Forest litter decomposition rate estimation method, system, device and storage medium

Abstract

The present application relates to the field of environmental analysis, in particular to a forest litter decomposition rate estimation method, system, device and storage medium. The present application aims at the problems of long cycle, great environmental influence, time-consuming and laborious of the existing nylon mesh bag method for determining the forest litter decomposition rate, and the problem of being unable to carry out decomposition research on large-scale forests, and provides a forest litter decomposition rate estimation method, system, device and storage medium, measures and calculates the current year input of the forest litter p and the annual input increment, determines the residual rate constant r of the forest litter through experimental method or searching for relevant data in the past, and combines the residual rate constant r with the OLson single index decomposition model of the forest litter to establish a solution equation of the forest litter decomposition rate. This method has short cycle, does not need to be measured in the field regularly and frequently, has small environmental influence, the parameters and variables in the equation are easy to obtain, time and labor are saved, and decomposition rate research can be carried out on large-scale forests.

Description

Technical Field

[0001] This invention relates to the field of environmental analysis, specifically to a method, system, apparatus, and storage medium for estimating the decomposition rate of forest litter. Background Technology

[0002] Forest litter generally refers to the metabolic products produced by plants during their growth and development. Common forest litter includes fallen branches, fallen logs, dead standing trees, fallen leaves, dead herbs, and dead tree branches. Forest litter is an important component of the forest ecosystem. Litter decomposition plays a vital role in promoting normal material cycling in the forest ecosystem, maintaining soil fertility and nutrient balance, improving the soil's physical and chemical environment, and conserving water resources. Currently, the most commonly used method in litter decomposition research is the nylon mesh bag method. This method typically uses specially made, expensive nylon mesh bags filled with litter, which are then placed in the field for measurement. This method is time-consuming, highly susceptible to environmental influences, and labor-intensive, making it unsuitable for large-scale forest decomposition studies. Summary of the Invention

[0003] The purpose of this invention is to solve the problems of long cycle, great influence from the environment, time-consuming and labor-intensive nature of existing nylon mesh bag methods for determining forest litter decomposition rate, as well as the inability to conduct decomposition research on large-scale forests. This invention provides a method, system, device and storage medium for estimating forest litter decomposition rate.

[0004] The technical solution of this application is:

[0005] A method for estimating the decomposition rate of forest litter includes the following steps:

[0006] S1: Obtain the existing surface litter topsoil load w, the average diameter at breast height (DBH) of the trees in the current year (D), the number of trees (c), and the forest area (s).

[0007] S2: Based on the average diameter at breast height (DBH) D, number of trees (c), and forest area (s) of trees obtained in S1, obtain the amount of litter p and the annual input increment Δp of litter for the trees in that year.

[0008] S3: Establish an equation based on the relationship between the residual rate constant r of the forest trees and the OLson single-exponential decomposition model of forest litter:

[0009]

[0010]

[0011] e -kt =r

[0012] Where: M0 is the initial amount of litter from the trees; M tt represents the amount of litter remaining when the litter decomposes from the upper layer to the lower layer; k represents the annual decomposition rate coefficient of the forest; t represents the time it takes for the litter to decompose from the upper layer to the lower layer.

[0013] S4: Using the existing top-layer litter load w determined in S1, the current year's litter load p obtained in S2, and the annual litter input increment Δp of the forest, a high-power equation for the forest decomposition rate is established:

[0014] p+(p-Δp)e -k +(p-2Δp)e -2k +(p-3Δp)e -3k +…+(p-tΔp)e -tk =w;

[0015] S5: Equation e established using S3 -kt Transforming the high-power equation for the forest decomposition rate in S5 with r, we obtain the low-power equation for the forest decomposition rate:

[0016]

[0017] The low-power equation for the decomposition rate of trees is equivalent to a quadratic equation in one variable with t as the unknown.

[0018] S6: Based on the low-power equation of the forest decomposition rate obtained in S5, the approximate solution t of the time for the forest litter to decompose from the upper layer to the lower layer is obtained.

[0019] S7: Using the t value obtained from S6 and the equation e from S3 -kt =r is used to calculate the annual decomposition rate coefficient k of the forest tree.

[0020] To achieve the above objectives, this application also provides a system for estimating the decomposition rate of forest litter, comprising:

[0021] The data acquisition unit is used by S1 to acquire the existing surface litter top layer load w, the average diameter at breast height D of the trees in the current year, the number of trees c, and the area of ​​the trees s;

[0022] The litter quantity calculation unit is used by S2 to use the data obtained by the data acquisition unit to calculate the forest litter quantity, and obtain the annual litter quantity p of the forest and the annual input increment of the forest litter quantity.

[0023] The litter decomposition model analysis unit is used in S3 and S4 to establish and analyze the decomposition model of the forest litter, determine the relationship between the forest residual rate constant r and the OLson single exponential decomposition model of forest litter, and then obtain the high power equation of the forest decomposition rate.

[0024] The litter decomposition model transformation unit is used to perform a logarithmic transformation on the high-power equation of the forest decomposition rate in S5 to obtain the low-power equation of the forest decomposition rate.

[0025] The litter decomposition model solution unit is used to solve the low-power equation of the forest decomposition rate in S6 and S7, obtain the approximate time t value, and then obtain the annual decomposition rate coefficient k of the forest.

[0026] To achieve the above objectives, this application also provides a forest litter decomposition rate estimation device, comprising: a processor and a memory.

[0027] Memory, used to store at least one instruction.

[0028] A processor for executing the at least one instruction to implement the above-described method for estimating the decomposition rate of forest litter.

[0029] To achieve the above objectives, this application also provides a computer storage medium storing at least one instruction, which is loaded and executed by a processor to implement the steps of the above-described method for estimating the decomposition rate of forest litter.

[0030] Compared with the prior art, this application has the following advantages:

[0031] 1. The present invention provides a method for estimating the decomposition rate of forest litter. By measuring conventional data easily obtained from forest surveys, the method calculates the annual input amount p and annual input increment Δp of forest litter. The method determines the residual rate constant r of the forest litter through experiments or literature review. Based on the residual rate constant r and the OLson single-exponential decomposition model of forest litter, an equation for solving the decomposition rate of forest litter is established. This method has a short cycle, does not require frequent field measurements, is less affected by the environment, and the parameters and variables in the equation are easy to obtain. It saves time and effort and can be used to study the decomposition rate of large-scale forests.

[0032] 2. This invention uses mathematical transformation methods to convert equations that are difficult to solve for higher powers into equations that are easy to solve for lower powers, thus simplifying the difficulty of solving the equations and increasing the practicality of the method.

[0033] 3. By combining knowledge from forest fire prevention and forest soil science, the stratified structural characteristics of litter are distinguished, allowing the same parameters to be used for the same forest litter, which can save a lot of experiments, reduce costs, and shorten experimental time. Detailed Implementation

[0034] Specific Implementation Method 1: This implementation method for estimating the decomposition rate of forest litter includes the following steps:

[0035] S1: Obtain the existing surface litter topsoil load w, the average diameter at breast height (DBH) of the trees in the current year (D), the number of trees (c), and the forest area (s).

[0036] S2: Based on the average diameter at breast height (DBH) D, number of trees (c), and forest area (s) of trees obtained in S1, obtain the amount of litter p and the annual input increment Δp of litter for the trees in that year.

[0037] S3: Establish an equation based on the relationship between the residual rate constant r of the forest trees and the OLson single-exponential decomposition model of forest litter:

[0038]

[0039]

[0040] e -kt =r

[0041] Where: M0 is the initial amount of litter from the trees; M t t represents the amount of litter remaining when the litter decomposes from the upper layer to the lower layer; k represents the annual decomposition rate coefficient of the forest; t represents the time it takes for the litter to decompose from the upper layer to the lower layer.

[0042] S4: Using the existing top-layer litter load w determined in S1, the current year's litter load p obtained in S2, and the annual litter input increment Δp of the forest, a high-power equation for the forest decomposition rate is established:

[0043] p+(p-Δp)e -k +(p-2Δp)e -2k +(p-3Δp)e -3k +…+(p-tΔp)e -tk =w;

[0044] S5: Equation e established using S3 -kt Transforming the high-power equation for the forest decomposition rate in S5 with r, we obtain the low-power equation for the forest decomposition rate:

[0045]

[0046] The low-power equation for the decomposition rate of trees is equivalent to a quadratic equation in one variable with t as the unknown.

[0047] S6: Based on the low-power equation of the forest decomposition rate obtained in S5, the approximate solution t of the time for the forest litter to decompose from the upper layer to the lower layer is obtained.

[0048] S7: Using the t value obtained from S6 and the equation e from S3 -kt =r is used to calculate the annual decomposition rate coefficient k of the forest tree.

[0049] Those skilled in the art can use the method of this invention to measure and calculate the annual input amount p and annual input increment Δp of forest litter, and determine the residual rate constant r of the forest litter through experimental methods or by consulting previous relevant data. The residual rate constant r is combined with the OLson single-exponential decomposition model of forest litter to establish an equation for solving the decomposition rate of forest litter. This method has a short cycle, does not require regular and frequent field measurements, is less affected by the environment, and the parameters and variables in the equation are easy to obtain. It saves time and effort and can be used to study the decomposition rate of large-scale forests.

[0050] Specific Implementation Method Two: In this implementation method for estimating the decomposition rate of forest litter, the general form of the forest biomass growth equation is:

[0051] y = aD b

[0052] Therefore, the annual litter volume p of S2 forest can be calculated using the following formula:

[0053]

[0054] In the formula: y is the amount of fallen leaves per tree, kg / tree; p is the amount of fallen material in the current year; D is the average diameter at breast height of trees in the current year, cm; c is the number of trees; s is the forest area; a and b are coefficients.

[0055] The general form of the equation for the increase in diameter at breast height (DBH) of trees is:

[0056] ΔD=a+bD

[0057] The average diameter at breast height (DBH) of the trees in the previous year was:

[0058] D i-1 =D-ΔD

[0059] Therefore, the annual increase in the amount of fallen forest debris, Δp, can be calculated using the following formula:

[0060]

[0061] In the formula: Δp is the annual increase in forest litter input; D i-1 The average diameter at breast height (DBH) of the trees in the previous year; other steps are the same as in Specific Implementation Method 1.

[0062] Specific Implementation Method Three: In the forest litter decomposition rate estimation method of this implementation method, S5

[0063] The steps for transforming the high-power equation for the forest decomposition rate in S4 are as follows:

[0064] p+(p-Δp)e -k +(p-2Δp)e-2k +(p-3Δp)e -3k +…+(p-tΔp)e -tk =w

[0065] Transformed into:

[0066] p+(pe -k +pe -2k +pe -3k …+pe -tk )-(Δpe -k +2Δpe -2k +3Δpe -3k …+tΔpe -tk ) = w

[0067] Continue to transform into:

[0068]

[0069] e -kt Combining r with the above equation, we get:

[0070]

[0071] The other steps are the same as in Specific Implementation Method 1 or 2.

[0072] Specific Implementation Method Four: In this implementation method for estimating the decomposition rate of forest litter, the residual rate constant r of the forest litter is determined through experiments or by consulting data. The residual rate constant r is the ratio of the amount of litter remaining when the forest litter decomposes from the upper layer to the lower layer to the initial amount of litter in the forest. Specific Implementation Method One, Two, or Three are the same.

[0073] Specific Implementation Method Five: In this implementation method for estimating the decomposition rate of forest litter, the experimental determination of the residual rate constant r of the forest litter includes: an indoor decomposition culture method. In forest fire prevention, litter is divided into upper and lower layers. The upper layer consists of dead branches and leaves in the early and semi-decomposed state, which are flammable and combustible materials; the lower layer is a layer of coarse humus in the later decomposition stage, which is flammable and difficult to burn. The two layers can be distinguished morphologically through mechanical separation, and their ignition points and calorific values ​​differ significantly. The indoor decomposition culture method is used to experimentally determine the residual rate constant r of the forest litter when it decomposes from the upper layer to the lower layer, combined with statistical analysis of ignition points and calorific values. Other steps are the same as in Specific Implementation Methods One, Two, Three, or Four.

[0074] Specific Implementation Method Six: In this implementation method for estimating the decomposition rate of forest litter, the statistical analysis of calorific value includes independent samples t-test and one-sample t-test. Since the experiment only needs to focus on the litter residue rate, appropriate experimental methods can be used to accelerate sample decomposition. In addition, the r-values ​​of different forests can be used as test parameters. In the experiment, the r-value for larch forest was determined to be 0.85, and the r-value for birch forest was 0.57. Other steps are the same as in Implementation Method One, Two, Three, Four, or Five.

[0075] Specific Implementation Method Seven: In S6 of the forest litter decomposition rate estimation method of this implementation method, the method for determining the t value includes: stepwise search method and iterative method. The following is the solution process of stepwise search method:

[0076] Let t be a positive integer, and the step size be 1, i.e., t = 1, 2, 3, 4, as shown in the table below:

[0077] t 1 2 3 4 5 6 7 f(t) f(1) f(2) f(3) f(4) f(5) f(6) f(7)

[0078] When checking the sign change of f(t) from left to right, if the function value of f(t) is negative and the function value of f(t-1) is positive, compare the absolute values ​​of f(t) and f(t-1). The t value with the smaller absolute value is the approximate t value we are looking for. The other steps are the same as in specific implementation methods one, two, three, four, five, or six.

[0079] Specific Implementation Method Eight: This application also provides a forest litter decomposition rate estimation system, including:

[0080] The data acquisition unit is used by S1 to acquire the existing surface litter top layer load w, the average diameter at breast height D of the trees in the current year, the number of trees c, and the area of ​​the trees s. The data acquisition unit includes human-computer interaction and other interactions through signals or instructions.

[0081] The litter quantity calculation unit is used by S2 to use the data obtained by the data acquisition unit to calculate the forest litter quantity, and obtain the annual litter quantity p of the forest and the annual input increment of the forest litter quantity.

[0082] The litter decomposition model analysis unit is used in S3 and S4 to establish and analyze the decomposition model of the forest litter, determine the relationship between the forest residual rate constant r and the OLson single exponential decomposition model of forest litter, and then obtain the high power equation of the forest decomposition rate.

[0083] The litter decomposition model transformation unit is used to perform a logarithmic transformation on the high-power equation of the forest decomposition rate in S5 to obtain the low-power equation of the forest decomposition rate.

[0084] The litter decomposition model solution unit is used to solve the low-power equation of the forest decomposition rate in S6 and S7, obtain the approximate time t value, and then obtain the annual decomposition rate coefficient k of the forest.

[0085] Specific Implementation Method Nine: This implementation method is a forest litter decomposition rate estimation device. The device includes a processor and a memory. It should be understood that it includes any device including a processor and a memory described in this invention. The device may also include other units and modules that perform display, interaction, processing, control and other functions through signals or instructions.

[0086] The memory stores at least one instruction, which is loaded and executed by the processor to implement the forest litter decomposition rate estimation method.

[0087] Specific Implementation Method 10: This implementation method is a computer storage medium that stores at least one instruction. The at least one instruction is loaded and executed by a processor to implement the steps of the forest litter decomposition rate estimation method.

[0088] It should be understood that the instructions include computer program products, software, or computerized methods corresponding to any method described in this invention; the instructions can be used to program computer systems or other electronic devices. Computer storage media may include readable media on which instructions are stored, and may include, but are not limited to, magnetic storage media, optical storage media; magneto-optical storage media include read-only memory (ROM), random access memory (RAM), erasable programmable memory (e.g., EPROM and EEPROM), and flash memory layers, or other types of media suitable for storing electronic instructions.

[0089] The above description is merely of preferred embodiments of the present invention. It should be understood that the present invention is not limited to the specific embodiments described above. Although the present invention has been disclosed above with reference to preferred embodiments, it is not intended to limit the present invention. Any person skilled in the art can make some modifications or alterations to the above-disclosed technical content to create equivalent embodiments without departing from the scope of the present invention. Any simple modifications, equivalent substitutions, and improvements made to the above embodiments without departing from the scope of the present invention, based on the technical essence of the present invention, and within the spirit and principles of the present invention, shall still fall within the protection scope of the present invention.

Claims

1. A method for estimating the decomposition rate of forest litter, characterized in that, Includes the following steps: S1: Obtain the existing surface litter topsoil load w, the average diameter at breast height (DBH) of the trees in the current year (D), the number of trees (c), and the forest area (s). S2: Based on the average diameter at breast height (DBH) D, number of trees (c), and forest area (s) obtained in S1, obtain the annual litter volume (p) and annual litter input increment of the forest. ; S3: Establish an equation based on the relationship between the residual rate constant r of the forest trees and the OLson single-exponential decomposition model of forest litter: In the formula: This represents the initial amount of litter from the trees. t represents the amount of litter remaining when the litter decomposes from the upper layer to the lower layer; k represents the annual decomposition rate coefficient of the forest; t represents the time it takes for the litter to decompose from the upper layer to the lower layer. S4: Using S1 to determine the existing topsoil litter load w of the forest, and S2 to obtain the current year's litter load p and the annual increase in litter input of the forest. Establish a high-power equation for the decomposition rate of this forest tree: ； S5: Equation established using S3 Transforming the high-power equation for the forest decomposition rate in S4, we obtain the low-power equation for the forest decomposition rate: The low-power equation for the forest decomposition rate is equivalent to a quadratic equation with t as the unknown. S6: Based on the low-power equation of the forest decomposition rate obtained in S5, the approximate solution t of the time for the forest litter to decompose from the upper layer to the lower layer is obtained. S7: Using the t value obtained from S6 and the equation in S3 The annual decomposition rate coefficient k of the trees was calculated.

2. The method for estimating the decomposition rate of forest litter according to claim 1, characterized in that: The amount of forest litter p in the current year mentioned in S2 is calculated by the following formula: In the formula: p is the amount of litter in the current year; D is the average diameter at breast height (DBH) of trees in the current year; c is the number of trees; s is the forest area; a and b are coefficients; S2 describes the annual input increment of forest litter. It is calculated using the following formula: In the formula: The annual increase in forest litter; The average diameter at breast height (DBH) of the trees in the previous year.

3. The method for estimating the decomposition rate of forest litter according to claim 2, characterized in that: The S5 The steps for transforming the high-power equation for the forest decomposition rate in S4 are as follows: Transformed into: Continue to transform into: Will Combining the above equations with the system of equations, we can obtain: =0。 4. A method for estimating the decomposition rate of forest litter according to claim 1 or 3, characterized in that: The residual rate constant r was determined through experiments or by consulting relevant literature.

5. The method for estimating the decomposition rate of forest litter according to claim 4, characterized in that: The method for experimentally determining the residual rate constant r of the forest litter includes the following steps: using an indoor decomposition culture method, wherein the residual rate constant r of the forest litter is determined by statistical analysis of ignition point and calorific value.

6. The method for estimating the decomposition rate of forest litter according to claim 5, characterized in that: The statistical analysis methods for the calorific value of the indoor decomposition culture method include: independent samples t-test and one-sample t-test.

7. The method for estimating the decomposition rate of forest litter according to claim 6, characterized in that: The methods for determining the value of t in S6 include: stepwise search method and iterative method.

8. A system for estimating the decomposition rate of forest litter, characterized in that: For implementing the forest litter decomposition rate estimation method as described in any one of claims 1 to 7, the system comprises: The data acquisition unit is used in S1 to acquire the existing surface litter top layer load w, the average diameter at breast height D of the trees in the current year, the number of trees c, and the area of ​​the trees s; The litter quantity calculation unit is used in S2 to calculate the forest litter quantity p based on the data acquired by the data acquisition unit, thereby obtaining the annual litter quantity p and the annual input increment of the forest litter quantity. ; The litter decomposition model analysis unit is used in S3 and S4 to establish and analyze the decomposition model of the forest litter, determine the relationship between the forest residual rate constant r and the OLson single exponential decomposition model of forest litter, and then obtain the high power equation of the forest decomposition rate. The litter decomposition model transformation unit is used in S5 to perform a logarithmic transformation on the high-power equation of the forest decomposition rate to obtain the low-power equation of the forest decomposition rate. The litter decomposition model solution unit is used to solve the low-power equation of the forest decomposition rate in S6 and S7, obtain the time approximate solution t, and then obtain the annual decomposition rate coefficient k of the forest.

9. A device for estimating the decomposition rate of forest litter, characterized in that: The forest litter decomposition rate estimation device includes a processor and a memory. Memory, used to store at least one instruction; A processor for executing the at least one instruction to implement a forest litter decomposition rate estimation method as described in any one of claims 1 to 7.

10. A computer storage medium, characterized in that: The storage medium stores at least one instruction, which is loaded and executed by a processor to implement a forest litter decomposition rate estimation method as described in any one of claims 1 to 7.

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