Measurement chamber for measuring stem autotrophic respiration carbon dioxide flux

Abstract

This invention relates to the field of carbon dioxide flux measurement technology, and provides a measuring chamber for measuring carbon dioxide flux from tree trunk autotrophic respiration. The chamber includes a shell, a top plate, a bottom plate, and a side plate disposed between the top and bottom plates, which together form a breathing chamber. Both the top and bottom plates have trunk passages communicating with the breathing chamber. At least a portion of a gas analysis chamber is disposed within the breathing chamber and is in fluid communication with it. A drive assembly, disposed within the shell, is configured to drive the side plate to move, thereby allowing or isolating the breathing chamber from the outside environment. Before measurement begins, the breathing chamber is closed, forming a highly airtight gas sampling space. During non-measurement periods, the breathing chamber remains open, connected to the natural environment. This resolves the contradiction between airtightness and openness in measuring carbon dioxide flux from tree trunk autotrophic respiration, enabling long-term, multi-process, unattended automatic measurement without damaging the tree.

Description

Technical Field

[0001] This invention relates to the field of carbon dioxide flux measurement technology, and in particular to a measuring box for measuring carbon dioxide flux during autotrophic respiration of tree trunks. Background Technology

[0002] Related studies indicate that approximately half of the carbon stored in global terrestrial ecosystems is in forest ecosystems. Trees' metabolic respiration consumes the carbon fixed by the forest ecosystems themselves through photosynthesis and releases it into the atmosphere as carbon dioxide. Of this, the amount of carbon dioxide released from tree trunks is comparable to the respiration flux from leaves. Therefore, conducting tree trunk respiration observations is of great significance for studying the coupling relationship between individual plant carbon stock / flux, carbon metabolism patterns in forest ecosystems, and accurately assessing the global carbon budget.

[0003] In recent years, with increasing attention to the ecological significance of trunk respiration, related research both domestically and internationally has shown a significant upward trend. However, due to the relatively harsh and variable environment for field measurement of trunk carbon dioxide emission rates, and the high requirements for data observation accuracy, traditional measurement methods (such as index extrapolation methods and static alkaline absorption methods) are difficult to effectively guarantee accuracy and efficiency. Furthermore, the development of instruments and equipment for measuring trunk respiration has lagged behind for a long time. These issues have introduced certain uncertainties into previous research results and caused considerable inconvenience to the research that urgently needs to be carried out. Summary of the Invention

[0004] This invention provides a measuring chamber for measuring carbon dioxide flux during autotrophic respiration of tree trunks, which resolves the contradiction between airtightness and openness of the respiration chamber in the measurement of carbon dioxide flux during autotrophic respiration of tree trunks, and realizes long-term, multi-process unattended automatic measurement without damaging the tree.

[0005] This invention provides a measuring box for measuring carbon dioxide flux during autotrophic respiration in tree trunks, comprising: The housing includes a top plate, a bottom plate, and a side plate disposed between the top plate and the bottom plate, wherein the top plate, the bottom plate, and the side plate enclose a breathing chamber; both the top plate and the bottom plate are provided with trunk channels communicating with the breathing chamber; wherein at least a portion of the gas analysis chamber is disposed within the breathing chamber, and the gas analysis chamber is in fluid communication with the breathing chamber; A drive assembly disposed in the housing and configured to drive the side plate to move such that the breathing chamber is connected to or isolated from the outside.

[0006] According to the present invention, a measuring box for measuring carbon dioxide flux of tree trunk autotrophic respiration is provided, wherein each of the top plate and the bottom plate includes a connected annular plate and an annular cylinder.

[0007] According to the present invention, a measuring box for measuring carbon dioxide flux of tree trunk autotrophic respiration is provided, each of the top plate and the bottom plate further includes a connector, and the annular plate of the top plate is connected to the annular plate of the bottom plate through the connector.

[0008] According to the present invention, a measuring box for measuring carbon dioxide flux during autotrophic respiration of tree trunks further includes: The sealing sleeve is provided in both the trunk channel corresponding to the top plate and the trunk channel corresponding to the bottom plate.

[0009] According to the present invention, a measuring box for measuring carbon dioxide flux of tree trunk autotrophic respiration is provided, wherein the sealing sleeve comprises a weather-resistant layer, a rubber layer, a support layer and a rigid layer arranged sequentially from the inside to the outside.

[0010] According to the present invention, a measuring box for measuring carbon dioxide flux of autotrophic respiration in tree trunks is provided. The driving assembly includes a driving motor, a lead screw and a lead screw nut. The driving motor is disposed on the top surface of the top plate. One end of the lead screw is connected to the bottom plate and the other end passes through the top plate to be connected to the output shaft of the driving motor. The lead screw nut is threadedly connected to the lead screw and is connected to the inner surface of the side plate.

[0011] According to the present invention, a measuring box for measuring carbon dioxide flux of autotrophic respiration in tree trunks is provided. The driving assembly further includes a first limit sensor and a second limit sensor. The first limit sensor is used to send a first positioning signal based on the position of the lead screw nut when it approaches the top plate, and the second limit sensor is used to send a second positioning signal based on the position of the lead screw nut when it approaches the bottom plate. The driving motor stops driving after acquiring the first positioning signal or the second positioning signal.

[0012] According to the present invention, a measuring box for measuring carbon dioxide flux of autotrophic respiration in tree trunks includes a side plate having a first end and a second end disposed opposite to each other. The second end is provided with a sealing flange extending toward the respiration chamber. A sealing rib is provided on the inner surface of the side plate, and the sealing rib extends from the first end to the sealing flange. A first snap-fit ​​groove and a second snap-fit ​​groove are provided on the bottom surface of the top plate. The first snap-fit ​​groove is adapted to the first end, and the second snap-fit ​​groove is adapted to the sealing rib. The bottom plate is provided with a clearance groove adapted to the sealing rib.

[0013] According to the present invention, a measuring box for measuring carbon dioxide flux of tree trunk autotrophic respiration is provided, wherein each of the top plate and the bottom plate includes a first part and a second part arranged in an axisymmetric manner; and the side plate includes two third parts arranged in a rotationally symmetrical manner.

[0014] According to the present invention, a measuring box for measuring carbon dioxide flux during autotrophic respiration of tree trunks further includes: A protective cover, which is a ring-shaped structure, is located above the top surface of the top plate to protect the functional devices located on the top surface of the top plate. The gas analysis chamber includes an analysis chamber body and a heat dissipation assembly. The heat dissipation assembly is used to dissipate heat from the analysis chamber body. The heat dissipation assembly includes a heat-conducting element and a heat dissipation element. One end of the heat-conducting element is in thermal communication with the analysis chamber body, and the other end passes through the top plate and is connected to the heat dissipation element.

[0015] The present invention provides a measuring chamber for measuring carbon dioxide flux during autotrophic respiration of tree trunks. Before measurement begins, the respiration chamber is closed, forming a highly airtight gas sampling space; during non-measurement periods, the respiration chamber remains open and connected to the natural environment. This resolves the contradiction between airtightness and openness of the respiration chamber in the determination of carbon dioxide flux during autotrophic respiration of tree trunks, enabling long-term, multi-process, unattended automatic measurement without damaging the tree. Attached Figure Description

[0016] To more clearly illustrate the technical solutions in this invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are some embodiments of this invention. For those skilled in the art, other drawings can be obtained from these drawings without creative effort.

[0017] Figure 1 This is a schematic diagram of the measuring box provided by the present invention.

[0018] Figure 2 This is an exploded schematic diagram of the trunk autotrophic respiration carbon dioxide flux measurement device provided by the present invention.

[0019] Figure 3 This is a schematic diagram of the side plate provided by the present invention.

[0020] Figure 4 This is one of the structural schematic diagrams of the housing provided by the present invention (with side plates removed).

[0021] Figure 5 This is the second structural schematic diagram of the housing provided by the present invention (with side plates removed).

[0022] Figure 6 This is a flowchart illustrating the method for measuring carbon dioxide flux during autotrophic respiration in tree trunks provided by the present invention.

[0023] Figure 7 This is a block diagram of the tree trunk autotrophic respiration carbon dioxide flux measurement system provided by the present invention.

[0024] Figure 8 This is one of the schematic diagrams of the operation interface of the human-computer interaction module provided by the present invention.

[0025] Figure 9 This is the second schematic diagram of the operation interface of the human-computer interaction module provided by the present invention.

[0026] Figure 10 This is the third schematic diagram of the operation interface of the human-computer interaction module provided by the present invention.

[0027] Figure 11 This is the fourth schematic diagram of the operation interface of the human-computer interaction module provided by the present invention.

[0028] Figure 12 This is the fifth schematic diagram of the operation interface of the human-computer interaction module provided by the present invention.

[0029] Figure label: 1. Measuring box; 101. Breathing chamber; 102. Gas analysis chamber; 103. Trunk passage; 11. Shell; 111. Top plate; 1111. Annular plate; 1112. Annular cylinder; 1113. First snap-fit ​​groove; 1114. Second snap-fit ​​groove; 112. Bottom plate; 1121. Clearance groove; 113. Side plate; 1131. Sealing flange; 1132. Sealing rib; 114. Connector; 12. Drive assembly; 121. Drive motor; 122. Lead screw; 123. Lead screw nut; 13. Sealing sleeve; 14. Heat dissipation assembly; 141. Heat dissipation component; 142. Heat conduction component; 15. Protective cover; 2. Trunk growth sensor; 3. Control main board; 4. Human-machine interaction module. Detailed Implementation

[0030] To make the objectives, technical solutions, and advantages of this invention clearer, the technical solutions of this invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some, not all, of the embodiments of this invention. All other embodiments obtained by those skilled in the art based on the embodiments of this invention without creative effort are within the scope of protection of this invention.

[0031] Firstly, such as Figure 1 , Figure 2 and Figure 4 As shown, the trunk autotrophic respiration carbon dioxide flux measurement device of this invention includes: a measurement box 1, a sensor module, and a control motherboard 3.

[0032] The measuring box 1 is provided with a breathing chamber 101 and a trunk passage 103 connected to the breathing chamber 101. A gas analysis chamber 102 is also provided in the breathing chamber 101 and is connected to the breathing chamber 101; wherein, at least part of the gas analysis chamber 102 is located in the breathing chamber 101.

[0033] The sensor module is used to measure the carbon dioxide concentration in the breathing chamber 101, the water vapor mole fraction in the breathing chamber 101, and the diameter of the tree trunk enclosed by the breathing chamber 101. The sensor module is electrically connected to the control motherboard 3. The control motherboard 3 is configured to acquire the total effective gas volume, the surface area of ​​the tree trunk wrapped by the breathing chamber, the water vapor mole fraction in the breathing chamber, and the change in carbon dioxide concentration in the breathing chamber within a certain time period; and to determine the carbon dioxide flux of the tree trunk's autotrophic respiration based on the total effective gas volume, the tree trunk surface area, the water vapor mole fraction, the change in carbon dioxide concentration, and the measurement time interval.

[0034] It should be noted that the shape of the measuring box 1 can be cylindrical, cuboid, or other shapes, and is not specifically limited here. The measuring box 1 includes a shell 11, which includes a top plate 111, a bottom plate 112, and a side plate 113 disposed between the top plate 111 and the bottom plate 112. The top plate 111, the bottom plate 112, and the side plate 113 enclose a breathing chamber 101. Both the top plate 111 and the bottom plate 112 are provided with a trunk channel 103 communicating with the breathing chamber 101. Each of the top plate 111 and the bottom plate 112 includes a connected annular plate 1111 and an annular cylinder 1112. Thus, a breathing chamber 101 is formed by the annular plate 1111 of the side plate 113, the annular plate 1111 of the top plate 111, and the annular plate 1111 of the bottom plate 112. A portion of the gas analysis chamber 102 is located within the breathing chamber 101. In other words, besides the functional components located within the breathing chamber 101, the gas analysis chamber 102 also occupies a portion of the space within the breathing chamber 101. Furthermore, both the annular cylinder 1112 of the top plate 111 and the annular cylinder 1112 of the bottom plate 112 form corresponding trunk channels 103.

[0035] Understandably, placing part of the gas analysis chamber 102 inside the breathing chamber 101 allows the gas analysis chamber 102 to directly sample and analyze from the breathing chamber 101. This eliminates the need for a gas sampling tube connection between the breathing chamber 101 and the gas analysis chamber 102, achieving a zero-distance connection. This solves the problems of low observation accuracy, inconvenient observation, and high maintenance costs caused by the long gas path between the breathing chamber 101 and the gas analysis chamber 102, while also improving equipment integration and safety.

[0036] In practical applications, the sensor module can send data such as the carbon dioxide concentration in the respiration chamber 101, the molar fraction of water vapor in the respiration chamber 101, and the diameter of the tree trunk enclosed by the respiration chamber 101 to the control motherboard 3. The control motherboard 3 determines the total effective gas volume, the surface area of ​​the tree trunk enclosed by the respiration chamber 101, the molar fraction of water vapor in the respiration chamber 101, and the change in carbon dioxide concentration in the respiration chamber 101 within a certain time period based on the received data. Furthermore, it determines the autotrophic carbon dioxide flux of the tree trunk based on the total effective gas volume, the surface area of ​​the tree trunk enclosed by the respiration chamber 101, the molar fraction of water vapor in the respiration chamber 101, the change in carbon dioxide concentration in the respiration chamber 101, and the measurement time interval. This allows for convenient, rapid, and accurate measurement of the autotrophic carbon dioxide flux of the tree trunk.

[0037] During long-term field measurements, sudden changes in temperature between day and night (such as a sudden rise in temperature at noon and a sudden drop at night) may occur. In such cases, it is necessary to correct the carbon dioxide concentration according to the ideal gas law to eliminate the influence of environmental changes on the molar volume of the gas. In an optional embodiment, the sensor module is also used to measure the atmospheric pressure and gas temperature inside the breathing chamber 101; wherein, the control motherboard 3 is also configured to correct the carbon dioxide concentration change value according to the ideal gas law.

[0038] Specifically, the method for obtaining the carbon dioxide flux of the tree trunk's autotrophic respiration is as follows: ; Where F is the carbon dioxide flux of trunk autotrophic respiration (μmolm). -2 s -1 ); ΔC is the change in carbon dioxide concentration (ppm) in breathing chamber 101; Δt is the measurement time interval (s); V total Total effective gas volume (m³) 3 A is the surface area of ​​the tree trunk (m²). 2 P is the atmospheric pressure at the measurement point (Pa); R is the ideal gas constant (8.314 Pa·m). 3 ·mol -1 ·K -1 T is the absolute temperature (K); W is the water vapor mole fraction (mmol / mol).

[0039] In an optional embodiment, the sensor module includes an atmospheric carbon dioxide and water vapor infrared analysis sensor, an atmospheric temperature sensor, an atmospheric relative humidity sensor, an atmospheric pressure sensor, and a tree trunk growth sensor 2. The atmospheric carbon dioxide and water vapor infrared analysis sensor is located in the gas analysis chamber 102, while the control motherboard 3, the atmospheric temperature sensor, the atmospheric relative humidity sensor, the atmospheric pressure sensor, and the tree trunk growth sensor 2 are located in the breathing chamber 101.

[0040] Specifically, the atmospheric carbon dioxide and water vapor infrared analysis sensor is used to measure the carbon dioxide concentration in the gas; the atmospheric temperature sensor and atmospheric relative humidity sensor are used to measure the temperature and humidity of the gas, respectively; and the atmospheric pressure sensor is used to measure the air pressure. The tree trunk growth sensor 2 can be used to measure the diameter of the tree trunk.

[0041] In an optional embodiment, the control board 3 is further configured to determine the total effective gas volume based on the volume of the gas analysis chamber 102 and the volume of the breathing chamber 101 over a certain period of time. The control board 3 is also configured to determine the volume of the breathing chamber 101 based on the total volume of the breathing chamber 101, the volume occupied within the breathing chamber 101, and the volume of the tree trunk enclosed by the breathing chamber 101 over a certain period of time.

[0042] Specifically, the total effective gas volume is obtained by adding the chamber volume of the gas analysis chamber 102 to the volume of the breathing chamber 101 within a certain time period. Among them, the volume of the breathing chamber 101 within a certain time period is equal to the total volume of the breathing chamber 101, minus the volume of the occupied part of the breathing chamber 101, and then minus the volume of the tree trunk enclosed by the breathing chamber 101 within that time period.

[0043] In the tree trunk autotrophic respiration carbon dioxide flux measurement device of the present invention, the respiration chamber 101 and the analysis chamber are seamlessly connected, and the total effective gas volume is the sum of the volumes of the respiration chamber 101 and the analysis chamber. Once the model of the analysis chamber is determined, its volume can be set to a constant and initialized. The volume of the respiration chamber 101 is affected by the total volume of the respiration chamber 101, the volume occupied by the sensor module, the volume occupied by the drive component 12, and the trunk volume. After the measuring device leaves the factory, the total volume of the respiration chamber 101, the volume of the sensor module, and the volume of the drive component 12 remain fixed and can be set to constant values ​​and initialized. However, during long-term field measurements, only the trunk volume changes, becoming the only variable in the total effective gas volume. Thus, the trunk volume can be determined after the trunk diameter is measured, thereby achieving real-time measurement of the total effective gas volume without manual intervention.

[0044] In an optional embodiment, the control board 3 is also configured to determine the volume of the tree trunk enclosed by the breathing chamber 101 based on the height of the breathing chamber 101 and the average diameter of the tree trunk enclosed by the breathing chamber 101 over a certain period of time.

[0045] Specifically, the volume of the tree trunk enclosed by breathing chamber 101 is obtained as follows: ; Where V1 is the volume of the tree trunk enclosed by the breathing chamber 101 (m³). 3 D is the average trunk diameter (m); π represents pi; H represents the height of the breathing chamber 101.

[0046] Understandably, within the area of ​​the tree trunk enclosed by the breathing chamber 101, multiple tree trunk growth sensors 2 are used for long-term automatic measurement to obtain multiple tree trunk circumference data. Based on these data, the volume of the tree trunk covered by the breathing chamber 101 is accurately calculated, thereby providing data support for the high-precision calculation of the total effective gas volume in the measurement of carbon dioxide flux during tree trunk autotrophic respiration.

[0047] Therefore, the specific method for obtaining the volume of respiration chamber 101 within a certain time period is as follows: in, The volume of the breathing chamber is 101 (m³). 3 ); The total volume of the breathing chamber 101 (m³) 3 ); The volume of the occupied portion within the breathing chamber 101 (m³) 3 ).

[0048] The specific method for obtaining the total effective gas volume is as follows: in, V total Total effective gas volume (m³) 3 ); The volume of the gas analysis chamber 102 (m³) 3 ).

[0049] In an optional embodiment, the control board 3 is also configured to determine the trunk surface area based on the height of the breathing chamber 101 and the average diameter of the trunk enclosed by the breathing chamber 101 over a certain period of time.

[0050] Specifically, the method for obtaining the trunk surface area is as follows: ; Where A is the surface area of ​​the tree trunk (m²) 2 C is the circumference of the trunk (i.e., perimeter, m); H is the height of the breathing chamber 101 (m).

[0051] Among them, C 围径 The calculation is based on the following formula: Where D is the average diameter of the tree trunk (m); Pi is the mathematical constant of a circle.

[0052] Therefore, the formula for calculating the surface area of ​​a tree trunk is derived: The following explains the change in carbon dioxide concentration (ΔC). Here, the change in carbon dioxide concentration refers to the initial and final concentrations of carbon dioxide in breathing chamber 101.

[0053] The formula reflecting the change in carbon dioxide concentration over a period of time is as follows: ΔC = C2 - C1; Where ΔC is the change in carbon dioxide concentration (ppm); C1 is the initial concentration of carbon dioxide measured (ppm); and C2 is the final concentration of carbon dioxide measured (ppm).

[0054] The measurement interval (Δt) is explained below. The measurement interval refers to the time interval between the start and end of the measurement of carbon dioxide concentration in breathing chamber 101.

[0055] The formula for the measurement interval Δt is as follows: Δt = t2 - t1; Where Δt is the interval time for measuring the change in carbon dioxide concentration (s); t1 is the recording time when the initial concentration of carbon dioxide is measured (s); and t2 is the recording time when the concentration of carbon dioxide is measured to terminate (s).

[0056] Based on the above analysis, we can conclude that: .

[0057] Where F is the carbon dioxide flux of trunk autotrophic respiration (μmolm). -2 s -1 ); ΔC is the change in carbon dioxide concentration (ppm) in breathing chamber 101; Δt is the measurement time interval (s); V total Total effective gas volume (m³) 3 A is the surface area of ​​the tree trunk (m²). 2 P is the atmospheric pressure at the measurement point (Pa); R is the ideal gas constant (8.314 Pa·m). 3 ·mol -1 ·K -1 T is the absolute temperature (K); W is the water vapor mole fraction (mmol / mol).

[0058] In an optional embodiment, the trunk autotrophic respiration carbon dioxide flux measurement device further includes: A safety protection module is provided to protect the measuring box 1. The safety protection measures include at least one of chemical protection, acoustic protection, and optical protection. For example, the safety protection measures include chemical protection, acoustic protection, and optical protection.

[0059] Specifically, the safety protection module is used to prevent biological intrusion into the measurement box 1 (such as rodents gnawing on it, birds building nests, spiders spinning webs, etc.), to ensure the normal operation of the equipment, ensure data quality, and reduce maintenance difficulty. This safety protection module can include three components: chemical protection, acoustic protection, and optical protection. Chemical protection uses the natural volatilization of chemical agents to repel small animals; chemical storage chambers can be set up inside or outside the measurement box 1. Acoustic protection uses ultrasound to repel birds and other animals; the ultrasonic protection component can be installed inside the measurement box 1. Optical protection uses the strong reflective properties of light to repel birds and large animals; optical protection components can be located at the top and bottom of the measurement box 1.

[0060] In an optional embodiment, the trunk autotrophic respiration carbon dioxide flux measurement device further includes: a power supply module, a sensor module, and a control motherboard 3, all of which are electrically connected to the power supply module.

[0061] Specifically, the power supply module is responsible for providing a safe and stable power supply to the equipment. This invention provides both DC and AC power supply modes, prioritizing AC power when conditions are suitable, followed by DC power. The AC power is provided by solar power generation; externally input AC power is stepped down by the power supply module before use. The DC power is supplied by both solar panels and a solar controller. The power supply module is equipped with a storage battery. The solar panels, solar controller, and battery are spatially independent of the measuring box 1, connected via electrical / signal lines. Both AC and DC power can charge the battery to achieve power storage.

[0062] In an optional embodiment, the trunk autotrophic respiration carbon dioxide flux measurement device further includes a human-machine interface module 4, which is electrically connected to the control motherboard 3. The human-machine interface module is configured to receive parameter setting instructions and measurement start, pause, and end control instructions, as well as to display data information. In other words, the human-machine interface module has the function of allowing manual intervention in the measurement process. The human-machine interface module 4 may include a touchscreen, display screen, or buttons, etc.

[0063] Specifically, users can input and set equipment operating parameters through the human-machine interface module 4, including measurement interval, measurement time, recording time, carbon dioxide threshold, and the height of the breathing chamber 101. These parameters are transmitted to the control motherboard 3. For example, the control motherboard 3 controls the drive motor 121 at regular intervals according to the set parameters, enabling the breathing chamber 101 to switch between measurement and ventilation states. At the same time, the control motherboard 3 will activate the electronic functions of the safety protection module as set to ensure equipment safety.

[0064] In addition, various sensors in the sensor module can collect measurement data through the data acquisition and storage module, complete the A / D conversion, and then transmit the data to the control motherboard 3. The control motherboard 3 calculates the measurement results based on the model algorithm, and the measurement results are then transmitted back to the data acquisition and storage module for storage, and presented by the human-machine interaction module 4. In other words, the human-machine interaction module 4 is responsible for the visualization output of equipment status, observation data and results, and the display of the setting interface for equipment measurement parameters, realizing human interaction with the equipment.

[0065] The following is a detailed description of the human-computer interaction module 4.

[0066] like Figure 8 As shown, the main interface has two main functions: "Manual Measurement" and "Settings". Before the first measurement, the measuring device parameters must be set. Click the "Settings" icon to enter the parameter setting interface. Figure 9 As shown, in this settings interface, you can manually input parameters to achieve the measurement purpose. If no changes are needed, click "←" to return to the main interface. If changes have been made, click "OK" to set the parameters, and you will then return to the main interface. Figure 10 As shown, clicking "Manual Measurement" and then "Confirm" will cause the measuring device to perform a height measurement according to the preset measurement task. Clicking "Return" will reopen the main interface, and subsequent measurements will automatically be performed according to the preset parameters. Figure 11 As shown, after entering the measurement state, the atmospheric carbon dioxide and water vapor infrared analysis sensors need to preheat. A prompt interface and preheating progress display will pop up at this time. Figure 12 As shown, after preheating, enter the measurement interface. The measurement interface will display data such as "trunk CO2 flux" and "CO2 concentration change value" in real time. The data will be displayed in real time after each collection until the measurement cycle ends. Click "←" to return to the main interface.

[0067] Secondly, such as Figure 1 , Figure 2 and Figure 4 As shown, the measuring box 1 for measuring carbon dioxide flux during autotrophic respiration of tree trunks according to an embodiment of the present invention includes: The shell 11 includes a top plate 111, a bottom plate 112, and a side plate 113 disposed between the top plate 111 and the bottom plate 112. The side plate 113 can be a transparent plate. The top plate 111, the bottom plate 112, and the side plate 113 enclose a breathing chamber 101. Both the top plate 111 and the bottom plate 112 are provided with trunk channels 103 that communicate with the breathing chamber 101. At least a portion of the gas analysis chamber 102 is disposed within the breathing chamber 101, and the gas analysis chamber 102 is in fluid communication with the breathing chamber 101. A drive assembly 12 is disposed in the housing 11 and configured to drive the side plate 113 to move so that the breathing chamber 101 is connected to or isolated from the outside.

[0068] It should be noted that the drive component 12 is electrically connected to the control motherboard 3. This electrical connection refers to both electrical and signal connections. The control motherboard 3 can control the drive component 12 to perform corresponding actions. Before measurement begins, the respiration chamber 101 is closed, forming a highly airtight gas sampling space. During non-measurement periods, the respiration chamber 101 remains open, connected to the natural environment. This resolves the contradiction between the airtightness and openness of the respiration chamber 101 in the determination of carbon dioxide flux during tree trunk autotrophic respiration, enabling long-term, multi-process unattended automatic measurement without damaging the tree.

[0069] It is particularly important to note that in the measurement of carbon dioxide flux during trunk autotrophic respiration, the automatic opening and closing of the respiration chamber 101 is achieved through two parallel execution methods: one is control based on a preset maximum time limit for a single closed measurement of the respiration chamber 101; the other is control based on a preset threshold for the highest carbon dioxide concentration within the respiration chamber 101. The control motherboard 3 monitors in real time, and once a preset condition is met, it immediately executes the corresponding operation, thereby completing one closed measurement task of the respiration chamber 101. The preset parameter settings for these two methods mainly take into account the actual situation of the trunk autotrophic respiration intensity of different tree species, as well as the need for environmental protection for the natural growth of the trunk.

[0070] In optional embodiments, such as Figure 4As shown, each of the top plate 111 and the bottom plate 112 includes a connected annular plate 1111 and an annular cylinder 1112. The annular plate 1111 can be square, circular, or similar in shape. Thus, the annular cylinder 1112 forms a corresponding trunk passage 103. Specifically, the annular plate 1111 of the top plate 111 is horizontally positioned, its outer diameter determined according to the overall dimensions of the equipment and installation requirements. It has a certain thickness to ensure structural strength and withstand a certain amount of external force without significant deformation. The annular cylinder 1112 is vertically connected to the center of the annular plate 1111, either integrally formed with the annular plate 1111 or fixed together using reliable connection methods such as welding. The inner diameter of the annular cylinder 1112 is designed based on the average diameter of the trunk to be measured, ensuring that the trunk can pass through smoothly while leaving appropriate gaps for convenient equipment installation and subsequent operation. The bottom plate 112 has a similar structural design to the top plate 111, also including an annular plate 1111 and an annular cylinder 1112. The annular plate 1111 of the base plate 112 corresponds to the annular plate 1111 of the top plate 111, and their dimensions and thickness are designed according to similar principles. The annular cylinder 1112 of the base plate 112 is also vertically connected to the center of the annular plate 1111, and its inner diameter is the same as that of the annular cylinder 1112 of the top plate 111, so as to ensure that the tree trunk can vertically penetrate the structure formed by the top plate 111 and the base plate 112.

[0071] After the top plate 111 and the bottom plate 112 are installed together according to the design requirements, the annular cylinders 1112 of the top plate 111 and the bottom plate 112 are aligned to form a complete, vertical trunk passage 103. This trunk passage 103 provides space for the trunk to pass through, allowing the equipment to be installed and measured around the trunk. At the same time, the structure of the annular cylinder 1112 can limit and protect the trunk, ensuring stability during the measurement process, and thus ensuring the accuracy and reliability of the measurement results.

[0072] In practical applications, each of the top plate 111 and the bottom plate 112 also includes a connector 114. The annular plate 1111 of the top plate 111 is connected to the annular plate 1111 of the bottom plate 112 via the connector 114. The connector 114 can be a connecting rod. As an example, both ends of the connecting rod are threaded to pre-drilled threaded holes on the annular plates 1111 of the top plate 111 and 1111 of the bottom plate 112, respectively, thereby achieving reliable assembly of the top plate 111 and the bottom plate 112 to form a complete structure that meets practical usage requirements.

[0073] In optional embodiments, such as Figure 2 and Figure 4As shown, the measuring box 1 for measuring the carbon dioxide flux of tree trunk autotrophic respiration also includes a sealing sleeve 13. The sealing sleeve 13 is provided with the tree trunk channel 103 corresponding to the top plate 111 and the tree trunk channel 103 corresponding to the bottom plate 112.

[0074] Understandably, the sealing sleeve 13, as the component in the entire system that directly contacts the tree trunk, bears the load of the system and equipment. It employs a deformable and compressible multi-layered composite material structure, ensuring that while encasing the equipment in the tree trunk, it does not significantly stress the natural growth of the trunk. Based on this, the sealing sleeve 13 possesses characteristics of adapting to tree trunk growth, ensuring good airtightness between the breathing chamber 101 and the tree trunk, maintaining volume stability, and being friendly to tree growth. For equipment used in long-term field measurements, the sealing sleeve 13 solves the problems of adaptive adjustment of the installation components as the trunk diameter increases and the airtightness between the breathing chamber 101 and the tree trunk, improving the measurement accuracy of the equipment, reducing maintenance difficulty, and meeting the needs of long-term unattended field observations for ecological environment monitoring equipment.

[0075] In practical applications, the sealing sleeve 13 is a multi-layered structure consisting of a weather-resistant layer, a rubber layer, a support layer, and a rigid layer, arranged sequentially from the inside out, forming a ring with a certain variable inner diameter. From the innermost layer to the outermost layer, the weather-resistant layer is formed by applying a weather-resistant coating, isolating the external environment, protecting the central material, and extending the equipment's observation lifespan. The rubber layer, made of deformable material, can fill the gaps in irregularly shaped, rough tree trunks, allowing the sealing sleeve 13 to be tightly physically coupled with the tree trunk, improving the airtightness of the measuring box 1 at the mounting neck. The support layer is made of a material with high hardness, deformable under pressure, and good airtightness; when the tree trunk grows outwards and presses against the mounting neck, the support layer deforms accordingly. The rigid layer serves to fix the external shape of the inner layer and prevent physical damage. Furthermore, fasteners can be used to fix the sealing sleeve 13 to the tree trunk.

[0076] In optional embodiments, such as Figure 1 , Figure 2 and Figure 4 As shown, the drive assembly 12 includes a drive motor 121, a lead screw 122, and a lead screw nut 123. The drive motor 121 can be disposed on the top surface of the top plate 111. One end of the lead screw 122 is connected to the bottom plate 112, and the other end passes through the top plate 111 to be connected to the output shaft of the drive motor 121. The lead screw nut 123 is threadedly connected to the lead screw 122 and is connected to the inner surface of the side plate 113. In this way, the lead screw 122 can be rotatably disposed in the breathing chamber 101.

[0077] It should be noted that the drive motor 121 is a high-performance stepper motor, characterized by high precision and high torque output, capable of accurately controlling the rotation angle and speed to meet the precise movement requirements of the side plate 113 of the breathing chamber 101. The length of the lead screw 122 is designed according to the height of the breathing chamber 101 to ensure that it can completely cover the movement range of the side plate 113. The lead screw 122 is rotatably mounted in the breathing chamber 101 via two bearings, with one end of the lead screw 122 passing through the top plate 111 and connected to the output shaft of the drive motor 121 via a coupling. The lead screw nut 123 is threadedly connected to the lead screw 122, and by rotating the lead screw 122, the lead screw nut 123 can move linearly along the lead screw 122. The lead screw nut 123 can be connected to the inner surface of the side plate 113 by welding.

[0078] In actual operation, when the drive motor 121 receives the control signal sent by the control motherboard 3, it starts to rotate, driving the lead screw 122 to rotate through the coupling. Due to the threaded connection between the lead screw nut 123 and the lead screw 122, as well as the fixed connection with the side plate 113, the lead screw nut 123 will move linearly along the lead screw 122, thereby driving the side plate 113 to move and realizing the opening and closing action of the breathing chamber 101.

[0079] In practical applications, the drive assembly 12 further includes a first limit sensor and a second limit sensor. The first limit sensor sends a first positioning signal based on the position of the lead screw nut 123 when it approaches the top plate 111, and the second limit sensor sends a second positioning signal based on the position of the lead screw nut 123 when it approaches the bottom plate 112. The drive motor 121 stops driving after receiving either the first or second positioning signal. The first positioning signal indicates that the breathing chamber 101 is in a closed state, and the second positioning signal indicates that the breathing chamber 101 is in an open state.

[0080] It is particularly important to note that the drive motor 121, the first limit sensor, and the second limit sensor are all electrically connected to the control motherboard 3.

[0081] This invention breaks through the current situation where the components and modules in the measurement of carbon dioxide flux of tree trunk autotrophic respiration are separate and fragmented. It integrates the measurement box 1, control motherboard 3, sensor module, data acquisition and storage, human-computer interaction module 4, safety protection module, drive component 12 and power supply module into a unified design, and constructs a seamless tree trunk autotrophic respiration carbon dioxide flux measurement device. From the hardware architecture perspective, it solves the problems of system function redundancy, low degree of intelligence and automation, and inaccurate calculation results caused by poor integration in the existing technology.

[0082] In optional embodiments, such as Figure 1 , Figure 2 , Figure 3 , Figure 4 and Figure 5 As shown, the side plate 113 has a first end and a second end that are disposed opposite to each other. The second end is provided with a sealing flange 1131 extending toward the breathing chamber 101. The inner surface of the side plate 113 is provided with a sealing rib 1132, and the sealing rib 1132 extends from the first end to the sealing flange 1131. The bottom surface of the top plate 111 is provided with a first snap-fit ​​groove 1113 and a second snap-fit ​​groove 1114 that are connected. The first snap-fit ​​groove 1113 is adapted to the first end, and the second snap-fit ​​groove 1114 is adapted to the sealing rib 1132. The bottom plate 112 is provided with a relief groove 1121 that is adapted to the sealing rib 1132.

[0083] Specifically, the first snap-fit ​​groove 1113 is an annular snap-fit ​​groove, which is adapted to the top end face of the side plate 113. A sealing element, which can be weather-resistant rubber, can be provided on the top end face of the side plate 113. When the breather chamber 101 is closed, the top end face of the side plate 113 is inserted into the first snap-fit ​​groove 1113, at which time the weather-resistant rubber serves both as a seal and a buffer during operation. At the same time, a sealing element can also be provided on the top surface of the sealing flange 1131. When the breather chamber 101 is closed, the weather-resistant rubber on the sealing flange 1131 contacts the bottom surface of the base plate 112, which also serves the dual purpose of sealing and buffering during operation.

[0084] In practical applications, in order to facilitate the placement of the measuring box 1 on the tree trunk, each of the top plate 111 and the bottom plate 112 includes a first part and a second part arranged in an axisymmetric manner; the side plate 113 includes two third parts arranged in a rotationally symmetrical manner.

[0085] To improve the sealing between the two third parts of the side plate 113, as an example, the third part corresponding to the side plate 113 includes an arc-shaped plate. The second end of the arc-shaped plate is provided with a sealing flange 1131 extending toward the breathing chamber 101. The inner surface of the arc-shaped plate is provided with a sealing rib 1132. The sealing rib 1132 extends from the first end to the sealing flange 1131. In the circumferential direction of the arc-shaped plate, the sealing rib 1132 extends to the outside of the arc-shaped plate. In other words, the sealing rib 1132 only partially overlaps with the arc-shaped plate.

[0086] In optional embodiments, such as Figure 1 and Figure 2 As shown, the gas analysis chamber includes an analysis chamber body and a heat dissipation assembly 14. The analysis chamber body is disposed within the breathing chamber 101. The heat dissipation assembly 14 is used to dissipate heat from the analysis chamber body. The heat dissipation assembly 14 includes a heat-conducting element 142 and a heat dissipation element 141. One end of the heat-conducting element 142 is in thermal communication with the analysis chamber body, and the other end passes through the top plate 111 and is connected to the heat dissipation element 141. The heat dissipation element 141 can be a cooling fan.

[0087] Specifically, the sampling inlet and outlet of the analysis chamber are both located within the breathing chamber 101, while the heat dissipation portion of the analysis chamber is located outside the breathing chamber 101. This achieves a seamless connection between the breathing chamber 101 and the analysis chamber, realizing the goals of integration and energy saving between the breathing chamber 101 and the gas analysis chamber, while effectively reducing the impact of the gas analysis chamber on the environment of the breathing chamber 101, especially in terms of temperature. The analysis chamber itself houses an air pump and infrared sensors for atmospheric carbon dioxide and water vapor analysis.

[0088] In practical applications, the measuring box 1 used for measuring carbon dioxide flux of tree trunk autotrophic respiration also includes a protective cover 15. The protective cover 15 is a ring-shaped structural component and is located above the top surface of the top plate 111 to protect the functional devices located on the top surface of the top plate 111.

[0089] It should be noted that the protective cover 15 can be a sheet-like ring-shaped structure. The protective cover 15 can be set above the top plate 111 by a support rod. The protective cover 15 can protect functional components such as the cooling fan and drive motor 121 to avoid direct sunlight and rain.

[0090] The following describes the operation of the trunk autotrophic respiration carbon dioxide flux measurement device.

[0091] Step 1: System startup, power supply self-test and parameter initialization.

[0092] After the device is powered on, the power supply module begins to supply power to the control motherboard 3 and various functional modules. The system starts up and performs a diagnostic check on the power status (battery voltage, solar panel charging current), then loads user-preset measurement parameters, including but not limited to measurement interval, measurement time, recording time, measurement chamber 1 status, breathing chamber 101 volume and height, and carbon dioxide concentration threshold. The system then executes a self-test program to diagnose the status of various types of sensors, drive motor 121, and the lifting status of the side plate 113, confirming that each module is functioning normally.

[0093] Step 2: Check or set measurement parameters Turn on the device display and check if the measurement parameters are normal. If this is the first time using the device, you need to set the date and time, measurement interval, measurement time, recording time, breathing chamber volume and height, and carbon dioxide concentration threshold.

[0094] Step 3: Turn on the equipment for measurement Touching the measurement icon in the human-machine interaction module 4 activates the control motherboard 3, which in turn controls the drive motor 121 to rotate clockwise. This causes the side plate 113 to rise, switching the breathing chamber 101 to a sealed state. The control motherboard 3 then collects data on temperature, humidity, air pressure, carbon dioxide concentration changes, and trunk diameter within the breathing chamber 101 according to a set recording time, calculating the carbon dioxide flux of the tree trunk's autotrophic respiration. The calculation results and recorded sensor data are displayed on the measurement results interface of the human-machine interaction module 4 and saved to the data acquisition and storage module.

[0095] Step 4: The equipment completes the measurement. Once the measurement time or carbon dioxide concentration threshold is reached, the main control board 3 controls the drive motor 121 to rotate counterclockwise, the side plate 113 descends, the equipment is in a ventilated state, and the measurement is completed.

[0096] Step 4: Device standby When the equipment is in a ventilated state, the safety protection module operates normally, while the control motherboard 3, sensor module, data acquisition and storage module, human-machine interaction module 4, and drive motor 121 are in a sleep state, and the power supply module is in a low-power state.

[0097] Step 5: Automatic cyclic measurement by the equipment After the device is in standby mode for the set measurement interval, the control motherboard 3 starts the drive motor 121 and various functional modules to perform a new round of measurements. After the measurement is completed, the device returns to ventilation mode. This process is repeated automatically to achieve the automatic measurement function.

[0098] Thirdly, such as Figure 6 As shown, this embodiment of the invention also provides a method for measuring the carbon dioxide flux of tree trunk autotrophic respiration, including: S100, acquires the total effective gas volume collected within a certain time period, the surface area of ​​the tree trunk wrapped by the breathing chamber 101, the water vapor mole fraction in the breathing chamber 101, and the change in carbon dioxide concentration in the breathing chamber 101.

[0099] Specifically, the sensor module is used to measure the carbon dioxide concentration in the breathing chamber 101, the water vapor mole fraction in the breathing chamber 101, and the diameter of the tree trunk enclosed by the breathing chamber 101. For example, the total effective gas volume and the surface area of ​​the tree trunk enclosed by the breathing chamber 101 can be determined based on the diameter of the tree trunk enclosed by the breathing chamber 101.

[0100] S200 determines the carbon dioxide flux of autotrophic respiration in the tree trunk based on the total effective gas volume, trunk surface area, water vapor mole fraction, carbon dioxide concentration change, and measurement time interval.

[0101] The time interval is equal to the difference between the end time and the start time. The start time can be selected arbitrarily, and the end time can be preset. Alternatively, after the start time is determined, the control motherboard 3 can intelligently determine the end time based on the subsequently measured carbon dioxide concentration, water vapor mole fraction, or gas temperature in the breathing chamber.

[0102] In this embodiment, the control motherboard 3 determines the total effective gas volume, the surface area of ​​the trunk enclosed by the breathing chamber 101, the water vapor mole fraction in the breathing chamber 101, and the change in carbon dioxide concentration within a certain time period based on the carbon dioxide concentration in the breathing chamber 101, the water vapor mole fraction in the breathing chamber 101, and the trunk diameter enclosed by the breathing chamber 101. It then determines the autotrophic carbon dioxide flux of the tree trunk based on the total effective gas volume, the surface area of ​​the trunk enclosed by the breathing chamber 101, the water vapor mole fraction in the breathing chamber 101, the change in carbon dioxide concentration, and the measurement time interval. This allows for convenient, rapid, and accurate measurement of the autotrophic carbon dioxide flux of the tree trunk.

[0103] In an optional embodiment, the method for collecting the total effective gas volume includes: The total effective gas volume is determined based on the volume of the gas analysis chamber 102 and the volume of the breathing chamber 101 over a certain period of time; wherein at least a portion of the gas analysis chamber 102 is located within the breathing chamber 101, and the gas analysis chamber 102 is in fluid communication with the breathing chamber 101.

[0104] Specifically, the total effective gas volume is obtained by adding the volume of the gas analysis chamber 102 to the volume of the breathing chamber 101 over a certain period of time.

[0105] In practical applications, the methods for collecting the volume of the breathing chamber 101 include: The volume of the breathing chamber 101 is determined based on its total volume, the volume occupied within the breathing chamber 101, and the volume of the tree trunk enclosed by the breathing chamber 101 during a certain time period. In other words, the volume of the breathing chamber 101 during a certain time period is equal to its total volume minus the volume of the occupied portion within the breathing chamber 101, and then minus the volume of the tree trunk enclosed by the breathing chamber 101 during that time period.

[0106] In practical applications, the methods for collecting the volume of the tree trunk enclosed by the breathing chamber 101 include: The volume of the tree trunk enclosed by the breathing chamber 101 is determined based on the height of the breathing chamber 101 and the average diameter of the tree trunk enclosed by the breathing chamber 101 within a certain time period.

[0107] It should be noted that the average diameter of the tree trunk can be determined by two tree diameter sensors installed vertically within the breathing chamber 101.

[0108] Specifically, the volume of the tree trunk enclosed by breathing chamber 101 is obtained as follows: ; Where V1 is the volume of the tree trunk enclosed by the breathing chamber 101 (m³). 3 D is the average trunk diameter (m); π represents pi; H represents the height of the breathing chamber 101.

[0109] Therefore, the specific method for obtaining the volume of respiration chamber 101 within a certain time period is as follows: in, The volume of the breathing chamber is 101 (m³). 3 ); The total volume of the breathing chamber 101 (m³) 3 ); The volume of the occupied portion within the breathing chamber 101 (m³) 3 ).

[0110] The specific method for obtaining the total effective gas volume is as follows: in, V total Total effective gas volume (m³) 3 ); The volume of the gas analysis chamber 102 (m³) 3 ).

[0111] In practical applications, methods for collecting tree trunk surface area include: The trunk surface area is determined based on the height of the breathing chamber 101 and the average diameter of the tree trunk enclosed by the breathing chamber 101 over a certain period of time.

[0112] Specifically, the method for obtaining the trunk surface area is as follows: ; Where A is the surface area of ​​the tree trunk (m²) 2 C is the circumference of the trunk (i.e., perimeter, m); H is the height of the breathing chamber 101 (m).

[0113] Among them, C 围径 The calculation is based on the following formula: Where D is the average diameter of the tree trunk (m); Pi is the mathematical constant of a circle.

[0114] Therefore, the formula for calculating the surface area of ​​a tree trunk is derived: To avoid the influence of environmental changes on the gas molar volume, in an optional embodiment, the method for measuring carbon dioxide flux during tree trunk autotrophic respiration further includes: The atmospheric pressure and gas temperature inside the breathing chamber 101 are collected within a certain time period. The change in carbon dioxide concentration is corrected according to the ideal gas law.

[0115] The following is a systematic description of the method for measuring carbon dioxide flux during autotrophic respiration in tree trunks.

[0116] Assuming that the carbon dioxide concentration in respiration chamber 101 increases linearly over a short period of time, the basic formula for calculating carbon dioxide flux is: ; Where F is the carbon dioxide flux of trunk autotrophic respiration (μmolm). -2 s -1 ); ΔC is the change in carbon dioxide concentration inside the chamber (ppm); Δt is the measurement time interval (s); V is the volume of the gas analysis chamber 102 (m³). 3 A is the surface area of ​​the tree trunk (m²). 2 ).

[0117] In long-term field measurements, phenomena such as sudden temperature rises at midday and sudden drops at night may occur. In such cases, it is necessary to correct for carbon dioxide concentration using the ideal gas law to eliminate the influence of the environment on the molar volume of the gas. The formula is extended as follows: Where P is the atmospheric pressure at the measurement point (Pa); R is the ideal gas constant (8.314 Pa·m). 3 ·mol -1 ·K -1 T is the absolute temperature (K, Kelvin) of the gas analysis chamber at 102°C; V total Total effective gas volume (m³) 3 ).

[0118] Considering the enclosed gas analysis chamber 102, water vapor may cause overlap in the infrared absorption bands of atmospheric carbon dioxide and water vapor infrared analysis sensors for carbon dioxide. Without correction, this could lead to an overestimation of carbon dioxide concentration, resulting in an inflated measurement. Therefore, the formula is extended as follows: .

[0119] Where W is the mole fraction of water vapor (mmol / mol) in gas analysis chamber 102.

[0120] In addition, the change in carbon dioxide concentration refers to the initial and final concentrations of carbon dioxide in the breathing chamber 101.

[0121] The formula reflecting the change in carbon dioxide concentration over a period of time is as follows: ΔC = C2 - C1; Where ΔC is the change in carbon dioxide concentration (ppm); C1 is the initial concentration of carbon dioxide measured (ppm); and C2 is the final concentration of carbon dioxide measured (ppm).

[0122] The measurement interval (Δt) is explained below. The measurement interval refers to the time interval between the start and end of the measurement of carbon dioxide concentration in breathing chamber 101.

[0123] The formula for the measurement interval Δt is as follows: Δt = t2 - t1; Where Δt is the interval time for measuring the change in carbon dioxide concentration (s); t1 is the recording time when the initial concentration of carbon dioxide is measured (s); and t2 is the recording time when the concentration of carbon dioxide is measured to terminate (s).

[0124] The specific method for obtaining the trunk surface area is as follows: ; Where A is the surface area of ​​the tree trunk (m²) 2 C is the circumference of the trunk (i.e., perimeter, m); H is the height of the breathing chamber 101 (m).

[0125] Among them, C 围径 The calculation is based on the following formula: Where D is the average diameter of the tree trunk (m); Pi is the mathematical constant of a circle.

[0126] Therefore, the formula for calculating the surface area of ​​a tree trunk is derived: The specific method for obtaining the volume of the tree trunk enclosed by breathing chamber 101 is as follows: ; Where V1 is the volume of the tree trunk enclosed by the breathing chamber 101 (m³). 3 D is the average trunk diameter (m); π represents pi; H represents the height of the breathing chamber 101.

[0127] Therefore, the specific method for obtaining the volume of respiration chamber 101 within a certain time period is as follows: in, The volume of the breathing chamber is 101 (m³). 3 ); The total volume of the breathing chamber 101 (m³) 3 ); The volume of the occupied portion within the breathing chamber 101 (m³) 3 ).

[0128] The specific method for obtaining the total effective gas volume is as follows: in, V total Total effective gas volume (m³) 3 ); The volume of the gas analysis chamber 102 (m³) 3 ).

[0129] Based on the above analysis: .

[0130] The trunk autotrophic respiration carbon dioxide flux measurement system provided by the present invention is described below. The trunk autotrophic respiration carbon dioxide flux measurement system described below can be referred to in correspondence with the trunk autotrophic respiration carbon dioxide flux measurement method described above.

[0131] like Figure 7 As shown, the tree trunk autotrophic respiration carbon dioxide flux measurement system includes: an acquisition module 700 and a calculation module 800.

[0132] The acquisition module 700 is used to acquire the total effective gas volume, the trunk surface area enclosed by the respiration chamber 101, the water vapor mole fraction in the respiration chamber 101, and the change in carbon dioxide concentration in the respiration chamber 101 within a certain time period. The calculation module 800 is used to determine the carbon dioxide flux of the tree trunk's autotrophic respiration based on the total effective gas volume, trunk surface area, water vapor mole fraction, change in carbon dioxide concentration, and the measurement time interval.

[0133] On the other hand, the present invention also provides a computer program product, which includes a computer program that can be stored on a non-transitory computer-readable storage medium. When the computer program is executed by a processor, the computer can execute the trunk autotrophic respiration carbon dioxide flux measurement method provided by the above methods. The method includes: step 100, acquiring the total effective gas volume, the trunk surface area enclosed by the respiration chamber 101, the water vapor mole fraction in the respiration chamber 101, and the change value of carbon dioxide concentration in the respiration chamber 101 collected within a certain time period; step 200, determining the trunk autotrophic respiration carbon dioxide flux based on the total effective gas volume, trunk surface area, water vapor mole fraction, change value of carbon dioxide concentration, and measurement time interval.

[0134] In another aspect, the present invention also provides a non-transitory computer-readable storage medium storing a computer program thereon. When executed by a processor, the computer program implements the method for measuring the carbon dioxide flux of tree trunk autotrophic respiration provided by the methods described above. This method includes: step 100, acquiring the total effective gas volume collected within a certain time period, the tree trunk surface area enclosed by the respiration chamber 101, the water vapor mole fraction within the respiration chamber 101, and the change in carbon dioxide concentration within the respiration chamber 101. Step 200, determining the carbon dioxide flux of tree trunk autotrophic respiration based on the total effective gas volume, tree trunk surface area, water vapor mole fraction, change in carbon dioxide concentration, and the measurement time interval.

[0135] The device embodiments described above are merely illustrative. The units described as separate components may or may not be physically separate. The components shown as units may or may not be physical units; that is, they may be located in one place or distributed across multiple network units. Some or all of the modules can be selected to achieve the purpose of this embodiment according to actual needs. Those skilled in the art can understand and implement this without any creative effort.

[0136] Through the above description of the embodiments, those skilled in the art can clearly understand that each embodiment can be implemented by means of software plus necessary general-purpose hardware platforms, and of course, it can also be implemented by hardware. Based on this understanding, the above technical solutions, in essence or the part that contributes to the prior art, can be embodied in the form of a software product. This computer software product can be stored in a computer-readable storage medium, such as ROM / RAM, magnetic disk, optical disk, etc., and includes several instructions to cause a computer device (which may be a personal computer, server, or network device, etc.) to execute the methods described in the various embodiments or some parts of the embodiments.

[0137] Finally, it should be noted that the terms "parallel" and "perpendicular" in the embodiments of this invention should not be strictly limited to a geometric sense. At least manufacturing and installation errors should be considered. For example, an error of ±10° should be within the protection range of the embodiments of this invention. The above embodiments are only used to illustrate the technical solutions of this invention, and not to limit it. Although the invention has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some of the technical features. These modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the spirit and scope of the technical solutions of the embodiments of this invention.

Claims

1. A measuring box for measuring carbon dioxide flux during autotrophic respiration of tree trunks, characterized in that, include: The housing includes a top plate, a bottom plate, and a side plate disposed between the top plate and the bottom plate, wherein the top plate, the bottom plate, and the side plate enclose a breathing chamber; both the top plate and the bottom plate are provided with trunk channels communicating with the breathing chamber; wherein at least a portion of the gas analysis chamber is disposed within the breathing chamber, and the gas analysis chamber is in fluid communication with the breathing chamber; A drive assembly disposed in the housing and configured to drive the side plate to move such that the breathing chamber is connected to or isolated from the outside.

2. The measuring box for measuring carbon dioxide flux during autotrophic respiration of tree trunks according to claim 1, characterized in that, Each of the top plate and the bottom plate includes a connected annular plate and an annular cylinder.

3. The measuring box for measuring carbon dioxide flux during autotrophic respiration of tree trunks according to claim 2, characterized in that, Each of the top plate and the bottom plate further includes a connector, wherein the annular plate of the top plate is connected to the annular plate of the bottom plate via the connector.

4. The measuring box for measuring carbon dioxide flux during autotrophic respiration of tree trunks according to claim 1, characterized in that, The measuring box for measuring carbon dioxide flux during autotrophic respiration of tree trunks also includes: The sealing sleeve is provided in both the trunk channel corresponding to the top plate and the trunk channel corresponding to the bottom plate.

5. The measuring box for measuring carbon dioxide flux during autotrophic respiration of tree trunks according to claim 4, characterized in that, The sealing sleeve includes a weather-resistant layer, a rubber layer, a support layer, and a rigid layer arranged sequentially from the inside to the outside.

6. The measuring box for measuring carbon dioxide flux during autotrophic respiration of tree trunks according to claim 1, characterized in that, The drive assembly includes a drive motor, a lead screw, and a lead screw nut. The drive motor is disposed on the top surface of the top plate. One end of the lead screw is connected to the bottom plate, and the other end passes through the top plate to be connected to the output shaft of the drive motor. The lead screw nut is threadedly connected to the lead screw and is connected to the inner surface of the side plate.

7. The measuring box for measuring carbon dioxide flux during autotrophic respiration of tree trunks according to claim 6, characterized in that, The drive assembly further includes a first limit sensor and a second limit sensor. The first limit sensor is used to send a first positioning signal based on the position of the lead screw nut when it approaches the top plate, and the second limit sensor is used to send a second positioning signal based on the position of the lead screw nut when it approaches the bottom plate. The drive motor stops driving after receiving the first positioning signal or the second positioning signal.

8. The measuring box for measuring carbon dioxide flux during autotrophic respiration of tree trunks according to claim 1, characterized in that, The side plate has a first end and a second end disposed opposite to each other. The second end is provided with a sealing flange extending toward the breathing chamber. The inner surface of the side plate is provided with a sealing rib, and the sealing rib extends from the first end to the sealing flange. The bottom surface of the top plate is provided with a first snap-fit ​​groove and a second snap-fit ​​groove that are connected. The first snap-fit ​​groove is adapted to the first end, and the second snap-fit ​​groove is adapted to the sealing rib. The bottom plate is provided with a clearance groove adapted to the sealing rib.

9. The measuring box for measuring carbon dioxide flux during autotrophic respiration of tree trunks according to claim 8, characterized in that, Each of the top plate and the bottom plate includes a first part and a second part arranged in an axisymmetric manner; the side plate includes two third parts arranged in a rotationally symmetrical manner.

10. The measuring box for measuring carbon dioxide flux during autotrophic respiration of tree trunks according to claim 1, characterized in that, The measuring box for measuring carbon dioxide flux during autotrophic respiration of tree trunks also includes: A protective cover, which is a ring-shaped structure, is located above the top surface of the top plate to protect the functional devices located on the top surface of the top plate. The gas analysis chamber includes an analysis chamber body and a heat dissipation assembly. The heat dissipation assembly is used to dissipate heat from the analysis chamber body. The heat dissipation assembly includes a heat-conducting element and a heat dissipation element. One end of the heat-conducting element is in thermal communication with the analysis chamber body, and the other end passes through the top plate and is connected to the heat dissipation element.

Images