Carbon reserve and carbon flux expression method of watershed scale ecosystem

Abstract

The invention discloses a watershed scale ecosystem carbon reserve and carbon flux expression method, which belongs to the technical field of carbon reserve and carbon flux expression methods, and realizes dynamic expression of watershed scale ecosystem carbon reserve and carbon flux by constructing a carbon reserve matrix and a carbon flux matrix and integrating transverse carbon migration and dissolved inorganic carbon flux. The carbon reserve matrix comprises overground and underground biomass carbon reserves of an arbor layer, a shrub layer and a herbaceous layer and carbon reserves of dead standing trees, litters, a soil layer, a wetland and an aquatic ecosystem of each pattern spot in the drainage basin, and calculating the total carbon reserves of each pattern spot and the drainage basin; the carbon flux matrix comprises the carbon reserve variable quantity and the carbon migration flux of each pattern spot carbon library in different time intervals, and the carbon exchange flux, the water body carbon flux and the DIC related flux of the ecological system and the atmosphere at the same time.

Description

Technical Field

[0001] This invention relates to a method for expressing carbon storage and carbon flux, and particularly to a method for expressing carbon storage and carbon flux in a watershed-scale ecosystem, belonging to the technical field of methods for expressing carbon storage and carbon flux. Background Technology

[0002] Research on watershed-scale ecosystem carbon storage and carbon flux is a key topic in the field of carbon cycling and carbon neutrality.

[0003] Traditional methods focus on changes in vegetation and soil carbon pools over time, but neglect lateral carbon migration caused by soil erosion and dissolved inorganic carbon (DIC) fluxes formed by the dissolution of carbonate rocks in karst regions.

[0004] DIC is often regarded as a carbon leak or carbon source and is not included in carbon accounting, resulting in incomplete carbon neutrality assessment. To address this issue, a watershed-scale ecosystem carbon storage and carbon flux expression method is designed. Summary of the Invention

[0005] The main objective of this invention is to provide a method for expressing carbon storage and carbon flux in watershed-scale ecosystems.

[0006] The objective of this invention can be achieved by adopting the following technical solution: A method for expressing carbon storage and carbon flux in watershed-scale ecosystems is proposed. By constructing carbon storage and carbon flux matrices and integrating lateral carbon migration and dissolved inorganic carbon flux, the dynamic expression of carbon storage and carbon flux in watershed-scale ecosystems can be achieved. The carbon storage matrix includes the aboveground and belowground biomass carbon storage of the tree layer, shrub layer, and herb layer of each patch within the watershed, as well as the carbon storage of dead standing trees, litter, soil layer, wetlands, and aquatic ecosystems, and calculates the total carbon storage of each patch and the watershed. The carbon flux matrix includes the changes in carbon storage and carbon migration flux of each patch carbon pool in different time intervals, and also incorporates the carbon exchange flux between the ecosystem and the atmosphere, water carbon flux, and DIC-related fluxes.

[0007] Preferably, the initial time of the carbon storage matrix is ​​t0, and the rows are arranged in the order of tree layer above ground, tree layer below ground, shrub layer above ground, shrub layer below ground, herb layer above ground, herb layer below ground, dead standing trees, litter, soil layer, wetland, and aquatic ecosystem. Each map patch within the watershed is a column, the matrix element is the carbon storage of the corresponding carbon pool, and the last row of the matrix is ​​the total carbon storage of each map patch. The matrix format is as follows: ; In the formula: —Total carbon pool of all patches within the watershed at time t0; Ci represents the aboveground carbon storage of the tree layer in the i-th patch, expressed in tons of carbon (tC). Ci - the underground carbon reserves of the tree layer in the i-th patch, in tons of carbon (tC). Ci represents the aboveground carbon storage of the shrub layer in the i-th plot, expressed in tons of carbon (tC). C under irrigation, i — underground carbon storage of the shrub layer of the i-th patch, in tons of carbon (tC). Cgrass, i—the aboveground carbon storage of the herbaceous layer of the i-th patch, in tons of carbon (tC). C under grass, i — underground carbon reserves of the herbaceous layer of the i-th patch, in tons of carbon (tC). C_dry, i — Carbon reserves of dead standing trees in the i-th plot, in tons of carbon (tC). Cij,i—The carbon storage of litter in the i-th patch, in tons of carbon (tC). Csoil,i — Carbon storage of the soil layer in the i-th patch, in tons of carbon (tC). C_wet, i — the carbon storage of the i-th wetland patch, in tons of carbon (tC). C_water,i — Carbon storage in the i-th map patch, including inorganic carbon and organic carbon, in tons of carbon (tC). ∑Ci——Total carbon reserves of the corresponding carbon layer, in tons of carbon (tC).

[0008] Preferably, the carbon flux matrix is ​​obtained by calculating the difference in carbon storage between any time t and the initial time t0. The row order of the matrix is ​​consistent with that of the carbon storage matrix, and the matrix elements are the changes in carbon storage of the corresponding carbon pool. The first row is the cumulative carbon exchange flux with the atmosphere for each patch from 0 to t, and the last row is the total change in carbon storage for each patch. .

[0009] Preferably, it also includes constructing a time-series carbon flux matrix within the watershed. This matrix has different time nodes as columns, and the row order is consistent with the carbon storage matrix. The matrix elements are the carbon flux values ​​at the corresponding time nodes, which are used to reflect the dynamic changes of carbon flux over time. The expression for the time series carbon flux matrix is: .

[0010] Preferably, the carbon storage of the aquatic ecosystem includes aquatic organic carbon and inorganic carbon, wherein aquatic organic carbon is further divided into exogenous organic carbon and endogenous organic carbon, and the proportion of each source is quantified by constructing an aquatic organic matter source matrix; Source matrix of organic matter in water bodies within the basin; .

[0011] Preferably, the method introduces a carbon transfer coefficient to quantify the carbon transfer efficiency from vegetation, litter, and soil carbon pools to aquatic ecosystems, as well as the conversion efficiency of soil respiration CO2 reacting with carbonate rocks to form DIC. The carbon transfer coefficient is determined by combining field monitoring data with model simulation, specifically the ratio of the carbon quantity variable of a certain carbon pool to the initial total carbon storage of that carbon pool.

[0012] ; 'a' is the carbon transfer coefficient. ; Preferably, the DIC flux is included in the aquatic ecosystem carbon pool of the carbon flux matrix, including DIC generated by the dissolution of carbonate rocks, DIC flux formed by the exchange of CO2 between water and the atmosphere, and DIC migration flux with water flow, which is calculated through water chemical analysis and hydrological monitoring data.

[0013] Preferably, the data for calculating carbon storage and carbon flux are derived from field measurements, flux observations, remote sensing inversion, land surveys, and soil surveys. The data are combined with the InVEST model and GIS spatial interpolation methods to estimate carbon storage and carbon flux at the watershed scale.

[0014] Preferably, the method is applicable to watersheds containing multiple ecosystems such as forests, grasslands, wetlands, rivers, and lakes, especially karst regions, and can quantify the impact of carbonate rock dissolution-related DIC fluxes on the watershed carbon cycle.

[0015] Preferably, by dynamically updating the carbon storage matrix and carbon flux matrix, real-time calculation and trend prediction of watershed-scale carbon storage and carbon flux can be achieved, providing complete carbon cycle data support for carbon neutrality assessment.

[0016] Beneficial technical effects of the present invention: This invention provides a method for expressing carbon storage and carbon flux in watershed-scale ecosystems. This method effectively overcomes the core deficiencies of traditional methods, achieving a breakthrough in the comprehensiveness and accuracy of carbon cycle accounting. By integrating lateral carbon migration and dissolved inorganic carbon (DIC) fluxes, it incorporates previously neglected processes such as carbon erosion / deposition fluxes caused by soil erosion and DIC transport related to karstification into the accounting system. Simultaneously, it covers vegetation carbon pools such as tree, shrub, and herbaceous layers, as well as all types of carbon pools including standing trees, litter, soil, wetlands, and aquatic ecosystems. This completely fills the gap in carbon transfer accounting in multi-ecosystem coexistence scenarios, providing comprehensive carbon cycle data support for carbon neutrality assessment.

[0017] Based on the construction of carbon storage and carbon flux matrices, this method achieves a dynamic and refined representation of the carbon cycle. The carbon storage matrix clearly presents the stock distribution of different carbon pools in each patch within the watershed. The carbon flux matrix, through time-node difference calculation, accurately reflects the changes in carbon storage, carbon migration flux, and carbon exchange flux with the atmosphere. The time-series carbon flux matrix further captures the dynamic evolution of carbon flux over time. Combined with the dynamic updating capability of the matrix, real-time accounting and trend prediction of carbon storage and carbon flux at the watershed scale can be completed, providing an efficient tool for dynamic monitoring of the carbon cycle.

[0018] By introducing a carbon transfer coefficient, this method successfully quantified the carbon transfer efficiency from vegetation, litter, and soil carbon pools to aquatic ecosystems, as well as soil respiration. The conversion efficiency of DIC (dissolved organic carbon) formed by reaction with carbonate rocks was determined by combining field monitoring data with model simulations, significantly improving the quantitative accuracy of carbon flow processes. Furthermore, for carbon storage in aquatic ecosystems, the study further distinguishes between exogenous and endogenous organic carbon and quantifies the proportion of their sources, making the calculation of carbon pool composition and migration pathways more detailed.

[0019] In terms of data support and applicability, this method integrates multi-source data such as field measurements, flux observations, remote sensing inversion, land surveys, and soil surveys. Combined with the InVEST model and GIS spatial interpolation methods, it ensures the reliability and spatial coverage of watershed-scale estimations. It is not only applicable to watersheds with multiple ecosystems such as forests, grasslands, wetlands, rivers, and lakes, but also, specifically tailored to the unique characteristics of karst regions, accurately quantifies the impact of carbonate rock dissolution-related DIC fluxes on the carbon cycle, significantly broadening the application scenarios of the technology.

[0020] Overall, this method simplifies the accounting process for carbon cycles in complex watersheds through a unified integrated framework of pool, flux, and migration. It not only improves the comprehensiveness, accuracy, and dynamism of the accounting, but also provides scientific and complete technical support for carbon neutrality assessment and ecological protection decision-making, thus promoting the upgrading of watershed-scale carbon cycle research from single static accounting to multi-dimensional dynamic quantification. Attached Figure Description

[0021] Figure 1 Technical roadmap for terrestrial ecosystem carbon storage surveys; Figure 2 An integrated expression process for watershed-scale ecosystem carbon storage and carbon flux; Figure 3 Carbon migration processes in watershed-scale ecosystems. Detailed Implementation

[0022] To enable those skilled in the art to understand the technical solution of the present invention more clearly, the present invention will be further described in detail below with reference to the embodiments and accompanying drawings, but the embodiments of the present invention are not limited thereto.

[0023] Definitions of abbreviations and key terms; Carbon storage: The total amount of carbon stored in an ecosystem, including aboveground biomass, belowground biomass, soil carbon storage, litter and fallen debris carbon storage, dead and standing wood carbon storage, wetland carbon pools (such as peatlands), and carbon storage in aquatic ecosystems.

[0024] Carbon flux: The total amount of carbon passing through a specific ecological section of an ecosystem. For example, the carbon flux of a river is the total amount of organic and inorganic carbon flowing through a section of the river. Carbon flux reflects the dynamic process of the carbon cycle in an ecosystem.

[0025] forest ecosystem; It is a functional system formed by forest biological communities and their environment during the process of material cycling and energy conversion.

[0026] carbon pool; In the carbon cycle, forest ecosystems store carbon in various components, including aboveground living plant biomass, belowground living plant biomass, litter, dead wood, and soil.

[0027] Forest carbon stock; The amount (or mass) of carbon in each carbon pool of a forest ecosystem.

[0028] Above-ground biomass; The weight of all living plants above the ground, expressed as dry weight, can be divided into the tree layer (including trunk, stump, branches, bark, seeds, and leaves) and the understory layer (shrubs, herbs, and saplings).

[0029] Below-ground biomass; The weight of all living plants below the earth's surface, expressed as dry weight. This includes all living roots, including rhizomes, tubers, and buttress roots.

[0030] Watershed scale: Using watersheds as spatial units, this study examines the scope of carbon cycling in ecosystems.

[0031] Fallen and decaying matter: plant remains such as fallen leaves and branches on the ground and their decomposition products.

[0032] Dead trees and dead standing trees: Trees that have died but have not fallen, and dead trees that have fallen.

[0033] Soil organic carbon; Organic carbon reserves in mineral soils and organic soils (including peat soils and gravel layers).

[0034] Wetland carbon pools: Carbon stored in wetland ecosystems such as peatlands.

[0035] Carbon storage in aquatic ecosystems: The amount of carbon stored in aquatic environments, including carbon storage in water bodies such as lakes, wetlands, rivers, and oceans. These ecosystems absorb and store carbon through processes such as photosynthesis and sediment accumulation, thus playing an important role in the global carbon cycle.

[0036] Dissolved inorganic carbon (DIC): The sum of all inorganic carbon compounds in a solution, primarily including carbon dioxide (CO2). ), carbonic acid ), bicarbonate ( ) and carbonates ( DIC plays an important role in aquatic ecosystems, participating in carbon cycling and regulating the acid-base balance of water bodies.

[0037] LUCC: Land Use / Land Cover Change; InVEST: Integrated Ecosystem Services and Trade-offs Model.

[0038] To address the issue of neglecting lateral carbon migration and DIC flux caused by soil erosion in existing technologies, this paper proposes a method to dynamically express carbon storage and flux in matrix form, filling the accounting gap for carbon transfer when multiple ecosystems coexist; and providing a dynamic expression of carbon storage and flux that changes over time. Quantify the DIC flux in carbonate rock distribution areas, including the transfer process of CO2 from soil respiration and the reaction of carbonate rocks, and improve carbon neutrality accounting; Introducing carbon transfer coefficients to quantify vegetation, litter, soil, and soil respiration. Carbon flow efficiency in DIC generation; To build a unified framework to fill the gaps in carbon transfer accounting related to litter and fallen leaves, dead and standing trees, wetlands, aquatic ecosystems, and DIC.

[0039] Carbon storage matrix construction; The initial time is t0. The matrix represents the carbon reserves of each patch, and the upper right corner shows the total carbon reserves, in tons of carbon (tC).

[0040] The matrix is ​​arranged from top to bottom as follows: tree layer above ground, tree layer below ground, shrub layer above ground, shrub layer below ground, herb layer above ground, herb layer below ground, dead standing trees, litter, soil layer, wetland, and aquatic ecosystem. Each column represents one map patch.

[0041] The matrix format is as follows: ; In the formula: —Total carbon pool of all patches within the watershed at time t0 Ci represents the aboveground carbon storage of the tree layer in the i-th patch, expressed in tons of carbon (tC). Ci - the underground carbon reserves of the tree layer in the i-th patch, in tons of carbon (tC). Ci represents the aboveground carbon storage of the shrub layer in the i-th plot, expressed in tons of carbon (tC). C under irrigation, i — underground carbon storage of the shrub layer of the i-th patch, in tons of carbon (tC). Cgrass, i—the aboveground carbon storage of the herbaceous layer of the i-th patch, in tons of carbon (tC). C under grass, i — underground carbon reserves of the herbaceous layer of the i-th patch, in tons of carbon (tC). C_dry, i — Carbon reserves of dead standing trees in the i-th plot, in tons of carbon (tC). Cij,i—The carbon storage of litter in the i-th patch, in tons of carbon (tC). Csoil,i — Carbon storage of the soil layer in the i-th patch, in tons of carbon (tC). C_wet, i — the carbon storage of the i-th wetland patch, in tons of carbon (tC). C_water,i — Carbon storage in the i-th map patch, including inorganic carbon and organic carbon, in tons of carbon (tC). ∑Ci——Total carbon reserves of the corresponding carbon layer, in tons of carbon (tC).

[0042] The carbon flux matrix F represents the carbon flux of each patch, in tons of carbon (tC). It includes the flux of CO2 exchange between the ecosystem canopy (top layer) and the atmosphere, and the flux of CO2 added to water and karst reactions at the bottom layer. ; Wherein, C_water = inorganic carbon flux + organic carbon flux; The time-series carbon flux variation matrix is ​​as follows; ; Source matrix of organic matter in water bodies within the basin; 。

[0043] Comprehensive accounting: quantifying soil erosion, DIC flux, and soil respiration. The transfer coefficient of DIC is generated to improve the carbon neutrality assessment.

[0044] Dynamic representation: The time series matrix combined with the carbon transfer coefficient reflects the trend of carbon change and flow efficiency.

[0045] System integration: covering carbon transfer across multiple ecosystems, including soil respiration and carbonate rock reaction processes.

[0046] High efficiency: Simplifies sampling and calculation processes, and improves accounting accuracy.

[0047] The above description is merely a further embodiment of the present invention, but the scope of protection of the present invention is not limited thereto. Any equivalent substitutions or modifications made by those skilled in the art within the scope disclosed in the present invention, based on the technical solution and concept of the present invention, shall fall within the scope of protection of the present invention.

Claims

1. A method for expressing carbon storage and carbon flux in a watershed-scale ecosystem, characterized in that: By constructing carbon storage matrix and carbon flux matrix, the lateral carbon migration and dissolved inorganic carbon flux are integrated to realize the dynamic expression of carbon storage and carbon flux of the basin-scale ecosystem; The carbon storage matrix includes the aboveground and underground biomass carbon storage of the tree layer, shrub layer and herb layer of each plot in the basin, the carbon storage of standing dead wood, litter, soil layer, wetland and aquatic ecosystem, and the total carbon storage of each plot and the basin is calculated; The carbon flux matrix includes the carbon storage change amount and carbon migration flux of each plot in different time intervals, and the carbon exchange flux between the ecosystem and the atmosphere and the water body carbon flux. 2.The method of claim 1, wherein: The initial time of the carbon storage matrix is t0, and the rows are arranged in the order of aboveground tree layer, underground tree layer, aboveground shrub layer, underground shrub layer, aboveground herb layer, underground herb layer, standing dead wood, litter, soil layer, wetland and aquatic ecosystem, and the columns are each plot in the basin, the matrix elements are the carbon storage of the corresponding carbon pool, and the last row of the matrix is the total carbon storage of each plot; The matrix format is as follows: ； In the formula: - t0 total carbon storage of all patches in the watershed at time point t0; C 乔上,i — the aboveground carbon storage of the i-th map patch arbor layer, in tons of carbon (tC); C 乔下,i — the underground carbon storage of the i-th map patch arbor layer, in tons of carbon (tC); C 灌上,i - the aboveground carbon storage of the i-th patch of shrub layer, in tons of carbon (tC); C 灌下,i — the underground carbon storage of the i-th picture patch shrub layer, in tons of carbon (tC); C 草上,i — the aboveground carbon storage of the i-th plot herb layer, in tons of carbon (tC); C 草下,i — the underground carbon storage of the i-th plot of herb layer, in ton of carbon (tC); C 枯,i - the carbon stock of the i-th picture spot deadwood, in tons of carbon (tC); C 凋,i - the carbon storage of the i-th map patch, in tons of carbon (tC); C 土,i - the carbon storage of the i-th soil patch, in tons of carbon (tC); C 湿,i - the carbon storage of the i-th patch of wetland, in tons of carbon (tC); C 水,i - the carbon storage of the i-th map spot water body, including inorganic carbon and organic carbon, in tons of carbon (tC); ∑C i - Total carbon storage of the i-th map spot in tons of carbon (tC).

3. The method of claim 1, wherein: The carbon flux matrix is obtained by calculating the carbon storage difference between any time t and the initial time t0, the row order of the matrix is consistent with the carbon storage matrix, the matrix elements are the carbon storage change amount of the corresponding carbon pool, the first row is the cumulative carbon exchange flux between each plot and the atmosphere from 0 to t, and the last row is the total carbon storage change amount of each plot; 。 4. The method of claim 1, wherein: It also includes the construction of time series carbon flux matrix, which takes different time nodes as columns, the row order is consistent with the carbon storage matrix, and the matrix elements are the carbon flux values of the corresponding time nodes, which are used to reflect the dynamic change of carbon flux with time; The expression of the time series carbon flux matrix is: 。 5. The method of claim 1, wherein: The carbon storage of the aquatic ecosystem includes organic carbon and inorganic carbon in the water body, wherein the organic carbon in the water body is further divided into external organic carbon and self-generating organic carbon, and the proportion of each source is quantified by constructing a water body organic matter source matrix; The water body organic matter source matrix of the basin; 。 6. The method of claim 1, wherein: The method introduces a carbon transfer coefficient to quantify the carbon transfer efficiency of vegetation, litter and soil carbon pool to the aquatic ecosystem, and the conversion efficiency of soil respiration CO2 and carbonate rock reaction to DIC; The carbon transfer coefficient is determined by field monitoring data combined with model simulation, which is the ratio of the carbon amount variable of a certain carbon pool to the initial total carbon storage of the carbon pool; 。 7. The method of claim 1, wherein: The DIC flux is included in the aquatic ecosystem carbon pool of the carbon flux matrix, including the DIC flux generated by the dissolution of carbonate rocks, the DIC flux formed by the CO2 exchange between the water body and the atmosphere, and the DIC migration flux with the water flow, which is calculated by water body chemical analysis and hydrological monitoring data.

8. The method of claim 1, wherein: The calculation data of carbon storage and carbon flux are derived from sample site measurement, flux observation, remote sensing inversion, national land survey and soil survey data, combined with InVEST model and GIS spatial interpolation method to realize the estimation of carbon storage and carbon flux at basin scale.

9. The method of claim 1, wherein: The method is suitable for basins containing forests, grasslands, wetlands, rivers and lakes, and is especially suitable for karst areas, and can quantify the influence of DIC flux related to carbonate rock dissolution on the carbon cycle of the basin.

10. The method of claim 1, wherein: Through dynamic updating of the carbon storage matrix and the carbon flux matrix, real-time accounting and trend prediction of carbon storage and carbon flux at the basin scale can be realized, providing complete carbon cycle data support for carbon neutral assessment.

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