An ecological restoration-based carbon sink capacity evaluation method

Abstract

The application discloses a kind of carbon sink capacity evaluation methods based on ecological restoration, belong to carbon sink evaluation technical field, including the following steps: S1, obtain the growth data of each plant in the repair period of ecological restoration area;S2, determine the function leaf of each plant, and obtain the carbon fixation transition coefficient of plant in the repair period according to the growth data of function leaf in the repair period;S3, the carbon fixation transition coefficient of each plant in the repair period is input into carbon fixation capacity stage model, and the carbon fixation capacity weight of each plant at each time in the repair period is obtained;S4, according to the carbon fixation capacity weight of each plant at each time in the repair period and the base carbon pool of ecological restoration area, determine the repair result of ecological restoration area.The application realizes the systematic evaluation of the carbon sink capacity of the whole repair area, greatly improves the accuracy and reliability of ecological restoration carbon sink evaluation.

Description

TECHNICAL FIELD

[0001] The application belongs to the technical field of carbon sink evaluation, and particularly relates to a carbon sink capacity evaluation method based on ecological restoration. BACKGROUND

[0002] As a key measure to improve the carbon sink capacity of the ecological system, the scientific evaluation of the carbon sink effect of ecological restoration is of great significance to quantifying the carbon emission reduction contribution of the ecological system, supporting regional carbon budget accounting, and optimizing ecological restoration strategies. The evaluation of the carbon sink capacity of the ecological system needs to accurately depict the carbon fixation dynamics, physiological mechanisms of plants during the restoration period, and overall changes in the regional carbon pool. However, the existing technologies have many limitations.

[0003] At present, the evaluation methods for the carbon sink capacity of the ecological system mainly fall into two categories: one is the method based on the observation of the carbon flux of the ecological system (such as the eddy correlation method), which can directly measure the CO2 exchange between the ecological system and the atmosphere, but the equipment is expensive, the maintenance cost is high, and the observation results represent a limited range, which is not suitable for the universal evaluation of large-scale, distributed ecological restoration projects. The second is the method based on biomass inventory and remote sensing inversion, which estimates the carbon storage by measuring the vegetation biomass and multiplying the carbon content coefficient, and is usually used to evaluate the carbon pool changes at a specific time point (such as before and after restoration). However, this method has obvious limitations: first, it is essentially a static or relatively static evaluation, which cannot reflect the dynamic changes of the carbon absorption capacity of plants during the entire growing season or restoration period, such as the huge difference in carbon fixation efficiency between the growing season and the dormant season; second, this method relies too much on “black box” macro data and fails to link to the key physiological process that determines carbon absorption, i.e., photosynthesis of plants, so it is difficult to reveal the internal mechanism of the formation of carbon sink capacity and cannot respond sensitively to the changes in the physiological state of plants during the restoration process. SUMMARY

[0004] The present application is to solve the above problems, and provides a carbon sink capacity evaluation method based on ecological restoration.

[0005] The technical scheme of the present application is as follows: a carbon sink capacity evaluation method based on ecological restoration comprises the following steps:

[0006] S1, obtaining the growth data of each plant in the ecological restoration area during the restoration period;

[0007] S2, determining the functional leaves of each plant, and obtaining the carbon fixation transition coefficient of the plant during the restoration period according to the growth data of the functional leaves during the restoration period;

[0008] S3, inputting the carbon fixation transition coefficient of each plant during the restoration period into a carbon fixation capacity stage model to obtain the carbon fixation capacity weight of each plant at each time during the restoration period.

[0009] S4, determining the restoration result of the ecological restoration region according to the carbon fixation ability weight of each plant at each moment during the restoration period and the base carbon pool of the ecological restoration region.

[0010] Further, S2 comprises the following sub-steps:

[0011] S21, collecting the leaf surface CO2 concentration, leaf surface CO2 compensation point concentration and photosynthetic rate of the functional leaf of the plant at each moment during the restoration period;

[0012] S22, calculating the relative conductance of the functional leaf according to the leaf surface CO2 concentration, leaf surface CO2 compensation point concentration and photosynthetic rate of the functional leaf at each moment during the restoration period;

[0013] S23, calculating the carbon fixation transition coefficient of the vegetation according to the relative conductance of the functional leaf during the restoration period.

[0014] The beneficial effect of the above further scheme is that in the present application, the carbon fixation ability of the plant is directly related to the leaf gas exchange characteristics (CO2 concentration, compensation point and photosynthetic rate). The functional leaf is defined as a mature leaf on the plant body that has active photosynthetic ability and can continuously transport synthesized organic matter to the growth center or storage organ. As long as the leaf is in a survival state, respiration will continuously release CO2, and photosynthesis will absorb CO2 according to the light conditions (photosynthesis stops in darkness, but respiration still exists). The CO2 exchange balance state of the two processes always exists, and the corresponding balance concentration is the CO2 compensation point at this moment. The CO2 compensation point is a physiological parameter that the leaf has at any survival moment, and only changes in value with the environment and physiological state, and does not disappear with time. The dynamic range of the conductance is mapped to the carbon fixation transition coefficient, which is used for time segmentation of the subsequent stage model.

[0015] Further, in S22, the expression of the relative conductance f of the functional leaf is:

[0016] ;

[0017] wherein, represents the photosynthetic rate of the functional leaf, represents the difference in saturated water vapor pressure, represents an empirical parameter, represents the leaf surface CO2 concentration, represents the leaf surface CO2 compensation point concentration.

[0018] The beneficial effect of the above further scheme is that in the present application, the photosynthetic rate is a direct manifestation of the carbon fixation of the plant, The difference of saturated water vapor pressure is a key environmental factor affecting the opening and closing of stomata (stomata are easy to close when the difference of water vapor pressure is large), The difference of leaf CO2 concentration and The difference of CO2 compensation point concentration reflects the availability of CO2, The empirical parameter is used to adapt the specificity of different plants or environments, and the empirical parameter is used to describe the response sensitivity of leaf stomata to the difference of saturated water vapor pressure.

[0019] Further, in S23, the inverse of the ratio of the minimum relative conductivity of the functional leaf during the repair period to the maximum relative conductivity is input into the exponential function to obtain the carbon fixation transition coefficient.

[0020] Further, in S3, the carbon fixation capacity stage model The expression is:

[0021] ;

[0022] Wherein, represents the carbon fixation transition coefficient of the plant during the repair period, represents the growth cycle of the plant, represents the time during the repair period.

[0023] The beneficial effects of the above further scheme are: in the present application, in order to ensure the normal operation of the carbon fixation capacity stage model, if the carbon fixation transition coefficient calculated in step S2 is Less than 0.5, it is directly brought into the carbon fixation capacity stage model for operation, and if the carbon fixation transition coefficient calculated in step S2 is Greater than 0.5, take the half value of the carbon fixation transition coefficient Bringing into the carbon fixation capacity stage model for operation.

[0024] The first segment : The carbon fixation capacity weight rises linearly from 0 to 1, corresponding to the increase of seedling stage carbon fixation capacity; the second segment : The weight remains 1, corresponding to the stable carbon fixation capacity in the growth period; the third segment : The weight linearly decreases from 1 to 0, corresponding to the decrease of carbon fixation capacity in the senescence period. It can effectively capture the core trend of rising-stable-decreasing and avoid the mutation error of traditional segmented linear model.

[0025] Further, S4 includes the following sub-steps:

[0026] S41, multiplying the carbon fixation capacity weight of the vegetation at each time, the coverage ratio of the vegetation in the ecological restoration area and the maximum carbon fixation rate of the vegetation during the repair period to obtain the carbon sink increment of the vegetation;

[0027] S42, calculate the total carbon sink capacity of the ecological restoration area according to the carbon sink increment of the plant and the base carbon pool of the ecological restoration area, and determine that the restoration result is qualified when the total carbon sink capacity is greater than a set threshold.

[0028] The beneficial effect of the above further scheme is that in the present application, the maximum carbon fixation rate of the target tree species obtained by actual measurement is the basic capability parameter, reflecting the carbon fixation potential of the vegetation in the mature and stable period. In actual restoration, the vegetation will not cover 100% (for example, trees may only cover 60% of the area), so the actual contribution of the vegetation in the unit restoration area is converted. There is a close and complex relationship between vegetation coverage and soil carbon content. When the vegetation coverage increases, the soil carbon content also tends to increase. This is because plants absorb carbon dioxide through photosynthesis and convert it into organic matter, part of which is used for life activities such as growth and reproduction, and the other part enters the soil in the form of litter, root exudates, etc. These organic matters entering the soil are important sources of soil carbon. The total carbon sink capacity is the sum (integral) of the original carbon amount of the base carbon pool and the carbon sink increment during the restoration period.

[0029] Further, in S42, the total carbon sink capacity of the ecological restoration area is expressed as:

[0030] ;

[0031] wherein, represents the carbon sink increment of the vegetation at time, represents the original carbon sink amount of the base carbon pool of the ecological restoration area, represents the restoration period. The base carbon pool is the original carbon sink

[0032] The beneficial effect of the present application is that the present application can capture the nonlinear change of the carbon fixation capacity of plants at each stage by establishing a carbon fixation capacity stage model at each time point during the restoration period, and the micro physiological parameters of plant leaves are associated with the carbon sink capacity of the ecological system, which is suitable for mixed restoration areas of multiple species. In addition, the present application also integrates and calculates the original carbon storage of the restoration area and the new carbon sink of the vegetation, realizes the systematic evaluation of the carbon sink capacity of the whole restoration area, and greatly improves the accuracy and reliability of the carbon sink evaluation of ecological restoration. BRIEF DESCRIPTION OF DRAWINGS

[0033] Figure 1 is a flowchart of the carbon sink capacity evaluation method based on ecological restoration. DETAILED DESCRIPTION

[0034] The embodiments of the present application will be further described below with reference to the accompanying drawings.

[0035] As Figure 1As shown, the present application provides a carbon sink capacity evaluation method based on ecological restoration, comprising the following steps:

[0036] S1, obtaining growth data of each plant in the ecological restoration area during the restoration period;

[0037] S2, determining the functional leaves of each plant, and obtaining the carbon fixation transition coefficient of the plant during the restoration period according to the growth data of the functional leaves during the restoration period;

[0038] S3, inputting the carbon fixation transition coefficient of each plant during the restoration period into the carbon fixation capacity stage model to obtain the carbon fixation capacity weight of each plant at each time during the restoration period;

[0039] S4, determining the restoration result of the ecological restoration area according to the carbon fixation capacity weight of each plant at each time during the restoration period and the base carbon pool of the ecological restoration area.

[0040] In the embodiment of the present application, S2 comprises the following sub-steps:

[0041] S21, collecting the leaf surface CO2 concentration, leaf surface CO2 compensation point concentration and photosynthetic rate of the functional leaves of the plant at each time during the restoration period;

[0042] S22, calculating the relative conductance of the functional leaves according to the leaf surface CO2 concentration, leaf surface CO2 compensation point concentration and photosynthetic rate of the functional leaves at each time during the restoration period;

[0043] S23, calculating the carbon fixation transition coefficient of the vegetation according to the relative conductance of the functional leaves during the restoration period.

[0044] In the present application, the carbon fixation capacity of the plant is directly related to the leaf gas exchange characteristics (CO2 concentration, compensation point and photosynthetic rate). The functional leaf is defined as a mature leaf on the plant body that has active photosynthetic capacity and can continuously transport synthesized organic matter to the growth center or storage organ. As long as the leaf is in a survival state, respiration will continuously release CO2, and photosynthesis will absorb CO2 according to the light conditions (photosynthesis stops in darkness, but respiration still exists). The CO2 exchange balance state of these two processes always exists, and the corresponding balance concentration is the CO2 compensation point at that time. The CO2 compensation point is a physiological parameter that the leaf has at any survival time, and only changes in value with the environment and physiological state, and does not disappear with time. The dynamic range of conductance is mapped to the carbon fixation transition coefficient, which is used for time segmentation in the subsequent stage model.

[0045] In the embodiment of the present application, in S22, the expression of the relative conductance f of the functional leaf is:

[0046] ;

[0047] in, Indicates the photosynthetic rate of functional leaves. Indicates the saturated water vapor pressure difference. Represents empirical parameters, This indicates the CO2 concentration on the leaf surface. This indicates the CO2 compensation point concentration on the leaf surface.

[0048] In this invention, (Photosynthetic rate) is a direct reflection of carbon fixation in plants. (Saturated vapor pressure difference) is a key environmental factor affecting the opening and closing of stomata (stomata are more likely to close when the vapor pressure difference is large). (Leaf CO2 concentration) and The difference in (CO2 compensation point concentration) reflects the availability of CO2. (Empirical parameters) are used to adapt to the specificity of different plants or environments. Empirical parameters are used to describe the response sensitivity of leaf stomata to saturated water vapor pressure difference.

[0049] In this embodiment of the invention, in S23, the negative of the ratio of the minimum relative conductivity to the maximum relative conductivity of the functional leaf during the repair period is input into the exponential function to obtain the carbon fixation transition coefficient.

[0050] In this embodiment of the invention, S3 is the carbon fixation capacity stage model. The expression is:

[0051] ;

[0052] in, This indicates the carbon fixation transition coefficient of plants during remediation. Indicates the plant's growth cycle. Indicates the time during the repair period.

[0053] In this invention, to ensure the normal operation of the carbon fixation capacity stage model, if the carbon fixation transition coefficient calculated in step S2 is... If the value is less than 0.5, it is directly substituted into the carbon fixation capacity stage model for calculation. If the carbon fixation transition coefficient calculated in step S2 is... If the value is greater than 0.5, then the carbon fixation transition coefficient is taken. Half of the value is substituted into the carbon sequestration capacity stage model for calculation.

[0054] First paragraph The carbon sequestration capacity weight increases linearly from 0 to 1, corresponding to an increase in carbon sequestration capacity during the seedling stage; (Second paragraph) The weight remains at 1, corresponding to stable carbon sequestration capacity during the growth period; third paragraph The weight linearly decreases from 1 to 0, corresponding to the decrease of the carbon fixation capacity in the aging period. The core trend of rising-stable-falling can be effectively captured, and the mutation error of the traditional segmented linear model is avoided.

[0055] In the embodiment of the present application, S4 comprises the following sub-steps:

[0056] S41, multiplying the carbon fixation capacity weight of the vegetation at each time, the coverage ratio of the vegetation in the ecological restoration area, and the maximum carbon fixation rate of the vegetation during the restoration period to obtain the carbon sink increment of the vegetation;

[0057] S42, calculating the total carbon sink capacity of the ecological restoration area according to the carbon sink increment of the vegetation and the base carbon pool of the ecological restoration area, and determining that the restoration result is qualified when the total carbon sink capacity is greater than a set threshold.

[0058] In the present application, the maximum carbon fixation rate of the target tree species obtained by actual measurement is a basic capability parameter, reflecting the carbon fixation potential of the vegetation in the mature and stable period. In actual restoration, the vegetation does not cover 100% (for example, trees may only cover 60% of the area), so the actual contribution of the vegetation in the unit restoration area is converted. There is a close and complex relationship between vegetation coverage and soil carbon content. When the vegetation coverage increases, the soil carbon content also tends to increase. This is because plants absorb carbon dioxide through photosynthesis and convert it into organic matter, part of which is used for life activities such as growth and reproduction, and the other part enters the soil in the form of litter, root exudates, etc. These organic matters entering the soil are important sources of soil carbon. The total carbon sink capacity is the sum (integral) of the original carbon amount of the base carbon pool and the carbon sink increment during the restoration period.

[0059] In the embodiment of the present application, in S42, the total carbon sink capacity of the ecological restoration area is expressed as:

[0060] ;

[0061] wherein, represents the carbon sink increment of the vegetation at time, represents the original carbon sink amount of the base carbon pool of the ecological restoration area, represents the restoration period. The base carbon pool is the original carbon sink before ecological restoration.

[0062] Those skilled in the art will appreciate that the embodiments described herein are presented for purposes of illustration and that the inventive principles are not limited to these particular embodiments. Other variations and modifications can be made to the embodiments without departing from the spirit and scope of the inventive principles.

Claims

1. An ecological restoration-based carbon sink capacity evaluation method, characterized in that, The method comprises the following steps: S1, acquiring growth data of each plant in the ecological restoration area during the restoration period; S2, determining functional leaves of each plant, and obtaining a carbon fixation transition coefficient of the plant during the restoration period according to growth data of the functional leaves during the restoration period; S3, inputting the carbon fixation transition coefficient of each plant during the restoration period into a carbon fixation capacity stage model to obtain a carbon fixation capacity weight of each plant at each time during the restoration period; S4, determining a restoration result of the ecological restoration area according to the carbon fixation capacity weight of each plant at each time during the restoration period and a base carbon pool of the ecological restoration area; The S2 comprises the following sub-steps: S21, collecting leaf surface CO2 concentration, leaf surface CO2 compensation point concentration and photosynthetic rate of the functional leaves of the plant at each time during the restoration period; S22, calculating a relative conductance of the functional leaves according to the leaf surface CO2 concentration, the leaf surface CO2 compensation point concentration and the photosynthetic rate of the functional leaves at each time during the restoration period; S23, calculating a carbon fixation transition coefficient of the vegetation according to the relative conductance of the functional leaves during the restoration period; In the S22, an expression of the relative conductance f of the functional leaves is: ； wherein, represents the photosynthetic rate of the functional leaves, represents the difference in saturated water vapor pressure, represents an empirical parameter, represents the CO2 concentration at the leaf surface, represents the CO2 compensation point concentration at the leaf surface; In the S23, inputting an inverse of a ratio of the minimum relative conductance to the maximum relative conductance of the functional leaves during the restoration period into an exponential function to obtain the carbon fixation transition coefficient; In the S3, the expression of the carbon sequestration capacity stage model is: ； wherein, represents a carbon fixation transition coefficient of the plant during the remediation, represents a growth cycle of the plant, represents a time instant during the remediation. 2.The ecological restoration-based carbon sink capacity evaluation method according to claim 1, characterized in that, The S4 comprises the following sub-steps: S41, multiplying the carbon fixation capacity weight of the vegetation at each time, a coverage ratio of the vegetation in the ecological restoration area and a maximum carbon fixation rate of the vegetation during the restoration period to obtain a carbon sink increment of the vegetation; S42, calculating a total carbon sink capacity of the ecological restoration area according to the carbon sink increment of the vegetation and the base carbon pool of the ecological restoration area, and determining that the restoration result is qualified when the total carbon sink capacity is greater than a set threshold. 3.The ecological restoration-based carbon sink capacity evaluation method according to claim 2, characterized in that, In the S42, the total carbon sink capacity of the ecological restoration region The expression is: ； wherein, represents the carbon sink increment of the vegetation at the time point, represents the original carbon sink amount of the base carbon pool of the ecological restoration area, represents the restoration period.

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