Method for simulating emission of lake greenhouse gases by submerged plants at extreme high temperature and application of method
By planting bitter grass in the lake ecosystem, the impact of submerged plants on lake greenhouse gas emissions under extreme high temperature conditions was simulated, and the problem of unclear greenhouse gas emissions in lakes was solved, and the effect of stably reducing CO2 and CH4 fluxes was achieved.
Patent Information
- Application Number
- CN202510687986.2
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2025-05-27
- Publication Date
- 2025-09-05
AI Technical Summary
The prior art is difficult to effectively simulate and reduce the emission of greenhouse gases in lakes under extreme high temperatures. In particular, the impact of submerged plants on greenhouse gas emissions in lakes is unclear under extreme high temperature conditions, and corresponding measures and management are lacking.
The submerged plant bitter grass was planted in the simulated lake ecosystem, with a temperature of 32-38℃ for 38-42 days. The gas flux at the critical surface of water and the atmosphere was detected, and submerged plants that could reduce greenhouse gas emissions were screened out, which were used in different types of lake ecosystems.
At extremely high temperatures, submerged plant bitter grass can stably reduce greenhouse gas emissions in lake ecosystems, with the increase in CO2 and CH4 fluxes no more than 10%, and may even decrease, providing a method and basis for reducing greenhouse gas emissions in lakes.
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Figure CN120594746A_ABST
Abstract
Description
Technical Field
[0001] The present invention relates to the field of environmental science and technology, and in particular to a method for simulating greenhouse gas emissions from submerged macrophytes to lakes under extreme high temperatures and an application thereof. Background Art
[0002] Lakes account for 87% of inland water bodies and contribute the vast majority of their primary productivity. Globally, the estimated gross primary production (GPP) of lakes is 1.3 Pg C / yr, and the amount of organic carbon buried annually by lakes is approximately 25-50% of that buried in the oceans.
[0003] Current research and engineering practices on lake ecological restoration mechanisms usually strengthen a certain function, such as water quality improvement, and often weaken or even ignore other ecological functions and services of lake ecosystems, making it difficult to restore lake functions to natural levels. This is because the functions of natural ecosystems are inherently multidimensional. Considering only a certain service function may weaken the ecosystem's ability to provide other service functions, and it is difficult to reflect the characteristics of the ecosystem in maintaining multiple functions simultaneously.
[0004] As external pollution levels increase, nutrient levels in shallow lakes rise accordingly, and the lakes gradually transition from a clear to a turbid state. This transition is primarily influenced by ecosystem resilience. Improving lake ecosystems requires comprehensive ecosystem restoration technologies. The core of lake ecosystem restoration is to disrupt the feedback mechanisms that maintain turbidity and reestablish those that support clear water. Lake restoration approaches primarily include controlling pollution sources, restoring aquatic plants, and adjusting and optimizing food web structures. The key to transitioning shallow lakes from a turbid to a clear water state is to shift primary producers from phytoplankton to large aquatic higher plants. Aquatic plants, particularly submerged plants, increase particulate settling, improve underwater light conditions, and compete with phytoplankton for nutrients. They also stabilize sediments, inhibit sediment suspension, and release oxygen to sediments through their roots, improving the sediment redox potential and inhibiting the release of nutrients and organic carbon from sediments. More importantly, aquatic plants contain large amounts of cellulose and lignin, both of which are recalcitrant organic carbon components. Once successfully established, submerged plant communities can convert CO2 into refractory organic carbon through photosynthesis, enhancing the carbon sequestration capacity of lake wetlands while also slowing the decomposition and release of organic carbon through the "microbial carbon pump." This inert organic carbon is not rapidly mineralized and can accumulate and persist in water bodies for long periods of time, forming an inert carbon reservoir and effectively storing carbon within the water.
[0005] Emergent, floating, and submerged plants influence greenhouse gas emissions through different mechanisms. Greenhouse gases are produced between the plant rhizosphere and sediments and released through diffusion of gas molecules and pressurized airflow. Emergent plants occur in the aquatic-terrestrial ecotone, ranging from intermittently flooded areas to depths of 3 meters. They possess well-developed aerenchyma. Floating-leaf plants typically inhabit water depths of 1 to 5 meters, while submerged plants are completely submerged, with their distribution depth affected by water clarity. Emergent plants contribute significantly to methane (CH4) emissions but also have a dual effect on CO2: absorbing CO2 from the air and mediating its release from sediments. Much remains unknown about the impact of floating-leaf plants on greenhouse gas emissions, and research results vary widely. For example, duckweed cover increases CH4 and CO2 emissions from ponds, while water covered by the invasive floating aquatic plant Eichhornia crassipes can reduce CH4 and CO2 emissions by 57% compared to open water. Clear water areas dominated by submerged macrophytes have higher or lower CH4 concentrations than turbid water areas dominated by phytoplankton. In summary, while some studies have reported on the relationship between aquatic plants and greenhouse gases, the extent to which greenhouse gases in lake systems dominated by aquatic plants change under extreme high temperature conditions remains unclear, and there is a lack of appropriate measures and management to effectively reduce greenhouse gas emissions from these systems. Summary of the Invention
[0006] The purpose of the present invention is to provide a method for simulating greenhouse gas emissions from submerged macrophytes to lakes under extremely high temperatures and its application.
[0007] In order to achieve the above-mentioned object of the invention, the present invention provides the following technical solutions:
[0008] The present invention provides a method for simulating greenhouse gas emissions from submerged macrophytes to lakes under extreme high temperatures, comprising the following steps:
[0009] (1) Submerged macrophytes were planted in a simulated lake ecosystem at a temperature of 32–38°C for 38–42 days.
[0010] (2) Collect gases from the water-atmosphere interface in a simulated lake ecosystem every 3–7 days and measure the fluxes of carbon dioxide and methane in the gases;
[0011] The simulated lake ecosystem includes a simulated grass-type lake ecosystem and a simulated algae-type lake ecosystem.
[0012] Preferably, the submerged plant is Vallisneria.
[0013] Preferably, the simulated grass-type lake ecosystem includes bottom mud and lake water in a clear water lake.
[0014] Preferably, the simulated algae lake ecosystem includes lake bottom mud and lake water in the algae bloom area.
[0015] Preferably, 0.003-0.007 mg / L of phosphorus and 0.1-0.15 mg / L of nitrogen are added to the simulated lake ecosystem every day.
[0016] Preferably, the carbon dioxide flux at the critical surface between water and atmosphere in the simulated lake ecosystem is -0.092 to -0.657 μmol / m 2 / s, and the methane flux is 0.0014~0.0062μmol / m 2 / s, the submerged plants planted in the lake ecosystem can reduce the emission of greenhouse gases in the lake ecosystem under extreme high temperatures.
[0017] The present invention also provides an application of the method in detecting the greenhouse gas emission efficiency of submerged plants in lake ecosystems under extremely high temperatures.
[0018] The present invention also provides application of the method in screening submerged plants that have a controlling effect on greenhouse gas emissions from lake ecosystems under extreme high temperatures.
[0019] The present invention also provides application of the method in a method for reducing greenhouse gas emissions from lakes under extremely high temperatures.
[0020] The present invention also provides a method for reducing greenhouse gas emissions from lakes under extreme high temperatures, comprising the following steps:
[0021] Planting submerged plants in lake ecosystems;
[0022] The lake ecosystem is a lake ecosystem in which submerged plants screened according to the method are capable of reducing greenhouse gas emissions under extreme high temperatures.
[0023] This invention provides a method and application for simulating greenhouse gas emissions from submerged macrophytes in lakes under extreme high temperatures. This experiment uses Vallisneria as the research species. Vallisneria has a wide pH range (6.5-8.5), prefers warm environments, and thrives in water temperatures between 15°C and 28°C. It can tolerate mild eutrophication and is a common species in ecological restoration projects. Given Vallisneria's strong adaptability and potential stability under extreme high temperatures, warming may have a smaller impact on greenhouse gas emissions in systems dominated by Vallisneria. Based on this, Vallisneria was used as a submerged macrophyte to restore different types of lake ecosystems (grass-based and algae-based), studying the effects of submerged macrophytes on these lakes under high temperature stress. Ultimately, it was concluded that after restoration with Vallisneria, shallow lakes dominated by submerged macrophytes exhibited a relatively stable response to extreme climate change, with increases in greenhouse gas CO2 and CH4 fluxes exceeding 10%, and possibly even decreasing.
[0024] The method of the present invention simulates the impact of submerged plants on greenhouse gas emissions of different types of lake ecosystems under extreme high temperature conditions. The flux of carbon dioxide at the critical surface between water and atmosphere in the system is -0.092 to -0.657 μmol / m 2 / s, and the methane flux is 0.0014~0.0062μmol / m 2 / s, indicating that submerged macrophytes can reduce greenhouse gas emissions from that type of lake ecosystem. This provides a basis for restoration efforts to reduce greenhouse gas emissions from that lake ecosystem. This method can also be used to screen for submerged macrophytes that can reduce greenhouse gas emissions from different lake ecosystem types, providing a basis for restoration efforts for different lake ecosystem types. BRIEF DESCRIPTION OF THE DRAWINGS
[0025] Figure 1 Schematic diagram of the setup for the extreme high temperature experiment;
[0026] Figure 2 The ventilation of carbon dioxide for different types of lake ecosystems under extreme high temperatures;
[0027] Figure 3 The methane flux of different types of lake ecosystems under extreme high temperatures. DETAILED DESCRIPTION
[0028] The present invention provides a method for simulating greenhouse gas emissions from submerged macrophytes to lakes under extreme high temperatures, comprising the following steps:
[0029] (1) Submerged macrophytes were planted in a simulated lake ecosystem at a temperature of 32–38°C for 38–42 days.
[0030] (2) Collect gases from the water-atmosphere interface in a simulated lake ecosystem every 3–7 days and measure the fluxes of carbon dioxide and methane in the gases;
[0031] The simulated lake ecosystem includes a simulated grass-type lake ecosystem and a simulated algae-type lake ecosystem.
[0032] In the present invention, the submerged plant is Vallisneria. Vallisneria has a wide adaptability to water pH values (6.5-8.5), prefers a warm environment, and has a suitable growth temperature of 15-28°C. It can tolerate a mild eutrophic environment and is the most common species in ecological restoration projects. Considering that Vallisneria has a strong adaptability and may still have a high stability under extremely high temperature conditions, the impact of temperature increase on the greenhouse gases released in a system dominated by Vallisneria may be small. Therefore, Vallisneria was selected as the submerged plant for the experiment.
[0033] In the present invention, the simulated grass-type lake ecosystem includes the bottom mud and lake water in a clear water lake. The clear water lake is the Dongshan Station Pond.
[0034] In the present invention, the simulated algae lake ecosystem includes lake sediment and lake water in the algae bloom area. The algae bloom area lake is Taihu Lake at Dongshan Station, and the algae species are mainly cyanobacteria.
[0035] In the present invention, 0.003-0.007 mg / L of phosphorus, preferably 0.005 mg / L, and 0.1-0.15 mg / L of nitrogen, preferably 0.13 mg / L, are added to the simulated lake ecosystem every day.
[0036] In the present invention, the carbon dioxide flux at the critical surface between water and atmosphere in the simulated lake ecosystem is -0.092 to -0.657 μmol / m 2 / s, and the methane flux is 0.0014~0.0062μmol / m 2 / s, the submerged plants planted in the lake ecosystem can reduce the emission of greenhouse gases in the lake ecosystem under extreme high temperatures.
[0037] The present invention also provides an application of the method in detecting the greenhouse gas emission efficiency of submerged plants in lake ecosystems under extremely high temperatures.
[0038] The present invention also provides application of the method in screening submerged plants that have a controlling effect on greenhouse gas emissions from lake ecosystems under extreme high temperatures.
[0039] The present invention also provides application of the method in a method for reducing greenhouse gas emissions from lakes under extremely high temperatures.
[0040] The present invention also provides a method for reducing greenhouse gas emissions from lakes under extreme high temperatures, comprising the following steps:
[0041] Planting submerged plants in lake ecosystems;
[0042] The lake ecosystem is a lake ecosystem in which submerged plants screened according to the method are capable of reducing greenhouse gas emissions under extreme high temperatures.
[0043] The technical solutions provided by the present invention are described in detail below with reference to the embodiments, but they should not be construed as limiting the scope of protection of the present invention.
[0044] The bottom mud in the simulated grass-type lake ecosystem described in the embodiment of the present invention is taken from the bottom mud of the pond at Dongshan Station of Taihu Lake, and the lake water is taken from the pond water at Dongshan Station;
[0045] The bottom mud in the simulated algae lake ecosystem is taken from the bottom mud of Taihu Lake at Dongshan Station, the algae species in Taihu Lake are mainly cyanobacteria, and the lake water is taken from the lake water of Taihu Lake at Dongshan Station.
[0046] Example 1
[0047] (1) Purchase 24 experimental barrels (300 L capacity, upper diameter 80 cm, lower diameter 65 cm, height 82 cm). Randomly divide them into 6 groups, each with 3 subgroups: Group C1, Group C2, Group C3, Group Z1, Group Z2, and Group Z3.
[0048] The bottom of the experimental barrels of Groups C1, C2, and C3 were paved with 15 cm of Dongshan Station pond mud, and then pond water from Dongshan Station was added (simulating a grass-type lake ecosystem).
[0049] The bottom of the experimental barrels of Group Z1, Group Z2, and Group Z3 were paved with 15 cm of sediment from Taihu Lake at Dongshan Station, and then lake water from Taihu Lake at Dongshan Station was added (to simulate the algae lake ecosystem).
[0050] The bottom mud in the experimental barrel is the bottom mud that has been exposed to the sun for 7 days to kill the plant seeds and benthic organisms in the bottom mud.
[0051] The bottom mud and water in each experimental barrel were mixed evenly using a blender, and then 20 Vallisneria spinulosa plants were planted in each experimental barrel. The biomass of Vallisneria spinulosa in each experimental barrel was 120 g, and each Vallisneria spinulosa plant in each experimental barrel had 5 to 8 leaves and a plant height of 20 cm.
[0052] During the experiment, the heating rod was turned on, and the temperature of group C1 and group Z1 was set to 32°C, the temperature of group C2 and group Z2 was set to 35°C, and the temperature of group C3 and group Z3 was set to 38°C. The experiment lasted for 40 days.
[0053] Schematic diagram of the extreme high temperature experiment setup Figure 1shown.
[0054] 0.005 mg / L phosphorus and 0.13 mg / L nitrogen were added to the experimental barrel every day to simulate the input of exogenous nutrients into the lake.
[0055] Samples were collected once before heating and then collected every 5 days for testing.
[0056] The gases at the critical surface between water and atmosphere in the simulated lake ecosystem in each treatment group were collected, and the contents of carbon dioxide and methane in the gases were detected (measured using a portable gas flux meter).
[0057] The results of carbon dioxide ventilation at the water-air interface in grass-type and algae-type lake ecosystems under different temperature gradients are as follows: Figure 2 The results of methane diffusion flux at the water-air interface in grass-type and algae-type lake ecosystems under different temperature gradients are shown in Figure 3 shown.
[0058] A static chamber method was used to collect gases at the water-atmosphere interface in a simulated lake ecosystem. The collection method involved placing a static chamber at the sampling point. Before sampling, the chamber was filled with air and placed upside down on the water surface. A fan was activated to mix the air inside the chamber and ensure stable sampling. The chamber's opening and closing, as well as the gas collection process, were automated. 100 mL of gas was periodically collected from the chamber and injected into an aluminum foil sampling bag. Six samples were collected at each sampling point, and gas concentrations were measured using a flux meter.
[0059] Figures 2-3 As shown, the mean carbon dioxide (CO2) fluxes of the simulated grass-type lake ecosystems were all lower than those of the algae-type lake ecosystems. Before heating, the effects of grass and algae types on CO2 diffusion flux were significant (P = 0.009), while the effect of temperature on CO2 diffusion flux was not significant (P = 0.485). As the experimental time increased, the effect of temperature on CO2 flux became less significant. Similar to the CO2 flux results, the mean CH4 fluxes of the grass-type lakes were all lower than those of the algae-type lakes. As the experimental time increased, CH4 fluxes in the grass-type lakes decreased across all groups, while the opposite trend was observed in the algae-type lakes, showing an increasing trend.
[0060] When the water temperature is 32℃, the CO2 flux at the critical surface between water and atmosphere in the grass-type system is -0.555±0.093μmol / m 2 / s, CH4 flux is 0.0018±0.0005μmol / m 2 / s; the CO2 flux at the critical surface between water and atmosphere in the algae system is -0.092±0.400μmol / m 2 / s, CH4 flux was 0.0031±0.0008μmol / m 2 / s;
[0061] When the water temperature is 35℃, the CO2 flux at the critical surface between water and atmosphere in the grass-type system is -0.657±0.123μmol / m 2 / s, CH4 flux was 0.0021±0.0018μmol / m 2 / s; the CO2 flux at the critical surface between water and atmosphere is -0.354±0.392μmol / m 2 / s, CH4 flux was 0.0044±0.0013μmol / m 2 / s;
[0062] When the water temperature is 38℃, the CO2 flux at the critical surface between water and atmosphere in the grass-type system is -0.496±0.069μmol / m 2 / s, CH4 flux was 0.0014±0.0007μmol / m 2 / s; the CO2 flux at the critical surface between water and atmosphere is -0.383±0.130μmol / m 2 / s, CH4 flux was 0.0062±0.0015μmol / m 2 / s.
[0063] In summary, the greenhouse gas emissions of algae-type systems are higher than those of grass-type systems, and increase with rising water temperature; the submerged plant Vallisneria sinensis has strong stability for grass-type lake ecosystems under extreme high temperatures, and Vallisneria sinensis can be used to reduce greenhouse gas emissions under extreme high temperatures.
[0064] Example 2
[0065] The control of eutrophication and water pollution in Taihu Lake has been carried out continuously since the 1980s. In the lake ecological restoration technology demonstration area of Lihu Lake (Wuli Lake), a bay of Taihu Lake, the water area of the restoration is about 400,000 m 2 , Vallisneria was planted in the sediment of algae-type lakes to repair the algae-type lake ecosystem. The planted biomass was 1470.54g / m 2 (fresh weight). Currently, the water transparency is maintained at 80-120 cm, the submerged vegetation coverage is 60%-75%, and the water quality has steadily reached the surface water Class III standard. The CO2 flux in the grass restoration area is -0.78 μmol / m 2 / s, significantly lower than the -0.24 μmol / m in the unrepaired area 2 / s, and there was no significant difference in CH4 flux between the two regions, both of which were 0.02 μmol / m 2 / s, indicating that the restoration area with Vallisneria as the main primary producer has a strong reduction effect on the total greenhouse gas flux.
[0066] As can be seen from the above embodiments, the present invention provides a method for simulating greenhouse gas emissions from submerged plants to lakes under extreme high temperatures and its application. This experiment intends to use Vallisneria as the research species. Vallisneria is used to restore the algae-type lake ecosystem, and the changes in greenhouse gas emissions from the lake ecosystem under high temperature stress are compared between the grass-type system dominated by Vallisneria and the algae-type system dominated by phytoplankton without restoration. It was finally concluded that after restoration with the submerged plant Vallisneria, the response of the grass-type shallow lake dominated by submerged plants to extreme climate was relatively stable, and the increase in the system's greenhouse gas CO2 and CH4 fluxes did not exceed 10%, and may even result in a decrease. This provides a basis for the restoration and improvement of grass-type ecosystems.
[0067] The above is only a preferred embodiment of the present invention. It should be pointed out that for ordinary technicians in this technical field, several improvements and modifications can be made without departing from the principles of the present invention. These improvements and modifications should also be regarded as within the scope of protection of the present invention.
Claims
1. A method for simulating greenhouse gas emissions from submerged plants to lakes under extreme high temperatures, characterized in that: The steps include: (1) Submerged macrophytes were planted in a simulated lake ecosystem at a temperature of 32–38°C for 38–42 days. (2) Collect gases from the water-atmosphere interface in a simulated lake ecosystem every 3–7 days and measure the fluxes of carbon dioxide and methane in the gases; The simulated lake ecosystem includes a simulated grass-type lake ecosystem and a simulated algae-type lake ecosystem.
2. The method according to claim 1, characterized in that The submerged plant is Vallisneria.
3. The method according to claim 2, characterized in that The simulated grass-type lake ecosystem includes bottom mud and lake water in a clear water lake.
4. The method according to claim 3, characterized in that The simulated algae lake ecosystem includes lake bottom mud and lake water in the algae bloom area.
5. The method according to claim 4, characterized in that 0.003-0.007 mg / L of phosphorus and 0.1-0.15 mg / L of nitrogen were added to the simulated lake ecosystem every day.
6. The method according to claim 5, characterized in that The carbon dioxide flux at the critical interface between water and atmosphere in the simulated lake ecosystem is -0.092 to -0.657 μmol / m 2 / s, and the methane flux is 0.0014~0.0062μmol / m 2 / s, the submerged plants planted in the lake ecosystem can reduce the emission of greenhouse gases in the lake ecosystem under extreme high temperatures.
7. Use of the method according to any one of claims 1 to 6 in detecting the greenhouse gas emission efficiency of submerged macrophytes in lake ecosystems under extreme high temperatures.
8. Use of the method according to any one of claims 1 to 6 in screening submerged plants that have a controlling effect on greenhouse gas emissions from lake ecosystems under extreme high temperatures.
9. Use of the method according to any one of claims 1 to 6 in a method for reducing greenhouse gas emissions from lakes under extreme high temperatures.
10. A method for reducing greenhouse gas emissions from lakes under extreme high temperatures, characterized in that: The steps include: Planting submerged plants in lake ecosystems; The lake ecosystem is a lake ecosystem in which submerged plants screened according to the method of any one of claims 1 to 6 are capable of reducing greenhouse gas emissions under extreme high temperatures.