Method for detecting annual carbon sequestration amount of single tree in forest region based on vortex wood volume source method

Abstract

The invention discloses a method for detecting the annual carbon sequestration amount of a single tree in a forest region based on a vortex wood volume method, and the method comprises the steps: obtaining the diameter at breast height of a target single tree, inputting the diameter at breast height into a wood volume-vortex carbon measurement model, and obtaining the annual carbon sequestration amount of the target single tree; the method for constructing the volume-vorticity carbon measurement model comprises the following steps of: acquiring the annual fixed carbon quantity of an ecological system in a flux contribution area by using a vorticity correlation method; obtaining the first year carbon sequestration amount of different diameters at breast height in each source region and the annual total carbon sequestration amount in the flux contribution region by a wood volume source biomass method; distributing the annual carbon sequestration amount of the ecological system according to the proportion of each first-year carbon sequestration amount in the annual total carbon sequestration amount to obtain the second-year carbon sequestration amount of different diameters at breast height in each source region, and dividing the second-year carbon sequestration amount by the number of trees at each diameter at breast height to obtain the annual carbon sequestration amount of a single tree at different diameters at breast height; and constructing a relation model of the diameter at breast height and the annual carbon sequestration amount. The method can efficiently and accurately detect the annual carbon sequestration amount of the hamiltonia hamiltonii in the ecological system, and facilitates real-time and accurate measurement of the carbon sequestration amount of the ecological system in a contribution area.

Description

Technical Field

[0001] The present invention relates to the technical field of carbon fixation detection, and more specifically to a method for detecting the annual carbon fixation of a single tree in a forest area based on an eddy volume source method. Background Art

[0002] Climate change is profoundly affecting the sustainable development of the global social economy. Forestry carbon sinks play a key role in addressing climate change and are increasingly receiving widespread attention. Forest carbon accounting is an estimation of the total amount of static carbon and dynamic carbon in forests, of which static carbon is stored in forests as carbon stocks, and dynamic carbon is also called carbon flux. Since the carbon sink estimation method based on plot felling biomass was proposed, two types of forest carbon sink estimation methods have been formed, one based on biomass carbon storage estimation and the other based on carbon flux monitoring, focusing on whether to directly monitor through the air, whether to conduct destructive sampling, whether to consider differences in tree species and ages, whether to consider differences in geographical space and environment, and whether it can be applied on a large scale, over a large range, and in different landform environments.

[0003] The biomass method indirectly expresses the change of carbon storage based on the change of plant biomass, and the stock method estimates carbon storage based on the stock volume of forest trees. Stock volume can be converted into biomass and is regarded as an extension of the biomass method. Fang Jingyun et al. used the biomass method and soil organic matter to estimate the carbon storage of China's forest vegetation and soil. Liu Yingchun et al. calculated China's forest carbon storage from 2001 to 2050 based on the stock volume method. The application of these two methods has been very mature and widely used in the inventory of forest resources, but it is easy to ignore soil microorganisms and underground parts, and there are errors in the conversion coefficient value, sample plots and climatic conditions. The volume source biomass method (BEF) uses the functional relationship between forest biomass and stock volume to estimate forest biomass. It has the advantages of simple technology, clear methods and strong practicality. It is suitable for the calculation of forest carbon storage in large-scale and tree species-prominent areas, but this method is easy to ignore the error in the conversion coefficient value and seriously underestimates the forest carbon sequestration capacity. In addition, this method is basically based on the data of the National Forest Resources Planning and Design Survey (Type II Survey) conducted every 10 years or the National Forest Resources Continuous Inventory (Type I Inventory) conducted every 5 years. The data is updated slowly and cannot reflect the carbon sequestration capacity of forest ecosystems in a timely manner, and the assessment data has a lag.

[0004] With the improvement of measurement technology, it has become possible to measure forest carbon sinks by observing the changes in the carbon content in the corresponding atmosphere caused by forests (carbon flux). The carbon flux method is a direct and more accurate method for measuring forest carbon sinks, which mainly includes micrometeorological method and box method. The eddy covariance method is a classic method for carbon flux monitoring based on micrometeorology. The application of eddy covariance technology in forest carbon flux monitoring began in the 1970s. In the early 1980s, ultrasonic anemometers and open-path infrared gas analyzers were successfully developed, and eddy covariance technology developed rapidly. In the early 1990s, Wofsy et al. (1993) conducted 20 months of continuous observations at the Harvard Forest Station and obtained the result that the net carbon fixation in the area was 3.7 tons per year, which was much larger than the previous estimate; Wang Jieshuai et al. found that the annual total net ecosystem carbon exchange (NEE) and ecosystem carbon exchange (GEE) of the coniferous and broad-leaved mixed forest in Jinyun Mountain were -566.49 and -1761.63 g C·m-2 respectively; Bai Xuejie et al. observed the carbon flux of wetland, farmland and grassland ecosystems in the Heihe River Basin for 7 years and found that the annual carbon fixation capacity of farmland was 648.90 g C·m-2, that of wetland was 627.51 g C·m-2, and that of grassland was 228.15 g C·m-2. Although the eddy covariance method is currently the internationally accepted standard method for carbon and water flux monitoring, it requires the construction of a flux observation site, which has high construction conditions and technical requirements, large investment, and is a single-point monitoring with many restrictions.

[0005] Based on the above analysis, forest carbon sink estimation methods based on biomass carbon storage estimation are mostly based on formula model calculations. When analyzing the spatial pattern of vegetation carbon sinks, they are affected by factors such as sample size, measurement error, parameter error, inconsistent data sources, and model universality, and the calculation results are uncertain. Forest carbon sink estimation methods based on carbon flux monitoring have high requirements for construction conditions and investment.

[0006] Therefore, how to efficiently and accurately detect the annual carbon fixation of monocotyledon in forest ecosystems in real time while reducing costs is an urgent problem that technicians in this field need to solve. Summary of the invention

[0007] In view of the above problems, the present invention provides a method for detecting the annual carbon fixation of individual trees in a forest area based on the eddy volume source method, so as to at least solve some of the technical problems mentioned in the above background technology.

[0008] In order to achieve the above object, the present invention adopts the following technical solution:

[0009] The present invention provides a method for detecting the annual carbon fixation of a single tree in a forest area based on the eddy volume source method, comprising the following steps:

[0010] In the target contribution area, obtain the DBH value of the target single tree;

[0011] Inputting the DBH value of the target single tree into the constructed volume-vorticity carbon measurement model to obtain the annual carbon sequestration amount corresponding to the target single tree;

[0012] The steps of constructing the volume-vorticity carbon measurement model include:

[0013] Divide the flux contribution area into multiple source areas;

[0014] The annual carbon fixation of the ecosystem in the flux contribution area is obtained by using the eddy covariance method;

[0015] The first-year carbon fixation corresponding to trees with different breast diameters in each source area and the annual total carbon fixation in the flux contribution area are obtained by the volume source biomass method;

[0016] According to the proportion of each first-year carbon fixation in the annual total carbon fixation, the annual carbon fixation of the ecosystem is distributed to trees with different breast diameters in each of the source areas, so as to obtain the second-year carbon fixation corresponding to the different breast diameters in each of the source areas;

[0017] Divide each second-year carbon sequestration amount by the number of trees at the corresponding breast diameter to obtain the annual carbon sequestration amount of a single tree at different breast diameters;

[0018] According to the DBH of each individual tree and the corresponding annual carbon sequestration, the regression analysis method was used to construct a relationship model between DBH and annual carbon sequestration, that is, a volume-vorticity carbon measurement model.

[0019] Furthermore, the obtaining of the breast diameter value of the target single tree is specifically: measuring the breast diameter value of the target single tree by using an unmanned aerial vehicle laser radar.

[0020] Furthermore, dividing the flux contribution area into a plurality of source areas specifically includes:

[0021] Analyze forest stand characteristics based on MODIS satellite data and ground survey data;

[0022] Determine the prevailing wind direction and wind speed distribution through weather station data;

[0023] Delineate the preliminary range of vegetation coverage based on the forest stand characteristics, the dominant wind direction and the wind speed distribution;

[0024] The source area division standard and quantity are set according to the topography of the flux contribution area, the forest stand characteristics and the wind speed distribution; and the source area is divided counterclockwise along the dominant wind direction with the observation point as the center.

[0025] Furthermore, the obtaining of the annual carbon fixation of the ecosystem in the flux contribution area by the eddy covariance method specifically includes:

[0026] The annual carbon sequestration per unit area corresponding to each source area is calculated using TOVI software;

[0027] The annual carbon fixation of each unit area is summarized to obtain the annual carbon fixation of the ecosystem in the flux contribution area.

[0028] Furthermore, the first-year carbon fixation corresponding to trees with different breast diameters in each source area and the annual total carbon fixation in the flux contribution area are obtained by using the volume source biomass method, specifically including:

[0029] The diameter at breast height of each tree in each source area is measured by using a UAV laser radar, and the result is input into the constructed diameter at breast height data relationship model to obtain the corrected diameter at breast height of each tree;

[0030] The corrected DBH of each tree is input into the biomass regression model to obtain the biomass of each tree, and then combined with the average carbon content of vegetation to obtain the first-year carbon fixation of trees with different DBH in each source area;

[0031] The carbon fixation in each first year is summed up to obtain the annual total carbon fixation in the flux contribution area.

[0032] Furthermore, the steps of constructing the DBH data relationship model include:

[0033] For multiple trees, obtain the measured DBH data and DBH data measured by UAV LiDAR for each tree;

[0034] According to the measured DBH data of each tree and the DBH data measured by UAV LiDAR, a DBH data relationship model is constructed; it is expressed as:

[0035] D′=(D-1.6773) / 1.7729

[0036] Among them, D′ represents the measured DBH data, that is, the calibrated DBH data; D represents the DBH data measured by the UAV laser radar.

[0037] Further, the first year carbon fixation amount is expressed as:

[0038] M = 0.14 × (D' 2 H) 0.782 × CF

[0039] Among them, M represents the first-year carbon fixation corresponding to trees with different breast diameters in each source area; D′ represents the corrected breast diameter; H represents the tree height; and CF represents the average carbon content of vegetation.

[0040] Furthermore, the volume-vorticity carbon measurement model is expressed as:

[0041] y=3.2591x-38.347

[0042] Where y represents the annual carbon fixation of a single plant; x represents the diameter at breast height.

[0043] Furthermore, it also includes:

[0044] According to the first-year carbon fixation corresponding to trees with different breast diameters in each of the source areas obtained by the volume source biomass method, the annual carbon fixation corresponding to each of the source areas is obtained;

[0045] Based on the annual carbon fixation corresponding to each source area obtained by the volume source biomass method and the annual carbon fixation per unit area corresponding to each source area obtained by the eddy covariance method, a linkage model for measuring carbon storage using the volume source biomass method and the eddy covariance method is constructed; it is expressed as:

[0046] M 材 =-0.0003M 涡 2 -45.245M 涡 +66709

[0047] Among them, M 材 represents the annual carbon fixation of each source area obtained by the volume source biomass method; M 涡 It represents the annual carbon sequestration per unit area corresponding to each source area obtained by the eddy covariance method.

[0048] It can be seen from the above technical solution that, compared with the prior art, the present invention discloses a method for detecting the annual carbon fixation of a single tree in a forest area based on the eddy volume source method, which has the following beneficial effects:

[0049] The present invention combines the eddy covariance method with the volume-source biomass method to construct a relationship model between the diameter at breast height and the annual carbon fixation, that is, a volume-vorticity carbon measurement model, which is expected to achieve accurate calculation of the carbon sink of forest ecosystems and help provide practical technical support for forest protection and restoration.

[0050] The invention is simple and easy to implement, avoids tedious calculation workload, is suitable for quantitative analysis of forest carbon reserves, and has strong practicality.

[0051] The technical solution of the present invention is further described in detail below through the accompanying drawings and embodiments. BRIEF DESCRIPTION OF THE DRAWINGS

[0052] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are only embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on the provided drawings without paying creative work.

[0053] Figure 1A schematic flow chart of a method for detecting annual carbon sequestration of individual trees in a forest area based on the eddy volume source method provided in an embodiment of the present invention.

[0054] Figure 2 A schematic diagram of a process for applying to a Populus euphratica forest provided by an embodiment of the present invention. DETAILED DESCRIPTION

[0055] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0056] The embodiment of the present invention discloses a method for detecting the annual carbon fixation of a single tree in a forest area based on the eddy volume source method. Figure 1 As shown, the following steps are included:

[0057] S1. Obtain the DBH value of the target single tree in the target contribution area;

[0058] S2. Input the DBH value of the target single tree into the constructed volume-vorticity carbon measurement model to obtain the annual carbon sequestration amount corresponding to the target single tree;

[0059] The steps for constructing the volume-vorticity carbon measurement model include:

[0060] P1. Divide the flux contribution area into multiple source areas;

[0061] P2. Obtain the annual carbon fixation of the ecosystem in the flux contribution area through the eddy covariance method;

[0062] P3. Obtain the first-year carbon fixation corresponding to trees with different breast diameters in each source area and the annual total carbon fixation in the flux contribution area through the volume source biomass method;

[0063] P4. According to the proportion of each first-year carbon fixation in the annual total carbon fixation, the annual carbon fixation of the ecosystem is distributed to trees with different breast diameters in each source area, and the second-year carbon fixation corresponding to different breast diameters in each source area is obtained;

[0064] P5. Divide the carbon sequestration in each second year by the number of trees at the corresponding DBH to obtain the annual carbon sequestration of individual trees at different DBH.

[0065] P6. Based on the DBH of each individual tree and the corresponding annual carbon fixation, the regression analysis method was used to construct a relationship model between DBH and annual carbon fixation, that is, to construct a volume-vorticity carbon measurement model.

[0066] Next, each of the above steps will be described respectively.

[0067] In the above step S1, within the target contribution area, the diameter at breast height of the target single tree is measured by the drone laser radar. The diameter at breast height value can be quickly obtained by the drone laser radar measurement.

[0068] In the above step S2, the DBH value of the target individual tree is input into the constructed volume-vorticity carbon measurement model to obtain the annual carbon fixation amount corresponding to the target individual tree; the volume-vorticity carbon measurement model can be used to quickly and accurately evaluate the carbon fixation capacity of individual trees, providing data support for forest carbon sink management.

[0069] The following steps P1-P6 are the steps for constructing the volume-vorticity carbon measurement model.

[0070] In the above step P1, the FSAM (Flux Source Area Model) model is used to calculate the flux contribution area range, and the flux contribution area is divided into multiple source areas; specifically, it includes:

[0071] (1) Analyze forest stand characteristics based on MODIS satellite data and ground survey data; MODIS satellite data include vegetation index, leaf area index, surface temperature, etc.; ground survey data include vegetation structure parameters, soil properties, environmental factors (such as meteorological data and topographic data), etc. After analysis, forest stand characteristics such as stand area, stand density, stand age height, crown width of DBH, and vegetation carbon content were obtained;

[0072] (2) Determine the prevailing wind direction and wind speed distribution through weather station data;

[0073] (3) Based on the forest stand characteristics, dominant wind direction and wind speed distribution, the preliminary range of vegetation coverage affected by the dominant wind direction is delineated;

[0074] (4) The source area division standard and quantity are set according to the topography, forest stand characteristics and wind speed distribution of the flux contribution area; and the source area is divided counterclockwise along the dominant wind direction with the observation point as the center.

[0075] In the above step P2, the annual carbon fixation of the ecosystem in the flux contribution area is obtained by the eddy covariance method; specifically, it includes:

[0076] (1) The annual carbon fixation per unit area corresponding to each source area was calculated using TOVI software; specifically, the annual amount of CO2 absorbed and fixed by the ecosystem was calculated using the CO2 flux value, time, and contributing area.

[0077] (2) The annual carbon sequestration per unit area is summarized to obtain the annual carbon sequestration of the ecosystem in the flux contribution area.

[0078] In the above step P3, the first-year carbon fixation corresponding to trees with different breast diameters in each source area and the annual total carbon fixation in the flux contribution area are obtained by the volume source biomass method; specifically, the following steps are used:

[0079] (1) The DBH of each tree in each source area is measured by UAV laser radar and input into the constructed DBH data relationship model to obtain the corresponding calibrated DBH of each tree;

[0080] The DBH data relationship model is actually the relationship model between the measured DBH data and the DBH data measured by the UAV laser radar. The steps of building the model include:

[0081] 1) For multiple trees, obtain the measured DBH data and DBH data measured by UAV LiDAR for each tree; specifically:

[0082] Set up sample plots, measure the DBH of the trees in the sample plots on the spot, and obtain the actual DBH data.

[0083] Use waypoint to solve POS, use Pegasus drone manager to solve the load DATA file, and solve the point cloud data with coordinates. Then use terrasolid software to denoise and classify the point cloud (ground points, high vegetation points, unclassified points and noise points), and finally use lidar360 software to segment the classified data into individual trees, and then calculate the breast diameter of individual trees to obtain the breast diameter data measured by drone lidar.

[0084] 2) Based on the measured DBH data of each tree and the DBH data measured by UAV LiDAR, a DBH data relationship model is constructed; it can be expressed as:

[0085] D′=(D-1.6773) / 1.7729(R1 2 =0.83)

[0086] Among them, D′ represents the measured breast diameter data, that is, the calibrated breast diameter, in centimeters; D represents the breast diameter data measured by the UAV laser radar, in centimeters; R1 represents the correlation coefficient between the measured breast diameter data D′ and the breast diameter data D measured by the UAV laser radar.

[0087] (2) Input the corrected DBH of each tree into the biomass regression model to obtain the biomass of each tree; the biomass regression model is expressed as:

[0088] W=0.14×(D 2 H)0.782

[0089] Where W represents the biomass corresponding to each tree;

[0090] Then, combined with the average carbon content of vegetation, the first-year carbon fixation corresponding to trees with different breast diameters in each source area was obtained; its expression is:

[0091] M = 0.14 × (D' 2 H) 0.782 × CF

[0092] Where M represents the first-year carbon fixation corresponding to trees with different breast diameters in each source area; D′ represents the corrected breast diameter; H represents the tree height; CF represents the average carbon content of vegetation, which can be 0.50 (organic carbon content is 0.4437 g / kg);

[0093] (3) Sum up the carbon sequestration in each first year to obtain the annual total carbon sequestration in the flux contribution area.

[0094] In the above step P4, the annual carbon fixation of the ecosystem is distributed to trees with different breast diameters in each source area according to the proportion of each first-year carbon fixation in the annual total carbon fixation, and the second-year carbon fixation corresponding to different breast diameters in each source area is obtained;

[0095] For example, in a certain area, saplings store a total of 100 tons of carbon, medium-sized trees store 300 tons of carbon, and large trees store 600 tons of carbon, then the total carbon storage in the area is 1,000 tons. This means that saplings store 10% of the total carbon, medium-sized trees store 30%, and large trees store 60%. If the annual carbon sequestration of the ecosystem obtained by the eddy covariance method is 500 tons of carbon, then these 500 tons of carbon are proportionally distributed to trees of different sizes. In other words, saplings should get 50 tons of carbon (10% of 500 tons), medium-sized trees should get 150 tons of carbon (30% of 500 tons), and large trees should get 300 tons of carbon (60% of 500 tons).

[0096] In the above step P5, the carbon sequestration amount in each second year is divided by the number of trees with the corresponding breast diameter to obtain the annual carbon sequestration amount of a single tree with different breast diameters;

[0097] In the above step P6, according to the DBH of each individual tree and the corresponding annual carbon sequestration, the R statistical software was used for regression analysis to construct a relationship model between DBH and annual carbon sequestration, that is, to construct a volume-vorticity carbon measurement model, which is expressed as:

[0098] y=3.2591x-38.347(R2 2 =0.9943)

[0099] Where y represents the annual carbon fixation of a single plant, unit: kg·a-1; x represents the breast diameter, unit: cm; R2 represents the correlation coefficient between the annual carbon fixation of a single plant y and the breast diameter x.

[0100] Based on the above content, the present invention can efficiently and accurately detect the annual carbon fixation of the monocotyledonous tree in the forest ecosystem in real time, which helps to achieve real-time and accurate measurement of the carbon sink of the ecosystem in the contribution area.

[0101] In another embodiment, it also includes: constructing a linkage model for measuring carbon storage using the eddy covariance method and the volume source biomass method, specifically:

[0102] According to the first-year carbon sequestration of trees with different breast diameters in each source area obtained by the volume source biomass method, the annual carbon sequestration corresponding to each source area was obtained;

[0103] Based on the annual carbon fixation of each source area obtained by the volume source biomass method and the annual carbon fixation per unit area of ​​each source area obtained by the eddy covariance method, a linkage model for measuring carbon storage using the volume source biomass method and the eddy covariance method was constructed; it can be expressed as:

[0104] M 材 =-0.0003M 涡 2 -45.245M 涡 +66709(R3 2 =0.9966)

[0105] Among them, M 材 represents the annual carbon fixation of each source area obtained by the volume source biomass method; M 涡 represents the annual carbon fixation per unit area of ​​each source area obtained by the eddy covariance method; R3 represents M 材 and M 涡 The larger the correlation coefficient, the closer the correlation is.

[0106] The eddy covariance method can directly measure carbon flux at the ecosystem scale, while the volume source biomass law can provide detailed information on the biomass of individual trees or populations. Combining the two can verify and complement each other at different scales, thereby improving the accuracy of carbon stock estimation. Moreover, when data is limited, the linkage model can help integrate data from different sources and different methods, making carbon stock estimation more comprehensive and reliable.

[0107] In another embodiment, the present invention provides a method for detecting the annual carbon sequestration of individual trees in a forest area based on the eddy volume source method, which is applicable to the Populus euphratica forest ecosystem and is expected to achieve accurate calculation of the carbon sink of the Populus euphratica forest ecosystem, in order to provide a reference for the carbon sink accounting standard of the Populus euphratica forest ecosystem in the Tahe River Basin. Figure 2 shown.

[0108] The various embodiments in this specification are described in a progressive manner, and each embodiment focuses on the differences from other embodiments. The same or similar parts between the various embodiments can be referenced to each other.

[0109] The above description of the disclosed embodiments enables one skilled in the art to implement or use the present invention. Various modifications to these embodiments will be apparent to one skilled in the art, and the general principles defined herein may be implemented in other embodiments without departing from the spirit or scope of the present invention. Therefore, the present invention will not be limited to the embodiments shown herein, but rather to the widest scope consistent with the principles and novel features disclosed herein.

Claims

1. A method for detecting annual carbon sequestration of individual trees in a forest area based on the eddy volume source method, characterized in that: The steps include: In the target contribution area, obtain the DBH value of the target single tree; Inputting the DBH value of the target single tree into the constructed volume-vorticity carbon measurement model to obtain the annual carbon sequestration amount corresponding to the target single tree; The steps of constructing the volume-vorticity carbon measurement model include: Divide the flux contribution area into multiple source areas; The annual carbon fixation of the ecosystem in the flux contribution area is obtained by using the eddy covariance method; The first-year carbon fixation corresponding to trees with different breast diameters in each source area and the annual total carbon fixation in the flux contribution area are obtained by the volume source biomass method; According to the proportion of each first-year carbon fixation in the annual total carbon fixation, the annual carbon fixation of the ecosystem is distributed to trees with different breast diameters in each of the source areas, so as to obtain the second-year carbon fixation corresponding to the different breast diameters in each of the source areas; Divide each second-year carbon sequestration amount by the number of trees at the corresponding breast diameter to obtain the annual carbon sequestration amount of a single tree at different breast diameters; According to the DBH of each individual tree and the corresponding annual carbon sequestration, the regression analysis method was used to construct a relationship model between DBH and annual carbon sequestration, that is, a volume-vorticity carbon measurement model.

2. The method for detecting annual carbon sequestration of individual trees in a forest area based on the eddy volume source method according to claim 1 is characterized in that: The obtaining of the breast diameter value of the target single tree specifically comprises: measuring the breast diameter value of the target single tree by using an unmanned aerial vehicle laser radar.

3. The method for detecting annual carbon sequestration of individual trees in a forest area based on eddy volume source method according to claim 1 is characterized in that: The step of dividing the flux contribution area into a plurality of source areas specifically includes: Analyze forest stand characteristics based on MODIS satellite data and ground survey data; Determine the prevailing wind direction and wind speed distribution through weather station data; Delineate the preliminary range of vegetation coverage based on the forest stand characteristics, the dominant wind direction and the wind speed distribution; The source area division standard and quantity are set according to the topography of the flux contribution area, the forest stand characteristics and the wind speed distribution; and the source area is divided counterclockwise along the dominant wind direction with the observation point as the center.

4. The method for detecting annual carbon sequestration of individual trees in a forest area based on the eddy volume source method according to claim 1 is characterized in that: The obtaining of the annual carbon fixation of the ecosystem in the flux contribution area by the eddy covariance method specifically includes: The annual carbon sequestration per unit area corresponding to each source area is calculated using TOVI software; The annual carbon fixation of each unit area is summarized to obtain the annual carbon fixation of the ecosystem in the flux contribution area.

5. The method for detecting annual carbon sequestration of individual trees in a forest area based on eddy volume source method according to claim 1, characterized in that: The obtaining of the first-year carbon fixation corresponding to trees with different breast diameters in each source area and the annual total carbon fixation in the flux contribution area by the volume source biomass method specifically includes: The diameter at breast height of each tree in each source area is measured by using a UAV laser radar, and the result is input into the constructed diameter at breast height data relationship model to obtain the corrected diameter at breast height of each tree; The corrected DBH of each tree is input into the biomass regression model to obtain the biomass of each tree, and then combined with the average carbon content of vegetation to obtain the first-year carbon fixation of trees with different DBH in each source area; The carbon fixation in each first year is summed up to obtain the annual total carbon fixation in the flux contribution area.

6. The method for detecting annual carbon sequestration of individual trees in a forest area based on the eddy volume source method according to claim 5 is characterized in that: The steps of constructing the DBH data relationship model include: For multiple trees, obtain the measured DBH data and DBH data measured by UAV LiDAR for each tree; According to the measured DBH data of each tree and the DBH data measured by UAV LiDAR, a DBH data relationship model is constructed; it is expressed as: D′=(D-1.6773) / 1.7729 Among them, D′ represents the measured DBH data, that is, the calibrated DBH data; D represents the DBH data measured by the UAV laser radar.

7. The method for detecting annual carbon sequestration of individual trees in a forest area based on eddy volume source method according to claim 5, characterized in that: The carbon sequestration in the first year is expressed as: M=0.14×(D′ 2 H)0.782×CF Among them, M represents the first-year carbon fixation corresponding to trees with different breast diameters in each source area; D′ represents the corrected breast diameter; H represents the tree height; and CF represents the average carbon content of vegetation.

8. The method for detecting annual carbon sequestration of individual trees in a forest area based on eddy volume source method according to claim 1, characterized in that: The volume-vorticity carbon measurement model is expressed as: y=3.2591x-38.347 Where y represents the annual carbon fixation of a single plant; x represents the diameter at breast height.

9. The method for detecting annual carbon sequestration of individual trees in a forest area based on eddy volume source method according to claim 4, characterized in that: Also includes: According to the first-year carbon fixation corresponding to trees with different breast diameters in each of the source areas obtained by the volume source biomass method, the annual carbon fixation corresponding to each of the source areas is obtained; Based on the annual carbon fixation corresponding to each source area obtained by the volume source biomass method and the annual carbon fixation per unit area corresponding to each source area obtained by the eddy covariance method, a linkage model for measuring carbon storage using the volume source biomass method and the eddy covariance method is constructed; it is expressed as: M 材 =-0.0003M 涡 2 -45.245M 涡 +66709 Among them, M 材 represents the annual carbon fixation of each source area obtained by the volume source biomass method; M 涡 It represents the annual carbon sequestration per unit area corresponding to each source area obtained by the eddy covariance method.

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