A device and method for monitoring forest litter decomposition rate

Abstract

The application discloses a device and method for monitoring forest litter decomposition rate, which comprises a sealed monitoring container, an internal sampling part for placing litter samples, and integrated gas concentration sensors, carbon dioxide sensors and carbon removal modules with carbon removal functions. The carbon removal module is connected with a weighing module for monitoring the carbon dioxide absorption amount through mass change. The application realizes quantitative evaluation of the litter decomposition process by real-time collection of dynamic changes of gas concentration in the monitoring space, combination of temperature and humidity environmental factors, and use of a decomposition rate correlation model constructed based on the principle of microbial metabolism. Compared with the traditional mass difference method, the application can effectively shield external environmental interference, realize in-situ, high-frequency and accurate real-time monitoring, and provide scientific data support for forest ecosystem carbon cycle research.

Description

Technical Field

[0001] This invention relates primarily to the field of environmental analysis technology, specifically to a device and method for monitoring the decomposition rate of forest litter. Background Technology

[0002] Coniferous forests, as a vital global ecosystem, play a crucial role in nutrient cycling, soil fertility, and carbon storage through litter decomposition. However, the decomposition of coniferous forest litter is extremely slow due to factors such as high lignin content and low ambient temperatures. Currently, the traditional method for monitoring litter decomposition rates is the mass difference method, which calculates the rate by analyzing the mass loss of litter before and after a long-term experiment under natural conditions. However, this technique has the following drawbacks in practical applications:

[0003] Poor timeliness: The changes in litter quality are small, and observation cycles of several months or even years are usually required, making it impossible to provide real-time dynamic feedback.

[0004] Limited monitoring accuracy: Traditional mass methods cannot distinguish between mass loss caused by microbial decomposition and errors caused by non-biological factors such as water evaporation and wind erosion.

[0005] Weak environmental coupling: It is difficult to capture in real time the dynamic impact of instantaneous environmental fluctuations such as temperature and humidity on the decomposition rate.

[0006] Low level of automation: It relies on manual sampling and weighing, which is labor-intensive and prone to human error.

[0007] Therefore, developing a litter decomposition rate assessment technology that can simulate the natural environment and achieve high-precision real-time monitoring has become an urgent need in the field of ecological monitoring. Summary of the Invention

[0008] The present invention addresses the problem that existing technical solutions are too simplistic by providing a solution that is significantly different from existing technologies. It mainly provides a device for monitoring the decomposition rate of forest litter, thereby solving the technical problems mentioned in the background section.

[0009] The technical solution adopted by the present invention to solve the above-mentioned technical problems is as follows:

[0010] A device for monitoring the decomposition rate of forest litter, comprising:

[0011] The experimental chamber is equipped with an air inlet, an exhaust outlet, a gas concentration sensor, and a temperature and humidity sensor.

[0012] A carbon removal module, installed inside the experimental chamber, is used to adsorb carbon dioxide;

[0013] A weighing module, which is installed inside the experimental chamber, is used to weigh the carbon removal module;

[0014] The waterproof and breathable shell has an isolation cavity for the weighing module and the carbon removal module to be installed. The waterproof and breathable shell has an opening that communicates with the inside of the experimental chamber, and a waterproof and breathable membrane is provided at the opening.

[0015] The waterproof and breathable membrane is used to prevent water vapor in the experimental chamber from entering the isolation chamber, and to allow carbon dioxide in the experimental chamber to pass through the waterproof and breathable membrane and be adsorbed by the carbon removal module.

[0016] The isolation chamber is connected to the exhaust port, and the carbon removal module forms a multi-microporous isolation adsorption layer between the opening and the exhaust port, forcing the gas in the experimental chamber to flow through the carbon removal module to the exhaust port.

[0017] The weighing module is used to monitor the mass change of the carbon removal module in real time.

[0018] The data processing module is used to determine the total amount of carbon dioxide absorbed by the carbon removal module during the monitoring period based on the mass change, and to calculate the decomposition rate of the litter sample by combining the concentration data collected by the gas concentration sensor and the preset decomposition rate correlation model.

[0019] Furthermore, the waterproof and breathable shell includes a perforated plate, a central beam, and a porous tubular membrane skeleton. The perforated plate has a central hole at its axis for the central beam to be inserted into. Both ends of the central beam are provided with perforated plates. The porous tubular membrane skeleton connects the perforated plates at both ends. The isolation cavity is formed between the central beam, the porous tubular membrane skeleton, and the perforated plates at both ends.

[0020] The perforated plate is provided with multiple air outlets that connect the isolation chamber and the exhaust port, and the porous tubular membrane skeleton is provided with multiple air inlets that connect the interior of the experimental chamber and the isolation chamber.

[0021] The weighing module is located on top of the central beam, and the carbon removal module is a rotating structure arranged around the central beam. The two ends of the carbon removal module cover the areas with multiple air outlets on the end plates. The ends of the carbon removal module are sealed to the end plates by a relaxed annular membrane.

[0022] Furthermore, the carbon removal module includes a conical porous skeleton and a carbon removal agent layer covering the conical porous skeleton. The two ends of the conical porous skeleton are conical tubes, and the narrowed section between the two ends is supported on the weighing module. Both ends of the conical porous skeleton are porous structures, and the carbon removal agent layer covers the porous areas at both ends of the conical porous skeleton.

[0023] Furthermore, exhaust vents are provided on both sides of the experimental chamber, and exhaust pipes communicating with the exhaust vents are provided on both sides of the inner wall of the experimental chamber.

[0024] The orifice plate is provided with an upper semi-circular tube at one end outside the isolation chamber, and the exhaust pipe is provided with a lower semi-circular tube that cooperates with the upper semi-circular tube. The upper semi-circular tube and the lower semi-circular tube are connected to form a closed pipe that connects the exhaust port and multiple air outlets.

[0025] The experimental chamber is detachably fitted with a lid.

[0026] Furthermore, the top of the central beam, located between the two end plates, is provided with an installation groove for the weighing module to be inserted.

[0027] Furthermore, the weighing module supports the conical porous skeleton through a limiting block, and the top of the limiting block is provided with an axial limiting groove that is adapted to the inner wall contour of the conical porous skeleton.

[0028] This invention also discloses a method for monitoring the decomposition rate of forest litter, comprising the following steps:

[0029] Place litter samples with known dry weight in a sealed experimental chamber 1;

[0030] An internal circulation device connected to the air inlet and exhaust outlet of the experimental chamber forces the gas inside the chamber to pass sequentially through a waterproof and breathable shell and a carbon removal module.

[0031] During the monitoring process, the weight of the carbon removal module 6 was detected by a weighing module, and the gas concentration inside the experimental chamber was detected by a gas concentration sensor. concentration;

[0032] Calculate Δt The concentration change was measured, and the weight change of the carbon removal module within Δt was converted into the carbon removal agent weight change and the reaction stoichiometry to obtain the carbon removal module's concentration within Δt. Adsorption capacity;

[0033] Based on Δt Concentration change and Adsorption capacity calculation of litter sample decomposition The net release rate, and the net release rate is taken into account. The decomposition rate of litter samples within Δt is calculated using a dedicated formula for flux and decomposition rate.

[0034] Furthermore, the decomposition of litter samples produces Net release rate The calculation formula is:

[0035] R CO2 =

[0036] In the formula:

[0037] V is the effective volume of the sealed experimental chamber (m³), Δt is the monitoring time interval (s), and m is the dry weight of the litter sample.

[0038] P is the atmospheric pressure inside the experimental chamber (Pa), R g is the universal gas constant (8.314 J / (mol・K)), and T is the absolute temperature (K);

[0039] , They are respectively time t and Real-time measurement Concentration (mol / m³);

[0040] C removed For the carbon removal module within Δt Adsorption capacity (mol / m³).

[0041] Furthermore, the core correlation model of decomposition rate, combining the chemical characteristics of litter samples with microbial metabolic patterns, establishes... Flux and decomposition rate ( The specific correlation formula for (unit: g / (g・d)) is as follows:

[0042]

[0043] In the formula:

[0044] α is the carbon conversion coefficient (unit: g・mol⁻¹), which reflects the quantitative relationship between carbon dioxide release and carbon loss from litter.

[0045] A quality correction function for litter samples was constructed based on lignin content (L) and carbon-nitrogen ratio (C / N).

[0046] Q10 is the temperature sensitivity coefficient, reflecting the effect of temperature on the decomposition process;

[0047] Tc is the measured temperature (°C) within the system. The difference in decomposition rate at non-25°C standard temperatures is corrected by (Tc−25) / 10 terms.

[0048] Furthermore, the decomposition rate and its changing trend are output in real time through a visual interface, and an alarm is automatically triggered when the decomposition rate changes abnormally and drastically.

[0049] Compared with the prior art, the beneficial effects of the present invention are as follows:

[0050] 1. This invention continuously collects carbon dioxide concentration through a high-sensitivity gas concentration sensor and detects the weight change of the carbon removal module in real time through a high-precision weighing module. The waterproof and breathable shell avoids water vapor adhering to the carbon removal module, which would increase data errors. This provides reliable data support for calculating the decomposition rate and breaks through the long cycle limitation of the traditional mass difference method, enabling instantaneous assessment of the instantaneous changes in microbial decomposition activity.

[0051] 2. The present invention adopts a sealed monitoring space design, which effectively shields the direct interference of external environmental variables such as wind, rain, and light on sample quality. At the same time, through the coordinated design of the weighing module and the carbon removal module, the carbon flux released by microbial respiration is accurately quantified, making the monitoring results more consistent with the actual biodegradation process.

[0052] 3. This invention introduces a temperature sensitivity coefficient and a mass correction function based on the chemical characteristics of coniferous forests, which can dynamically correct model parameters according to different tree species (such as Korean pine and spruce) and environmental fluctuations, ensuring universality in complex climates such as cold and temperate zones;

[0053] 4. The automated data acquisition and processing flow of this invention replaces frequent manual weighing and sampling, reducing labor intensity and avoiding system errors caused by human operation.

[0054] The present invention will be explained in detail below with reference to the accompanying drawings and specific embodiments. Attached Figure Description

[0055] Figure 1 This is a schematic diagram of the overall structure of the present invention;

[0056] Figure 2 This is a schematic diagram of the waterproof and breathable shell and test chamber of the present invention;

[0057] Figure 3 This is a schematic diagram of the exhaust pipe structure of the present invention;

[0058] Figure 4 This is a schematic diagram of the structure of the waterproof and breathable shell of the present invention;

[0059] Figure 5 This is a schematic diagram of the structure of the orifice plate, central beam, and weighing module of the present invention;

[0060] Figure 6 This is a schematic diagram of the structure of the central beam of the present invention;

[0061] Figure 7 This is a schematic diagram of the structure of the limiting block of the present invention;

[0062] Figure 8 This is a schematic diagram of the waterproof and breathable membrane, the conical porous skeleton, and the porous tubular membrane skeleton of the present invention.

[0063] Figure 9 This is a cross-sectional view of the waterproof and breathable membrane, the conical porous skeleton, and the porous tubular membrane skeleton of the present invention.

[0064] Figure 10 This is a schematic diagram of the porous tubular membrane skeleton of the present invention;

[0065] Figure 11 This is a schematic diagram of the conical porous skeleton of the present invention;

[0066] Figure 12 This is a schematic diagram of the carbon removal agent layer of the present invention.

[0067] Numbering on the map:

[0068] 1. Experimental chamber; 2. Air inlet; 3. Exhaust outlet; 4. Gas concentration sensor; 5. Temperature and humidity sensor; 6. Carbon removal module; 7. Weighing module; 8. Waterproof and breathable shell; 9. Isolation chamber; 10. Waterproof and breathable membrane; 11. Center hole; 12. Air outlet; 13. Air inlet; 14. Exhaust pipe; 15. Upper semi-circular tube; 16. Lower semi-circular tube; 17. Chamber cover; 18. Mounting groove; 19. Limiting block; 20. Axial limiting slot; 21. Self-positioning semi-circular tube;

[0069] 601. Conical porous skeleton; 602. Carbon removal agent layer;

[0070] 801. Perforated plate; 802. Central beam; 803. Porous tubular membrane skeleton. Detailed Implementation

[0071] To facilitate understanding of the present invention, a more comprehensive description of the present invention will be given below with reference to the accompanying drawings, which illustrate several embodiments of the present invention. However, the present invention can be implemented in different forms and is not limited to the embodiments described in the text. Rather, these embodiments are provided to make the disclosure of the present invention more thorough and complete.

[0072] It should be noted that when an element is referred to as being "fixed to" another element, it can be directly on the other element or there may be an intervening element. When an element is referred to as being "connected to" another element, it can be directly connected to the other element or there may be an intervening element. The terms "vertical," "horizontal," "left," "right," and similar expressions used in this document are for illustrative purposes only.

[0073] Please refer to the appendix carefully. Figure 1-12 A device for monitoring the decomposition rate of forest litter, comprising:

[0074] Experimental chamber 1 is equipped with an air inlet 2, an exhaust outlet 3, a gas concentration sensor 4, and a temperature and humidity sensor 5;

[0075] Carbon removal module 6 is installed inside experimental chamber 1 and is used to adsorb carbon dioxide;

[0076] Weighing module 7, which is installed inside the experimental chamber 1, is used to weigh the carbon removal module 6;

[0077] The waterproof and breathable shell 8 has an isolation chamber 9 for the weighing module 7 and the carbon removal module 6 to be installed. The waterproof and breathable shell 8 has an opening that communicates with the interior of the experimental chamber 1, and a waterproof and breathable membrane 10 is provided at the opening.

[0078] The waterproof and breathable membrane 10 is used to prevent water vapor in the experimental chamber 1 from entering the isolation chamber 9, and to allow carbon dioxide in the experimental chamber 1 to pass through the waterproof and breathable membrane 10 and be adsorbed by the carbon removal module 6.

[0079] The isolation chamber 9 is connected to the exhaust port 3, and the carbon removal module 6 forms a multi-microporous isolation adsorption layer between the open and the exhaust port 3, forcing the gas in the experimental chamber 1 to flow through the carbon removal module 6 to the exhaust port 3.

[0080] Weighing module 7 is used to monitor the mass change of carbon removal module 6 in real time;

[0081] The data processing module is used to determine the total amount of carbon dioxide absorbed by the carbon removal module during the monitoring period based on the mass change, and to calculate the decomposition rate of the litter sample by combining the concentration data collected by the gas concentration sensor 4 and the preset decomposition rate correlation model.

[0082] This application avoids water vapor in the gas inside the experimental chamber 1 from adhering to the carbon removal module 6 by placing the weighing module 7 and the carbon removal module 6 inside the waterproof and breathable shell 8 with a waterproof and breathable membrane 10, thus ensuring the reliability of the data on the decomposition rate of litter samples calculated based on the weight change and carbon dioxide concentration change of the carbon removal module 6.

[0083] The waterproof and breathable shell 8 includes a perforated plate 801, a central beam 802, and a porous tubular membrane skeleton 803. The perforated plate 801 has a central hole 11 at its axis for the central beam 802 to be inserted into. Both ends of the central beam 802 are provided with perforated plates 801. The porous tubular membrane skeleton 803 connects the perforated plates 801 at both ends. The isolation cavity 9 is formed between the central beam 802, the porous tubular membrane skeleton 803, and the perforated plates 801 at both ends.

[0084] The perforated plate 801 is provided with multiple air outlets 12 that connect the isolation chamber 9 and the exhaust port 3, and the porous tubular membrane skeleton 803 is provided with multiple air inlets 13 that connect the interior of the experimental chamber 1 and the isolation chamber 9.

[0085] The weighing module 7 is set on the top of the central beam 802. The carbon removal module 6 is a rotating structure set around the central beam 802. The two ends of the carbon removal module 6 cover the area where the end plate 801 has multiple air outlets 12. The ends of the carbon removal module 6 are sealed to the end plate 801 by a loose annular membrane.

[0086] The cylindrical waterproof and breathable shell 8 facilitates the collection of water droplets that condense on the surface of the waterproof and breathable membrane 10 under the action of gravity, which then fall off the bottom of the waterproof and breathable membrane 10. This prevents water droplets from condensing on the surface of the waterproof and breathable shell 8 and affecting the passage of gas.

[0087] The porous tubular membrane skeleton 803 does not contact the carbon removal module 6. The relaxed annular membrane ensures a sealed connection between the end of the carbon removal module 6 and the orifice plate 801, while ensuring that the carbon removal module 6 is supported only by the weighing module 7, thus avoiding interference with the weighing of the carbon removal module 6.

[0088] The carbon removal module 6 includes a conical porous skeleton 601 and a carbon removal agent layer 602 covering the conical porous skeleton 601. The two ends of the conical porous skeleton 601 are conical tubes, and the narrowed section between the two ends is supported on the weighing module 7. Both ends of the conical porous skeleton 601 are porous structures, and the carbon removal agent layer 602 covers the porous areas at both ends of the conical porous skeleton 601.

[0089] The conical porous skeleton 601, with its narrowed middle and tapered ends, concentrates the weight at the narrowed section, improving the detection accuracy of the weighing module 7 and fully utilizing the space of the isolation chamber 9, ensuring sufficient area for the decarbonizing agent to be distributed in the carbon removal module 6. If a cylindrical skeleton were used directly, the length / diameter of the carbon removal module 6 would need to be increased to ensure sufficient area for the decarbonizing agent. Since the original weight and post-adsorption weight of the decarbonizing agent may differ at different locations, a longer and larger diameter carbon removal module 6 would result in a significant shift in the center of gravity, making it difficult to concentrate the weight at the detection component of the weighing module 7, thus affecting the reliability of the weighing module 7 data.

[0090] The experimental chamber 1 has exhaust ports 3 on both sides of the chamber wall, and exhaust pipes 14 connected to the exhaust ports 3 are provided on both sides of the inner wall of the experimental chamber 1.

[0091] The orifice plate 801 is provided with an upper semi-circular tube 15 at one end outside the isolation chamber 9, and the exhaust pipe 14 is provided with a lower semi-circular tube 16 that cooperates with the upper semi-circular tube 15. The upper semi-circular tube 15 and the lower semi-circular tube 16 are connected to form a closed pipe that connects the exhaust port 3 and multiple air outlets 12.

[0092] The top of the experimental chamber 1 is detachably equipped with a chamber cover 17.

[0093] After opening the cover 17, the waterproof and breathable shell 8 and the exhaust pipe 14 are connected through the upper semicircular pipe 15 and the lower semicircular pipe 16, so that the waterproof and breathable shell 8 equipped with the weighing module 7 and the carbon removal module 6 can be connected and separated from the exhaust pipe 14 by vertical lifting, which facilitates the disassembly and assembly of the waterproof and breathable shell 8.

[0094] To facilitate the positioning of the waterproof and breathable shell 8, a self-positioning semi-circular tube 21 with the same outer diameter as the inner diameter of the upper semi-circular tube 15 can be installed above the lower semi-circular tube 16. That is, when the upper semi-circular tube 15 is connected to the lower semi-circular tube 16, the self-positioning semi-circular tube 21 plays a role in radial self-positioning of the upper semi-circular tube 15. Furthermore, the installation of the self-positioning semi-circular tube 21 also helps to seal the exhaust pipe 14 and the upper semi-circular tube 15.

[0095] The top of the central beam 802, located between the two end perforated plates 801, has an installation slot 18 for the weighing module 7 to be inserted, thus creating space for the installation of the weighing module 7. The two ends of the central beam 802 are adapted to the size and shape of the central hole 11, and the size and shape of the middle section of the central beam 802 are not specifically required, provided that it does not contact the inner wall of the conical porous skeleton 601 and leaves a certain gap.

[0096] The weighing module 7 supports the conical porous skeleton 601 through the limiting block 19. The top of the limiting block 19 is provided with an axial limiting groove 20 that is adapted to the inner wall contour of the conical porous skeleton 601, thereby preventing the axial movement of the conical porous skeleton 601 from causing the vertical line of the center of gravity to deviate from the position of the detection component of the weighing module 7.

[0097] This invention also discloses a method for monitoring the decomposition rate of forest litter, comprising the following steps:

[0098] Place litter samples with known dry weight in a sealed experimental chamber 1;

[0099] The gas inside the experimental chamber 1 is forced to pass through the waterproof and breathable shell 8 and the carbon removal module 6 in sequence by an internal circulation device connected to the air inlet 2 and the exhaust outlet 3 of the experimental chamber 1.

[0100] During the monitoring process, the weight of the carbon removal module 6 is detected by the weighing module 7, and the gas concentration sensor 4 detects the concentration of carbon in the experimental chamber 1. concentration;

[0101] Calculate Δt The concentration change was measured, and the weight change of the carbon removal module 6 within Δt was converted into the weight change of the carbon removal agent and the reaction stoichiometry to obtain the carbon removal module 6 within Δt. Adsorption capacity;

[0102] Based on Δt Concentration change and Adsorption capacity calculation of litter sample decomposition The net release rate, and the net release rate is taken into account. The decomposition rate of litter samples within Δt is calculated using a dedicated formula for flux and decomposition rate.

[0103] Among them, the decomposition of litter samples produced Net release rate The calculation formula is:

[0104] R CO2 =

[0105] In the formula:

[0106] V is the effective volume of the sealed test chamber 1 (m³), Δt is the monitoring time interval (s), and m is the dry weight of the litter sample;

[0107] P is the atmospheric pressure inside test chamber 1 (Pa), R g is the universal gas constant (8.314 J / (mol・K)), and T is the absolute temperature (K);

[0108] and They are respectively time t and Real-time measurement Concentration (mol / m³);

[0109] C removed For the carbon removal module 6 within Δt The adsorption capacity (mol / m³) is obtained by converting the weight change of carbon removal module 6 with the stoichiometric ratio of the reaction. For example, in a system using K₂CO₃ / AC as the carbon removal agent in carbon removal module 6, every 1 mol of CO₂ corresponds to 1 mol of K₂CO₃ being converted to KHCO₃, resulting in a weight increase of 44 g / mol.

[0110] The core correlation model of decomposition rate combines the chemical characteristics of litter samples with the metabolic patterns of microorganisms to establish a correlation between carbon dioxide flux and decomposition rate. The specific correlation formula for (unit: g / (g・d)) is as follows:

[0111]

[0112] In the formula:

[0113] α is the carbon conversion coefficient (unit: g・mol⁻¹), reflecting the quantitative relationship between carbon dioxide release and carbon loss from litter. It is obtained by fitting the decomposition experiments of typical coniferous litter such as pine and cypress, and its value ranges from 0.41 to 0.47, as in the case of Korean pine. =0.43, spruce =0.46;

[0114] A litter sample quality correction function is constructed based on lignin content (L) and carbon-nitrogen ratio (C / N), with values ​​specific to coniferous forest characteristics (L / C > 0.25, C / N > 50). The function expression is as follows: =0.72·(C / N) -0.15 · (L / N) -0.09 It corrects metabolic deviations caused by lignin inhibition;

[0115] Q10 is the temperature sensitivity coefficient, which reflects the effect of temperature on the decomposition process. It was determined based on experiments with a temperature gradient of 10-30℃ in cold-temperate coniferous forests, and its value ranges from 1.9 to 2.3.

[0116] Tc is the measured temperature (°C) within the system. The difference in decomposition rate at non-25°C standard temperatures is corrected by (Tc−25) / 10 terms.

[0117] Furthermore, the decomposition rate and its changing trend are output in real time through a visual interface, and an alarm is automatically triggered when the decomposition rate changes abnormally and drastically.

[0118] This application innovatively calculates the decomposition rate of litter samples by detecting the amount of carbon dioxide produced during decomposition. Compared to some research and monitoring techniques that mainly rely on mass difference methods under laboratory or natural conditions, this method effectively shortens the experimental cycle, reduces workload and labor intensity, avoids human error, and provides real-time feedback. Furthermore, it solves the problem that calculating the decomposition rate through mass loss cannot eliminate various interfering factors, leading to poor reliability of the calculated decomposition rate.

[0119] Furthermore, this application employs a weighing module 7 to detect the amount of carbon dioxide adsorbed in the experimental chamber 1 by the carbon removal module 6 (a key method to shorten the experimental cycle, unlike existing technologies), and also detects the carbon dioxide concentration in the experimental chamber 1 (an auxiliary measure, taking into account changes in carbon dioxide concentration in the experimental chamber 1 to ensure the reliability of the calculation results and reduce errors). This combination avoids the problems of solely using the carbon removal module 6 to detect the amount of carbon dioxide released by the decomposition of litter samples, which would result in inaccurate decomposition rate calculations due to the consideration of carbon dioxide not absorbed by the carbon removal module 6 in the experimental chamber 1, and solely using changes in carbon dioxide concentration to calculate the decomposition rate, which would result in a slow response to changes in carbon dioxide concentration and uneven carbon dioxide concentration in the experimental chamber 1, leading to poor reliability of the detection data and affecting the accuracy of the decomposition rate.

[0120] Although the present invention has been disclosed above with reference to preferred embodiments, it is not intended to limit the present invention. Any person skilled in the art can make possible changes and modifications to the technical solutions of the present invention by utilizing the methods and techniques disclosed above without departing from the spirit and scope of the present invention. Therefore, any simple modifications, equivalent changes and alterations made to the above embodiments based on the technical essence of the present invention without departing from the content of the technical solutions of the present invention shall fall within the protection scope of the technical solutions of the present invention.

Claims

1. A device for monitoring the decomposition rate of forest litter, characterized in that, include: The experimental chamber (1) is equipped with an air inlet (2), an exhaust outlet (3), a gas concentration sensor (4), and a temperature and humidity sensor (5). A carbon removal module (6) is installed inside the experimental chamber (1) for adsorbing carbon dioxide; Weighing module (7), which is installed inside the experimental chamber (1), is used to weigh the carbon removal module (6); The waterproof and breathable shell (8) is provided with an isolation cavity (9) for the weighing module (7) and the carbon removal module (6) to be installed. The waterproof and breathable shell (8) is provided with an opening that communicates with the interior of the experimental chamber (1). A waterproof and breathable membrane (10) is provided at the opening. The waterproof and breathable membrane (10) is used to block water vapor in the experimental chamber (1) from entering the isolation chamber (9) and to allow carbon dioxide in the experimental chamber (1) to pass through the waterproof and breathable membrane (10) and be adsorbed by the carbon removal module (6). The isolation chamber (9) is connected to the exhaust port (3), and the carbon removal module (6) forms a multi-microporous isolation adsorption layer between the opening and the exhaust port (3), forcing the gas in the experimental chamber (1) to flow to the exhaust port (3) through the carbon removal module (6). The weighing module (7) is used to monitor the mass change of the carbon removal module (6) in real time; The data processing module is used to determine the total amount of carbon dioxide absorbed by the carbon removal module during the monitoring period based on the mass change, and to calculate the decomposition rate of the litter sample by combining the carbon dioxide concentration data collected by the gas concentration sensor (4) and the preset decomposition rate correlation model.

2. The device for monitoring the decomposition rate of forest litter according to claim 1, characterized in that, The waterproof and breathable shell (8) includes a perforated plate (801), a central beam (802), and a porous tubular membrane skeleton (803). The perforated plate (801) has a central hole (11) at its axis for the central beam (802) to be inserted into. Both ends of the central beam (802) are provided with perforated plates (801). The porous tubular membrane skeleton (803) connects the perforated plates (801) at both ends. The isolation cavity (9) is formed between the central beam (802), the porous tubular membrane skeleton (803), and the perforated plates (801) at both ends. The perforated plate (801) is provided with multiple air outlets (12) that connect the isolation chamber (9) and the exhaust port (3), and the porous tubular membrane skeleton (803) is provided with multiple air inlets (13) that connect the interior of the experimental chamber (1) and the isolation chamber (9). The weighing module (7) is set on the top of the central beam (802). The carbon removal module (6) is a rotating structure set around the central beam (802). The two ends of the carbon removal module (6) cover the area where the end plate (801) has multiple air outlets (12). The end of the carbon removal module (6) is sealed to the end plate (801) by a relaxed annular membrane.

3. The device for monitoring the decomposition rate of forest litter according to claim 1, characterized in that, The carbon removal module (6) includes a conical porous skeleton (601) and a carbon removal agent layer (602) covering the conical porous skeleton (601). The two ends of the conical porous skeleton (601) are conical tubes, and the narrowed section between the two ends is supported on the weighing module (7). Both ends of the conical porous skeleton (601) are porous structures, and the carbon removal agent layer (602) covers the porous areas at both ends of the conical porous skeleton (601).

4. The device for monitoring the decomposition rate of forest litter according to claim 1, characterized in that, The experimental box (1) has exhaust ports (3) on both sides of the box wall, and exhaust pipes (14) connected to the exhaust ports (3) are provided on both sides of the inner wall of the experimental box (1). The orifice plate (801) is provided with an upper semi-circular tube (15) at one end outside the isolation chamber (9), and the exhaust pipe (14) is provided with a lower semi-circular tube (16) that cooperates with the upper semi-circular tube (15). The upper semi-circular tube (15) and the lower semi-circular tube (16) are connected to form a closed pipe that connects the exhaust port (3) and multiple air outlets (12). The experimental box (1) is detachably equipped with a box cover (17) on top.

5. The device for monitoring the decomposition rate of forest litter according to claim 2, characterized in that, The center beam (802) has an installation slot (18) at the top and between the two end plates (801) for the weighing module (7) to be installed.

6. The device for monitoring the decomposition rate of forest litter according to claim 3, characterized in that, The weighing module (7) supports the conical porous skeleton (601) through the limiting block (19), and the top of the limiting block (19) is provided with an axial limiting groove (20) that is adapted to the inner wall contour of the conical porous skeleton (601).

7. A method for monitoring the decomposition rate of forest litter according to any one of claims 1-6, characterized in that, Includes the following steps: Place litter samples with known dry weight in a sealed experimental chamber (1); The gas inside the experimental chamber (1) is forced to pass through the waterproof and breathable shell (8) and the carbon removal module (6) in sequence by an internal circulation device connected to the air inlet (2) and the exhaust port (3) of the experimental chamber (1). During the monitoring process, the weight of the carbon removal module (6) is detected by the weighing module (7), and the gas concentration in the experimental chamber (1) is detected by the gas concentration sensor (4). concentration; Calculate Δt The concentration change was calculated, and the weight change of the carbon removal module (6) within Δt was converted into the carbon removal agent weight change and the reaction stoichiometry to obtain the carbon removal module (6) within Δt. Adsorption capacity; Based on Δt Concentration change and Adsorption capacity calculation of litter sample decomposition The net release rate, and the net release rate is taken into account. The decomposition rate of litter samples within Δt is calculated using a dedicated formula for flux and decomposition rate.

8. The method for monitoring the decomposition rate of forest litter according to claim 7, characterized in that, Produced by the decomposition of litter samples Net release rate The calculation formula is: R CO2 = ； In the formula: V is the effective volume (m³) of the sealed experimental chamber (1), Δt is the monitoring time interval (s), and m is the dry weight of the litter sample; P is the atmospheric pressure (Pa) inside the experimental chamber (1), R g is the universal gas constant (8.314 J / (mol・K)), and T is the absolute temperature (K); , They are respectively time t and Real-time measurement Concentration (mol / m³); C removed For the carbon removal module (6) within Δt Adsorption capacity (mol / m³).

9. The method for monitoring the decomposition rate of forest litter according to claim 8, characterized in that, A core correlation model for decomposition rate was established by combining the chemical characteristics of litter samples with microbial metabolic patterns. Flux and decomposition rate ( The specific correlation formula for (unit: g / (g・d)) is as follows: ； In the formula: α is the carbon conversion coefficient (unit: g・mol⁻¹), which reflects the quantitative relationship between carbon dioxide release and carbon loss from litter. A quality correction function for litter samples was constructed based on lignin content (L) and carbon-nitrogen ratio (C / N). Q10 is the temperature sensitivity coefficient, reflecting the effect of temperature on the decomposition process; Tc is the measured temperature (°C) within the system. The difference in decomposition rate at non-25°C standard temperatures is corrected by (Tc−25) / 10 terms.

10. A method for monitoring the decomposition rate of forest litter according to any one of claims 7-9, characterized in that, The decomposition rate and its changing trend are output in real time through a visual interface, and an alarm is automatically triggered when the decomposition rate changes abnormally and drastically.

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