Analysis method for total carbon transverse transport flux of mangrove forest ecosystem

Abstract

The invention belongs to the technical field of environmental monitoring, and discloses a method for analyzing the total carbon transverse transport flux of a mangrove forest ecosystem. According to the analysis method provided by the invention, the monitoring target area is established at the joint of the mangrove forest tidal creek and the adjacent water body, and the corresponding hydrological parameters and chemical parameters are acquired regularly, so that the monitoring of the transverse transportation flux of the non-large plant debris carbon is realized; meanwhile, large plant debris samples are collected, and the amount of carbon in the large plant debris is measured, so that the monitoring of the transverse transportation flux of the carbon in the large plant debris is realized, and the transverse transportation flux of the carbon in different forms is quantified and weighted operation is carried out; the obtained total carbon transverse transport flux of the mangrove forest ecosystem has high accuracy and certainty, long-time-sequence all-form continuous observation of the carbon transverse transport condition of the mangrove forest ecosystem can be well achieved, and the method has good application prospects.

Description

Technical Field

[0001] The invention belongs to the technical field of environmental monitoring, and in particular relates to an analysis method for the total carbon lateral transport flux of a mangrove ecosystem. Background Art

[0002] Mangroves are one of the typical coastal blue carbon ecosystems. They are special forests distributed in the transition from tropical and subtropical land to the ocean. They are important "blue carbon sinks" in the coastal zone. Although their area accounts for only 0.5% of the global coastal zone, their carbon reserves are about 2.4 million tons per year, accounting for 10-15% of the carbon reserves in nearshore sediments. At the same time, mangroves have ecological service functions such as providing habitats, purifying seawater, preventing wind and waves, and protecting biodiversity. They are the blue carbon system with the highest total value of blue carbon and other ecological services, and are an important ecological barrier for the sustainable development of coastal social economy.

[0003] The carbon cycle process of mangrove ecosystem is relatively complex, including the vertical exchange of carbon dioxide (CO2) and methane (CH4) between the vegetation-atmosphere interface, the lateral transport of carbon between the land-sea interface, mangrove and estuarine ecosystems, terrestrial organic carbon deposition and aquatic deposition as well as organic carbon burial, and coastal biogeochemical cycle processes. Studies have shown that the organic carbon fixed and buried in the mangrove ecosystem cannot be permanently sealed in the mangrove system. Among them, a part of the carbon (dissolved organic carbon (DOC), dissolved inorganic carbon (DIC), particulate organic carbon (POC) and CO2 and CH4 gases dissolved in water can leave the mangrove system through the lateral transport of carbon between mangroves and estuarine ecosystems. Complete quantification of the carbon flux of lateral transport in the mangrove system is a necessary part of establishing a complete carbon budget inventory for the mangrove system. However, since the lateral transport process of the mangrove system is strongly affected by tides and the carbon transported laterally has multiple forms, it is necessary to carry out long-term continuous observation of all forms of carbon to accurately quantify the total carbon flux of lateral transport.

[0004] At present, there is still a lack of such long-term continuous observation technology for the full morphology of carbon. Summary of the invention

[0005] The purpose of the present invention is to provide an analysis method for the total carbon lateral transport flux of a mangrove ecosystem. The analysis method fully considers the influencing factors such as the lateral transport of carbon of macrophyte debris and non-macrophyte debris, the transition of astronomical high and low tides, and integrates the lateral transport flux of carbon in different forms in the mangrove ecosystem to achieve accurate quantification of the total carbon lateral transport flux of the mangrove ecosystem.

[0006] Specifically, the analysis method of the carbon lateral transport flux of a mangrove ecosystem provided by the present invention takes the connection between a mangrove tidal ditch and an adjacent water body as the monitoring target area, and specifically includes: obtaining the hydrological parameters and chemical parameters of the water body in the monitoring target area in each tidal cycle within a unit monitoring time; determining the lateral transport flux of non-macro-plant debris carbon in the mangrove ecosystem within the unit monitoring time based on the hydrological parameters and chemical parameters; obtaining the amount of macro-plant debris carbon passing through the monitoring target area and the width of the monitoring target area within multiple tidal cycles within the unit monitoring time in the monitoring target area; determining the amount of macro-plant debris carbon passing through the monitoring target area and the width of the monitoring target area and the hydrological parameters within the unit monitoring time. The lateral transport flux of macrophyte debris carbon in the target area is monitored during each tidal cycle within the unit monitoring time; the lateral transport flux of macrophyte debris carbon in the mangrove ecosystem within the unit monitoring time is determined according to the lateral transport flux of macrophyte debris carbon in each tidal cycle; the total carbon lateral transport flux of the mangrove ecosystem is determined according to the lateral transport flux of non-macrophyte debris carbon and the lateral transport flux of macrophyte debris carbon; wherein the hydrological parameters include water body depth, the chemical parameters include dissolved inorganic carbon concentration, dissolved organic carbon concentration, particulate organic carbon concentration of non-macrophyte debris and water body methane concentration, and the tidal cycle includes a high tide duration and a low tide duration.

[0007] Furthermore, the calculation formula for the lateral transport flux of non-macrophyte debris carbon includes:

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

[0009] Among them, F NLD is the lateral transport flux of non-macrophyte debris 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 in non-macrophyte debris, in mol·m -2 ·d -1 ; F CH4 is the lateral transport flux of methane in water, in mol·m -2 ·d -1 .

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

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

[0012] Among them, A i+1 and A i are the dissolved inorganic carbon concentrations at the i+1th and ith moments within the unit monitoring time, in mol·L -1 ;H i+1 and H i They are the water depths of the monitoring target area at the i+1th moment and the ith moment within the unit monitoring time, in meters.

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

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

[0015] Among them, B i+1 and B i are the dissolved organic carbon concentrations at the i+1th and ith moments within the unit monitoring time, in mol·L -1 ;H i+1 and H i They are the water depths of the monitoring target area at the i+1th moment and the ith moment within the unit monitoring time, in meters.

[0016] Furthermore, in formula (1), the lateral transport flux of particulate organic carbon of non-macrophyte debris is F POC The calculation formula includes:

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

[0018] Among them, C i+1 and C i are the particulate organic carbon concentrations of non-macrophyte debris at the i+1th and ith moments within the unit monitoring time, in mol·L-1 ;H i+1 and H i They are the water depths of the monitoring target area at the i+1th moment and the ith moment within the unit monitoring time, in meters.

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

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

[0021] Among them, D i+1 and D i are the water body methane concentrations at the i+1th and ith moments within the unit monitoring time, in mol·L -1 ;H i+1 and H i They are the water depths of the monitoring target area at the i+1th moment and the ith moment within the unit monitoring time, in meters.

[0022] Furthermore, the calculation formula for the lateral transport flux of macrophyte debris carbon includes:

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

[0024] Among them, F LD is the lateral transport flux of macrophyte debris carbon, in mol·m -2 ·d -1 ;M j is the amount of carbon in macrophyte debris during 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 during the ebb duration of the jth tidal cycle within the unit monitoring duration, in meters; L j is the average width of the monitoring target area during the ebb duration of the jth tidal cycle within the unit monitoring duration, in meters; M k is the amount of macrophyte detrital carbon in the high tide 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 during the high tide duration of the kth tidal cycle within the unit monitoring duration, in meters; Lk It is the average width of the monitoring target area during the high tide duration of the kth tidal cycle within the unit monitoring duration, in meters.

[0025] Furthermore, the calculation formula of the total carbon lateral transport flux includes:

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

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

[0028] Beneficial effects:

[0029] In the analysis method provided by the present invention, a monitoring target area is established at the connection between the mangrove tidal channel and the adjacent water body, and the corresponding hydrological parameters and chemical parameters are obtained by regularly monitoring the monitoring target area to obtain the lateral transport flux of non-macrophyte debris carbon within the corresponding unit monitoring time; at the same time, considering that macrophytes in the mangrove ecosystem may also have a large contribution to the total carbon lateral transport flux, the corresponding amount of macrophyte debris carbon is obtained by collecting macrophyte debris samples in each tidal cycle and measuring the carbon content, and based on this, the lateral transport flux of macrophyte debris carbon within the corresponding unit monitoring time is obtained; the lateral transport of carbon in different forms is quantitatively distinguished 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 macrophyte debris carbon, astronomical high and low tide conversion, and the obtained carbon lateral transport flux of the mangrove ecosystem has high accuracy and certainty, and can well realize the long-term full-form continuous observation of the carbon lateral transport of the mangrove ecosystem, and has good application prospects. DETAILED DESCRIPTION

[0030] Embodiments of the present invention are described in detail below, and the examples of the embodiments are intended to be used to explain the present invention, but should not be construed as limiting the present invention. In the embodiments, if specific techniques or conditions are not specified, the techniques or conditions described in the literature in this area or the product specifications are used. If the manufacturer is not specified for reagents or instruments used, they are all conventional products that can be obtained commercially.

[0031] In view of the problems that the existing total carbon lateral transport flux observation technology of mangrove ecosystems does not take into account the lateral transport of large plant debris carbon, and the observation of other forms of carbon often ignores the impact of astronomical high and low tide transitions on the lateral transport of carbon, resulting in inaccurate estimation results of the carbon lateral transport flux and high uncertainty; the inventors of the present invention have creatively obtained the analysis method of the total carbon lateral transport flux of mangrove ecosystems provided by the present invention after extensive and in-depth research.

[0032] In the present invention, the analysis method uses the connection between the mangrove tidal gully and the adjacent water body as the monitoring target area, wherein the adjacent water body is a river and / or sea water.

[0033] In the present invention, the analysis method specifically includes the following steps: obtaining hydrological parameters and chemical parameters in each tidal cycle within a unit monitoring time of the water body in the monitoring target area; determining the lateral transport flux of non-macrophyte debris carbon in the mangrove ecosystem within the unit monitoring time according to the hydrological parameters and chemical parameters; obtaining the amount of macrophyte debris carbon passing through the monitoring target area and the width of the monitoring target area within a unit monitoring time in the monitoring target area in multiple tidal cycles; determining the lateral transport flux of macrophyte debris carbon passing through the monitoring target area in each tidal cycle within the unit monitoring time according to the amount of macrophyte debris carbon, the width of the monitoring target area and the hydrological parameters; determining the lateral transport flux of macrophyte debris carbon in the mangrove ecosystem within the unit monitoring time according to the lateral transport flux of macrophyte debris carbon in each tidal cycle; determining the total carbon lateral transport flux of the mangrove ecosystem according to the lateral transport flux of non-macrophyte debris carbon and the lateral transport flux of macrophyte debris carbon.

[0034] In the present invention, the unit monitoring duration refers to the monitoring time segment covering the complete tidal cycle, which is usually 1 day (24 hours). The time interval between two adjacent unit monitoring durations can be selected according to the temporal scale of the carbon lateral transport flux of the mangrove ecosystem to be analyzed, and the present invention does not impose any special limitation thereto. The tidal cycle specifically includes a high tide duration and a low tide duration.

[0035] In the present invention, the hydrological parameters refer to indicators reflecting the hydrological performance of mangroves, estuaries and the main exchange channels between the two, which specifically include water depth. More specifically, the detection method for obtaining the hydrological parameters is a technical means conventionally used in the field, and those skilled in the art can make adaptive choices according to actual needs, and the present invention does not impose any particular limitation on it.

[0036] In the present invention, the chemical parameters refer to the quantitative description of the material properties and behaviors of water samples at the connection between mangrove tidal channels and adjacent water bodies, which specifically include: dissolved inorganic carbon concentration, dissolved organic carbon concentration, particulate organic carbon concentration of non-macroplant debris and water body methane concentration.

[0037] In the present invention, the detection method for obtaining the chemical parameters is a technical means conventionally used in the art, and those skilled in the art can make adaptive choices according to actual needs, and the present invention does not impose any particular limitation thereto. In some specific embodiments, the chemical parameters are obtained by testing with a DIC analyzer (ApolloAS-C3, USA) or a total organic carbon analyzer (TOC-V CPH, Shimadzu, Japan).

[0038] In the present invention, the method for determining the lateral transport flux of non-macro-plant debris carbon in the mangrove ecosystem within a unit monitoring time includes: adding and calculating the lateral transport flux of dissolved inorganic carbon, the lateral transport flux of dissolved organic carbon, the lateral transport flux of particulate organic carbon of non-macro-plant debris, and the lateral transport flux of water methane within a unit monitoring time to obtain the lateral transport flux of the non-macro-plant debris carbon. That is, the calculation formula of the lateral transport flux of the non-macro-plant debris carbon specifically includes:

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

[0040] Among them, F NLD is the lateral transport flux of non-macrophyte debris 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 in non-macrophyte debris, in mol·m -2 ·d -1 ; F CH4 is the lateral transport flux of methane in water, in mol·m -2 ·d -1 .

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

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

[0043] Among them, A i+1 and A i are the dissolved inorganic carbon concentrations at the i+1th and ith moments within the unit monitoring time, in mol·L -1 ;H i+1 and H i They are the water depths of the monitoring target area at the i+1th moment and the ith moment within the unit monitoring time, in meters.

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

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

[0046] Among them, B i+1 and B i are the dissolved organic carbon concentrations at the i+1th and ith moments within the unit monitoring time, in mol·L -1 ;H i+1 and H i They are the water depths of the monitoring target area at the i+1th moment and the ith moment within the unit monitoring time, in meters.

[0047] More specifically, in formula (1), the lateral transport flux F of the non-macrophyte particulate organic carbon is POC The calculation formula includes:

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

[0049] Among them, C i+1 and C i are the particulate organic carbon concentrations of non-macrophyte debris at the i+1th and ith moments within the unit monitoring time, in mol·L -1 ;H i+1 and H iThey are the water depths of the monitoring target area at the i+1th moment and the ith moment within the unit monitoring time, in meters.

[0050] More specifically, in formula (1), the lateral transport flux of methane in the water body F is CH4 The calculation formula includes:

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

[0052] Among them, D i+1 and D i are the water body methane concentrations at the i+1th and ith moments within the unit monitoring time, in mol·L -1 ;H i+1 and H i They are the water depths of the monitoring target area at the i+1th moment and the ith moment within the unit monitoring time, in meters.

[0053] In the present invention, the method for determining the lateral transport flux of macrophyte debris carbon in the mangrove ecosystem within a unit monitoring time includes: performing a difference calculation between "the integral of the amount of macrophyte debris carbon during the ebb tide time of the tidal cycle within the unit monitoring time" and "the integral of the amount of macrophyte debris carbon during the flood tide time of the tidal cycle within the unit monitoring time" to obtain the lateral transport flux of the macrophyte debris carbon. That is, the calculation formula of the lateral transport flux of the macrophyte debris 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 is the lateral transport flux of macrophyte debris carbon, in mol·m -2 ·d -1 ;M j is the amount of carbon in macrophyte debris during 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 during the ebb duration of the jth tidal cycle within the unit monitoring duration, in meters; L j is the average width of the monitoring target area during the ebb duration of the jth tidal cycle within the unit monitoring duration, in meters; M kis the amount of macrophyte detrital carbon in the high tide 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 during the high tide duration of the kth tidal cycle within the unit monitoring duration, in meters; L k It is the average width of the monitoring target area during the high tide duration of the kth tidal cycle within the unit monitoring duration, in meters.

[0056] In the present invention, the method for determining the total carbon transverse transport flux of the mangrove ecosystem includes: adding the transverse transport flux of non-macro-plant debris carbon and the transverse transport flux of macro-plant debris carbon per unit monitoring time to obtain the total carbon transverse transport flux. That is, the calculation formula of the total carbon transverse transport flux includes:

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

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

[0059] Although the embodiments of the present invention have been shown and described above, it is to be understood that the above embodiments are exemplary and are not to be construed as limitations on the present invention. A person skilled in the art may change, modify, replace and modify the above embodiments within the scope of the present invention without departing from the principles and intent of the present invention.

Claims

1. A method for analyzing the total carbon lateral transport flux of a mangrove ecosystem, characterized in that: The connection between the mangrove tidal gully and the adjacent water body is taken as the monitoring target area, and the analysis method includes: Obtaining hydrological parameters and chemical parameters in each tidal cycle within a unit monitoring time of the water body in the monitoring target area; determining the lateral transport flux of non-macrophyte debris carbon in the mangrove ecosystem within the unit monitoring time based on the hydrological parameters and chemical parameters; Obtain the amount of large plant debris carbon passing through the monitoring target area and the width of the monitoring target area during multiple tidal cycles within a unit monitoring time in the monitoring target area; determine the lateral transport flux of large plant debris carbon passing through the monitoring target area in each tidal cycle within the unit monitoring time based on the amount of large plant debris carbon, the width of the monitoring target area and the hydrological parameters; determine the lateral transport flux of large plant debris carbon in the mangrove ecosystem within the unit monitoring time based on the lateral transport flux of large plant debris carbon in each tidal cycle; Determining the total carbon lateral transport flux of the mangrove ecosystem according to the lateral transport flux of each of the non-macrophyte debris carbon and the lateral transport flux of the macrophyte debris carbon; Among them, the hydrological parameters include water body depth, the chemical parameters include dissolved inorganic carbon concentration, dissolved organic carbon concentration, particulate organic carbon concentration of non-macroplant debris and water body methane concentration, and the tidal cycle includes a high tide duration and a low tide duration.

2. The method for analyzing the total carbon lateral transport flux of a mangrove ecosystem according to claim 1, characterized in that: The calculation formula for the lateral transport flux of non-macrophyte debris carbon includes: F NLD =F DIC +F DOC +F POC +F CH4 Formula (1) Among them, F NLD is the lateral transport flux of non-macrophyte debris 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 in non-macrophyte debris, in mol·m -2 ·d -1 ; F CH4 is the lateral transport flux of methane in water, in mol·m -2 ·d -1 .

3. The method for analyzing the total carbon lateral transport flux of a mangrove ecosystem according to claim 2, characterized in that: In formula (1), the lateral transport flux of dissolved inorganic carbon is DIC The calculation formula includes: F DIC =Σ(A i+1 ×H i+1 –A i ×H i ) expression(2) Among them, A i+1 and A i are the dissolved inorganic carbon concentrations at the i+1th and ith moments within the unit monitoring time, in mol·L -1 ;H i+1 and H i They are the water depths of the monitoring target area at the i+1th moment and the ith moment within the unit monitoring time, in meters.

4. The method for analyzing the total carbon lateral transport flux of a mangrove ecosystem according to claim 2, characterized in that: In formula (1), the lateral transport flux of dissolved organic carbon F DOC The calculation formula includes: F DOC =Σ(B i+1 ×H i+1 –B i ×H i ) Formula (3) Among them, B i+1 and B i are the dissolved organic carbon concentrations at the i+1th and ith moments within the unit monitoring time, in mol·L -1 ;H i+1 and H i They are the water depths of the monitoring target area at the i+1th moment and the ith moment within the unit monitoring time, in meters.

5. The method for analyzing the total carbon lateral transport flux of mangrove ecosystem according to claim 2, characterized in that: In formula (1), the lateral transport flux of particulate organic carbon of non-macrophyte debris is F POC The calculation formula includes: F POC =Σ(C i+1 ×H i+1 –C i ×H i ) Formula (4) Among them, C i+1 and C i are the particulate organic carbon concentrations of non-macrophyte debris at the i+1th and ith moments within the unit monitoring time, in mol·L -1 ;H i+1 and H i They are the water depths of the monitoring target area at the i+1th moment and the ith moment within the unit monitoring time, in meters.

6. The method for analyzing the total carbon lateral transport flux of a mangrove ecosystem according to claim 2, characterized in that: In formula (1), the lateral transport flux of methane in the water body F is CH4 The calculation formula includes: F CH4 =Σ(D i+1 ×H i+1 –D i ×H i ) expression(5) Among them, D i+1 and D i are the water body methane concentrations at the i+1th and ith moments within the unit monitoring time, in mol·L -1 ;H i+1 and H i They are the water depths of the monitoring target area at the i+1th moment and the ith moment within the unit monitoring time, in meters.

7. The method for analyzing the total carbon lateral transport flux of a mangrove ecosystem according to claim 1, characterized in that: The calculation formula for the lateral transport flux of macrophyte debris carbon includes: F LD =Σ(M j × / (H j ×L j ))–Σ(M k × / (H k ×L k )) expression(7) Among them, F LD is the lateral transport flux of macrophyte debris carbon, in mol·m -2 ·d -1 ;M j is the amount of macrophyte detrital 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 during the ebb duration of the jth tidal cycle within the unit monitoring duration, in meters; L j is the average width of the monitoring target area during the ebb duration of the jth tidal cycle within the unit monitoring duration, in meters; M k is the amount of macrophyte detrital carbon in the high tide 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 during the high tide duration of the kth tidal cycle within the unit monitoring duration, in meters; L k It is the average width of the monitoring target area during the high tide duration of the kth tidal cycle within the unit monitoring duration, in meters.

8. The method for analyzing the total carbon lateral transport flux of a mangrove ecosystem according to claim 1, characterized in that: The calculation formula of the total carbon lateral transport flux includes: F T =F NLD +F LD Formula (8) Among them, F T is the lateral transport flux of total carbon, in mol·m -2 ·d -1 .