In-situ measuring device and method for plant root respiration

Abstract

The invention relates to the technical field of vegetation root respiration measurement, and discloses a plant root respiration in-situ measurement device and method, the plant root respiration in-situ measurement device comprises a center frame, transparent isolation covers and a center collection cylinder, the transparent isolation covers are arranged on the two sides of the center frame in a mirror symmetry mode, and the lower ends of the transparent isolation covers are open; a sealing groove is jointly formed between the center frame and the transparent isolation cover, and a sealing plate is movably installed in the sealing groove through a driving assembly. In the measuring process, the plant root system does not need to be removed, the natural state of the rhizosphere environment is maintained to the maximum extent, and the authenticity of measured data is ensured; by creating a locally controlled small environment, the influence of the outside atmosphere is effectively isolated, so that the measured data can accurately reflect the respiration of the plant root system without being interfered by other factors, and the method has the characteristics of high practicability and accurate measurement.

Description

Technical Field

[0001] The present invention relates to the technical field of plant root respiration measurement, and in particular to an in-situ measurement device and a measurement method for plant root respiration. Background Art

[0002] The root system plays an important regulatory role in plant growth and development, and its physiological and biochemical processes are weak links in agronomic and ecological research. Root respiration leads to carbon emissions and is an important link in the carbon cycle of underground ecosystems. Since most studies focus on the aboveground part, there is still a lack of understanding of the turnover of underground carbon pools. Currently, the underground carbon pool is regarded as an elusive "black hole" in the global carbon cycle, and its slight changes will have a profound impact on the atmospheric carbon pool. Measuring root respiration can provide important data support for the assessment and prediction of global and regional carbon sources / sinks.

[0003] Although some studies have measured root respiration rate or activity through methods such as solution culture, aeroponics and root separation, these experimental conditions often deviate from the actual situation under natural conditions and are difficult to accurately reflect the true situation of plant carbon balance and distribution. Traditional root respiration measurement methods have many limitations. Traditional methods often require the removal of roots for measurement, which not only changes the natural state of the rhizosphere environment, but also may damage plants, resulting in measurement results that cannot truly reflect the respiration of plants under natural conditions. In addition, because traditional equipment is difficult to completely exclude the influence of the external atmosphere on the measurement area, the measured data contains interference from other non-target factors, such as soil microbial activity, external air flow, etc., and lack of effective isolation measures reduces the accuracy of the data. Therefore, it is very necessary to design an in-situ measurement device and method for plant root respiration that is highly practical and accurate. Summary of the invention

[0004] The object of the present invention is to provide an in-situ measuring device and method for plant root respiration to solve the problems raised in the above-mentioned background technology.

[0005] In order to solve the above technical problems, the present invention provides the following technical solutions: an in-situ measurement device for plant root respiration, comprising a central frame, a transparent isolation cover and a central collection tube, wherein the transparent isolation cover is arranged on both sides of the central frame in a mirror-symmetrical manner, the lower end of the transparent isolation cover is arranged to be open for placing plant roots, a sealing groove is provided between the central frame and the transparent isolation cover, a sealing plate is movably installed in the sealing groove through a driving component, a closed measurement area is formed between the transparent isolation cover and the sealing plate, which is used to seal and isolate the plant roots, through holes are evenly distributed on one end of the sealing plate adjacent to the transparent isolation cover, an ion exchange membrane is provided in the middle position of the through holes, a placement area is provided in the middle position of the upper end of the central frame, the central collection tube is arranged in the placement area, a collection channel is provided between the central frame, the transparent isolation cover and the central collection tube, the collection channel is arranged in a linear array along the height direction of the transparent isolation cover, a partition component is provided in the central collection tube, which is used to divide the central collection tube into a plurality of collection chambers, and the collection chambers and the collection channels are arranged in a one-to-one correspondence.

[0006] According to the above technical solution, the driving assembly includes a servo motor, bevel gear one, bevel gear two, a shaft seat and a connecting shaft. A driving cavity is opened at the bottom of the center frame. The servo motor is fixedly installed on the top of the driving cavity. The output end of the servo motor is fixedly installed with the bevel gear one. The shaft seat is symmetrically arranged in the driving cavity. The connecting shaft is movably installed in the shaft seat. The bevel gear two is fixedly installed at one end of the connecting shaft adjacent to the bevel gear one. The bevel gear two is respectively meshed and connected with the bevel gear one. The end of the connecting shaft away from the bevel gear one is threadedly connected in the corresponding sealing plate.

[0007] According to the above technical solution, the partition assembly includes a multi-stage telescopic cylinder, a transverse partition plate, a connecting column, a longitudinal partition plate and a transverse suction plate. The multi-stage telescopic cylinder is fixedly installed on the inner top wall of the central collection tube and the connecting column is fixedly installed on the telescopic end of the multi-stage telescopic cylinder. The longitudinal partition plate is symmetrically arranged in the central collection tube. The transverse suction plate and the transverse partition plate are respectively arranged on both sides of the connecting column and are alternately arranged from top to bottom. The collection channel is located between the transverse suction plate and the transverse partition plate. The transverse partition plate is fixedly installed on the inner side wall of the central collection tube. The transverse suction plate is fixedly installed on the side wall of the connecting column. The central collection tube, the transverse partition plate, the connecting column, the longitudinal partition plate and the transverse suction plate jointly form the collection chamber.

[0008] According to the above technical solution, sealing member 1 and sealing member 2 are respectively provided in the collection channel. Sealing member 1 is arranged in the collection channel in the central collection tube, and sealing member 2 is arranged in the collection channel in the center frame and the transparent isolation cover. Sealing member 1 and sealing member 2 are arranged correspondingly.

[0009] According to the above technical solution, the sealing member includes a plug, a sealing plug, a spring and a magnet. A circulation cavity is provided in the plug. A central hole is provided through one end of the circulation cavity adjacent to the collection cavity. The central hole is located in the middle of one side wall of the plug. An edge hole is provided through one end of the circulation cavity away from the collection cavity. The edge holes are arranged in a circular array on one side wall of the plug. The edge holes and the central hole are connected through the circulation cavity. The spring is fixedly installed in the circulation cavity at one end away from the collection cavity and the sealing plug is fixedly installed on the telescopic end of the spring. The magnet is embedded in the sealing plug.

[0010] According to the above technical solution, the second sealing component includes a second plug, a second sealing plug, a second spring, a second magnet and a filter head, the second plug is provided with a second circulation chamber, the second circulation chamber is provided with a second central hole at one end adjacent to the transparent isolation cover, the second central hole is located in the middle position of the second side wall of the plug, the second circulation chamber is provided with two edge holes at one end away from the transparent isolation cover, the second edge holes are arranged in a circular array on the second side wall of the plug, the second edge hole and the second central hole are connected through the second circulation chamber, the second spring is fixedly installed at one end away from the transparent isolation cover in the second circulation chamber and the second sealing plug is fixedly installed at the telescopic end of the second spring, the second magnet is embedded in the second sealing plug, the second magnet and the corresponding first magnet attract each other, the second plug is threadedly connected to the filter head at one end adjacent to the transparent isolation cover, the inner wall of the transparent isolation cover is provided with an embedding groove, and the filter head and the embedding groove are arranged in a one-to-one correspondence.

[0011] According to the above technical solution, the side wall of the central collection tube is provided with an external accessory, and the external accessory is arranged on the side wall of the central collection tube in a mirror-symmetrical manner. The side wall of the placement area is symmetrically provided with docking grooves, and the external accessory is arranged in the corresponding docking groove. The external accessory includes an external block, an air outlet pipe and a sealing cover. The external block is symmetrically fixedly installed on the side wall of the central collection tube, and the external block is movably installed in the corresponding docking groove. The air outlet pipes are evenly distributed between the external blocks, and the air outlet pipes and the collection chamber are arranged in a one-to-one correspondence. The sealing cover is threadedly connected to the air outlet pipe.

[0012] According to the above technical solution, a conical propulsion block is fixedly mounted on one end of the sealing plate adjacent to the transparent isolation cover, a conical propulsion groove is provided in the transparent isolation cover, and the conical propulsion block and the conical propulsion groove are correspondingly arranged.

[0013] According to the above technical solution, handle one is symmetrically fixedly installed on the upper end of the central frame, handle one is symmetrically arranged on both sides of the central collection tube, and handle two is symmetrically fixedly installed on the upper end of the central collection tube.

[0014] A method for in situ determination of plant root respiration. S1, preparation phase S11, set the experimental conditions: set the target plant roots on one side as the experimental group, and only set the soil on the other side as the control group; S12, equipment assembly: firstly, place the center frame at the predetermined position and ensure that it is stable, and then install the transparent isolation cover on both sides of the center frame to maintain mirror symmetry. At this time, the lower end opening of the transparent isolation cover should be ready to receive plant roots or control group soil; S13, installing the central collection tube: placing the central collection tube with the partition assembly into the placement area on the central frame, and ensuring that the central collection tube is firmly fixed on the central frame through the cooperation of the external accessories and the docking groove. At the same time, the design of the handle 1 and the handle 2 makes this process more convenient; S2, sealing and isolation stage S21, manufacturing micro-environment: starting the servo motor, driving the connecting shaft to rotate through the bevel gear 1 and the bevel gear 2, thereby pushing the sealing plate into the transparent isolation cover to form a closed space, and the conical push block on the sealing plate will gradually embed into the conical push groove in the transparent isolation cover, increasing the sealing pressure and reducing the possibility of gas leakage; S22, water flow: the ion exchange membrane in the through hole allows water to pass through but restricts the flow of most gas molecules, maintaining a relatively stable gas environment in the measurement area; S3, gas collection stage S31, the collection channel is opened: when the central collection tube is correctly installed, the magnet 1 in the sealing member 1 and the magnet 2 in the sealing member 2 attract and engage with each other, and with the attraction between the magnets, the sealing plugs of the sealing member 1 and the sealing member 2 are respectively pulled apart, so that the collection channel is opened; S32, multi-stage telescopic cylinder action: the multi-stage telescopic cylinder adjusts its telescopic length according to the preset program or external control signal, drives the connecting column to move up and down, thereby driving the lateral suction plate to change the volume of the collection chamber. As the volume of the collection chamber increases, the internal air pressure decreases, forming a negative pressure environment, which prompts the external gas to enter the collection chamber through the collection channel; S33, stratified sampling: two collection chambers at the same height are set, corresponding to the experimental group and the control group respectively. By setting the working cycle of the multi-stage telescopic cylinder and adjusting the position of the horizontal suction plate at regular intervals, gas samples at different soil depths can be collected multiple times on the same day to reveal the daily variation characteristics of root respiration; S4, Data processing and analysis phase S41, gas sample extraction: After completing a gas extraction, spring 1 returns to its original state, pushing sealing plug 1 to reclose central hole 1; similarly, spring 2 also returns to its original state, pushing sealing plug 2 to close central hole 2, thereby ensuring that the collected gas sample is safely retained in the collection chamber and is ready to be transported to the laboratory for inspection; S42, data analysis: Bring the collected gas samples back to the laboratory, and use professional analytical instruments such as infrared gas analyzers to measure the changes in CO2 concentration. By comparing the data of the experimental group and the control group, the CO2 emissions caused only by plant roots can be obtained, and then the contribution of root respiration to the total soil respiration can be evaluated.

[0015] Compared with the prior art, the beneficial effects achieved by the present invention are: (1) Maintaining the rhizosphere environment in its natural state: There is no need to remove the plant roots during the measurement process, which maximizes the maintenance of the natural state of the rhizosphere environment and ensures the authenticity of the measurement data.

[0016] (2) Precise control of experimental conditions: By creating a locally controlled microenvironment, the influence of the external atmosphere is effectively isolated, so that the measured data can accurately reflect the respiration of the plant roots themselves rather than being interfered by other factors.

[0017] (3) Enhance the comparability and reliability of experimental results: Synchronous monitoring of the experimental group and the control group reduces the errors caused by time and space differences. By comparison, the CO2 emissions caused only by plant roots can be obtained, which enhances the credibility of the experimental results.

[0018] (4) Layered sampling improves accuracy: The equipment enables independent collection of gas samples at different soil depths, which helps to understand the changes in root respiration along the soil profile and improves the sampling accuracy and research depth.

[0019] (5) Automated operation improves efficiency: Automated designs such as the servo motor driving the sealing plate and the multi-stage telescopic cylinder adjusting the volume of the collection chamber simplify the operation process and improve the accuracy and efficiency of sampling.

[0020] (6) Sample protection and transportation safety: The design of the sealing piece ensures the sealing and independence of the collected gas samples, avoids sample contamination or leakage, and ensures the quality of subsequent analysis.

[0021] (7) Reduce cross contamination: The horizontal suction plates and horizontal partition plates are arranged alternately to ensure that gas samples are drawn out and collected separately from each collection chamber, effectively preventing the mixing of gases between different collection chambers.

[0022] (8) Supporting the study of daily variation characteristics: The working cycle of the multi-stage telescopic cylinder can be set, the position of the horizontal suction plate can be adjusted regularly, and gas samples at different soil depths can be collected multiple times on the same day to reveal the daily variation characteristics of root respiration.

[0023] (9) Easy to operate and maintain: The design of handle 1 and handle 2 facilitates the installation and removal of the central collection tube, while the combination of external accessories and docking slots ensures the convenience and stability of equipment assembly. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] The accompanying drawings are used to provide a further understanding of the present invention and constitute a part of the specification. Together with the embodiments of the present invention, they are used to explain the present invention and do not constitute a limitation of the present invention. In the accompanying drawings: Figure 1 is a first stereoscopic schematic diagram of the present invention; Figure 2 is a second stereoscopic schematic diagram of the present invention; Figure 3 is a first partial stereoscopic schematic diagram of the present invention; Figure 4 is a second partial stereoscopic schematic diagram of the present invention; Figure 5 is a third partial stereoscopic schematic diagram of the present invention; Figure 6 is a fourth partial stereoscopic schematic diagram of the present invention; Figure 7 is a fifth partial stereoscopic schematic diagram of the present invention; Figure 8 is a sixth partial stereoscopic schematic diagram of the present invention; Fig. 9 is a seventh partial stereoscopic schematic diagram of the present invention; Fig.10 is an eighth partial stereoscopic schematic diagram of the present invention; Fig.11 The present invention Figure 3 The enlarged schematic diagram of point A in the middle; Fig.12 The present invention Figure 3 The enlarged schematic diagram of point B in the middle; In the figure: 1-center frame, 11-sealing groove, 12-placing area, 13-driving chamber, 14-docking groove, 15-handle 1, 2-transparent isolation cover, 21-embedded groove, 22-conical propulsion groove, 3-central collection tube, 31-handle 2, 4-driving assembly, 41-servo motor, 42-conical gear 1, 43-conical gear 2, 44-axle seat, 45-connecting shaft, 5-sealing plate, 51-through hole, 52-ion exchange membrane, 53-conical propulsion block, 6-partition assembly, 61-multi-stage telescopic cylinder, 62-transverse partition plate, 63-connecting column, 64-longitudinal partition plate, 65-transverse suction plate, 7-sealing piece one, 71-plug one, 711-circulation chamber one, 712-central hole one, 713-edge hole one, 72-sealing plug one, 73-spring one, 74-magnet one, 8-sealing piece two, 81-plug two, 811-circulation chamber two, 812-central hole two, 813-edge hole two, 82-sealing plug two, 83-spring two, 84-magnet two, 85-filter head, 9-external accessories, 91-external block, 92-air outlet pipe, 93-sealing cover. DETAILED DESCRIPTION

[0025] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0026] See also Figure 1-12 The present invention provides a technical solution: an in-situ measuring device for plant root respiration, comprising a central frame 1, a transparent isolation cover 2 and a central collection tube 3, wherein the transparent isolation cover 2 is arranged on both sides of the central frame 1 in a mirror-symmetrical manner, and the lower end of the transparent isolation cover 2 is open for placing plant roots, a sealing groove 11 is provided between the central frame 1 and the transparent isolation cover 2, a sealing plate 5 is movably installed in the sealing groove 11 through a driving component 4, and a closed measuring area is formed between the transparent isolation cover 2 and the sealing plate 5 for sealing and isolating the plant roots, and the sealing plates 5 are adjacent to each other. One end of the transparent isolation cover 2 is evenly distributed with through holes 51, and an ion exchange membrane 52 is arranged in the middle of the through holes 51. A placement area 12 is arranged in the middle of the upper end of the central frame 1, and the central collection tube 3 is arranged in the placement area 12. A collection channel is commonly provided between the central frame 1, the transparent isolation cover 2 and the central collection tube 3, and the collection channel is arranged in a linear array along the height direction of the transparent isolation cover 2. A partition component 6 is arranged in the central collection tube 3 for dividing the central collection tube 3 into a plurality of collection chambers, and the collection chambers and the collection channels are arranged one by one; The central frame 1 of the present application serves as the supporting framework of the entire system to ensure the stability and accuracy of each component. The placement area 12 is located in the middle of the upper end of the central frame 1 and is used to place the central collection tube 3, providing a fixed and controlled space for gas collection. A pair of transparent isolation covers 2 are arranged on both sides of the central frame 1 in a mirror-symmetrical manner. The lower end opening on each side is used to place or not place plant roots. When conducting measurements, plants are placed on one side and the other side is a blank control, which are set as an experimental group and a control group respectively. Experimental group: plant roots and soil are placed in a transparent isolation cover on one side to measure actual root respiration. Control group: the transparent isolation cover on the other side remains empty and only contains soil to evaluate background gas flux, such as microbial respiration, so as to distinguish additional CO2 emissions caused by plant roots, and a closed measurement area is formed by a sealing plate 5 to ensure that the internal environment is not disturbed by the outside world and maintain a relatively stable microenvironment. The sealing plate 5 is movably installed in the sealing groove 11 through the driving component 4 and can be closed when needed to form a complete The closed space, the through holes 51 are evenly distributed at one end of the sealing plate 5, and an ion exchange membrane 52 is provided in the middle of the through holes 51, which allows water to pass through but limits the circulation of most gas molecules, thereby maintaining a relatively stable gas environment in the measurement area and reducing the influence of external air. At the same time, the ion exchange membrane 52 in the present application can be replaced by a hydrophobic microporous membrane, a silicone rubber membrane, a hydrophilic modified polymer membrane and other membranes with the same effect. The central collection tube 3 is located in the placement area 12 on the central frame 1, responsible for collecting gas samples from different layers, and the collection channels are arranged in a linear array along the height direction of the transparent isolation cover 2, connected to different collection chambers of the central collection tube 3, to achieve layered gas sampling, which is helpful to obtain gas concentration change information at different soil depths, and helps to understand the law of root respiration changing with soil profile. The partition component 6 divides the central collection tube 3 into several independent collection chambers, each of which corresponds to a specific collection channel, to ensure that the gas samples obtained from different soil depths will not be mixed, which is convenient for subsequent analysis; In the present application, the root system does not need to be removed during the measurement, and the rhizosphere environment in the natural state is maintained to the maximum extent. By creating a local, controlled microenvironment to simulate the rhizosphere microenvironment under natural conditions, the enclosed space formed by the transparent isolation cover and the sealing plate can effectively isolate the influence of the external atmosphere, ensuring that the measured data reflects the respiration of the root system itself rather than the interference of other factors. The selective permeability of the ion exchange membrane further enhances this isolation effect, so that water can be normally supplied to the root system, while gas exchange is controlled. By using the transparent isolation covers on both sides at the same time, synchronous monitoring can be performed under the same environmental conditions to reduce the errors caused by time and space differences. The data of the experimental group minus the data of the control group can obtain the CO2 emissions caused only by the plant roots, which helps to more accurately evaluate the contribution of root respiration to the total soil respiration and enhance the comparability and reliability of the experimental results. In addition, the stratified sampling design allows researchers to obtain information on changes in gas concentrations at different soil depths, which is very important for understanding the law of root respiration changing with soil profiles. In this way, not only can the root respiration rate be measured more accurately, but also data support can be provided for studying the mechanism of root carbon loss. Specifically, the driving assembly 4 includes a servo motor 41, a bevel gear 1 42, a bevel gear 2 43, a shaft seat 44 and a connecting shaft 45. A driving chamber 13 is opened at the bottom of the central frame 1. The servo motor 41 is fixedly installed at the top of the driving chamber 13. The output end of the servo motor 41 is fixedly installed with the bevel gear 1 42. The shaft seat 44 is symmetrically arranged in the driving chamber 13. The connecting shaft 45 is movably installed in the shaft seat 44. The bevel gear 2 43 is fixedly installed at one end of the connecting shaft 45 adjacent to the bevel gear 1 42. The bevel gear 2 43 is respectively meshed and connected with the bevel gear 1 42. The end of the connecting shaft 45 away from the bevel gear 1 42 is threadedly connected in the corresponding sealing plate 5. When the sealing plate 5 needs to be closed or opened, the control system sends a command to the servo motor 41, and the servo motor 41 starts to rotate at a preset angle and speed. The rotational motion of the servo motor 41 is first transmitted to the bevel gear 2 43 through the fixed bevel gear 1 42, and the latter then drives the connecting shaft 45 to rotate. The rotation of the connecting shaft 45 is converted into the linear motion of the sealing plate 5 through the threaded connection. If the servo motor 41 rotates forward, the sealing plate 5 will be pushed into the transparent isolation cover 2 to form a closed space; on the contrary, the reverse rotation will cause the sealing plate 5 to withdraw and open the measurement area; Specifically, the partition assembly 6 includes a multi-stage telescopic cylinder 61, a transverse partition plate 62, a connecting column 63, a longitudinal partition plate 64 and a transverse suction plate 65. The multi-stage telescopic cylinder 61 is fixedly mounted on the inner top wall of the central collection tube 3 and the connecting column 63 is fixedly mounted on the telescopic end of the multi-stage telescopic cylinder 61. The longitudinal partition plate 64 is symmetrically arranged in the central collection tube 3. The transverse suction plate 65 and the transverse partition plate 62 are respectively arranged on both sides of the connecting column 63 and are alternately arranged from top to bottom. The collection channel is located between the transverse suction plate 65 and the transverse partition plate 62. The transverse partition plate 62 is fixedly mounted on the inner side wall of the central collection tube 3. The transverse suction plate 65 is fixedly mounted on the side wall of the connecting column 63. The central collection tube 3, the transverse partition plate 62, the connecting column 63, the longitudinal partition plate 64 and the transverse suction plate 65 together form the collection chamber. The multi-stage telescopic cylinder 61 serves as a power source, responsible for driving the connecting column 63, and drives the transverse suction plate 65 to move up and down through the connecting column 63. The multi-stage telescopic cylinder 61 can adjust its telescopic length according to a preset program or an external control signal to meet the needs under different experimental conditions. The transverse partition plate 62 is fixed and directly fixed on the inner wall of the central collection tube 3. The transverse suction plate 65 is fixedly installed on the side wall of the connecting column 63 and is arranged alternately with the transverse partition plate 62. The collection channel is located between the transverse suction plate 65 and the transverse partition plate 62, ensuring that the gas sample can be separately drawn out and collected from each collection chamber, effectively preventing cross-contamination of gases between different collection chambers and improving the sampling accuracy. During the startup or preparation stage of the equipment, the transverse suction plate 65 is at its lowest position. At this time, the distance between it and the transverse partition plate 62 below is the smallest, and the collection chamber is in a relatively small state. When the multi-stage telescopic cylinder 61 drives the connecting column 63 , and then drive the lateral suction plate 65 to move upward, increasing the distance between the lateral suction plate 65 and the lateral partition plate 62 fixed below. As the volume of the collection chamber increases, the internal air pressure will decrease accordingly, forming a negative pressure environment. This internal and external pressure difference prompts the external gas to enter the collection chamber through the collection channel to complete a gas extraction process. The design of the lateral suction plate 65 not only utilizes the internal and external pressure difference to achieve gas extraction, but also ensures that the gas sample can efficiently enter the collection channel, reducing cross contamination between samples, and further improving the sampling accuracy and reliability. Two collection chambers at the same height are set, corresponding to the experimental group and the control group respectively. When studying the daily variation law of plant root respiration, the position of the lateral suction plate 65 can be adjusted regularly by setting the working cycle of the multi-stage telescopic cylinder 61, so as to collect gas samples at different soil depths multiple times on the same day, thereby revealing the daily variation characteristics of root respiration; Specifically, a sealing member 1 7 and a sealing member 2 8 are respectively provided in the collection channel, the sealing member 1 7 is arranged in the collection channel in the central collection tube 3, the sealing member 2 8 is arranged in the collection channel in the central frame 1 and the transparent isolation cover 2, and the sealing member 1 7 and the sealing member 2 8 are arranged correspondingly; The sealing member 1 7 is arranged in the collection channel in the central collection tube 3, and can timely close or open the corresponding collection chamber to ensure that the gas in each collection chamber will not mix with the gas in other collection chambers. The sealing member 2 8 is arranged in the collection channel in the central frame 1 and the transparent isolation cover 2. It is located at the other end of the system and is responsible for isolation from the external environment to ensure that the collected gas sample will not be affected by the external air. Specifically, the sealing member 7 includes a plug 71, a sealing plug 72, a spring 73 and a magnet 74. A circulation cavity 711 is provided in the plug 71. A central hole 712 is provided through one end of the circulation cavity 711 adjacent to the collection cavity. The central hole 712 is located in the middle of the side wall of the plug 71. An edge hole 713 is provided through one end of the circulation cavity 711 away from the collection cavity. The edge holes 713 are arranged in a circular array on the side wall of the plug 71. The edge holes 713 and the central hole 712 are connected through the circulation cavity 711. The spring 73 is fixedly installed in one end of the circulation cavity 711 away from the collection cavity and the sealing plug 72 is fixedly installed at the telescopic end of the spring 73. The magnet 74 is embedded in the sealing plug 72. Under normal conditions, the pressure applied by the spring 73 causes the sealing plug 72 to tightly seal the central hole 712, thereby preventing the gas from flowing out of the collection chamber. When it is necessary to extract a gas sample, the external control device can overcome the force of the spring 1 through magnetic force or other means, so that the sealing plug 72 temporarily separates from the central hole 712, allowing the gas to enter the flow chamber 711 and be discharged through the edge hole 713. After the extraction is completed, the spring 73 returns to its original state, pushing the sealing plug 72 to re-seal the central hole 712 and restore the sealing state. Specifically, the sealing member 8 includes a plug 81, a sealing plug 82, a spring 83, a magnet 84 and a filter 85. The plug 81 is provided with a flow chamber 811. The end of the flow chamber 811 adjacent to the transparent isolation cover 2 is provided with a central hole 812. The central hole 812 is located in the middle of the side wall of the plug 81. The end of the flow chamber 811 away from the transparent isolation cover 2 is provided with an edge hole 813. The edge holes 813 are arranged in a circular array on the side wall of the plug 81. The edge holes 813 and the central hole 812 are provided in a circular array on the side wall of the plug 81. The second holes 812 are connected through the second circulation chamber 811, the second spring 83 is fixedly installed in the second circulation chamber 811 at one end away from the transparent isolation cover 2, and the second sealing plug 82 is fixedly installed at the telescopic end of the second spring 83, the second magnet 84 is embedded in the second sealing plug 82, the second magnet 84 and the corresponding first magnet 74 are attracted to each other, the second plug 81 is threadedly connected to the filter head 85 at one end adjacent to the transparent isolation cover 2, the inner side wall of the transparent isolation cover 2 is provided with an embedding groove 21, and the filter head 85 and the embedding groove 21 are arranged one-to-one; Sealing piece 2 8 is similar to sealing piece 1 7. Under normal conditions, when the central collection tube 3 is not installed, sealing piece 1 7 and sealing piece 2 8 are both in a closed state. The sealing plug 1 72 in sealing piece 1 7 tightly closes the central hole 1 712 under the action of spring 1 73 to prevent any gas from entering the collection channel. The sealing plug 2 82 in sealing piece 2 8 also tightly closes the central hole 2 812 under the action of spring 2 83 to prevent external gas from entering the collection system. When the central collection tube 3 is correctly installed in place, the magnet 1 74 in sealing piece 1 7 and the magnet 2 84 in sealing piece 2 8 attract and engage with each other. As magnet 1 74 and magnet 2 84 engage with each other, the sealing plugs of sealing piece 1 7 and sealing piece 2 8 are pulled apart respectively, so that the collection channel is opened. At this time, the lateral suction plate 65 can change the volume of the collection chamber by moving up and down, and realize gas extraction by using the pressure difference between the inside and the outside. After the collection is completed, The central collection tube 3 is removed from the system. This action causes the magnet 1 74 and the magnet 2 84 to separate and lose their magnetic attraction. As the attraction between the magnets disappears, the spring 1 73 and the spring 2 83 return to their original state, pushing their respective sealing plugs to re-seal the central hole 1 712 and the central hole 2 812. The collected gas sample is safely retained in the collection chamber and is ready to be transported to the laboratory for inspection. At the same time, a new central collection tube 3 can be installed immediately, and the above process can be repeated to perform gas collection work at different time periods. Gas samples of different time periods can be continuously collected without affecting the quality of the samples collected previously. The installation and unloading of the central collection tube 3 directly controls the state of the sealing member 1 7 and the sealing member 2 8, ensuring the sealing and independence of the gas sample during the collection and transportation process. This design not only simplifies the operation process, but also greatly improves the accuracy and efficiency of sampling. Specifically, the side wall of the central collection tube 3 is provided with an external accessory 9, and the external accessory 9 is arranged on the side wall of the central collection tube 3 in a mirror-symmetrical manner. The side wall of the placement area 12 is symmetrically provided with a docking groove 14, and the external accessory 9 is arranged in the corresponding docking groove 14. The external accessory 9 includes an external block 91, an air outlet pipe 92 and a sealing cover 93. The external block 91 is symmetrically fixedly installed on the side wall of the central collection tube 3, and the external block 91 is movably installed in the corresponding docking groove 14. The air outlet pipe 92 is evenly distributed between the external blocks 91, and the air outlet pipe 92 and the collection chamber are arranged one by one. The air outlet pipe 92 is threadedly connected to the sealing cover 93; When the central collection tube 3 is installed in place, the external block 91 will automatically fit into the docking groove 14 on the side wall of the placement area 12 to form a tight mechanical connection. This docking method not only ensures the position accuracy of the external accessory 9, but also enhances the overall stability of the system. The sealing cover 93 is threadedly connected to the gas outlet pipe 92. When not in use, it can be tightened to close the gas outlet pipe to prevent gas leakage. When gas transmission is required, the sealing cover can be unscrewed to ensure smooth passage of gas. At the same time, the sealing cover 93 can be replaced by a control valve. Using the manual or electric switch mechanism of the control valve, the user can complete the gas output operation more quickly, reducing waiting time; Specifically, a conical push block 53 is fixedly installed at one end of the sealing plate 5 adjacent to the transparent isolation cover 2, a conical push groove 22 is opened in the transparent isolation cover 2, and the conical push block 53 and the conical push groove 22 are correspondingly arranged; As the sealing plate 5 is gradually pushed forward, the conical push block 53 will penetrate into the conical push groove 22 in the transparent isolation cover 2. Since both are conical designs, the sealing pressure is naturally increased during the pushing process, ensuring the close fit between the sealing plate 5 and the transparent isolation cover 2, and reducing the possibility of gas leakage. When the sealing plate 5 pushes the conical push block 53 to move forward, the cutting edge of the conical push block 53 will exert a cutting force on the soil around the plant root zone. This force mainly comes from the pushing force of the sealing plate 5 and the gravity of the conical push block 53 itself, and the effective cutting of the soil is achieved under the joint action. When the central collection tube 3 is installed in place, the magnet 1 74 and the magnet 2 84 are attracted, and the collection channel is opened. At the same time, the conical push block 53 on the sealing plate 5 will also automatically embed into the conical push groove 22 in the transparent isolation cover 2 to complete the sealing action. On the contrary, when the central collection tube 3 is removed, the contact pressure between the sealing plate 5 and the transparent isolation cover 2 is reduced, and finally completely separated; Specifically, a handle 15 is symmetrically fixedly installed on the upper end of the central frame 1, and the handle 15 is symmetrically arranged on both sides of the central collection tube 3, and a handle 2 31 is symmetrically fixedly installed on the upper end of the central collection tube 3; The handle 15 is symmetrically arranged on both sides of the upper end of the central frame 1, and is mainly used to assist the user in applying force when installing or removing the central collection tube 3. It can provide a stable gripping point, making the operation more labor-saving and safe. The handle 2 31 is symmetrically fixedly installed on both sides of the upper end of the central collection tube 3, and corresponds to the handle 15. They are not only convenient for lifting the central collection tube 3 alone, but also can ensure the stable connection and synchronous movement between the two when used in conjunction with the central frame 1; A method for in situ determination of plant root respiration. S1, preparation phase S11, set the experimental conditions: set the target plant roots on one side as the experimental group, and only set the soil on the other side as the control group; S12, equipment assembly: first, place the center frame 1 at a predetermined position and ensure that it is stable, then install the transparent isolation cover 2 on both sides of the center frame 1 to maintain mirror symmetry. At this time, the lower end opening of the transparent isolation cover 2 should be ready to receive plant roots or control group soil; S13, installing the central collection tube 3: placing the central collection tube 3 with the partition assembly 6 into the placement area 12 on the central frame 1, and ensuring that the central collection tube 3 is firmly fixed on the central frame 1 through the cooperation between the external attachment 9 and the docking groove 14. At the same time, the design of the handle 1 15 and the handle 2 31 makes this process more convenient; S2, sealing and isolation stage S21, creating a micro-environment: starting the servo motor 41, driving the connecting shaft 45 to rotate through the bevel gear 1 42 and the bevel gear 2 43, thereby pushing the sealing plate 5 into the transparent isolation cover 2 to form a closed space, and the conical push block 53 on the sealing plate 5 will gradually embed into the conical push groove 22 in the transparent isolation cover 2, thereby increasing the sealing pressure and reducing the possibility of gas leakage; S22, water circulation: the ion exchange membrane 52 in the through hole 51 allows water to pass through but restricts the circulation of most gas molecules, thus maintaining a relatively stable gas environment in the measurement area; S3, gas collection stage S31, the collection channel is opened: when the central collection tube 3 is correctly installed, the magnet 1 74 in the sealing member 1 7 and the magnet 2 84 in the sealing member 2 8 attract and engage with each other, and with the attraction between the magnets, the sealing plugs of the sealing member 1 7 and the sealing member 2 8 are respectively pulled open, so that the collection channel is opened; S32, multi-stage telescopic cylinder action: the multi-stage telescopic cylinder 61 adjusts its telescopic length according to the preset program or external control signal, drives the connecting column 63 to move up and down, thereby driving the lateral suction plate 65 to change the volume of the collection chamber. As the volume of the collection chamber increases, the internal air pressure decreases, forming a negative pressure environment, which prompts the external gas to enter the collection chamber through the collection channel; S33, stratified sampling: two collection chambers at the same height are set, corresponding to the experimental group and the control group respectively. By setting the working cycle of the multi-stage telescopic cylinder 61 and adjusting the position of the horizontal suction plate 65 at regular intervals, gas samples at different soil depths can be collected multiple times on the same day to reveal the daily variation characteristics of root respiration; S4, Data processing and analysis phase S41, gas sample extraction: After completing one gas extraction, the spring 1 73 returns to its original state, pushing the sealing plug 1 72 to reclose the central hole 1 712; similarly, the spring 2 83 also returns to its original state, pushing the sealing plug 2 82 to close the central hole 2 812, thereby ensuring that the collected gas sample is safely retained in the collection chamber and is ready to be transported to the laboratory for inspection; S42, data analysis: Bring the collected gas samples back to the laboratory, and use professional analytical instruments such as infrared gas analyzers to measure the changes in CO2 concentration. By comparing the data of the experimental group and the control group, the CO2 emissions caused only by plant roots can be obtained, and then the contribution of root respiration to the total soil respiration can be evaluated.

[0027] Working principle: First, the core components of the equipment include the central frame 1, the transparent isolation cover 2 and the central collection tube 3. These components together constitute a small environment that can isolate the influence of the external atmosphere. The lower end opening of the transparent isolation cover 2 is used to place the plant roots, and the transparent isolation covers on both sides are respectively set as the experimental group (plant roots and soil) and the control group (soil only) to evaluate the background gas flux. This design allows researchers to distinguish the additional CO2 emissions caused by plant roots and reduce the errors caused by time and space differences. The sealing plate 5 cooperates with the driving component 4 and closes when necessary to form a completely enclosed space to ensure the stability of the internal environment. The ion exchange membrane 52 in the through hole 51 allows water to pass through but restricts the circulation of most gas molecules to maintain a relatively stable gas environment in the measurement area. This design not only maintains the natural state of the rhizosphere environment, but also enhances the isolation effect, so that water can be normally supplied to the roots, while gas exchange is controlled. A partition component 6 is provided in the central collection tube 3 to divide the central collection tube 3 into It is divided into several independent collection chambers, each of which corresponds to a collection channel at a specific height, to ensure that gas samples obtained from different soil depths will not mix, which helps to obtain information on changes in gas concentration at different soil depths and helps to understand the changing patterns of root respiration with soil profiles. In addition, the equipment is also equipped with a sealing member 1 7 and a sealing member 2 8, which are respectively located in the collection channel in the central collection tube 3 and in the collection channel between the central frame 1 and the transparent isolation cover 2. Through the action of springs and magnets, they remain closed when there is no need to extract gas samples to prevent gas mixing; when it is necessary to extract samples, the sealing member can be opened by an external control device, and closed again after the gas extraction is completed, ensuring that each gas sample collected is independent and uncontaminated. Finally, for ease of operation, the equipment is symmetrically equipped with a handle 15 on the upper end of the central frame 1, and a handle 2 31 is also installed on the upper end of the central collection tube 3. These two handles not only facilitate users to lift or remove the central collection tube 3, but also ensure stable connection and synchronous movement between the two.

[0028] It should be noted that, in this article, relational terms such as first and second, etc. are only used to distinguish one entity or operation from another entity or operation, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Moreover, the terms "include", "comprise" or any other variants thereof are intended to cover non-exclusive inclusion, so that a process, method, article or device including a series of elements includes not only those elements, but also other elements not explicitly listed, or also includes elements inherent to such process, method, article or device.

[0029] Finally, it should be noted that the above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Although the present invention has been described in detail with reference to the aforementioned embodiments, those skilled in the art can still modify the technical solutions described in the aforementioned embodiments or replace some of the technical features therein by equivalents. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present invention shall be included in the protection scope of the present invention.

Claims

1. An in-situ measuring device for plant root respiration, comprising a central frame (1), a transparent isolation cover (2) and a central collection tube (3), characterized in that: The transparent isolation cover (2) is arranged on both sides of the central frame (1) in a mirror-symmetrical manner. The lower end of the transparent isolation cover (2) is opened for placing plant roots. A sealing groove (11) is provided between the central frame (1) and the transparent isolation cover (2). A sealing plate (5) is movably installed in the sealing groove (11) through a driving component (4). A closed measurement area is formed between the transparent isolation cover (2) and the sealing plate (5) for sealing and isolating plant roots. One end of the sealing plate (5) adjacent to the transparent isolation cover (2) is evenly distributed with through holes (51). An ion exchange membrane (52) is provided in the middle of the through hole (51); a placement area (12) is provided in the middle of the upper end of the central frame (1); the central collection tube (3) is arranged in the placement area (12); a collection channel is provided between the central frame (1), the transparent isolation cover (2) and the central collection tube (3); the collection channels are arranged in a linear array along the height direction of the transparent isolation cover (2); a partition assembly (6) is provided in the central collection tube (3) for partitioning the central collection tube (3) into a plurality of collection chambers; the collection chambers and the collection channels are arranged in a one-to-one correspondence.

2. The in-situ measuring device for plant root respiration according to claim 1, characterized in that: The driving assembly (4) comprises a servo motor (41), a bevel gear one (42), a bevel gear two (43), a shaft seat (44) and a connecting shaft (45); a driving chamber (13) is provided at the bottom of the central frame (1); the servo motor (41) is fixedly mounted on the top of the driving chamber (13); the output end of the servo motor (41) is fixedly mounted with the bevel gear one (42); the shaft seat (44) is symmetrically arranged in the driving chamber (13); the connecting shaft (45) is movably mounted in the shaft seat (44); the bevel gear two (43) is fixedly mounted on one end of the connecting shaft (45) adjacent to the bevel gear one (42); the bevel gear two (43) is respectively meshedly connected with the bevel gear one (42); and the end of the connecting shaft (45) away from the bevel gear one (42) is threadedly connected in the corresponding sealing plate (5).

3. The in-situ measuring device for plant root respiration according to claim 1, characterized in that: The partition assembly (6) comprises a multi-stage telescopic cylinder (61), a transverse partition plate (62), a connecting column (63), a longitudinal partition plate (64) and a transverse suction plate (65); the multi-stage telescopic cylinder (61) is fixedly mounted on the top wall of the central collection tube (3) and the connecting column (63) is fixedly mounted on the telescopic end of the multi-stage telescopic cylinder (61); the longitudinal partition plate (64) is symmetrically arranged in the central collection tube (3); the transverse suction plate (65) and the transverse partition plate (62) are respectively arranged on the connecting column (63) and the longitudinal partition plate (64) are symmetrically arranged in the central collection tube (3); The collecting channels are arranged alternately from top to bottom on both sides of the connecting column (63); the collecting channels are located between the transverse suction plates (65) and the transverse partition plates (62); the transverse partition plates (62) are fixedly mounted on the inner side wall of the central collecting tube (3); the transverse suction plates (65) are fixedly mounted on the side walls of the connecting columns (63); the central collecting tube (3), the transverse partition plates (62), the connecting columns (63), the longitudinal partition plates (64) and the transverse suction plates (65) together form the collecting chamber.

4. The in-situ measuring device for plant root respiration according to claim 1, characterized in that: A sealing member 1 (7) and a sealing member 2 (8) are respectively provided in the collection channel. The sealing member 1 (7) is arranged in the collection channel in the central collection tube (3), and the sealing member 2 (8) is arranged in the collection channel in the central frame (1) and the transparent isolation cover (2). The sealing member 1 (7) and the sealing member 2 (8) are arranged correspondingly.

5. The in-situ measuring device for plant root respiration according to claim 4, characterized in that: The sealing member (7) comprises a plug (71), a sealing plug (72), a spring (73) and a magnet (74); a flow chamber (711) is provided in the plug (71); a central hole (712) is provided through one end of the flow chamber (711) adjacent to the collection chamber; the central hole (712) is located in the middle of the side wall of the plug (71); an edge hole (712) is provided through one end of the flow chamber (711) away from the collection chamber. 3), the edge holes (713) are arranged in a circular array on the side wall of the plug (71), the edge holes (713) and the central hole (712) are connected through the circulation chamber (711), the spring (73) is fixedly installed in the circulation chamber (711) at one end away from the collection chamber, and the sealing plug (72) is fixedly installed at the telescopic end of the spring (73), and the magnet (74) is embedded in the sealing plug (72).

6. The in-situ measuring device for plant root respiration according to claim 5, characterized in that: The second sealing member (8) comprises a second plug (81), a second sealing plug (82), a second spring (83), a second magnet (84) and a filter head (85). The second plug (81) is provided with a second flow chamber (811). The second flow chamber (811) is provided with a second central hole (812) at one end adjacent to the transparent isolation cover (2). The second central hole (812) is located in the middle of the side wall of the second plug (81). The second flow chamber (811) is provided with a second edge hole (813) at one end away from the transparent isolation cover (2). The second edge holes (813) are arranged in a circular array on the side wall of the second plug (81). The second edge holes (813) and the second central hole (812) are arranged in a circular array on the side wall of the second plug (81). (812) are connected through the second circulation chamber (811), the second spring (83) is fixedly installed in the second circulation chamber (811) at one end away from the transparent isolation cover (2), and the second sealing plug (82) is fixedly installed at the telescopic end of the second spring (83), the second magnet (84) is embedded in the second sealing plug (82), the second magnet (84) and the corresponding first magnet (74) are attracted to each other, the second plug (81) is threadedly connected to the filter head (85) at one end adjacent to the transparent isolation cover (2), the inner side wall of the transparent isolation cover (2) is provided with an embedding groove (21), and the filter head (85) and the embedding groove (21) are arranged in a one-to-one correspondence.

7. The in-situ measuring device for plant root respiration according to claim 1, characterized in that: The side wall of the central collection tube (3) is provided with an external accessory (9), and the external accessory (9) is arranged on the side wall of the central collection tube (3) in a mirror-symmetrical manner. The side wall of the placement area (12) is symmetrically provided with a docking groove (14), and the external accessory (9) is arranged in the corresponding docking groove (14). The external accessory (9) comprises an external connection block (91), an air outlet pipe (92) and a sealing cover (93). The external connection block (91) is symmetrically fixedly installed on the side wall of the central collection tube (3), and the external connection block (91) is movably installed in the corresponding docking groove (14). The air outlet pipes (92) are evenly distributed between the external connection blocks (91), and the air outlet pipes (92) and the collection chamber are arranged in a one-to-one correspondence. The air outlet pipe (92) is threadedly connected to the sealing cover (93).

8. The in-situ measuring device for plant root respiration according to claim 1, characterized in that: A conical propulsion block (53) is fixedly mounted on one end of the sealing plate (5) adjacent to the transparent isolation cover (2), a conical propulsion groove (22) is provided in the transparent isolation cover (2), and the conical propulsion block (53) and the conical propulsion groove (22) are arranged correspondingly.

9. The in-situ measuring device for plant root respiration according to claim 1, characterized in that: A handle 1 (15) is symmetrically fixedly mounted on the upper end of the central frame (1), and the handle 1 (15) is symmetrically arranged on both sides of the central collection tube (3). A handle 2 (31) is symmetrically fixedly mounted on the upper end of the central collection tube (3).

10. The in-situ determination method of plant root respiration according to any one of claims 1 to 9, characterized in that: S1, preparation phase S11, set the experimental conditions: set the target plant roots on one side as the experimental group, and only set the soil on the other side as the control group; S12, equipment assembly: first, place the center frame (1) at a predetermined position and ensure that it is stable, then install the transparent isolation cover (2) on both sides of the center frame (1) to maintain mirror symmetry. At this time, the lower end opening of the transparent isolation cover (2) should be ready to receive plant roots or control group soil; S13, installing the central collection tube (3): placing the central collection tube (3) with the partition assembly (6) into the placement area (12) on the central frame (1), and ensuring that the central collection tube (3) is firmly fixed on the central frame (1) through the cooperation of the external attachment (9) and the docking groove (14). At the same time, the design of the handle 1 (15) and the handle 2 (31) makes this process more convenient; S2, sealing and isolation stage S21, creating a micro-environment: starting the servo motor (41), driving the connecting shaft (45) to rotate through the bevel gear 1 (42) and the bevel gear 2 (43), thereby pushing the sealing plate (5) into the transparent isolation cover (2) to form a closed space, and the conical push block (53) on the sealing plate (5) will gradually embed into the conical push groove (22) in the transparent isolation cover (2), thereby increasing the sealing pressure and reducing the possibility of gas leakage; S22, water flow: the ion exchange membrane (52) in the through hole (51) allows water to pass through but restricts the flow of most gas molecules, thereby maintaining a relatively stable gas environment in the measurement area; S3, gas collection stage S31, the collection channel is opened: when the central collection tube (3) is correctly installed, the magnet 1 (74) in the sealing member 1 (7) and the magnet 2 (84) in the sealing member 2 (8) attract and engage with each other, and with the attraction between the magnets, the sealing plugs of the sealing member 1 (7) and the sealing member 2 (8) are respectively pulled apart, so that the collection channel is opened; S32, the multi-stage telescopic cylinder acts: the multi-stage telescopic cylinder (61) adjusts its telescopic length according to a preset program or an external control signal, drives the connecting column (63) to move up and down, thereby driving the lateral suction plate (65) to change the volume of the collection chamber. As the volume of the collection chamber increases, the internal air pressure decreases, forming a negative pressure environment, which promotes external gas to enter the collection chamber through the collection channel; S33, stratified sampling: two collection chambers at the same height are set, corresponding to the experimental group and the control group respectively. By setting the working cycle of the multi-stage telescopic cylinder (61) and adjusting the position of the horizontal suction plate (65) at regular intervals, gas samples at different soil depths can be collected multiple times on the same day to reveal the daily variation characteristics of root respiration; S4, Data processing and analysis phase S41, gas sample extraction: After completing a gas extraction, spring 1 (73) returns to its original state, pushing sealing plug 1 (72) to re-close central hole 1 (712); similarly, spring 2 (83) also returns to its original state, pushing sealing plug 2 (82) to close central hole 2 (812), thereby ensuring that the collected gas sample is safely retained in the collection chamber and is ready to be transported to the laboratory for inspection; S42, data analysis: Bring the collected gas samples back to the laboratory, and use professional analytical instruments such as infrared gas analyzers to measure the changes in CO2 concentration. By comparing the data of the experimental group and the control group, the CO2 emissions caused only by plant roots can be obtained, and then the contribution of root respiration to the total soil respiration can be evaluated.

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