Methods for Identifying the Mechanisms of Carbon Balance Processes in Forest Succession of Natural Vegetation-Soil Systems

Abstract

This invention provides a method for identifying the mechanism of carbon balance processes in natural vegetation-soil systems through forest succession. It determines the natural vegetation succession pathway through regional surveys, obtains dynamic changes in aboveground vegetation, litter, soil, root biomass, and carbon storage, monitors atmospheric precipitation and total water carbon content per unit time, determines the carbon input of atmospheric precipitation to the natural forest ecosystem, and, based on the above data, determines the changes in carbon storage of each component and the overall carbon storage of the natural forest ecosystem at different succession stages. It also obtains the carbon flux of the natural vegetation ecosystem, verifies the dynamic changes in carbon storage, and quantifies the magnitude of carbon storage changes in each component of the natural forest ecosystem at different succession levels and their contribution to the carbon balance process. This invention clarifies the mechanism by which forest succession affects the carbon balance process by applying ecological stoichiometry theory, providing a theoretical basis for understanding the participation of natural forests in the carbon cycle and for natural forest protection.

Description

Technical Field

[0001] This invention belongs to the field of ecological technology, and in particular relates to a method for identifying the mechanism of carbon balance process in forest succession of natural vegetation-soil systems. Background Technology

[0002] Under the influence of climate change and human activities, forest succession has led to a sharp increase in atmospheric CO2 concentration, exacerbating water-related disasters such as droughts and floods, and profoundly impacting human society and the economy. Forests, as a representative of vegetation, play an irreplaceable role in mitigating climate change. For example, forest ecosystems, covering one-third of the land area, store half of the terrestrial carbon, holding 86% of the carbon pool in terrestrial vegetation and 73% in the carbon pool in soil. Furthermore, the annual carbon exchange between forests and the atmosphere through photosynthesis and respiration accounts for as much as 90% of the total terrestrial carbon exchange. Therefore, forest ecosystems dominate the global carbon budget and play an irreplaceable role in regulating global ecological balance, mitigating the greenhouse effect, and improving global climate. Soil, a crucial component of terrestrial ecosystems, provides habitat and nutrient support for the growth, survival, and reproduction of surface plants, soil animals, and microorganisms. However, changes in soil material and energy cycling processes caused by climate warming will affect the activity of soil animals and microorganisms, as well as the physiological and biochemical processes of plants. This will also impact root nutrient uptake and nutrient supply to surface vegetation. These changes in soil environment and vegetation distribution patterns will inevitably alter the processes by which organisms participate in the carbon cycle, ultimately affecting the carbon cycle of the entire terrestrial ecosystem. While the roles and functions of forests and grasslands in the carbon balance process are clearly understood at the macro level, the mechanisms and effects of natural vegetation within specific vegetation sub-sectors on the carbon cycle remain unclear. Furthermore, the mechanisms by which key elements such as soil organic carbon, roots, and litter affect carbon release processes differ under different environmental conditions, necessitating further exploration. Summary of the Invention

[0003] To address the aforementioned shortcomings in existing technologies, this invention provides a method for identifying the mechanism of carbon balance processes in natural vegetation-soil systems through forest succession. This invention calculates the growth rate of carbon storage in aboveground vegetation, litter, roots, and soil of natural forest ecosystems under different succession levels, thereby completing the method for identifying the mechanism of the impact of natural vegetation-soil systems through forest succession on carbon balance processes, and making an exploration for investigating the changes in natural vegetation-soil carbon cycle processes under the background of climate change.

[0004] To achieve the above objectives, the technical solution adopted by this invention is: a method for identifying the mechanism of carbon balance process in forest succession of natural vegetation-soil systems, comprising the following steps:

[0005] S1. Determine the succession pathway of natural vegetation according to the area occupied by each type of vegetation within the study area.

[0006] S2. Based on the succession pathway of natural vegetation, determine the impact of natural vegetation succession on aboveground biomass and carbon storage.

[0007] S3. Based on the effective soil depth and soil bulk density in each experimental area, the impact of natural vegetation succession on soil organic carbon and carbon storage was obtained by determining the dynamic changes in soil organic carbon storage.

[0008] S4. By determining the root biomass and carbon storage per unit area, the influence of natural vegetation succession on root carbon storage is obtained.

[0009] S5. By determining the amount of litter and carbon storage per unit area, the influence of natural vegetation succession on litter carbon storage is obtained.

[0010] S6. Collect vegetation atmospheric precipitation and total organic carbon content of water bodies in each study area to determine the impact of natural vegetation succession on atmospheric precipitation carbon input.

[0011] S7. Based on the impact data determined in steps S2-S6, calculate the change range of carbon storage of each component of the natural forest ecosystem under different natural vegetation succession levels, and quantify its contribution to the carbon balance process, thus completing the impact mechanism identification process.

[0012] The beneficial effects of this invention are as follows: This invention collects data through field observation experiments, determines the natural vegetation succession pathway through regional surveys, and establishes mechanistic equations based on forest surveys and field sampling to obtain dynamic changes in aboveground vegetation, litter, soil, root biomass, and carbon storage. Simultaneously, it monitors atmospheric precipitation and total water carbon content per unit time to determine the carbon input of atmospheric precipitation to the natural forest ecosystem. Based on the above data, it determines the changes in carbon storage of each component and the overall carbon storage of the natural forest ecosystem at different succession stages. It uses the eddy covariance method to obtain the carbon flux of the natural vegetation ecosystem and verifies the dynamic changes in carbon storage. Finally, by quantifying the magnitude of carbon storage changes in each component of the natural forest ecosystem at different succession levels and their contribution to the carbon balance process, it completes the identification method for the influence mechanism of forest succession in the natural vegetation-soil system on the carbon balance process. This invention, by studying the dynamic changes in carbon storage during natural vegetation succession, helps to clarify the influence mechanism of the natural vegetation-soil system succession process on the carbon balance process and its impact on the ecosystem carbon cycle process.

[0013] Further, step S1 includes the following steps:

[0014] S101. Obtain vegetation information within the study area;

[0015] S102. Based on the obtained vegetation information, according to the area occupied by each type of vegetation within the zoning of the study area, and taking a cumulative proportion of 95% as the boundary, determine the succession pathways of several types of natural vegetation.

[0016] The beneficial effect of the above-mentioned further scheme is that it can preliminarily determine the natural forest succession process within the study area through field investigation, providing theoretical support for subsequent experiments.

[0017] Furthermore, step S2 includes the following steps:

[0018] S201. Based on the succession pathway of natural vegetation, select several representative experimental areas with similar conditions within the region to conduct a natural vegetation survey.

[0019] S202. Based on the survey results, construct the allometric growth equation;

[0020] S203. Based on the allometric growth equation, determine the impact of natural vegetation succession on aboveground biomass and carbon storage.

[0021] Furthermore, the expressions for the mean biomass and carbon storage in step 203 are as follows:

[0022]

[0023] B i =f(r i ,h i )

[0024] U c =C u ×AGB m

[0025] Among them, AGB m This represents the mean biomass, expressed in t / hm². 2 B i a represents the biomass of the i-th tree, in tons (t). i This indicates the tree density within the forest survey area, expressed in trees / hm². 2 r i ,h i Let f(·) represent the maximum radius and height of the i-th tree within the forest survey area, in meters (m). Let f(·) represent the tree biomass, which is a parametric equation related to tree indicators, in t / hm². 2 U c This represents the carbon storage of the aboveground forest vegetation, expressed in t / hm². 2 C u This represents the carbon density of the aboveground vegetation, expressed as a percentage.

[0026] The beneficial effects of the above-mentioned further scheme are: by measuring the biomass and vegetation characteristics of the aboveground parts to establish a growth equation, the aboveground biomass and carbon storage can be quickly calculated, which is conducive to providing data support for subsequent carbon balance process analysis.

[0027] Furthermore, step S3 includes the following steps:

[0028] S301. Based on the effective soil depth h in each experimental area, the soil is divided into several layers, and the organic carbon content and bulk density of each layer are measured by ring sampling method.

[0029] S302. Based on the soil organic carbon content and soil bulk density, the soil organic carbon storage and its dynamic changes are obtained.

[0030] S303. Based on soil organic carbon storage and its dynamic changes, the impact of natural vegetation succession on soil organic carbon and carbon storage is obtained:

[0031]

[0032] Among them, S c This indicates the soil organic carbon storage at the effective depth, expressed in t / hm². 2 , n represents the number of soil profile layers, C i' This represents the soil organic carbon content of the i'th layer, in g / kg, γ i This represents the bulk density of the i'th soil layer, in g / cm³. 3 10 represents the unit conversion factor in the formula, T i' This represents the depth of the i'th soil layer, in cm.

[0033] The beneficial effect of the above-mentioned further scheme is that by measuring in the field, the soil organic carbon storage value per unit area can be calculated, which is conducive to providing data support for subsequent carbon balance process analysis.

[0034] Furthermore, step S4 specifically includes:

[0035] The root biomass and carbon storage per unit area were determined using the pit digging method, and the changes in net root growth and carbon storage per unit time under different natural vegetation succession conditions were calculated:

[0036]

[0037] Among them, R c This indicates the root carbon storage at the effective soil depth, expressed in t / hm². 2 , n represents the number of soil profile layers, R bi' This represents the root biomass of the i'th layer per unit area, expressed in t / hm². 2 R ci'This represents the carbon content of the roots beneath the i'th soil layer, expressed in g / kg.

[0038] The beneficial effects of the above-mentioned further scheme are: by conducting field measurements, the distribution of soil root biomass and carbon storage per unit area can be calculated, which is helpful for providing data support for subsequent carbon balance process analysis.

[0039] Furthermore, step S5 includes the following steps:

[0040] S501. In natural forests with different degrees of natural vegetation succession, m a×am sites are set up respectively. 2 The sample plots were selected, and litter was collected from the plots. The litter was then dried in a 75°C oven for 24 hours. After weighing, the biomass B in the i-th litter plot was calculated. li , where a represents the side length of the collection net, in meters;

[0041] S502, Based on biomass B li To determine the impact of natural vegetation succession per unit area on litter biomass and carbon storage:

[0042] L c =B l ×B lc

[0043]

[0044] Among them, L c This indicates the carbon storage of the litter layer, expressed in t / hm². 2 B l This represents the biomass of the litter layer within a quadrat, expressed in t / hm². 2 B lc B indicates the carbon content of litter, expressed in g / kg. li” S represents the biomass in the i”-th litter quadrat, in kg, i” = 1, 2, ..., m, where m represents the m-th litter quadrat. l This represents the area of ​​litter samples, in hectares (hm²). 2 1000 represents the unit conversion factor in the formula.

[0045] The beneficial effect of the above-mentioned further scheme is that the distribution of litter biomass and carbon storage per unit area can be obtained by calculating the quadrat sampling method, which is conducive to providing data support for subsequent carbon balance process analysis.

[0046] Furthermore, step S6 specifically includes:

[0047] In open areas at the edge of natural vegetation, atmospheric precipitation was collected from vegetation in each study area, and the total organic carbon content of each water body was measured to obtain the carbon input of atmospheric precipitation to the natural forest ecosystem under natural vegetation succession.

[0048]

[0049] Among them, W c This represents the amount of carbon input from atmospheric precipitation to the forest ecosystem, expressed in t / hm². 2 P i”' W represents the rainfall amount of the i”'th rainfall event per unit time, in mm. ci”' Let represent the average carbon content of atmospheric precipitation under the i”'th precipitation event, in %; k represents the number of precipitation events; and ρ represents the density of water, in g / cm³. 3 .

[0050] The beneficial effects of the above-mentioned further scheme are: by obtaining the rainfall and TOC content in the region through rain gauges, the amount of carbon input of atmospheric precipitation per unit area to the natural forest ecosystem can be calculated, providing data support for subsequent carbon balance calculations.

[0051] Furthermore, step S7 includes the following steps:

[0052] S701. Based on the impact data determined in steps S2-S6, calculate the changes in carbon storage in the soil layer, litter layer, and canopy based on the carbon balance process:

[0053] ΔC=C m -C0

[0054] C m =S cm +R cm +U cm +L cm +W c

[0055] C0 = S c0 +R c0 +U c0 +L c0

[0056] Wherein, ΔC represents the change in carbon storage of each component of the natural forest ecosystem during the observation period, in units of t / hm². 2 C m C0 and C0 represent the carbon storage of each component of the natural forest ecosystem at the initial and final stages of observation, respectively, in t / hm². 2 S cm R cm U cm and L cmThese represent the carbon storage in soil, roots, aboveground parts, and litter at the end of the observation period, respectively, in t / hm². 2 W c This represents the amount of carbon transported by atmospheric precipitation to the natural forest ecosystem during the observation period, expressed in t / hm². 2 S c0 R c0 U c0 and L c0 These represent the carbon storage in soil, roots, aboveground parts, and litter at the initial stage of observation, in units of t / hm². 2 ;

[0057] S702. Using the eddy covariance method, determine the carbon flux of the natural vegetation-soil ecosystem per unit time, and use the carbon flux to verify the changes in carbon storage calculated based on the carbon balance process:

[0058]

[0059] Where r represents the relative deviation of carbon storage changes in the natural forest ecosystem during the observation period, in percentage (%). c This represents the total flux of the natural forest ecosystem during the observation period, expressed in t / hm². 2 ;

[0060] S703. Based on the verification results, calculate the changes in carbon storage of aboveground vegetation, litter, roots and soil in natural forest ecosystems under different degrees of natural vegetation succession, and quantify their contribution to the carbon balance process to complete the identification of the influencing mechanism.

[0061] The beneficial effects of the above-mentioned further scheme are: by comprehensively analyzing the carbon storage of each component of the natural forest ecosystem obtained in steps S2-S6, the magnitude of the impact of vegetation succession on the carbon storage of the forest ecosystem is quantified, and the above calculation results are verified by the results of the eddy covariance method. Finally, the magnitude of the impact of natural forest succession is clarified by the change range of carbon storage of each component of the natural forest, thereby completing the identification method of the impact mechanism of forest succession of the natural vegetation-soil system on the carbon balance process, and exploring the changes of the natural vegetation-soil carbon cycle process under the background of climate change. Attached Figure Description

[0062] Figure 1 This is a flowchart of the method of the present invention. Detailed Implementation

[0063] The specific embodiments of the present invention are described below to enable those skilled in the art to understand the present invention. However, it should be understood that the present invention is not limited to the scope of the specific embodiments. For those skilled in the art, various changes are obvious as long as they are within the spirit and scope of the present invention as defined and determined by the appended claims. All inventions utilizing the concept of the present invention are protected.

[0064] Example

[0065] This invention preliminarily determines the natural vegetation succession pathway in the study area, obtains forest aboveground characteristic data based on forest land surveys, and establishes an allometric growth equation to determine vegetation biomass and carbon storage; determines soil carbon storage using ring sampling; measures litter biomass and carbon storage values ​​using quadrat sampling; determines root biomass and carbon storage distribution using pit digging; simultaneously monitors atmospheric precipitation and total water carbon content per unit time to determine the carbon input of atmospheric precipitation to the natural forest ecosystem; based on the above data, determines the changes in carbon storage of each component and the overall carbon storage of the natural forest ecosystem at different succession stages; obtains the carbon flux of the natural vegetation ecosystem using eddy covariance and verifies the dynamic changes in carbon storage; finally, by quantifying the magnitude of carbon storage changes in each component of the natural forest ecosystem at different succession levels and their contribution to the carbon balance process, it completes a method for identifying the impact mechanism of forest succession in the natural vegetation-soil system on the carbon balance process. This invention elucidates the relationship between vegetation type and vegetation carbon storage by revealing the overall and component carbon storage of natural forests at different successional stages, thus providing methodological support for the scientific question of the impact of natural vegetation succession on carbon balance processes. Figure 1 As shown, this invention provides a method for identifying the mechanism of carbon balance processes in natural vegetation-soil systems through forest succession, the implementation of which is as follows:

[0066] S1. Based on the area occupied by each type of vegetation within the study area's administrative division, determine the succession pathways of natural vegetation. The method for achieving this is as follows:

[0067] S101. Obtain vegetation information within the study area;

[0068] S102. Based on the obtained vegetation information, according to the area occupied by each type of vegetation within the zoning of the study area, and taking a cumulative proportion of 95% as the boundary, determine the succession pathways of several types of natural vegetation.

[0069] In this embodiment, the basic vegetation conditions in the region are understood through forest land surveys, and the area of ​​each natural forest region within the study area is preliminarily determined. Multiple major forest succession stages are determined with a cumulative proportion of 95% as the boundary.

[0070] S2. Based on the succession pathway of natural vegetation, determine the impact of natural vegetation succession on aboveground biomass and carbon storage. The method for achieving this is as follows:

[0071] S201. Based on the succession pathway of natural vegetation, select several representative experimental areas with similar conditions within the region to conduct a natural vegetation survey.

[0072] S202. Based on the survey results, construct the allometric growth equation;

[0073] S203. Based on the allometric growth equation, determine the impact of natural vegetation succession on aboveground biomass and carbon storage.

[0074] In this embodiment, based on the determined natural vegetation succession pathway, multiple representative experimental areas with similar conditions are selected within the region for vegetation surveys. Allometric growth equations are established to determine the dynamic changes in the carbon storage of the main vegetation body per unit time. The same applies to dead trees. In this way, the impact of natural vegetation succession on aboveground biomass and carbon storage is determined.

[0075] In this embodiment, based on the determined natural forest succession pathway, several representative experimental areas with similar conditions within the region are selected for vegetation surveys, including basic information, vegetation type, tree measurement, stand indicators, and understory indicators. An allometric growth equation is established to determine the dynamic changes in the carbon storage of the main vegetation species per unit time, and the same applies to dead trees, thereby determining the impact of natural vegetation succession on aboveground biomass and carbon storage.

[0076] In this embodiment, the expressions for the mean biomass and carbon storage are as follows:

[0077]

[0078] B i =f(r i ,h i )

[0079] U c =C u ×AGB m

[0080] Among them, AGB m This represents the mean biomass, expressed in t / hm². 2 B i a represents the biomass of the i-th tree, in tons (t). i This indicates the tree density within the forest survey area, expressed in trees / hm². 2 r i ,h iLet f(·) represent the maximum radius and height of the i-th tree within the forest survey area, in meters (m). Let f(·) represent the tree biomass, which is a parametric equation related to tree indicators, in t / hm². 2 U c This represents the carbon storage of the aboveground forest vegetation, expressed in t / hm². 2 C u This represents the carbon density of the aboveground vegetation, expressed as a percentage.

[0081] S3. Based on the effective soil depth and bulk density in each experimental area, the impact of natural vegetation succession on soil organic carbon and carbon storage is obtained by determining the dynamic changes in soil organic carbon storage. The method for achieving this is as follows:

[0082] S301. Based on the effective soil depth h in each experimental area, the soil is divided into several layers, and the organic carbon content and bulk density of each layer are measured by ring sampling method.

[0083] S302. Based on the soil organic carbon content and soil bulk density, the soil organic carbon storage and its dynamic changes are obtained.

[0084] S303. Based on soil organic carbon storage and its dynamic changes, the impact of natural vegetation succession on soil organic carbon and carbon storage is obtained:

[0085] In this embodiment, based on the effective soil depth h in each experimental area, the soil was divided into multiple layers, and the organic carbon content C of each layer was measured using a ring sampler method. i' and soil bulk density γ i Based on the soil organic carbon content and bulk density obtained from soil layers at different depths, the soil organic carbon storage and its dynamic changes are calculated, thereby determining the impact of natural vegetation succession on soil carbon storage.

[0086]

[0087] Among them, S c This indicates the soil organic carbon storage at the effective depth, expressed in t / hm². 2 , n represents the number of soil profile layers, C i' This represents the soil organic carbon content of the i'th layer, in g / kg, γ i This represents the bulk density of the i'th soil layer, in g / cm³. 3 10 represents the unit conversion factor in the formula, T i' This represents the depth of the i'th soil layer, in cm.

[0088] S4. By determining the root biomass and carbon storage per unit area, the impact of natural vegetation succession on root carbon storage is obtained, specifically as follows:

[0089] The root biomass and carbon storage per unit area were determined using the pit digging method, and the changes in net root growth and carbon storage per unit time under different natural vegetation succession conditions were calculated:

[0090]

[0091] Among them, R c This indicates the root carbon storage at the effective soil depth, expressed in t / hm². 2 , n represents the number of soil profile layers, R bi' This represents the root biomass of the i'th layer, in t / hm². 2 R ci' This represents the carbon content of the roots beneath the i'th soil layer, expressed in g / kg.

[0092] S5. By determining the amount of litter and carbon storage per unit area, the impact of natural vegetation succession on litter carbon storage is obtained. The method for achieving this is as follows:

[0093] S501. In natural forests with different degrees of natural vegetation succession, m a×am sites are set up respectively. 2 The sample plots were selected, and litter was collected from the plots. The litter was then dried in a 75°C oven for 24 hours. After weighing, the biomass B in the i-th litter plot was calculated. li , where a represents the side length of the collection net, in meters;

[0094] S502, Based on biomass B li To determine the impact of natural vegetation succession per unit area on litter biomass and carbon storage:

[0095] L c =B l ×B lc

[0096]

[0097] Among them, L c This indicates the carbon storage of the litter layer, expressed in t / hm². 2 B l This represents the biomass of the litter layer within a quadrat, expressed in t / hm². 2 B lc B indicates the carbon content of litter, expressed in g / kg. li” S represents the biomass in the i”-th litter quadrat, in kg, i” = 1, 2, ..., m, where m represents the m-th litter quadrat. l This represents the area of ​​litter samples, in hectares (hm²). 2 1000 represents the unit conversion factor in the formula.

[0098] S6. Collect atmospheric precipitation data and total organic carbon content of water bodies in each study area to determine the impact of natural vegetation succession on atmospheric precipitation carbon input, specifically:

[0099] In open areas at the edge of natural vegetation, atmospheric precipitation was collected from vegetation in each study area, and the total organic carbon content of each water body was measured to obtain the carbon input of atmospheric precipitation to the natural forest ecosystem under natural vegetation succession.

[0100]

[0101] Among them, W c This represents the amount of carbon input from atmospheric precipitation to the forest ecosystem, expressed in t / hm². 2 P i”' W represents the rainfall amount of the i”'th rainfall event per unit time, in mm. ci”' Let represent the average carbon content of atmospheric precipitation under the i”'th precipitation event, in %; k represents the number of precipitation events; and ρ represents the density of water, in g / cm³. 3 .

[0102] S7. Based on the impact data determined in steps S2-S6, and based on the carbon balance process, calculate the change range of carbon storage of each component of the natural forest ecosystem under different natural vegetation succession levels, and quantify its contribution to the carbon balance process, thus completing the impact mechanism identification process. The implementation method is as follows:

[0103] S701. Based on the impact data determined in steps S2-S6, calculate the changes in carbon storage in the soil layer, litter layer and canopy based on the carbon balance process.

[0104] S702. Determine the carbon flux of the natural vegetation-soil ecosystem per unit time using the eddy covariance method, and use the carbon flux to verify the changes in carbon storage calculated based on the carbon balance process.

[0105] S703. Based on the verification results, calculate the changes in carbon storage of aboveground vegetation, litter, roots and soil in natural forest ecosystems under different degrees of natural vegetation succession, and quantify their contribution to the carbon balance process to complete the identification of the influencing mechanism.

[0106] In this embodiment, based on the impact data obtained in steps S2-S6, and based on the carbon balance process, the changes in carbon storage in the soil layer, litter layer, and canopy are calculated, thereby determining the impact mechanism of natural vegetation succession on the carbon balance process. The calculation formula is shown below:

[0107] ΔC=C m -C0

[0108] C m =Scm +R cm +U cm +L cm +W c

[0109] C0 = S c0 +R c0 +U c0 +L c0

[0110] Wherein, ΔC represents the change in carbon storage of each component of the natural forest ecosystem during the observation period, in units of t / hm². 2 C m C0 and C0 represent the carbon storage of each component of the natural forest ecosystem at the initial and final stages of observation, respectively, in t / hm². 2 S cm R cm U cm and L cm These represent the carbon storage in soil, roots, aboveground parts, and litter at the end of the observation period, respectively, in t / hm². 2 W c This represents the amount of carbon transported by atmospheric precipitation to the natural forest ecosystem during the observation period, expressed in t / hm². 2 S c0 R c0 U c0 and L c0 These represent the carbon storage in soil, roots, aboveground parts, and litter at the initial stage of observation, in units of t / hm². 2 ;

[0111] In this embodiment, the carbon flux F of the natural vegetation-soil ecosystem per unit time is determined by the eddy covariance method. c And used to verify the carbon balance process of the natural forest ecosystem in step S701:

[0112]

[0113] Where r represents the relative deviation of carbon storage changes in the natural forest ecosystem during the observation period, in percentage (%). c This represents the total flux of the natural forest ecosystem during the observation period, expressed in t / hm². 2 .

[0114] This invention collects data through field observation experiments, determines the succession pathway of natural vegetation through regional surveys, and obtains dynamic changes in aboveground vegetation, litter, soil, root biomass, and carbon storage. It also monitors atmospheric precipitation and total water carbon content per unit time to determine the carbon input of atmospheric precipitation to the natural forest ecosystem. Based on the above data, it determines the changes in carbon storage of each component and the overall carbon storage of the natural forest ecosystem at different succession stages. The carbon flux of the natural vegetation ecosystem is obtained using the eddy covariance method, and the dynamic changes in carbon storage are verified. Finally, the invention quantifies the magnitude of carbon storage changes in each component of the natural forest ecosystem at different succession levels and their contribution to the carbon balance process.

Claims

1. A method for identifying the mechanism of carbon balance processes in forest succession of natural vegetation-soil systems, characterized in that, Includes the following steps: S1. Determine the succession pathway of natural vegetation according to the area occupied by each type of vegetation within the study area. S2. Based on the succession pathway of natural vegetation, determine the impact of natural vegetation succession on aboveground biomass and carbon storage. S3. Based on the effective soil depth and soil bulk density in each experimental area, the impact of natural vegetation succession on soil organic carbon and carbon storage was obtained by determining the dynamic changes in soil organic carbon storage. S4. By determining the root biomass and carbon storage per unit area, the influence of natural vegetation succession on root carbon storage is obtained. S5. By determining the amount of litter and carbon storage per unit area, the influence of natural vegetation succession on litter carbon storage is obtained. S6. Collect vegetation atmospheric precipitation and total organic carbon content of water bodies in each study area to determine the impact of natural vegetation succession on atmospheric precipitation carbon input. S7. Based on the impact data determined in steps S2-S6, calculate the change range of carbon storage of each component of the natural forest ecosystem under different natural vegetation succession levels, and quantify its contribution to the carbon balance process, thus completing the impact mechanism identification process.

2. The method for identifying the mechanism of carbon balance process in forest succession of natural vegetation-soil systems according to claim 1, characterized in that, Step S1 includes the following steps: S101. Obtain vegetation information within the study area; S102. Based on the obtained vegetation information, according to the area occupied by each type of vegetation within the zoning of the study area, and taking a cumulative proportion of 95% as the boundary, determine the succession pathways of several types of natural vegetation.

3. The method for identifying the mechanism of carbon balance process in forest succession of natural vegetation-soil systems according to claim 1, characterized in that, Step S2 includes the following steps: S201. Based on the succession pathway of natural vegetation, select several representative experimental areas with similar conditions within the region to conduct a natural vegetation survey. S202. Based on the survey results, construct the allometric growth equation; S203. Based on the allometric growth equation, determine the impact of natural vegetation succession on aboveground biomass and carbon storage.

4. The method for identifying the mechanism of carbon balance process in forest succession of natural vegetation-soil systems according to claim 3, characterized in that, The expressions for the mean biomass and carbon storage in step 203 are as follows: B i =f(r i ,h i ) U c =C u ×AGB m Among them, AGB m This represents the mean biomass, expressed in t / hm². 2 B i The biomass of the i-th tree is expressed in tons (t). i This indicates the tree density within the forest survey area, expressed in trees / hm². 2 r i ,h i Let f(·) represent the maximum radius and height of the i-th tree within the forest survey area, in meters (m). Let f(·) represent the tree biomass, which is a parametric equation related to tree indicators, in t / hm². 2 U c This represents the carbon storage of the aboveground forest vegetation, expressed in t / hm². 2 C u This represents the carbon density of the aboveground vegetation, expressed as a percentage.

5. The method for identifying the mechanism of carbon balance process in forest succession of natural vegetation-soil systems according to claim 1, characterized in that, Step S3 includes the following steps: S301. Based on the effective soil depth h in each experimental area, the soil is divided into several layers, and the organic carbon content and bulk density of each layer are measured by ring sampling method. S302. Based on the soil organic carbon content and soil bulk density, the soil organic carbon storage and its dynamic changes are obtained. S303. Based on soil organic carbon storage and its dynamic changes, the impact of natural vegetation succession on soil organic carbon and carbon storage is obtained: Among them, S c This indicates the soil organic carbon storage at the effective depth, expressed in t / hm². 2 , n represents the number of soil profile layers, C i' This represents the soil organic carbon content of the i'th layer, in g / kg, γ i This represents the bulk density of the i'th soil layer, in g / cm³. 3 10 represents the unit conversion factor in the formula, T i' This represents the depth of the i'th soil layer, in cm.

6. The method for identifying the mechanism of carbon balance process in forest succession of natural vegetation-soil systems according to claim 1, characterized in that, Step S4 specifically involves: The root biomass and carbon storage per unit area were determined using the pit digging method, and the changes in net root growth and carbon storage per unit time under different natural vegetation succession conditions were calculated: Among them, R c This indicates the root carbon storage at the effective soil depth, expressed in t / hm². 2 , n represents the number of soil profile layers, R bi' This represents the root biomass of the i'th layer per unit area, expressed in t / hm². 2 R ci' This represents the carbon content of the roots beneath the i'th soil layer, expressed in g / kg.

7. The method for identifying the mechanism of carbon balance process in forest succession of natural vegetation-soil systems according to claim 1, characterized in that, Step S5 includes the following steps: S501. In natural forests with different degrees of natural vegetation succession, m a×am sites are set up respectively. 2 The sample plots were selected, and litter was collected from the plots. The litter was then dried in a 75°C oven for 24 hours. After weighing, the biomass B in the i-th litter plot was calculated. li , where a represents the side length of the collection net, in meters; S502, Based on biomass B li To determine the impact of natural vegetation succession per unit area on litter biomass and carbon storage: L c =B l ×B lc Among them, L c This indicates the carbon storage of the litter layer, expressed in t / hm². 2 B l This represents the biomass of the litter layer within a quadrat, expressed in t / hm². 2 B lc B indicates the carbon content of litter, expressed in g / kg. li” S represents the biomass in the i”-th litter quadrat, in kg, i” = 1, 2, ..., m, where m represents the m-th litter quadrat. l This represents the area of ​​litter samples, in hectares (hm²). 2 1000 represents the unit conversion factor in the formula.

8. The method for identifying the mechanism of carbon balance process by forest succession in natural vegetation-soil systems according to claim 1, characterized in that, Step S6 specifically involves: In open areas at the edge of natural vegetation, atmospheric precipitation was collected from vegetation in each study area, and the total organic carbon content of each water body was measured to obtain the carbon input of atmospheric precipitation to the natural forest ecosystem under natural vegetation succession. Among them, W c This represents the amount of carbon input from atmospheric precipitation to the forest ecosystem, expressed in t / hm². 2 P i”' W represents the rainfall amount of the i”'th rainfall event per unit time, in mm. ci”' Let represent the average carbon content of atmospheric precipitation under the i”'th precipitation event, in %; k represents the number of precipitation events; and ρ represents the density of water, in g / cm³. 3 .

9. The method for identifying the mechanism of carbon balance process in forest succession of natural vegetation-soil systems according to claim 1, characterized in that, Step S7 includes the following steps: S701. Based on the impact data determined in steps S2-S6, calculate the changes in carbon storage in the soil layer, litter layer, and canopy based on the carbon balance process: ΔC=C m -C0 C m =S cm +R cm +U cm +L cm +W c C0=S c0 +R c0 +U c0 +L c0 Wherein, ΔC represents the change in carbon storage of each component of the natural forest ecosystem during the observation period, in units of t / hm². 2 C m C0 and C0 represent the carbon storage of each component of the natural forest ecosystem at the initial and final stages of observation, respectively, in t / hm². 2 S cm R cm U cm and L cm These represent the carbon storage in soil, roots, aboveground parts, and litter at the end of the observation period, respectively, in t / hm². 2 W c This represents the amount of carbon transported by atmospheric precipitation to the natural forest ecosystem during the observation period, expressed in t / hm². 2 S c0 R c0 U c0 and L c0 These represent the carbon storage in soil, roots, aboveground parts, and litter at the initial stage of observation, in units of t / hm². 2 ; S702. Using the eddy covariance method, determine the carbon flux of the natural vegetation-soil ecosystem per unit time, and use the carbon flux to verify the changes in carbon storage calculated based on the carbon balance process: Where r represents the relative deviation of carbon storage changes in the natural forest ecosystem during the observation period, in percentage (%). c This represents the total flux of the natural forest ecosystem during the observation period, expressed in t / hm². 2 ; S703. Based on the verification results, calculate the changes in carbon storage of aboveground vegetation, litter, roots and soil in natural forest ecosystems under different degrees of natural vegetation succession, and quantify their contribution to the carbon balance process to complete the identification of the influencing mechanism.

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