A method and application for evaluating the community development and carbon sink dynamics of mangroves after their northward migration

Abstract

The present invention provides a method and application for evaluating the community development and carbon sink dynamics of mangroves after they move northward, the method comprising: obtaining the distribution of objects as the initial input data of the model through identification of remote sensing image data sets; calibrating and predicting the model based on the seasonal change trend of the carbon community changes and carbon sink capacity of newly planted mangroves; constructing a mangrove community and carbon sink dynamic evaluation model; correcting the model parameters; using the model to calculate the area of ​​newly planted mangroves, primary productivity, ecosystem respiration and net CO2 exchange flux to obtain a community development and carbon sink dynamic evaluation. The evaluation method based on the verification model is helpful to understand and predict the health status and carbon sink function of the mangrove system in coastal wetlands, and can realize the comprehensive evaluation of the community development and carbon sink capacity of mangroves after they move northward and the prediction of future trends, providing a scientific basis and data support for the accurate accounting of coastal wetland protection and restoration after the mangroves move northward and the effective management of blue carbon resources.

Description

Technical Field

[0001] The present invention relates to the technical field of processing forestry carbon sinks with computer technology, and specifically to a method for evaluating vegetation growth, community development and carbon sink capacity after mangroves are planted in coastal wetlands using a computer, and more particularly to a method and application for evaluating community development and carbon sink dynamics after mangroves move northward. Background Art

[0002] Mangroves are tropical and subtropical thermophilic plants, and temperature has always been the main factor restricting the northward migration of mangroves. Whether the growth, development and reproduction of mangrove plants can adapt to the climate environment of higher latitudes requires in-depth research. Moreover, although siltation in coastal areas is conducive to the colonization of coastal wetland plants, the strong hydrodynamics generated by tides and waves can also have a negative effect on plant growth and carbon sequestration in wetland ecosystems. Therefore, the evaluation method based on the validation model is helpful to understand and predict the health status and carbon sequestration function of coastal wetland mangrove systems.

[0003] There is still a great deal of uncertainty in the composition of blue carbon in coastal wetlands, and in many cases there are large discrepancies between the estimated results of the blue carbon inventory and the actual observed values. In addition, the dynamic data, emission factors and other related measurement parameters involved in the existing observation technology are not complete, resulting in the impact of environmental climate change on mangrove growth, community dynamics and carbon sinks.

[0004] The survival, growth and reproduction of northward-migrating mangroves and the carbon sequestration capacity of coastal wetlands will fluctuate in time and space due to changes in environmental climate. For example, temperature is an important external factor affecting the carbon sequestration capacity of mangroves and affects the carbon accumulation of plant biomass. At suitable temperatures, the activity of plant photosynthetic enzymes is enhanced, and the mangrove system has a higher carbon fixation capacity. However, when the temperature is too high, the respiration of mangrove plants will be enhanced. In addition, forest age is also an important factor in the change of mangrove carbon sequestration. The organic carbon in the bottom of mangroves at different growth stages increases with age. At present, there is a lack of dynamic simulation tools for coastal wetland vegetation communities that take into account the influence of multiple factors.

[0005] Moreover, coastal tides usually present two types of hydrological cycles at different time scales, namely semi-diurnal and diurnal cycles. It is generally believed that tidal flooding can affect the carbon fixation capacity of plants by changing the photosynthetic efficiency of plants, soil permeability and chemical characteristics, and also affects the structural characteristics and distribution pattern of plant communities. Due to different flooding frequencies and durations, the impact of tides on carbon processes in coastal wetland ecosystems may vary greatly.

[0006] Therefore, understanding the absorption, synthesis, transport and release mechanism of greenhouse gases by mangroves, optimizing blue carbon accounting technology, refining the classification and accounting indicators of carbon pools in coastal wetland ecosystems, and improving the emission factors of various blue carbon ecosystems under the influence of human management activities are of great significance for evaluating the role of mangroves in the global carbon balance.

[0007] Modeling techniques for ecosystem processes help to understand and evaluate the spatiotemporal dynamics of vegetation communities and carbon sequestration capacity in coastal wetland ecosystems. In recent years, a series of process-based vegetation dynamics and carbon dynamics models have been developed. Most of the existing modeling techniques focus on the short-term photosynthetic performance of plants in response to climate change, and in the models, biological activities such as plant vertical growth, reproduction, and carbon exchange processes are parameterized with idealized random function quantities, which often leads to uncertainty in model assessment results and deviations in simulation accuracy.

[0008] At present, most ecological models cannot take into account the impact of complex climate, hydrology, and sediment changes on biogeomorphological and geochemical processes such as coastal wetland landforms, vegetation carbon fixation, and system carbon cycles. The complex interactions between biological and abiotic processes in coastal wetland ecosystems are rarely described in detail. Moreover, existing technologies rarely consider the multi-dimensional impacts of coastal tidal processes on tidal flat landform changes, mangrove growth and reproduction, vegetation wave elimination and siltation, and ecosystem carbon exchange. This leads to insufficient assessment and prediction capabilities for the carbon sink function of northward-migrating mangroves. However, the community development and carbon sink dynamics of mangroves after northward migration and their influencing factors are still unclear, and the differences in community dynamics and carbon fixation capacity of mangroves under different environmental and climatic conditions after northward migration also need to be studied. Testing according to the carbon sink calculation method in existing technologies often makes it difficult to accurately assess the community development and carbon sink capacity of mangroves after northward migration.

[0009] Therefore, it is necessary to clarify the effects of various environmental factors on their growth and community dynamics, as well as the carbon sequestration mechanism and regulation mechanism, and to explore the carbon storage and carbon sequestration capacity of mangrove wetlands and their research methods and principles.

[0010] The above-mentioned record of background technical knowledge is intended to help ordinary technicians in this field understand the existing technologies that are relatively close to the present invention, and at the same time facilitate the understanding of the inventive concept and technical solution of the present invention. It should be clear that in the absence of clear evidence that the above-mentioned content has been disclosed before the filing date of this patent application, the above-mentioned background technology should not be used to evaluate the novelty of the technical solution of this application. Summary of the invention

[0011] Technical issues

[0012] In order to solve the above problems, the purpose of the present invention is to provide a method and application for evaluating the community development and carbon sink dynamics after the northward migration of mangroves. Based on the development of a grid process model, the ecological module is coupled with the hydrodynamic module. In addition to considering the adaptability of vegetation growth, development, and reproduction characteristics to the climate environment after the northward migration of mangroves, the influence of coastal tidal processes on tidal flat landform changes, mangrove growth and reproduction, and vegetation wave dissipation and siltation, as well as the spatiotemporal dynamics of ecosystem carbon exchange are also considered. The biological-physical feedback relationship between the dynamics of mangrove vegetation and landform changes is derived at a fine scale, the interaction between coastal wetland mangrove plants and water-sand-sedimentation-geomorphological processes is parameterized, and the biological processes such as plant growth, diffusion, and establishment are parameterized in more detail. Finally, the carbon cycle multi-process calculation module is incorporated to calculate the spatiotemporal dynamics of carbon sink indicators such as total primary productivity, net primary productivity, ecosystem respiration, and net ecosystem exchange, which are used to evaluate the community development and carbon sink capacity of mangroves after the northward migration.

[0013] Technical Solution

[0014] In order to achieve the above-mentioned objectives, the inventors of the present application conducted in-depth research, coupled the complex bio-geomorphology and geochemical processes such as the complex climate, hydrology, sediment, vegetation and carbon cycle of coastal wetlands, and provided a method for evaluating the community development and carbon sink dynamics of mangroves after their northward migration. The evaluation method based on the verification model of the present invention is helpful to understand and predict the health status and carbon sink function of mangrove systems in coastal wetlands, and can realize the comprehensive evaluation of the community development and carbon sink capacity of mangroves after their northward migration and the prediction of future trends. It can provide a scientific basis and data support for accurately calculating the protection and restoration of coastal wetlands after the northward migration of mangroves and the effective management of blue carbon resources.

[0015] That is, the present invention is:

[0016] (1) A method for evaluating the community development and carbon sink dynamics of mangroves after their northward migration, comprising:

[0017] S1. Obtain the remote sensing image dataset of the mangrove planting area to be evaluated, and identify the distribution of ground objects as the initial input data of the model;

[0018] S2. Obtain the seasonal variation trend of carbon community changes and carbon sequestration capacity of newly planted mangroves for model calibration and prediction;

[0019] S3. Taking the newly planted mangrove distribution area as the simulation domain, and local meteorological data, tidal processes, and terrain elevation as model driving parameters, a dynamic assessment model of mangrove communities and carbon sinks was constructed;

[0020] S4. Based on the measured mangrove growth and system CO 2The model parameters are calibrated using the ground feature distribution data identified by flux and remote sensing images and the plant biomass data measured in the field;

[0021] S5. Use the model to analyze the area of ​​newly planted mangroves, primary productivity, ecosystem respiration and net CO 2 The exchange flux was calculated to evaluate the community development and carbon sink dynamics of mangroves after their northward migration and predict their future changes.

[0022] Furthermore, in step S1, the remote sensing image dataset includes: landform categories such as mangroves, salt marshes, tidal flats and water, as well as the area of ​​newly planted mangroves, the area of ​​silty tidal flats, coverage ratio, and elevation distribution data. By interpreting and identifying the remote sensing image dataset of the mangrove planting area, the identified areas and coverage ratios of mangroves and tidal flats, as well as the elevation distribution data of tidal flats are used as the basic initial input data of the model.

[0023] Furthermore, in step S2, the seasonal trend of carbon community changes and carbon sequestration capacity of the newly planted mangroves is determined by measuring the area changes, biomass growth, plant photosynthesis / respiration, soil CO 2 Emissions obtained.

[0024] Furthermore, in step S2, the static box method or eddy covariance technology is used to analyze the CO2 of the newly planted mangrove system moving northward. 2 The exchange flux is observed seasonally, and the net exchange of ecosystems, soil respiration, and total ecosystem respiration are quantified to understand the CO2 exchange between the newly formed mangrove wetlands and the atmosphere. 2 Flux characteristics.

[0025] Furthermore, the static chamber method was used to study the CO2 content of the newly planted mangrove system in the north. 2 The seasonal observation of exchange flux includes: using a portable trace gas analyzer to observe CO2 in mangrove sample plots in the early growth stage in spring, summer and autumn each year. 2 For gas exchange measurement, the volume of the measuring chamber is designed according to the height of the plant. The box support can be made of stainless steel pipe and connected through a three-way joint. The support is sealed with a transparent polyvinyl chloride film, the joint is sealed, and connected to the trace gas analyzer through a rubber tube. A battery-driven fan is installed on the support to mix the gas in the box, and a thermometer is installed. The CO in the box is calculated by linear regression analysis. 2 Changes in gas concentrations; plant net ecosystem CO 2 Exchange (Netecosystem CO 2 exchange, NEE) is based on the daytime CO 2Flux calculation, assuming that there is no photosynthesis in the night environment, the NEE value obtained at night is regarded as the ecosystem respiration (ER) flux, and the sum of NEE and ER is regarded as the gross primary productivity (GPP). The measured NEE, ER and GPP are used to verify the series of plant photosynthetic carbon fixation and respiration models.

[0026] Furthermore, the static box method calculates the gas flux based on the ideal gas equation according to the formula shown in equation (1):

[0027] (1)

[0028] Among them, F represents gas flux; M represents gas molar mass; V represents gas molar volume under standard conditions; c represents gas concentration; t represents unit time; H represents the effective height of the test chamber; and T represents the average temperature in the test chamber.

[0029] Furthermore, in step S3, the mangrove community and carbon sink dynamic assessment model is coupled with a vegetation dynamic model, a photosynthetic carbon fixation and respiration model, and an ecosystem respiration model.

[0030] Furthermore, the vegetation dynamic model is a spatial grid matrix composed of interconnected grids constructed on the Matlab® platform with a resolution of 1m×1m. These grids are connected to all adjacent grids, and each connection has a distribution probability associated with vegetation expansion. The "vegetation distribution" is mainly obtained through equations (2) and (3), and the "vegetation distribution" is the initial input data required for model startup.

[0031] Furthermore, the vegetation dynamic model includes the relationship between the number of hypocotyls and the survival rate during the sexual reproduction of mangroves as shown in formula (2):

[0032] (2)

[0033] Where N represents the number of embryonic axes that survived in the end; N max represents the largest hypocotyl pool; t v Indicates the month; E indicates the tidal flat elevation; E 0v Indicates the elevation threshold required for seed retention; S v represents the seed bank decay rate; g s represents the sediment coefficient related to sediment particle size; coefT represents the temperature tolerance threshold related to hypocotyl occurrence; coefW represents the hydrological tolerance threshold related to hypocotyl establishment. The model takes into account the competitive balance between salt marsh species, including space occupation, succession and inhibition; in this model, salt marshes and mangroves usually show non-aggression in the intertidal zone and share similar ecological niches.

[0034] Furthermore, in the vegetation dynamics model, the expansion of mangrove communities is mainly carried out by sexual reproduction strategies, and the sexual reproduction process follows the geometric distribution (GE) shown in formula (3):

[0035] (3)

[0036] Among them, X represents the Chebyshev distance; P represents the percentage of propagules distributed from the central grid to the peripheral grid; k represents the distance between the diffused grid and the diffused central grid.

[0037] Furthermore, the photosynthetic carbon fixation and respiration model includes the relationship between plant biomass carbon accumulation and carbon partition coefficient shown in formula (4):

[0038] (4)

[0039] Among them, AGB represents aboveground plant biomass; GB represents total biomass accumulation; NPP represents net primary productivity; LB represents litter biomass; BGB represents belowground biomass; z represents the average tidal range; g represents biomass allocation correction coefficient; and E represents tidal flat elevation.

[0040] Furthermore, the photosynthetic carbon fixation and respiration model includes calculating and measuring the leaf-level photosynthetic gross primary productivity GPP, leaf-level ecosystem respiration ER and leaf-level ecosystem exchange NEE at multiple sampling points during low tide in July and November, as shown in formula (5):

[0041] (5)

[0042] Among them, GPP represents the gross primary productivity of photosynthesis at the leaf level; NEE represents the net ecosystem exchange at the leaf level; ER represents the ecosystem respiration at the leaf level; R L Represents the respiration of the above-ground ecosystem; R S Represents underground ecosystem respiration; P g.sun represents the total primary productivity of the sun-side leaves; P g.sh represents the total primary productivity of leaves on the shaded side; f(x) represents a function with x as the independent variable, where f is the corresponding calculation rule; PAR sun Represents the photosynthetically active radiation component on the sun side; PAR sh represents the photosynthetically active radiation component on the shaded side; T a Indicates atmospheric temperature; D a Represents atmospheric water vapor pressure difference; C a Represents atmospheric CO 2 Concentration; N L Indicates the nitrogen content of leaves; gs stands for stomatal conductance; LAI sun Represents the leaf area index on the sunny side; LAI sh Represents the shaded leaf area index.

[0043] Furthermore, the ecosystem respiration model includes a vegetation canopy respiration part, a soil respiration part and a tidal influence part, wherein the vegetation canopy respiration part includes the relationship between the plant biomass carbon accumulation and the carbon partition coefficient shown in formula (4) and the relationship between the change rate of coastal wetland soil respiration shown in formula (6):

[0044] (6)

[0045] Among them, R s is the soil respiration rate; C WT represents the tidal flooding factor of gas emission; B b represents plant root biomass; R n represents soil basal respiration (with nighttime respiration as a reference); k r represents the soil respiration temperature sensitivity ratio; T a Indicates atmospheric temperature; W D Indicates the depth of tidal flooding; θ w Indicates the curvature of gas emission with respect to water depth; m b Represents the coefficient.

[0046] Furthermore, the deposition dynamics and elevation changes (dE / dt) of tidal characteristics, suspended sediment concentration and vegetation attributes in the model are determined by the combined effects of suspended sediment input and the water column above the surface of the bare beach and mangrove beach, sediment deposition and additional sediment capture by vegetation; therefore, the tidal influence part includes the relationship between tidal flat sediment deposition and elevation change rate shown in equation (7):

[0047] (7)

[0048] Where E represents the tidal flat elevation; t represents time; S r represents sedimentation rate; SSC represents suspended sediment concentration; W D represents the depth of flooding caused by tide; A represents the area of ​​the grid; S cap represents the mass of sediment captured by vegetation; CF represents the conversion factor between mass and thickness; AGB represents the aboveground biomass of plants; S r.v represents the sedimentation rate in the vegetation area; S r.min represents the minimum sedimentation rate in the mudflat area; S r.m represents the deposition rate of the light beach area; T h represents the daily maximum tide height; ρ b Indicates soil bulk density; a vrepresents the correction coefficient of the relationship curve between gas emission rate and water depth; c and d are the correction coefficients of the sedimentation rate curve in the light beach area. When fitting, a needs to be corrected according to the measured value. v , c, and d.

[0049] The respiration of mangrove ecosystems includes two parts: vegetation canopy respiration and soil respiration. The vegetation canopy respiration follows the above algorithm. The simulation of soil respiration is based on the relationship between respiration rate and temperature sensitivity. In addition, in tidal flat wetland environments, intermittent flooding will significantly affect the soil respiration of coastal wetlands. When the wetland sediments are completely submerged by the tide at high tide, CO 2 The diffusion of water is hindered. During low tide, soil re-exposure stimulates gas emission. Therefore, a modified water depth exponential function is used to describe the changes in soil respiration in coastal wetlands under flooding conditions.

[0050] Furthermore, in step S4, the model needs to repeat the parameter correction for at least 10 times to check the simulation deviation, and the model output results are corrected using the observed vegetation growth and system carbon flux data. If the error meets the preset requirements, the model training is completed.

[0051] Furthermore, in step S5, the evaluation results of the community development and carbon sink dynamics of mangroves after their northward migration and the prediction of future changes include the distribution area of ​​mangroves, primary productivity GPP, ecosystem respiration ER and net ecosystem exchange NEE.

[0052] The scheme of the present invention couples the complex bio-geomorphology and geochemical processes such as the complex climate, hydrology, sediment, vegetation and carbon cycle of coastal wetlands, and describes in detail the complex interaction between the biological and non-biological processes of coastal wetland ecosystems. In addition to considering the adaptability of vegetation growth, development, and reproduction characteristics to the climate environment after the northward migration of mangroves, it also considers the impact of coastal tidal processes on tidal flat landform changes, mangrove growth and reproduction, vegetation wave dissipation and siltation, and the spatiotemporal dynamics of ecosystem carbon exchange. The present invention can achieve a comprehensive assessment of the community development and carbon sequestration capacity of mangroves after the northward migration and the prediction of future trends. The evaluation method based on the verification model of the present invention helps to understand and predict the health status and carbon sequestration function of the mangrove system in coastal wetlands, and can provide a scientific basis and data support for the accurate accounting of coastal wetland protection and restoration after the northward migration of large areas of mangroves and the effective management of blue carbon resources.

[0053] (2) Application of the aforementioned method for assessing the community development and carbon sink dynamics of mangroves after they move north, including the assessment of the community development and carbon sink dynamics of mangroves after they are planted north of the northern limit of their natural distribution.

[0054] (3) A system for evaluating the community development and carbon sink dynamics of mangroves after their northward migration, comprising:

[0055] A data collection unit, used to collect data on the ecosystem of the mangrove planting area to be assessed to obtain an original data set;

[0056] A data analysis unit, used to analyze and identify the original data set;

[0057] The assessment unit uses the mangrove community and carbon sink dynamics assessment model to assess the community development and carbon sink dynamics of mangroves after their northward migration and their future change trends;

[0058] A data storage unit, used for storing raw data and evaluation results;

[0059] When the system is running, the aforementioned method for evaluating the community development and carbon sink dynamics after the northward migration of mangroves is executed.

[0060] (4) A computer device, comprising a memory, a processor, a communication interface and a communication bus; wherein the memory, the processor and the communication interface communicate with each other via the communication bus; the memory is used to store computer programs; the processor is used to execute the computer programs stored in the memory, and when the processor executes the computer program, the aforementioned method for evaluating the community development and carbon sink dynamics of mangroves after their northward migration is implemented.

[0061] (5) A computer-readable storage medium having a computer program stored thereon, wherein the computer program, when executed by a processor, implements the aforementioned method for evaluating the community development and carbon sink dynamics of mangroves after their northward migration.

[0062] Based on the common knowledge in this field, the above-mentioned preferred conditions can be combined with each other to obtain a specific implementation method.

[0063] Beneficial Effects

[0064] 1) The scheme of the present invention incorporates the life history characteristics and environmental adaptability of mangrove plants in the coastal tidal environment into the modeling technology, and provides the environmental pressures and response thresholds of different life history stages such as establishment, growth, and reproduction of northward migrating mangroves.

[0065] 2) In the assessment model, the environmental influencing conditions of basic biological activities such as hypocotyl production, propagule dispersal, plant photosynthesis / respiration, and biomass accumulation of the northward-migrating mangroves were determined.

[0066] 3) The population expansion range of the northward-migrating mangroves on the coastal tidal flats is closely related to the number of effective hypocotyls, tidal carrying effect, and seedling survival rate. During the modeling process, the tidal flat elevation gradient was extracted as the main regulating parameter for the development of the above mangrove communities.

[0067] 4) After planting, mangroves have the ability to capture suspended sediment. The sediment deposition rate is positively correlated with the aboveground biomass of mangroves. This assessment model embeds the calculation of sediment deposition rate and tidal flat elevation changes.

[0068] 5) Since meteorological factors such as atmospheric temperature, photosynthetically active radiation, and relative humidity are key determinants driving the development of plant leaves and canopies, the quantitative relationship between the large leaf model-canopy photosynthetic efficiency and the annual accumulated temperature-leaf area index was incorporated into the carbon sink module to quantify the photosynthetic carbon fixation efficiency and seasonal changes of the northward-migrating mangroves.

[0069] 6) In order to cope with tidal inundation pressure, ground plants use an equidistant allocation strategy to transfer their biomass to underground organs to achieve stable settlement and efficient reproduction. Therefore, the biomass allocation factor that changes with the increase in the altitude of mangrove habitats is used to achieve the seasonal allocation of aboveground and underground biomass.

[0070] 7) Due to the frequent dry-wet alternation caused by tidal movement, when the tidal flat is completely submerged by the tide, plant photosynthesis and soil gas diffusion will be hindered, and soil respiration will increase significantly when the flooding is restored. The model provides the concept of flooding barrier at the water-beach interface as a regulator of ecosystem respiration and vegetation photosynthesis rate, which more scientifically depicts the impact of tidal dynamics on the carbon cycle process of mangrove ecosystems.

[0071] 8) The present invention couples atmospheric temperature, atmospheric CO 2 The study also studies the influence of environmental factors such as concentration, tidal flat water level changes, and sediment deposition on ecological processes such as mangrove colonization, growth, reproduction, photosynthesis / respiration, and soil respiration, and sets corresponding biotic-abiotic interaction driving, regulation, and threshold parameters. This can realize the prediction of future trends in community development and carbon sequestration capacity after the northward migration of mangroves, and provide a scientific basis and data support for accurately calculating the protection and restoration of coastal wetlands after the northward migration of large areas of mangroves, as well as the effective management of blue carbon resources.

[0072] The present invention adopts the above technical solution to achieve the above purpose, which makes up for the shortcomings of the prior art and has reasonable design and convenient operation. BRIEF DESCRIPTION OF THE DRAWINGS

[0073] In order to make the above and / or other purposes, features, advantages and examples of the present invention more obvious and easy to understand, the drawings required for use in the specific implementation of the present invention will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without paying creative work.

[0074] Figure 1A flow chart showing the modeling technology for assessing the community dynamics and carbon sequestration capacity of mangroves after northward planting;

[0075] Figure 2 It represents the seasonal variation of photosynthetic gross primary productivity (GPP) at the leaf level of mangroves (comparison between simulated and measured values);

[0076] Figure 3 The seasonal variation of ecosystem respiration (ER) at leaf level in a northward-migrating mangrove forest in an observational example (comparison between simulated and measured values);

[0077] Figure 4 It shows the seasonal variation of leaf-level net ecosystem exchange (NEE) of a northward-migrating mangrove forest in an observational example (comparison between simulated and measured values);

[0078] Figure 5 It shows the seasonal variation of aboveground biomass (AGB) of northward-migrating mangroves in an observation case (comparison between simulated and measured values);

[0079] Figure 6 represents the vegetation area change of the mangrove habitat in Yueqing Bay simulated by the evaluation model (2023-2032);

[0080] Figure 7 represents the annual dynamics of cumulative GPP of the mangroves in Yueqing Bay simulated by the evaluation model (2023-2032);

[0081] Figure 8 Represents the cumulative NEE annual dynamics of the Yueqing Bay mangroves simulated by the evaluation model (2023-2032). DETAILED DESCRIPTION

[0082] Those skilled in the art can refer to the content of this article and appropriately replace and / or modify the process parameters to achieve the same. However, it should be particularly noted that all similar replacements and / or modifications are obvious to those skilled in the art and are considered to be included in the present invention. The products and preparation methods described in the present invention have been described through preferred examples. It is obvious that relevant personnel can modify or appropriately change and combine the products and preparation methods described herein without departing from the content, spirit and scope of the present invention to implement and apply the technology of the present invention.

[0083] Unless otherwise defined, technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which the invention belongs. The present invention uses the methods and materials described herein; however, other suitable methods and materials known in the art may also be used. The materials, methods, and examples described herein are illustrative only and are not intended to be limiting. All publications, patent applications, patents, provisional applications, database entries, and other references mentioned herein are incorporated herein by reference in their entirety. In the event of a conflict, the present specification, including definitions, shall prevail.

[0084] Unless specifically stated, the materials, methods, and examples described herein are illustrative only and not limiting. Although methods and materials similar or equivalent to those described herein can be used in the practice or testing of the present invention, suitable methods and materials are still described herein.

[0085] The technical solutions in the embodiments of the present invention are described clearly and completely below. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments in the present invention, all other embodiments obtained by ordinary technicians in the field without creative work are within the scope of protection of the present invention. At the same time, the embodiments in this application and the features in the embodiments can be combined with each other without conflict.

[0086] The present invention is described in detail below with reference to specific embodiments.

[0087] The present invention relates to a method for evaluating vegetation growth, community development and carbon sink capacity after mangroves are planted in coastal wetlands by using a computer, and in particular to a method and application for evaluating the dynamics of plant community development and carbon sink after mangroves are planted in an area above about 27° north latitude (mangroves moving northward). Taking a mangrove northward migration project in an observation case as an example, the northward migration mangrove species in this observation case is Kandelia obovata.

[0088] The evaluation method includes steps one to five.

[0089] Step 1: Obtain a remote sensing image dataset of the mangrove planting area to be evaluated. The dataset includes the location and area of ​​mangrove planting, coastal tidal flats and water areas, and other landform categories. The interpreted and identified landform distribution serves as the initial input data for the mangrove dynamic module and carbon sink dynamic module.

[0090] By interpreting and identifying multi-phase remote sensing images, the area, coverage ratio and elevation distribution data of newly planted mangroves and muddy beaches were obtained.

[0091] ENVI 5.2 software was used for supervised classification to obtain the categories of mangroves, muddy beaches, etc.

[0092] The ArcGIS 10.0 platform was used to delineate coastal tidal flats, mangroves, bare beaches, shallow waters, and land habitats. The results of the land feature classification were further optimized through field observations of mangroves during the growing season. The interpreted and identified areas and coverage ratios of mangroves and bare beaches, as well as the tidal flat elevation distribution data, were used as the basic initial data for plant growth, reproduction, and carbon sink models.

[0093] Step 2: Determine the area change, biomass growth, plant photosynthesis / respiration, and soil CO 2 Emissions were calculated to obtain seasonal trends of mangrove carbon community changes and carbon sequestration capacity for model calibration and prediction.

[0094] The static chamber method or eddy covariance technique was used to analyze the CO2 of the newly planted mangrove system (K. obovata in this observation example) moving northward. 2 The exchange flux is observed seasonally, and the net exchange of ecosystems, soil respiration, and total ecosystem respiration are quantified to understand the CO2 exchange between the newly formed mangrove wetlands and the atmosphere. 2 Flux characteristics.

[0095] The static chamber measurement method is to use a portable trace gas analyzer to measure CO in the early growth period of Kandelia candel plots in spring (e.g., March to May), summer (e.g., July to September), and autumn (e.g., October to November) every year. 2 Gas exchange measurement. The volume of the measuring chamber is designed according to the height of the plant. The box support can be made of stainless steel pipe and connected through a three-way joint. The support is closed with a sealed transparent polyvinyl chloride (PVC) film, the joint is sealed, and connected to the trace gas analyzer through a rubber tube. A battery-driven fan is installed on the support to mix the gas in the box, and a thermometer is installed. The CO in the box is calculated by linear regression analysis. 2 Changes in gas concentration.

[0096] Plant net ecosystem CO 2 Net ecosystem exchange (NEE) at leaf level is based on the diurnal CO 2 Flux calculation; assuming that there is no photosynthesis in the night environment, the NEE value obtained at night was regarded as the leaf-level ecosystem respiration (ER) flux; the sum of NEE and ER was regarded as the leaf-level photosynthetic gross primary productivity (GPP).

[0097] The calculation of the gas concentration in the static chamber (based on the ideal gas equation) is based on formula (1):

[0098] (1)

[0099] Among them, F represents gas flux; M represents gas molar mass; V represents gas molar volume under standard conditions; c represents gas concentration; t represents unit time; H represents the effective height of the test chamber; and T represents the average temperature in the test chamber.

[0100] Step 3. Construction of plant growth, reproduction and carbon sink model: Taking the newly planted mangrove distribution area as the simulation domain, and local meteorological data, tidal processes, and terrain elevation as model driving parameters, a mangrove community and carbon sink dynamic assessment model is constructed, which is obtained by coupling the vegetation dynamic model, photosynthetic carbon fixation and respiration model, and ecosystem respiration model.

[0101] 3.1 Vegetation dynamic model

[0102] The vegetation dynamics model was developed on the MATLAB® platform and consisted of a spatial matrix of interconnected grids with a resolution of 1 m × 1 m.

[0103] The hypocotyl of mangrove plants is restricted by temperature. If the annual average temperature and the minimum temperature of the northward mangrove forest are not lower than the temperature tolerance threshold of hypocotyl, the mangrove plants will produce hypocotyls. On the contrary, the northward mangrove forest cannot produce reproductive organs. (Note: The mangrove forests currently use the low-temperature acclimated Kandelia candel variety. Based on the planting effect of mangroves in the coastal zone of a certain observation case in recent years, the low-temperature lethality parameter is not set in the model evaluation of this method)

[0104] Each grid connection in the vegetation dynamics model has a distribution probability associated with vegetation expansion. The spatiotemporal dynamics of the hypocotyl pool of mangrove plants is affected by seasonal changes.

[0105] The relationship between the number of hypocotyls and the survival rate of vegetation reproduction is based on formula (2):

[0106] (2)

[0107] Where N represents the number of embryonic axes that survived in the end; N max represents the largest hypocotyl pool; t v Indicates the month; E indicates the tidal flat elevation; E 0v Indicates the elevation threshold required for seed retention; S v represents the seed bank decay rate; g s represents the sediment coefficient related to sediment particle size; coefT represents the temperature tolerance threshold related to hypocotyl initiation; coefW represents the hydrological tolerance threshold related to hypocotyl establishment.

[0108] According to the biological characteristics of wetland plants, the expansion of mangrove communities is mainly carried out through sexual reproduction strategies (hypocotyl production, hypocotyl drifting with the tide, hypocotyl colonization and new plant growth).

[0109] During the reproductive spread of mangroves, the probability of hypocotyls being distributed from the diffusion center to the peripheral grid ring is random, similar to the Chebyshev distance distribution rule of the vegetation grid in the expansion center.

[0110] The geometric distribution followed by the sexual reproduction process in the vegetation dynamic model is based on formula (3):

[0111] (3)

[0112] Where X represents the Chebyshev distance; P represents the percentage of propagules distributed from the central grid to the peripheral grid; k represents the distance of the diffused grid from the diffused central grid. Formula (3) describes the sexual reproduction process of mangroves and aims to update the initial input data vegetation distribution required for model startup.

[0113] During the sexual propagation of mangrove plants, if the elevation of the dispersed propagules does not exceed the minimum hydrological tolerance threshold, the propagules will be successfully established and grown.

[0114] 3.2 Photosynthetic carbon fixation and respiration model

[0115] The daily variation of mangrove plant biomass growth is calculated based on vegetation photosynthesis / respiration. The biomass growth of mangroves can be regarded as the difference between gross primary productivity (GPP) and plant autotrophic respiration.

[0116] The changes in plant biomass carbon accumulation and carbon partition coefficient are calculated according to formula (4):

[0117] (4)

[0118] Among them, AGB represents plant aboveground biomass; GB represents total biomass accumulation; NPP represents net primary productivity; LB represents litter biomass; BGB represents underground biomass; z represents the average tidal range; g represents the biomass allocation correction coefficient; and E represents the tidal flat elevation. Formula (4) is mainly used to obtain the plant aboveground biomass AGB, total primary productivity, and plant autotrophic respiration mentioned in the model. The plant aboveground biomass AGB participates in the calculation of the subsequent tidal flat sediment deposition and elevation change rate formula, aiming to obtain the deposition rate of the vegetation area.

[0119] The net ecosystem carbon exchange (NEE) of mangroves is the difference between gross primary productivity (GPP) and ecosystem respiration (ER).

[0120] The photosynthetic / respiratory rate of plants is affected by atmospheric temperature, photosynthetically active radiation, leaf stomatal conductance, intercellular CO 2 concentration, and seasonal changes in leaf nitrogen content. Stomatal conductance is regulated by photosynthetically active radiation, atmospheric temperature, and atmospheric CO 2Concentration adjustment.

[0121] The carbon process at the individual tree-canopy level is further divided into net photosynthesis and respiration at different levels. According to the characteristics of the vertical canopy structure, based on the contribution components of direct radiation and diffuse radiation in the "large leaf mode", the direct radiation and diffuse radiation contribution rate algorithm is used to achieve the separation of different vertical distributions of the canopy, that is, the top of the mangrove canopy includes the total radiation contribution (direct radiation and diffuse radiation), and the lower canopy is the contribution of diffuse radiation. Finally, the photosynthetic carbon fixation and plant respiration rate at the entire canopy level are synthesized.

[0122] Leaf and canopy development are key factors in radiation absorption, and leaf and canopy development is mainly driven by temperature. Changes in phenolic vegetation in response to cumulative air temperature were quantified by calculating LAI at the plant-canopy level.

[0123] Net ecosystem CO2 of plants in the model 2 The cross-carbon exchange process is calculated according to formula (5):

[0124] (5)

[0125] Among them, GPP represents the gross primary productivity of photosynthesis at the leaf level; NEE represents the net ecosystem exchange at the leaf level; ER represents the ecosystem respiration at the leaf level; R L Represents the respiration of the above-ground ecosystem; R S Represents underground ecosystem respiration; P g.sun represents the total primary productivity of the sun-side leaves; P g.sh represents the total primary productivity of leaves on the shaded side; f(x) represents a function with x as the independent variable, where f is the corresponding calculation rule; PAR sun Represents the photosynthetically active radiation component on the sun side; PAR sh represents the photosynthetically active radiation component on the shaded side; T a Indicates atmospheric temperature; D a Represents atmospheric water vapor pressure difference; C a Represents atmospheric CO 2 Concentration; N L Indicates the nitrogen content of leaves; g s stands for stomatal conductance; LAI sun Represents the leaf area index on the sunny side; LAI sh represents the shaded leaf area index. Formula (5) is intended to obtain the net ecosystem CO 2 The exchange is the net ecosystem exchange (NEE) at the leaf level, which is used to calculate the gross primary productivity (GPP) at the leaf level in the series of formulas.

[0126] 3.3 Ecosystem breathing model

[0127] The respiration of mangrove ecosystems includes two parts: vegetation canopy respiration and soil respiration. Vegetation canopy respiration follows the above algorithm. The simulation of soil respiration is based on the relationship between respiration rate and temperature sensitivity. In addition, in tidal flat wetland environments, intermittent flooding will significantly affect the soil respiration of coastal wetlands. When the wetland sediments are completely submerged by the tide during high tide, CO 2 The diffusion of water is hindered. During low tide, soil re-exposure stimulates gas emission. Therefore, a modified water depth exponential function is used to describe the changes in soil respiration in coastal wetlands under flooding conditions.

[0128] The change rate of soil respiration in the coastal wetland is calculated according to formula (6):

[0129] (6)

[0130] Among them, R s is the soil respiration rate; C WT represents the tidal flooding factor of gas emission; B b represents plant root biomass; R n represents soil basal respiration (with nighttime respiration as a reference); k r represents the soil respiration temperature sensitivity ratio; T a Indicates atmospheric temperature; W D Indicates the depth of tidal flooding; θ w Indicates the curvature of gas emission with respect to water depth; m b Represents the coefficient. Formula (6) aims to obtain the soil respiration rate R s , used for plant net ecosystem CO in carbon sink models 2 Carbon exchange.

[0131] Sedimentation dynamics of tidal characteristics, suspended sediment concentrations, and vegetation attributes in the model. Daily sedimentation dynamics and elevation changes (dE / dt) are determined by the combined effects of suspended sediment input and the water column above the surface of the bare beach and mangrove beach, sediment deposition, and additional sediment capture by vegetation. The sediment deposition and elevation change rate of the tidal flat are calculated according to formula (7):

[0132] (7)

[0133] Where E represents the tidal flat elevation; t represents time; S r represents sedimentation rate; SSC represents suspended sediment concentration; W D represents the depth of flooding caused by tide; A represents the area of ​​the grid; S cap represents the mass of sediment captured by vegetation; CF represents the conversion factor between mass and thickness; AGB represents the aboveground biomass of plants; S r.v represents the sedimentation rate in the vegetation area; S r.min represents the minimum sedimentation rate in the mudflat area; Sr.m represents the deposition rate of the light beach area; T h represents the daily maximum tide height; ρ b Indicates soil bulk density; a v represents the correction coefficient of the relationship curve between gas emission rate and water depth, and the correction value is 50; c and d are the correction coefficients of the sedimentation rate curve of the light beach area, and the correction values ​​are 0.024369 and 0.0005 respectively. The determination of the above formula (5) mainly involves the calculation of "elevation change", because the elevation determines the flooding depth of mangroves and soil, which in turn affects the carbon exchange of the mangrove ecosystem and soil respiration. In addition, the parameter tidal flat elevation E involves the calculation of the number and survival rate of hypocotyls in the sexual reproduction process of mangroves shown in formula (2), and the parameter tidal flooding depth W D It involves the calculation of the change rate of soil respiration in coastal wetlands as shown in equation (6).

[0134] Step 4: Based on the measured mangrove growth and system CO 2 The model parameters are calibrated using the flux, the distribution data of objects identified by remote sensing images and the plant biomass data measured in the field.

[0135] Due to the randomness of the dynamic process of mangrove communities and carbon sinks, the model needs to be repeated more than 10 times to check the simulation deviation. The model output results are corrected using the observed vegetation growth and system carbon flux data. If the error meets the preset requirements, the model parameters can be confirmed.

[0136] Step 5. Use the model to calculate the area of ​​newly planted mangroves, primary productivity, ecosystem respiration and net CO2 exchange flux, and obtain an assessment of the community development and carbon sink dynamics after the mangroves move northward and predict future changes.

[0137] Output the calculation results of vegetation community distribution and carbon flux, namely the distribution area of ​​mangroves, primary productivity (GPP), ecosystem respiration (ER) and net ecosystem exchange (NEE) values.

[0138] Attached Figure 1 The flowchart of the modeling technology of the technical solution of the present invention for evaluating the community dynamics and carbon sequestration capacity after the planting of northward-migrated mangroves in Yueqing Bay in an observation example is shown.

[0139] Figure 1 The medium-altitude distribution map, vegetation distribution map, and temperature data represent the vegetation growth and population diffusion module, which is the initial input data required for the operation of the vegetation dynamics model. The vegetation growth and population diffusion module includes simulations of ecological processes such as hypocotyl growth, hypocotyl diffusion, seedling growth, biomass accumulation, and population expansion.

[0140] The driving parameters of the carbon sink module, i.e. the photosynthetic carbon fixation and respiration model and the ecosystem respiration model, are photosynthetically active radiation, relative humidity, and air temperature. It includes the calculation of leaf-level photosynthetic rate, canopy-level photosynthetic total, electron transport rate, carboxylation efficiency, leaf area, plant tissue litter, primary productivity, soil respiration, leaf respiration and other processes.

[0141] The changed vegetation distribution data output by the vegetation growth and population diffusion module will be used as the input data required to start the carbon dynamics model, and will participate in the calculation of plant photosynthesis and biomass accumulation processes, until the updated vegetation distribution, biomass accumulation and net ecosystem exchange data are output again as the model simulation for the next time period.

[0142] The present invention couples the complex bio-geomorphology and geochemical processes of the coastal wetlands, such as the complex climate, hydrology, sediment, vegetation and carbon cycle, and describes in detail the complex interactions between the biological and abiotic processes of the coastal wetland ecosystem. In addition to considering the adaptability of vegetation growth, development and reproduction characteristics to the climate environment after the northward migration of mangroves, it also considers the impact of coastal tidal processes on tidal flat landform changes, mangrove growth and reproduction, vegetation wave dissipation and siltation promotion, and the spatiotemporal dynamics of ecosystem carbon exchange. The present invention can achieve a comprehensive assessment of the community development and carbon sequestration capacity of mangroves after the northward migration and the prediction of future trends.

[0143] Figure 2 The seasonal variation of leaf-level photosynthetic gross primary productivity (GPP) of a northward-migrating mangrove forest is shown in an observation example. The observation results show that the GPP of K. obovata exhibits obvious seasonal dynamics, with the annual GPP ranging from 3.40±0.90 to 15.23±0.36 μmol m -2 s -1 The GPP was the smallest in January, at 3.40±0.90 μmol m -2 s -1 ; As the temperature rises with the season, the photosynthetic rate of plants increases accordingly, and the CO 2 The fixed amount reached the maximum in July, which was 15.23±0.36 μmol m -2 s -1 After autumn, the photosynthetic rate of plants gradually decreases as the temperature drops, and GPP also decreases accordingly. The seasonal changes in GPP of the mangrove system simulated by the carbon sink model are basically consistent with the observation results.

[0144] Figure 3 The seasonal variation of ecosystem respiration (ER) at the leaf level of a northward-migrating mangrove forest is shown in an observational example. The respiration intensity of the Kandelia candel ecosystem is the weakest in December, and the CO produced by respiration is 2 The emission was only 0.97 ± 0.21 μmol m-2 s -1 As the temperature rises in spring, the respiration of the Kandelia candel ecosystem increases and reaches its maximum respiration rate (CO 2 The emission flux was 5.54±1.33 μmol m -2 s -1 ), a four-fold increase compared to December. In autumn, the temperature gradually decreases, and CO 2 The emissions began to decrease gradually. The seasonal changes of ER in the mangrove system simulated by the carbon sink model are basically consistent with the observation results.

[0145] Figure 4 The seasonal variation of leaf-level net ecosystem exchange (NEE) in a northward-migrating mangrove forest is shown. The NEE of the Kandelia candel ecosystem showed the same seasonal variation trend as GPP. Kandelia candel photosynthesis and respiration were weakest in January, and the NEE was the lowest at this time, which was -1.86±0.37 μmol m -2 s -1 The GPP and ER of mangroves reached their annual maximum in July, and NEE also reached its seasonal maximum at this time, which was -9.69±0.75 μmol m -2 s -1 , which is 5 times the NEE in January. The seasonal variation of NEE in mangrove system simulated by carbon sink model is basically consistent with the observation results.

[0146] Figure 5 The seasonal variation of aboveground biomass (AGB) of northward-migrating mangrove plants is shown in an observation case. The AGB of Kandelia candel showed an overall daily increasing trend. The measured annual increase in AGB was 42.625 gm -2 The average daily growth rate is 0.117 gm -2 The simulation reflects the growth trend and growth rate of the measured AGB very well. The measured annual increase is 39.661gm -2 The average daily growth rate is 0.109 gm -2 The simulation results are basically consistent with the measured results.

[0147] Figure 6 to Figure 8 The model's predictions for the interannual changes in the area of ​​mangroves in Yueqing Bay, the interannual changes in the cumulative GPP and the interannual changes in the cumulative NEE in an observation case are shown, with a span from 2023 to 2032. It can be seen that the scheme of the present invention can realize the comprehensive evaluation of the community development and carbon sequestration capacity of mangroves after the northward migration and the prediction of future trends, which is helpful to understand and predict the health status and carbon sequestration function of coastal wetland mangrove systems, and can provide scientific basis and data support for accurately calculating the protection and restoration of coastal wetlands after the northward migration of large areas of mangroves and the effective management of blue carbon resources.

[0148] In some specific implementations, the effect of the growth factor adjustment coefficient is taken into account for the results estimated by the model. The calculation formula of the growth factor adjustment coefficient is shown in formula (8):

[0149] (8)

[0150] in, It represents the adjustment coefficient of the output result after considering the growth factor adjustment within the time interval i; The variable representing the jth beneficial factor in the i time interval; represents the influence weight of the jth beneficial factor, which needs to be substituted into the model and determined based on the simulated value and the measured value; m represents the number of beneficial factors considered in the i time interval; The variable representing the pth harmful factor in the i-th time interval; It represents the impact weight of the pth harmful factor, which needs to be substituted into the model and determined based on the simulated value and the measured value; p represents the number of harmful factors considered in the time interval i. The beneficial factors include: an increase in the average number of days with sufficient sunlight, an increase in the average temperature within a certain range, an increase in the average precipitation, an increase in the average humidity, and a decrease in the sea level; the harmful factors include: a significant increase in the average temperature, a decrease in the average temperature, a decrease in the average precipitation, a decrease in the average humidity, a rise in the sea level, an increase in typhoons, extreme low temperature damage, and an increase in pests and diseases and alien species. The growth, reproduction and total productivity of mangroves are affected by many factors. The inventors further found that after embedding the growth factor adjustment coefficient in the model, the model output can be corrected and adjusted within unit time to make the model output result closer to the measured value, thereby significantly improving the evaluation accuracy of the model. On this basis, the interannual changes in mangrove area, cumulative GPP and cumulative NEE can be predicted more finely. The results show that the model output is more refined and accurate. When some unexpected situations affecting growth occur on about the 54th, 120th, 210th and 312th days, the simulated values ​​evaluated are consistent with the actual measured values. Furthermore, according to changes in average weather changes, extreme weather, sea level changes, pests and diseases, alien species and other unexpected situations, the coastal wetland protection and restoration measures after the northward migration of large areas of mangroves and the effective management of blue carbon resources can be accurately calculated.

[0151] Some specific embodiments also provide the application of the aforementioned method for evaluating the community development and carbon sink dynamics after the mangroves move northward, including evaluating the community development and carbon sink dynamics after mangroves are planted in areas above approximately 27° north latitude.

[0152] Some specific embodiments also provide a computer-readable storage medium, which stores a computer program that can be executed by a processor. When the computer program is executed by the processor, it runs at least one step of the aforementioned method for evaluating community development and carbon sink dynamics after the northward migration of mangroves, and can achieve the same technical effect. To avoid repetition, this embodiment will not be described in detail.

[0153] Some specific embodiments also provide a computer device, which includes a memory, a processor, a communication interface and a communication bus; wherein the memory, the processor and the communication interface communicate with each other via the communication bus; the memory is used to store computer programs; the processor is used to execute the computer programs stored in the memory, and when the processor executes the computer program, it implements at least one step of the aforementioned method for evaluating community development and carbon sink dynamics after the northward migration of mangroves, and can achieve the same technical effect. To avoid repetition, this embodiment will not be described in detail.

[0154] Computer readable media include permanent and non-permanent, removable and non-removable media, and can be implemented by any method or technology to store information. Information can be computer readable instructions, data structures, program modules or other data. Examples of computer storage media include, but are not limited to, phase change memory (PR AM), static random access memory (SRAM), dynamic random access memory (DRAM), other types of random access memory (RAM), read-only memory (ROM), electrically erasable programmable read-only memory (EEPROM), flash memory or other memory technology, read-only compact disk read-only memory (CD-ROM), digital versatile disk (DVD) or other optical storage, magnetic cassettes, magnetic tape magnetic disk storage or other magnetic storage devices or any other non-transmission media that can be used to store information that can be accessed by a computing device. As defined herein, computer readable media does not include temporary computer readable media (transitory media), such as modulated data signals and carrier waves.

[0155] The conventional techniques in the above embodiments are prior arts known to those skilled in the art, and thus will not be described in detail here.

[0156] The specific embodiments described herein are merely examples of the spirit of the present invention. Those skilled in the art may make various modifications or additions to the specific embodiments described or replace them in similar ways, but they will not deviate from the spirit of the present invention or exceed the scope defined by the appended claims.

[0157] Although the present invention has been described in detail and some specific embodiments have been cited, it is obvious to those skilled in the art that various changes and modifications can be made without departing from the spirit and scope of the present invention.

[0158] Although the above-mentioned specific embodiments have been shown, described and pointed out the novel features applied to various embodiments, it should be understood that various omissions, substitutions and changes can be made to the form and details of the described device or method without departing from the spirit of the present disclosure. In addition, the above-mentioned various features and methods can be used independently of each other, or can be combined in various ways. All possible combinations and sub-combinations are intended to fall within the scope of the present disclosure. Many of the above-mentioned embodiments include similar components, and therefore, these similar components are interchangeable in different embodiments. Although the present invention has been disclosed in the context of certain embodiments and examples, it should be understood by those skilled in the art that the present invention can extend beyond the specifically disclosed embodiments to other alternative embodiments and / or applications and obvious modifications and equivalents thereof. Therefore, the present invention is not intended to be limited by the specific disclosure of the preferred embodiments herein.

[0159] Matters not covered in the present invention are all known technologies.

Claims

1. A method for evaluating the community development and carbon sink dynamics of mangroves after their northward migration, characterized in that include: S1. Obtain the remote sensing image dataset of the mangrove planting area to be evaluated, and identify the distribution of ground objects as the initial input data of the model; S2. Obtain the seasonal variation trend of carbon community changes and carbon sequestration capacity of newly planted mangroves for model calibration and prediction; S3. Taking the newly planted mangrove distribution area as the simulation domain, and local meteorological data, tidal processes, and terrain elevation as model driving parameters, a dynamic assessment model of mangrove communities and carbon sinks was constructed; S4, calibrating the model parameters based on the measured mangrove growth, system CO2 flux, ground feature distribution data identified by remote sensing images, and plant biomass data measured in the field; S5. Use the model to calculate the area of ​​newly planted mangroves, primary productivity, ecosystem respiration and net CO2 exchange flux, and obtain the evaluation of community development and carbon sink dynamics after the northward migration of mangroves and the prediction of future changes; In step S3, the mangrove community and carbon sink dynamic assessment model is coupled with a vegetation dynamic model, a photosynthetic carbon fixation and respiration model, and an ecosystem respiration model; The vegetation dynamic model includes the relationship between the number of hypocotyls and the survival rate during the sexual reproduction of mangroves as shown in the following formula: Where N represents the number of embryonic axes that survived in the end; N max represents the largest hypocotyl pool; t v Indicates the month; E indicates the tidal flat elevation; E 0v Indicates the elevation threshold required for seed retention; S v represents the seed bank decay rate; g s represents the sediment coefficient related to sediment particle size; coefT represents the temperature tolerance threshold related to hypocotyl initiation; coefW represents the hydrological tolerance threshold related to hypocotyl establishment; The photosynthetic carbon fixation and respiration model includes the relationship between plant biomass carbon accumulation and carbon partition coefficient shown in the following formula: Among them, AGB represents plant aboveground biomass; GB represents total biomass accumulation; NPP represents net primary productivity; LB represents litter biomass; BGB represents belowground biomass; z represents the average tidal range; g represents biomass allocation correction coefficient; E represents tidal flat elevation; The photosynthetic carbon fixation and respiration model also includes calculating and measuring the leaf-level photosynthetic gross primary productivity GPP, leaf-level ecosystem respiration ER and leaf-level ecosystem exchange NEE at multiple sampling points during low tide in July and November, as shown in the following formula: Among them, GPP represents the gross primary productivity of photosynthesis at the leaf level; NEE represents the net ecosystem exchange at the leaf level; ER represents the ecosystem respiration at the leaf level; R L Represents the respiration of the above-ground ecosystem; R S Represents underground ecosystem respiration; P g.sun represents the total primary productivity of the sun-side leaves; P g.sh represents the total primary productivity of leaves on the shaded side; f(x) represents a function with x as the independent variable, where f is the corresponding calculation rule; PAR sun Represents the photosynthetically active radiation component on the sun side; PAR sh represents the photosynthetically active radiation component on the shaded side; T a Indicates atmospheric temperature; D a Represents atmospheric water vapor pressure difference; C a Indicates atmospheric CO2 concentration; N L Indicates the nitrogen content of leaves; g s stands for stomatal conductance; LAI sun Represents the leaf area index on the sunny side; LAI sh represents the shaded leaf area index; The ecosystem respiration model includes the relationship between the plant biomass carbon accumulation and the carbon partition coefficient and the relationship between the rate of change of coastal wetland soil respiration shown in the following formula: Among them, R s is the soil respiration rate; C WT represents the tidal flooding factor of gas emission; B b represents plant root biomass; R n represents soil basal respiration; k r represents the soil respiration temperature sensitivity ratio; T a Indicates atmospheric temperature; W D Indicates the depth of tidal flooding; θ w Indicates the curvature of gas emission with respect to water depth; m b Represents the coefficient.

2. The method according to claim 1, characterized in that: In step S1, the remote sensing image data set includes: mangroves, salt marshes, light beaches and water, as well as the area of ​​newly planted mangroves, muddy light beach area, coverage ratio, and elevation distribution data.

3. The method according to claim 1, characterized in that: In step S2, the static box method or eddy covariance technology is used to conduct seasonal positioning observations on the CO2 exchange flux of the newly planted mangrove system moving northward. By quantifying the net exchange of the ecosystem, soil respiration and total ecosystem respiration, the CO2 flux characteristics between the newly planted mangrove wetlands and the atmosphere are understood.

4. The application of the method for evaluating the community development and carbon sink dynamics of mangroves after northward migration according to any one of claims 1 to 3, characterized in that: This includes assessing the population development and carbon sink dynamics of mangroves after planting them north of the northern limit of their natural distribution.

5. A computer device, comprising a memory, a processor, a communication interface and a communication bus; wherein: The memory, processor, and communication interface communicate with each other via the communication bus; the memory is used to store computer programs; the processor is used to execute the computer programs stored in the memory, and is characterized in that: when the processor executes the computer program described in any one of claims 1-3, it implements the aforementioned method for evaluating the community development and carbon sink dynamics after the northward migration of mangroves.

6. A computer-readable storage medium having a computer program stored thereon, characterized in that: When the computer program is executed by a processor, the method for evaluating the community development and carbon sink dynamics of mangroves after their northward migration as described in any one of claims 1 to 3 is implemented.

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