An analysis method for total carbon transverse transport flux of mangrove ecosystem

Abstract

The present application belongs to the technical field of environmental monitoring, and discloses a kind of analysis method of total carbon lateral transport flux of mangrove ecosystem.The analysis method provided by the present application establishes monitoring target area at the connection of mangrove tidal ditch and adjacent water body and obtains corresponding hydrological parameters and chemical parameters at regular time, to realize the monitoring of lateral transport flux of non-large plant detritus carbon, while collecting large plant detritus samples and measuring the amount of large plant detritus carbon, to realize the monitoring of lateral transport flux of large plant detritus carbon, by quantifying the lateral transport of different forms of carbon and performing weighted operation, so that the obtained total carbon lateral transport flux of mangrove ecosystem has higher accuracy and certainty, can well realize long-time sequence full-form continuous observation of carbon lateral transport of mangrove ecosystem, and has good application prospect.

Description

TECHNICAL FIELD

[0001] The present application belongs to the technical field of environmental monitoring, and particularly relates to a method for analyzing total carbon transverse transport flux of a mangrove ecosystem. BACKGROUND

[0002] Mangrove is one of the typical coastal blue carbon ecosystems, is a special forest distributed in the transition from land to sea in the tropics and subtropics, and is an important "blue carbon sink" in the coastal zone. Although the area accounts for only 0.5% of the global coastal area, the carbon storage is about 2.4 million tons per year, accounting for 10-15% of the carbon storage in the nearshore sediments. At the same time, mangrove has the ecological service functions of providing habitat, purifying seawater, preventing wind and reducing waves, protecting biodiversity, etc., is the blue carbon system with the highest total value of blue carbon and other ecological services, and is an important ecological barrier for the sustainable development of coastal society and economy.

[0003] The carbon cycle process of the mangrove ecosystem is relatively complex, including the vertical exchange of carbon dioxide (CO2) and methane (CH4) between the vegetation-atmosphere interface, the transverse transport of carbon between the land-sea interface, the mangrove and the estuary ecosystem, the deposition of terrestrial organic carbon and aquatic deposition, the burial of organic carbon, and the biogeochemical cycle process in the coastal zone. Studies have shown that the organic carbon fixed and buried in the mangrove ecosystem cannot be permanently sealed in the mangrove system. Part of the carbon (dissolved organic carbon (DOC), dissolved inorganic carbon (DIC), particulate organic carbon (POC), and CO2 and CH4 gas dissolved in water) can leave the mangrove system through the transverse transport of carbon between the mangrove and the estuary ecosystem. Quantifying the transverse transport carbon flux of the mangrove system is necessary for establishing a complete carbon budget of the mangrove system. However, the transverse transport process of the mangrove system is strongly affected by tides, and the transversely transported carbon has various forms, so it is necessary to carry out long-term continuous observation of all forms of carbon to accurately quantify the total carbon transverse transport flux.

[0004] At present, there is still a lack of such long-term continuous observation technology of all forms of carbon. SUMMARY

[0005] The present application aims to provide a method for analyzing the total carbon transverse transport flux of a mangrove ecosystem. The analysis method fully considers the transverse transport of large plant detritus and non-large plant detritus carbon, the astronomical tide conversion, and other influencing factors, and comprehensively considers the transverse transport flux of different forms of carbon in the mangrove ecosystem, so as to accurately quantify the total carbon transverse transport flux of the mangrove ecosystem.

[0006] Specifically, the method for analyzing the carbon transverse transport flux of the mangrove ecosystem provided by the application takes the connection between a mangrove tidal creek and a neighboring water body as a monitoring target area, and specifically comprises: obtaining hydrological parameters and chemical parameters of the water body in the monitoring target area within a unit monitoring time period and in each tidal cycle; determining the transverse transport flux of non-large plant detritus carbon of the mangrove ecosystem within the unit monitoring time period according to the hydrological parameters and the chemical parameters; obtaining the amount of large plant detritus carbon passing through the monitoring target area and the width of the monitoring target area within a plurality of tidal cycles within the unit monitoring time period in the monitoring target area; determining the transverse transport flux of the large plant detritus carbon passing through the monitoring target area in each tidal cycle within the unit monitoring time period according to the amount of the large plant detritus carbon and the width of the monitoring target area and the hydrological parameters; determining the transverse transport flux of the large plant detritus carbon of the mangrove ecosystem within the unit monitoring time period according to the transverse transport flux of the large plant detritus carbon in each tidal cycle; and determining the total carbon transverse transport flux of the mangrove ecosystem according to the transverse transport fluxes of the non-large plant detritus carbon and the large plant detritus carbon; wherein the hydrological parameters comprise water depth, and the chemical parameters comprise dissolved inorganic carbon concentration, dissolved organic carbon concentration, non-large plant detritus particle organic carbon concentration and water body methane concentration, and the tidal cycle comprises a rising tide time period and a falling tide time period.

[0007] Further, the calculation formula of the transverse transport flux of the non-large plant detritus carbon comprises:

[0008] F NLD = F DIC +F DOC +F POC +F CH4 Formula (1)

[0009] wherein F NLD is the transverse transport flux of the non-large plant detritus carbon, the unit being mol·m -2 ·d -1 ; F DIC is the transverse transport flux of dissolved inorganic carbon, the unit being mol·m -2 ·d -1 ; F DOC is the transverse transport flux of dissolved organic carbon, the unit being mol·m -2 ·d -1 ; F POC is the transverse transport flux of non-large plant detritus particle organic carbon, the unit being mol·m -2 ·d -1 ; and F CH4 is the transverse transport flux of water body methane, the unit being mol·m -2 ·d -1 .

[0010] Further, in formula (1), the calculation formula of the lateral transport flux F DIC of dissolved inorganic carbon includes:

[0011] F DIC =∑(A i+1 ×H i+1 –A i ×H i ) Formula (2)

[0012] wherein, A i+1 and A i are the dissolved inorganic carbon concentrations at the i+1 moment and the i moment within a unit monitoring duration, respectively, in units of mol·L -1 ; H i+1 and H i are the water depths of the monitoring target area at the i+1 moment and the i moment within a unit monitoring duration, respectively, in units of m.

[0013] Further, in formula (1), the calculation formula of the lateral transport flux F DOC of dissolved organic carbon includes:

[0014] F DOC =∑(B i+1 ×H i+1 –B i ×H i ) Formula (3)

[0015] wherein, B i+1 and B i are the dissolved organic carbon concentrations at the i+1 moment and the i moment within a unit monitoring duration, respectively, in units of mol·L -1 ; H i+1 and H i are the water depths of the monitoring target area at the i+1 moment and the i moment within a unit monitoring duration, respectively, in units of m.

[0016] Further, in formula (1), the calculation formula of the lateral transport flux F POC of the particulate organic carbon of non-large plant detritus includes:

[0017] F POC =∑(C i+1 ×H i+1 –C i ×H i ) Formula (4)

[0018] wherein, C i+1 and C i are the particulate organic carbon concentrations of non-large plant detritus at the i+1 moment and the i moment within a unit monitoring duration, respectively, in units of mol·L-1 ; H i+1 and H i are the water depth of the monitoring target area at the i+1th moment and the ith moment within the unit monitoring duration, respectively, in units of m.

[0019] Further, in formula (1), the lateral transport flux F CH4 of the water body methane includes the following formula:

[0020] F CH4 =∑(D i+1 ×H i+1 –D i ×H i ) Formula (5)

[0021] wherein D i+1 and D i are the water body methane concentration at the i+1th moment and the ith moment within the unit monitoring duration, respectively, in units of mol·L -1 ; H i+1 and H i are the water depth of the monitoring target area at the i+1th moment and the ith moment within the unit monitoring duration, respectively, in units of m.

[0022] Further, the calculation formula of the lateral transport flux of the large plant detritus carbon includes:

[0023] F LD =∑(M j × / (H j ×L j ))–∑(M k × / (H k ×L k )) Formula (7)

[0024] wherein F LD is the lateral transport flux of the large plant detritus carbon, in units of mol·m -2 ·d -1 ; M j is the amount of large plant detritus carbon within the ebb duration of the jth tidal cycle within the unit monitoring duration, in units of mol; H j is the average water depth of the monitoring target area within the ebb duration of the jth tidal cycle within the unit monitoring duration, in units of m; L j is the average width of the monitoring target area within the ebb duration of the jth tidal cycle within the unit monitoring duration, in units of m; M k is the amount of large plant detritus carbon within the flood duration of the kth tidal cycle within the unit monitoring duration, in units of mol; H k is the average water depth of the monitoring target area within the flood duration of the kth tidal cycle within the unit monitoring duration, in units of m; Lk the average width of the monitoring target area in the flood period of the kth tidal period in the unit monitoring time length, in m.

[0025] Further, the calculation formula of the total carbon lateral transport flux comprises:

[0026] F T = F NLD +F LD Formula (8)

[0027] wherein F T is the total carbon lateral transport flux, in mol·m -2 ·d -1 .

[0028] Beneficial effects:

[0029] In the analysis method provided by the present application, a monitoring target area is established at the connection between a mangrove tidal creek and adjacent water bodies, and corresponding hydrological parameters and chemical parameters are obtained by regularly monitoring the monitoring target area, so as to obtain the lateral transport flux of non-large plant detritus carbon in the corresponding unit monitoring time length. Meanwhile, it is also considered that the large plants in the mangrove ecosystem also have a great contribution to the total carbon lateral transport flux, and the corresponding amount of large plant detritus carbon is obtained by collecting and determining the carbon content of large plant detritus samples in each tidal period, and the lateral transport flux of large plant detritus carbon in the corresponding unit monitoring time length is obtained based on this. Different forms of carbon lateral transport are quantitatively distinguished, so as to finally obtain the total carbon lateral transport flux of the mangrove ecosystem. The analysis method includes weighting of multiple factors such as lateral transport of large plant detritus carbon, astronomical spring-neap tide conversion, etc., and the obtained carbon lateral transport flux of the mangrove ecosystem has high accuracy and certainty, and can well realize long-term sequential and full-form continuous observation of the carbon lateral transport of the mangrove ecosystem, and has good application prospect. DETAILED DESCRIPTION

[0030] Embodiments of the present application are described in detail below, and examples of the embodiments are intended to explain the present application, and cannot be understood as a limitation of the present application. If specific techniques or conditions are not mentioned in the embodiments, the techniques or conditions described in the literature in the art or according to the product manual are used. If the reagents or instruments used are not mentioned by the manufacturer, they are all conventional products that can be obtained by purchase.

[0031] The analysis method for the total carbon transverse transport flux of the mangrove ecological system is provided by the present application.

[0032] In the present application, the analysis method takes the connection between the mangrove tidal creek and the adjacent water body as the monitoring target area.

[0033] In the present application, the analysis method specifically comprises the following steps: obtaining the hydrological parameters and chemical parameters of the water body in the monitoring target area within a unit monitoring time length and in each tidal period; determining the transverse transport flux of the non-large plant detritus carbon of the mangrove ecological system within a unit monitoring time length according to the hydrological parameters and chemical parameters; obtaining the amount of large plant detritus carbon passing through the monitoring target area and the width of the monitoring target area within a plurality of tidal periods within a unit monitoring time length in the monitoring target area; determining the transverse transport flux of the large plant detritus carbon passing through the monitoring target area in each tidal period according to the amount of large plant detritus carbon and the width of the monitoring target area and the hydrological parameters; determining the transverse transport flux of the large plant detritus carbon of the mangrove ecological system within a unit monitoring time length according to the transverse transport flux of the large plant detritus carbon in each tidal period; and determining the total carbon transverse transport flux of the mangrove ecological system according to the transverse transport flux of the non-large plant detritus carbon and the transverse transport flux of the large plant detritus carbon.

[0034] In the present application, the unit monitoring time length refers to a monitoring time section covering a complete tidal period, which is usually 1 day (24 h), and the time interval between adjacent two unit monitoring time lengths can be selected according to the scale of the carbon transverse transport flux of the mangrove ecological system in time that is expected to be analyzed, and the present application does not particularly limit it. The tidal period specifically comprises a rising tide time length and a falling tide time length.

[0035] In the present application, the hydrological parameters refer to indexes reflecting the hydrological performance of the mangrove, the estuary and the main exchange channel thereof, which specifically comprise the water depth. More specifically, the detection method for obtaining the hydrological parameters is a technical means commonly used in the art, and the person skilled in the art can make adaptive selection according to the actual needs, and the present application does not particularly limit it.

[0036] In the present application, the chemical parameter refers to a quantitative description of the material properties and behaviors of the water sample at the connection between the mangrove tidal creek and the adjacent water body, which specifically includes: dissolved inorganic carbon concentration, dissolved organic carbon concentration, non-large plant detritus particulate organic carbon concentration, and water body methane concentration.

[0037] In the present application, the detection method for obtaining the chemical parameter is a technical means commonly used in the art, and those skilled in the art can make adaptive selection according to actual needs, and the present application does not particularly limit it. In some specific embodiments, the chemical parameter is obtained by testing with a DIC analyzer (Apollo AS-C3, USA), a total organic carbon analyzer (TOC-V CPH, Shimadzu, Japan) instrument.

[0038] In the present application, the method for determining the lateral transport flux of non-large plant detritus carbon in the mangrove ecosystem within a unit monitoring time length comprises: summing the lateral transport flux of dissolved inorganic carbon, the lateral transport flux of dissolved organic carbon, the lateral transport flux of non-large plant detritus particulate organic carbon, and the lateral transport flux of water body methane within a unit monitoring time length to obtain the lateral transport flux of non-large plant detritus carbon. That is, the calculation formula of the lateral transport flux of non-large plant detritus carbon specifically comprises:

[0039] F NLD = F DIC + F DOC + F POC + F CH4 Formula (1)

[0040] Wherein, F NLD is the lateral transport flux of non-large plant detritus carbon, with a unit of mol·m -2 ·d -1 ; F DIC is the lateral transport flux of dissolved inorganic carbon, with a unit of mol·m -2 ·d -1 ; F DOC is the lateral transport flux of dissolved organic carbon, with a unit of mol·m -2 ·d -1 ; F POC is the lateral transport flux of non-large plant detritus particulate organic carbon, with a unit of mol·m -2 ·d -1 ; F CH4 is the lateral transport flux of water body methane, with a unit of mol·m -2 ·d -1 .

[0041] More specifically, in formula (1), the calculation formula of the lateral transport flux F DIC of dissolved inorganic carbon comprises:

[0042] F DIC =∑(A i+1 ×H i+1 –A i ×H i ) Formula (2)

[0043] wherein, A i+1 and A i are the dissolved inorganic carbon concentration at the i+1 moment and the i moment within the unit monitoring duration, respectively, in mol·L -1 ; H i+1 and H i are the water depth of the monitoring target area at the i+1 moment and the i moment within the unit monitoring duration, respectively, in m.

[0044] More specifically, in Formula (1), the calculation formula of the lateral transport flux F DOC of the dissolved organic carbon includes:

[0045] F DOC =∑(B i+1 ×H i+1 –B i ×H i ) Formula (3)

[0046] wherein, B i+1 and B i are the dissolved organic carbon concentration at the i+1 moment and the i moment within the unit monitoring duration, respectively, in mol·L -1 ; H i+1 and H i are the water depth of the monitoring target area at the i+1 moment and the i moment within the unit monitoring duration, respectively, in m.

[0047] More specifically, in Formula (1), the calculation formula of the lateral transport flux F POC of the non-large plant detritus particulate organic carbon includes:

[0048] F POC =∑(C i+1 ×H i+1 –C i ×H i ) Formula (4)

[0049] wherein, C i+1 and C i are the non-large plant detritus particulate organic carbon concentration at the i+1 moment and the i moment within the unit monitoring duration, respectively, in mol·L -1 ; H i+1 and H iThese are the water depths of the target area at time i+1 and time i within the unit monitoring time, respectively, in meters.

[0050] More specifically, in equation (1), the lateral transport flux F of methane in the water body CH4 The calculation formulas include:

[0051] F CH4 =Σ(D i+1 ×H i+1 –D i ×H i Equation (5)

[0052] Among them, D i+1 and D i These represent the methane concentrations in the water at time i+1 and time i within a unit monitoring period, respectively, in mol·L⁻¹. -1 H i+1 and H i These are the water depths of the target area at time i+1 and time i within the unit monitoring time, respectively, in meters.

[0053] In this invention, the method for determining the lateral transport flux of macrophyte carbon in a mangrove ecosystem within a unit monitoring period includes: calculating the difference between the integral of the amount of macrophyte carbon during the ebb tide duration of the tidal cycle within a unit monitoring period and the integral of the amount of macrophyte carbon during the flood tide duration of the tidal cycle within a unit monitoring period, thereby obtaining the lateral transport flux of macrophyte carbon. That is, the formula for calculating the lateral transport flux of macrophyte carbon includes:

[0054] F LD =Σ(M j × / (H j ×L j ))–Σ(M k × / (H k ×L k Formula (7)

[0055] Among them, F LD The lateral transport flux of carbon in large plant debris is expressed in mol·m³. -2 ·d -1 M j The amount of carbon in large plant debris during the ebb tide duration of the j-th tidal cycle within a unit monitoring time period is expressed in mol; H j L represents the average water depth of the target area monitored within the ebb tide duration of the j-th tidal cycle within a unit monitoring time period, expressed in meters. j M is the average width of the monitored target area within the ebb tide duration of the j-th tidal cycle within a unit monitoring time, expressed in meters; kHkis the amount of large plant detritus carbon in the rising tide duration of the kth tidal cycle in the unit monitoring duration, in mol; H k Lkis the average water depth of the monitoring target area in the rising tide duration of the kth tidal cycle in the unit monitoring duration, in m; L k Wkis the average width of the monitoring target area in the rising tide duration of the kth tidal cycle in the unit monitoring duration, in m.

[0056] In the present application, the method for determining the total carbon lateral transport flux of the mangrove ecosystem comprises: adding the lateral transport flux of the non-large plant detritus carbon and the lateral transport flux of the large plant detritus carbon in the unit monitoring duration to obtain the total carbon lateral transport flux. That is, the calculation formula of the total carbon lateral transport flux comprises:

[0057] F T = F NLD + F LD Equation (8)

[0058] Wherein, F T is the total carbon lateral transport flux, in mol·m -2 ·d -1 .

[0059] Although the embodiments of the present application have been shown and described above, it should be understood that the above-mentioned embodiments are exemplary and should not be construed as limiting the present application, and those skilled in the art can make changes, modifications, replacements and variations to the above-mentioned embodiments without departing from the principles and purposes of the present application within the scope of the present application.

Claims

1. A method of analyzing total carbon lateral transport flux of a mangrove ecosystem, characterized by, The analysis method comprises: obtaining hydrological parameters and chemical parameters of a water body in a monitoring target area in each tidal cycle within a unit monitoring time length; determining a lateral transport flux of non-large plant detritus carbon of a mangrove ecosystem in the unit monitoring time length according to the hydrological parameters and the chemical parameters; obtaining an amount of large plant detritus carbon passing through the monitoring target area and a width of the monitoring target area in a plurality of tidal cycles within the unit monitoring time length; determining a lateral transport flux of the large plant detritus carbon passing through the monitoring target area in each tidal cycle within the unit monitoring time length according to the amount of the large plant detritus carbon and the width of the monitoring target area and the hydrological parameters; and determining a lateral transport flux of the large plant detritus carbon of the mangrove ecosystem in the unit monitoring time length according to the lateral transport flux of the large plant detritus carbon in each tidal cycle; determining the total carbon lateral transport flux of the mangrove ecosystem according to the lateral transport fluxes of the non-large plant detritus carbon and the large plant detritus carbon; wherein the hydrological parameters comprise water depth, and the chemical parameters comprise dissolved inorganic carbon concentration, dissolved organic carbon concentration, non-large plant detritus particulate organic carbon concentration, and water body methane concentration, and the tidal cycle comprises a rising tide time length and a falling tide time length.

2. The method of claim 1, wherein the total carbon lateral transport flux of the mangrove ecosystem is analyzed by the steps of: The calculation formula of the lateral transport flux of the non-large plant detritus carbon comprises: F NLD =F DIC +F DOC +F POC +F CH4 Formula (1) where F NLD is the lateral transport flux of non-macrophyte detritus carbon, in mol m -2 d -1 ; F DIC is the lateral transport flux of dissolved inorganic carbon, in mol m -2 d -1 ; F DOC is the lateral transport flux of dissolved organic carbon, in mol m -2 d -1 ; F POC is the lateral transport flux of particulate organic carbon of non-macrophyte detritus, in mol m -2 d -1 ; F CH4 is the lateral transport flux of water body methane, in mol m -2 d -1 .

3. The method of claim 2, wherein the total carbon lateral transport flux of the mangrove ecosystem is analyzed by the steps of: In formula (1), the lateral transport flux F of dissolved inorganic carbon DIC The calculation formula includes: F DIC = (A i+1 ×H i+1 –A i ×H i ) formula (2) Wherein, A i+1 and A i are the dissolved inorganic carbon concentrations at the i+1th moment and the ith moment in the unit monitoring duration, respectively, in units of mol L -1 ;H i+1 and H i are the water depths of the monitoring target region at the i+1th moment and the ith moment in the unit monitoring duration, respectively, in units of m.

4. The method of claim 2, wherein the total carbon lateral transport flux of the mangrove ecosystem is analyzed by the steps of: In formula (1), the lateral transport flux F of dissolved organic carbon DOC The calculation formula includes: F DOC = (B i+1 ×H i+1 –B i ×H i ) formula (3) B i+1 and B i are the dissolved organic carbon concentrations at the i+1th and ith moments within the unit monitoring duration, respectively, in units of mol L -1 ; H i+1 and H i are the water depths of the monitoring target region at the i+1th and ith moments within the unit monitoring duration, respectively, in units of m.

5. The method of claim 2, wherein the total carbon lateral transport flux of the mangrove ecosystem is analyzed by the steps of: In formula (1), the lateral transport flux F of particulate organic carbon of the non-large plant detritus POC The calculation formula includes: F POC = (C i+1 ×H i+1 –C i ×H i ) formula (4) wherein C i+1 and C i are the concentrations of particulate organic carbon of non-macrophyte detritus at the i+1th and ith time points within the unit monitoring duration, respectively, in mol L -1 ; H i+1 and H i are the water depths of the monitoring target region at the i+1th and ith time points within the unit monitoring duration, respectively, in m.

6. The method of claim 2, wherein the total carbon lateral transport flux of the mangrove ecosystem is analyzed by the steps of: In formula (1), the lateral transport flux F of the water body methane CH4 The calculation formula includes: F CH4 = (D i+1 ×H i+1 –D i ×H i ) formula (5) wherein D i+1 and D i are the methane concentrations of the water body at the i+1th moment and the ith moment within a unit monitoring duration, respectively, in mol L -1 ; H i+1 and H i are the water depths of the monitoring target region at the i+1th moment and the ith moment within a unit monitoring duration, respectively, in m.

7. The method of claim 1, wherein the total carbon lateral transport flux of the mangrove ecosystem is analyzed by the steps of: The calculation formula of the lateral transport flux of the large plant detritus carbon comprises: F LD = (M j × / (H j ×L j ))– (M k × / (H k ×L k )) wherein F LD is the lateral transport flux of macrophyte detritus carbon, in mol m -2 d -1 ; M j is the amount of macrophyte detritus carbon in the ebb duration of the jth tidal cycle within the unit monitoring duration, in mol; H j is the average water depth of the monitoring target area in the ebb duration of the jth tidal cycle within the unit monitoring duration, in m; L j is the average width of the monitoring target area in the ebb duration of the jth tidal cycle within the unit monitoring duration, in m; M k is the amount of macrophyte detritus carbon in the flood duration of the kth tidal cycle within the unit monitoring duration, in mol; H k is the average water depth of the monitoring target area in the flood duration of the kth tidal cycle within the unit monitoring duration, in m; L k is the average width of the monitoring target area in the flood duration of the kth tidal cycle within the unit monitoring duration, in m.

8. The method of claim 1, wherein the total carbon lateral transport flux of the mangrove ecosystem is analyzed by the steps of: The calculation formula of the total carbon lateral transport flux comprises: F T =F NLD +F LD Formula (8) where F T is the lateral transport flux of total carbon in mol m -2 d -1 ; F NLD is the lateral transport flux of non-macrophyte detritus carbon in mol m -2 d -1 ; F LD is the lateral transport flux of macrophyte detritus carbon in mol m -2 d -1 .

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