good simulation pattern consistency and capable of simulating the influence of transpiration, targeting the pore structure of vegetation roots and taking into account the influence of root transpiration.

[0007] To this end, the specific technical solution adopted by the present invention is as follows:

[0008] A method for preparing an ultra-fine vegetation root system capable of simulating the influence of transpiration, characterized in that the method for preparing an ultra-fine vegetation root system capable of simulating the influence of transpiration comprises the following steps:

[0009] 1) Select angiosperm shrubs that are sown and growing well, dig them up using the whole plant digging method, remove the soil on the surface of the roots, and clean the roots;

[0010] 2) Calculate the total surface area of ​​the taproot and the total surface area of ​​the lateral roots of the root system of angiosperm shrubs;

[0011] 3) Use scanning electron microscopy to obtain the pore size and distribution characteristics of the vessels in the main root and lateral root sections;

[0012] 4) simplify the obtained conduits with dense distribution of taproots and lateral roots, and simplify the real root systems of angiosperm shrubs dug out on site;

[0013] 5) Modeling the simplified root system of the angiosperm shrub in step 4) and the vessels obtained from the simplified main root and lateral root sections, and exporting the established model in an STL format file;

[0014] 6) Import the STL format file into the 3D printer and select the 3D printing material to obtain an ultra-fine vegetation root system that can simulate the influence of transpiration.

[0015] The specific implementation of the above step 2) is:

[0016] 2.1) Measure the cleaned angiosperm shrub roots every 2 cm in depth, and use a vernier caliper to measure the root diameter at each depth level;

[0017] 2.2) The roots of angiosperms and shrubs were classified into 0.5 mm diameter categories, and the main roots and lateral roots were classified and counted, and the number of roots in each classification range was counted;

[0018] 2.3) Assuming that the roots of shrubs are all cylinders, use the cylinder lateral area formula to calculate the surface areas of the main roots and lateral roots respectively. Calculate the surface area of ​​the roots in each depth direction according to the root diameter measured in each depth direction in step 2.1). Add up the surface areas calculated in each depth direction to get the surface area of ​​a single root. Finally, add up the surface areas of the main roots of the root system to get the total surface area of ​​the main roots of the angiosperm shrub roots. Add up the surface areas of the lateral roots of the root system to get the total surface area of ​​the lateral roots of the angiosperm shrub roots.

[0019] The specific implementation of the above step 3) is:

[0020] 3.1) Select some taproots and lateral roots and fix them in 50 v / v% ethanol solution, then use a blade to cut the taproots and lateral roots into 2 mm long segments;

[0021] 3.2) Rinse three times with distilled water at 50°C to remove excess impurities;

[0022] 3.3) placing the small section after step 3.2) between a pair of glass slides and applying pressure, using a clamp to ensure the flatness of the dried part; the drying is carried out by placing the glass slides on a heating table at 50°C until the roots are dry;

[0023] 3.4) Observe the root system under an electron microscope and obtain SEM images of the main root and lateral root cross-sections;

[0024] 3.5) Input the SEM images of the main root and lateral root cross sections obtained in step 3.4) into Nano Measurer1.2 software, measure the chordal diameter of the trachea, and analyze the trachea distribution characteristics of the root cross section.

[0025] In the above step 4), the method of simplifying the real root system of the angiosperm shrub dug on site is: select four lateral roots and one main root, and the lateral roots are symmetrically arranged on both sides of the main root; the area of ​​the simplified main root is the same as the sum of the main root surface areas calculated in step 2), the area of ​​the simplified lateral roots is the same as the sum of the lateral root surface areas calculated in step 2), the main root is simplified to a columnar structure with a diameter of 5 mm and a depth of 10 cm; the lateral roots are simplified to a columnar structure with a diameter of 1 mm and a length of 4 cm.

[0026] The specific simplification of the conduit with densely distributed taproots and lateral roots in the above step 4) is as follows:

[0027] First, the conduit in the taproot is simplified: the conduit in the taproot is simplified into a conduit with a hole diameter of 1 mm, the conduit is located in the center of the taproot, the conduit at the top of the taproot is not closed, and the conduit at the bottom is closed;

[0028] Secondly, the ducts in the lateral roots were simplified. The ducts in the lateral roots were evenly distributed on the cross section and distributed near the surface of the lateral roots. The duct apertures near the surface of the lateral roots were simplified to 50 μm. A water-permeable channel was left between the ducts near the surface of the lateral roots and the surface of the lateral roots at intervals of 0.1 mm, and the ducts were connected to the ducts at the center of the lateral roots at intervals of 0.1 mm. The duct apertures at the center of the lateral roots were simplified to 100 μm. At the junction of the lateral roots and the main root, the simplified ducts at the center of the four lateral roots were connected to the ducts of the main root. Except for the duct at the center, the other ducts in the lateral roots were not connected to the duct of the main root, and the bottom ends of the lateral root ducts were not closed and were in contact with the air.

[0029] The specific implementation method of the above step 5) is: using Sketch Up to model the root system of the angiosperm shrub simplified in step 4) and the vessels obtained in the simplified main root and lateral root sections, and exporting the established model in an STL format file.

[0030] The above-mentioned 3D printing material is engineering plastic polyamide.

[0031] The above 3D printer is a 3D printer with a precision of 10 μm.

[0032] A 3D model of an ultra-fine vegetation root system is prepared based on the ultra-fine vegetation root system preparation method as described above that can simulate the influence of transpiration.

[0033] The present invention has the following beneficial effects:

[0034] The invention provides a method for preparing an ultra-fine vegetation root system capable of simulating the influence of transpiration, the method comprising: 1) selecting angiosperm shrubs that are planted and growing well, digging them by whole-plant digging method, removing soil on the surface of the root system, and cleaning the root system; 2) calculating the sum of the main root surface area and the sum of the lateral root surface area of ​​the root system of the angiosperm shrub; 3) using a scanning electron microscope to obtain the aperture and distribution characteristics of the ducts in the main root and lateral root cross-section; 4) simplifying the ducts in which the main root and lateral root are densely distributed, and simplifying the real root system of the angiosperm shrub dug on site; 5) modeling the simplified root system of the angiosperm shrub in step 4) and the ducts obtained in the simplified main root and lateral root cross-section together, and exporting the established model in an STL format file; 6) importing the STL format file into a 3D printer, and selecting 3D printing materials to obtain an ultra-fine vegetation root system capable of simulating the influence of transpiration. The present invention proposes an ultra-fine artificial plant root system that can be used to simulate the influence of transpiration and can finely simulate the root duct structure. The surface area equivalent method is used to simplify the main root and lateral roots of the real root system. The ducts in the main root and the lateral root are obtained by using a scanning electron microscope (SEM), and the dense ducts in the main root are simplified into one duct, the top end is not closed and in contact with the air, and the bottom end duct is closed. The simplified lateral root ducts are distributed on one side close to the surface, and a water passage is left with the surface. A water passage is provided at the center of the lateral root cross section to connect the lateral root with the duct of the main root so that the water in the lateral root can be collected in the main root. The engineering plastic polyamide (PA) is used as a 3D printing material. The ultra-fine artificial plant root system prepared by the method is convenient for applying transpiration tension to simulate the influence of transpiration on the mechanical properties and permeability properties of the soil. The ultra-fine vegetation root system prepared by the present invention can reflect the vascular pore structure and can also be used to simulate the influence of transpiration on the mechanical properties and permeability characteristics of soil. The material cost used to prepare the simulation sample is low. The properties of the simulation sample printed by high-precision 3D printing are similar to those of the original plant root system, and the simulation sample has good consistency. BRIEF DESCRIPTION OF THE DRAWINGS

[0035] Figure 1 This is a flowchart of the method for preparing the ultra-fine vegetation root system capable of simulating the influence of transpiration provided by the present invention. DETAILED DESCRIPTION

[0036] The technical solution provided by the present invention is further described below in conjunction with the accompanying drawings. It should be noted that the embodiments are exemplary and are only used to disclose and explain the present invention so as to fully understand the present invention, but the present invention is not limited to the scope of the embodiments.

[0037] See also Figure 1The present invention provides a method for preparing an ultra-fine vegetation root system capable of simulating the influence of transpiration, the method comprising the following steps:

[0038] 1) Selection of vegetation root systems: Select angiosperm shrubs that are sown and growing well, dig them up using the whole plant digging method, remove the soil on the root surface, and clean the roots;

[0039] In this step, direct field sampling methods are used to obtain the shrub root system, including digging method, profile method, whole-section specimen method and other methods. The present invention adopts the whole plant digging method to dig out the shrub root system, and its main idea is to directly dig out the root system for research from the soil. The direct field sampling method is widely used because it is intuitive and simple. When cleaning the soil of the shrub root system, a specially designed flushing container is used for cleaning. The use of the above-mentioned cleaning method will reduce the impact force of the water flow and reduce the damage to the shrub root system during the cleaning process.

[0040] 2) Calculate the root area, calculate the sum of the main root surface area and the sum of the lateral root surface area of ​​all plant root systems, the specific implementation method is:

[0041] 2.1) Measure the cleaned shrub roots every 2 cm in depth, and use a vernier caliper to measure the root diameter at each depth level;

[0042] 2.2) Classify the roots by diameter of 0.5 mm, and classify them by taproot and lateral root, and count the number of roots in each range. Roots with a diameter less than 0.5 mm are difficult to measure and account for a small proportion of the entire root system, so this part of the root system can be ignored;

[0043] 2.3) When calculating the surface area, assume that the roots of shrubs are all cylinders, and use the cylindrical lateral area formula to calculate the areas of the main root and lateral root respectively. Calculate the surface area of ​​the roots in each depth direction based on the root diameter measured in step 2.1). Add the surface areas calculated in each depth direction to get the surface area of ​​a single root. Finally, add up the surface areas of the main roots of the root system to get the total surface area of ​​the main roots of the angiosperm shrub roots, and add up the surface areas of the lateral roots of the root system to get the total surface area of ​​the lateral roots of the angiosperm shrub roots.

[0044] 3) Scanning electron microscopy (SEM) was used to obtain the pore size and distribution characteristics of the conduits in the main root and lateral root sections, wherein some main roots and lateral roots were selected and fixed in an ethanol solution with a concentration of 50 v / v%, and then cut into 2 mm long segments using a blade, and then rinsed three times with distilled water at 50 ° C to remove excess impurities, and then the slices were placed between pairs of glass slides and pressure was applied, and clamps were used to ensure the flatness of the dried part. Drying was performed by placing the slides on a heating table at 50 ° C until the roots were dry. The roots were placed under an electron microscope for observation, and SEM images of the main root and lateral root cross-sections of the root system were obtained. Since the conduits are mostly elliptical, the tangential diameter of the conduits is used as the pore size of the conduits, and this method is used to determine the pore size of the conduits. The SEM images of the main root and lateral root cross-sections obtained were input into the NanoMeasurer1.2 software to measure the tangential diameter of the conduits and analyze the distribution characteristics of the conduits in the root cross-sections.

[0045] 4) Simplify the conduit with dense distribution of taproots and lateral roots, and simplify the real root system of the shrub dug on site. In the process of simplifying the real root system of the shrub dug on site, the simplified taproot area and lateral root area should be the same as the sum of the taproot surface area and the sum of the lateral root surface area calculated in the second step. Through calculation, the taproot is simplified to a diameter of 5mm and a depth of 10cm, and the lateral roots are simplified to 4 roots with a diameter of 1mm and a length of 4cm. The lateral roots are symmetrically distributed on both sides of the taproot.

[0046] In this step, the conduits of the main root and lateral root densely distributed obtained by scanning electron microscopy are simplified, specifically: first simplify the conduits in the main root, simplify the conduits in the main root to one conduit with an aperture of 1 mm, the conduit at the top is not closed and should be in contact with the air, and the conduit at the bottom is closed. The conduits in the lateral roots are evenly distributed in the cross section and distributed at a position close to the surface, and the conduit aperture close to the lateral root surface in the lateral root is simplified to 50 μm, and a channel for water flow is left between the conduit close to the lateral root surface and the lateral root surface every 0.1 mm, and the conduit at the center is connected every 0.1 mm. The conduit aperture at the center of the lateral root is simplified to 100 μm, and at the junction of the lateral root and the main root, the simplified conduits at the center of the 4 lateral roots are connected to the conduit of the main root, and the conduits in the lateral root except the conduit at the center are not connected to the conduit of the main root, and the bottom ends of the conduits of the lateral roots are not closed and in contact with the air.

[0047] 5) Modeling the simplified root system of the angiosperm shrub in step 4) and the vessels obtained in the simplified main root and lateral root sections, and exporting the established model in an STL format file. For example, the modeling can be performed using Sketch Up;

[0048] 6) The 3D model output in STL format is imported into a 3D printer with an accuracy of 10 μm, and a material with good mechanical properties for simulating plant roots is selected as the material for 3D printing in the present invention to obtain an ultra-fine vegetation root model that can reflect the pore structure and consider the influence of transpiration.

[0049] When performing 3D printing, a printing material that is closer to the properties of the original plant roots should be selected. At present, common materials for 3D printing mainly include engineering plastics, photosensitive resins, metal materials, gypsum materials, etc. Among them, photosensitive resins have high technical content and complex formulas, and are not suitable for the materials used in the present invention; the tensile properties of metal materials are greatly different from those of plant roots; and the samples printed using gypsum materials have certain brittleness. The 3D printing material of the high-precision printer described in the present invention is engineering plastic polyamide (PA), which has high material strength, low cost, and certain flexibility. It is easy to prefabricate into spherical fine powders with uniform particles, good material fluidity, high loose density, and can print plant roots quickly and accurately. The tensile strength and flexibility of the material are similar to those of the original plant root sample, ensuring that a simulated sample with properties closer to the original plant root sample is obtained.

[0050] In the present invention, a 3D printer with an accuracy of 10 μm is selected, which can print the pore structure in the plant root system more accurately. The printed simplified vegetation root model is tightly bonded to the hollow metal joint at the top of the main root using epoxy resin, and the other end of the metal joint is a gas quick connector to facilitate the application of transpiration tension to simulate the influence of transpiration on the mechanical properties and permeability characteristics of the soil.

[0051] While providing the above method, the present invention also provides an ultra-fine vegetation root system 3D model prepared based on the method. The ultra-fine vegetation root system 3D model can reflect the vascular pore structure and can also be used to simulate the influence of transpiration on the mechanical properties and permeability characteristics of the soil. The material cost used to prepare the simulation sample is low, and the properties of the simulation sample printed by high-precision 3D printing are similar to those of the original plant root system, and the simulation sample has good consistency.

[0052] The preferred specific embodiments of the present invention are described in detail above. It should be understood that a person skilled in the art can make many modifications and changes based on the concept of the present invention without creative work. Therefore, any technical solution that can be obtained by a person skilled in the art through logical analysis, reasoning or limited experiments based on the concept of the present invention in the prior art should be within the scope of protection determined by the claims.

Claims

1. A method for preparing ultra-fine vegetation roots that can simulate the effects of transpiration, Features: The method for preparing the ultra-fine vegetation root system capable of simulating the influence of transpiration comprises the following steps: 1) Select angiosperm shrubs that are planted and growing well, dig them up using the whole plant digging method, remove the soil on the surface of the roots, and clean the roots; 2) Calculate the total surface area of ​​the taproot and the total surface area of ​​the lateral roots of the root system of angiosperm shrubs; 3) Use scanning electron microscopy to obtain the pore size and distribution characteristics of the vessels in the main root and lateral root sections; 4) Simplify the conduits with dense distribution of taproots and lateral roots, and simplify the real root system of angiosperm shrubs dug on site; the specific method of simplifying the conduits with dense distribution of taproots and lateral roots is as follows: first, simplify the conduits in the taproot into a conduit with an aperture of 1 mm, the conduit is located at the center of the taproot, the conduit at the top of the taproot is not closed, and the conduit at the bottom is closed; second, simplify the conduits in the lateral roots, the conduits in the lateral roots are evenly distributed on the cross section and partly distributed near the surface of the lateral roots, The diameter of the conduit near the surface of the lateral root is simplified to 50 μm, and a water-permeable channel is left between the conduit near the surface of the lateral root and the surface of the lateral root at intervals of 0.1 mm. The conduit near the surface of the lateral root is connected with the conduit at the center of the lateral root at intervals of 0.1 mm; the diameter of the conduit at the center of the lateral root is simplified to 100 μm, and at the junction of the lateral root and the main root, the conduits at the center of the four simplified lateral roots are connected with the conduit of the main root. Except for the conduit at the center, the other conduits in the lateral root are not connected to the conduit of the main root, and the bottom ends of the conduits of the lateral roots are not closed and are in contact with the air; The method of simplifying the real root system of the angiosperm shrub dug out on site is: select four lateral roots and one main root, and the lateral roots are symmetrically arranged on both sides of the main root; the area of ​​the simplified main root is the same as the sum of the main root surface areas calculated in step 2); the area of ​​the simplified lateral root is the same as the sum of the lateral root surface areas calculated in step 2); the main root is simplified to a columnar structure with a diameter of 5 mm and a depth of 10 cm; the lateral root is simplified to a columnar structure with a diameter of 1 mm and a length of 4 cm; 5) Model the simplified root system of the angiosperm shrub in step 4) and the vessels obtained from the simplified main root and lateral root sections, and export the established model in an STL format file; 6) Import the STL format file into the 3D printer and select the 3D printing material to obtain an ultra-fine vegetation root system that can simulate the influence of transpiration.

2. The method for preparing an ultra-fine vegetation root system capable of simulating the influence of transpiration according to claim 1, Features: The specific implementation method of step 2) is: 2.1) Measure the cleaned angiosperm shrub roots every 2 cm in depth. Use a vernier caliper to measure the root diameter at each depth level. 2.2) The roots of angiosperms and shrubs were classified into 0.5 mm diameter categories, and were classified and counted into taproots and lateral roots, and the number of roots within each classification range was counted; 2.3) Assuming that the roots of shrubs are all cylinders, use the cylinder lateral area formula to calculate the surface area of ​​the main root and lateral root respectively. Calculate the surface area of ​​the root system in each depth direction according to the root diameter measured in each depth direction in step 2.1). Add up the surface areas calculated in each depth direction to get the surface area of ​​a single root. Finally, add up the surface areas of the main roots of the root system to get the total surface area of ​​the main roots of the angiosperm shrub roots. Add up the surface areas of the lateral roots of the root system to get the total surface area of ​​the lateral roots of the angiosperm shrub roots.

3. The method for preparing an ultra-fine vegetation root system capable of simulating the influence of transpiration according to claim 1, Features: The specific implementation method of step 3) is: 3.1) Select some taproots and lateral roots and fix them in 50 v / v % ethanol solution, then use a blade to cut the taproots and lateral roots into 2 mm long segments; 3.2) Rinse three times with distilled water at 50°C to remove excess impurities; 3.3) Place the small section after step 3.2) between a pair of glass slides and apply pressure, using a clamp to ensure the flatness of the dried section; the drying is carried out by placing the slides on a heating table at 50°C until the roots are dry; 3.4) Observe the root system under an electron microscope and obtain SEM images of the main root and lateral root cross-sections; 3.5) Input the SEM images of the main root and lateral root cross sections obtained in step 3.4) into Nano Measurer1.2 software, measure the chordal diameter of the trachea, and analyze the trachea distribution characteristics of the root cross section.

4. The method for preparing an ultra-fine vegetation root system capable of simulating the influence of transpiration according to claim 1, Features: The specific implementation method of step 5) is: using Sketch Up to model the root system of the angiosperm shrub simplified in step 4) and the vessels obtained from the simplified main root and lateral root sections, and exporting the established model in an STL format file.

5. The method for preparing an ultra-fine vegetation root system capable of simulating the influence of transpiration according to any one of claims 1 to 4, Features: The 3D printing material is engineering plastic polyamide.

6. The method for preparing an ultra-fine vegetation root system capable of simulating the influence of transpiration according to claim 5, Features: The 3D printer has a precision of 10 μm.

7. A 3D model of an ultra-fine vegetation root system prepared based on the method for preparing an ultra-fine vegetation root system capable of simulating the influence of transpiration as described in any one of claims 1 to 6.

Images