Comprehensive evaluation method for ecological service function of rubber composite planting system

Abstract

The invention discloses a comprehensive evaluation method for ecological service functions of a rubber composite planting system, and the method comprises the following steps: 1, carrying out the classification of the ecological service functions of a rubber agriculture and forestry composite system, and obtaining a plurality of function items; 2, determining indexes related to a plurality of function items according to actual conditions; step 3, carrying out measurement and data standardization conversion on the indexes of the plurality of function items to obtain initial scores of the plurality of function items and an initial comprehensive score of the ecological service function; and step 4, carrying out weight distribution on the indexes of the plurality of functions to obtain weight scores of the plurality of function items, and carrying out superposition calculation to obtain a comprehensive evaluation result of the ecological service function of the rubber agriculture and forestry composite system. According to the method, the ecological service function of the rubber agriculture and forestry composite system can be reflected more visually, reliable data support is provided for development of the rubber agriculture and forestry composite system, and exploration and practice of a more sustainable rubber forest development mode are promoted.

Description

Technical Field

[0001] The invention relates to the field of ecological evaluation of farming systems, and in particular to a comprehensive evaluation method for ecological service functions of a rubber composite planting system. Background Art

[0002] With the rapid expansion of rubber tree monoculture, the impact of rubber planting on the ecological environment has attracted increasing attention. Some studies have compared it with the original natural forest and pointed out that it may bring negative impacts such as biodiversity decline and soil erosion. In response to these problems, many studies have proposed to improve ecological diversity, resource utilization efficiency and comprehensive output through the composite planting model of rubber agroforestry, which has become an important direction for optimizing the rubber planting system.

[0003] Rubber agroforestry technology is widely regarded as an effective way to improve rubber monoculture. However, the comprehensive evaluation of its ecological benefits still needs to be further deepened. In fact, the ecological benefits of agricultural and forestry planting systems involve multiple dimensions, and a single or a few indicators often cannot fully reflect their overall advantages and disadvantages. Therefore, it is particularly important to adopt a multi-dimensional comprehensive evaluation method. Among them, ecosystem service function evaluation, as a comprehensive evaluation method, has been widely used in the fields of agriculture and forestry to scientifically measure the ecological benefits and sustainability of these planting systems.

[0004] Ecosystem service functions refer to the natural environmental conditions and benefits provided by ecosystems and their processes on which human survival depends. Over the years, the evaluation methods of ecosystem service functions have been widely used in many research fields at home and abroad. According to the ecosystem service function classification framework proposed by the Millennium Assessment (MA), the current ecosystem service functions can be divided into four categories: product supply, regulation function, support function and cultural function.

[0005] However, agricultural and forestry ecosystems are extremely rich and diverse in types, and the application scenarios of ecosystem service functions also have certain limitations. Taking the rubber forest-based ecosystem as an example, although it can be effectively evaluated in terms of product supply, regulatory functions and support functions (except for the coastal windbreak and sand fixation function), there are certain difficulties in evaluating cultural service functions. Obviously, the applicability of existing ecosystem service function evaluation methods in rubber forest ecosystems is still insufficient.

[0006] Therefore, it is necessary to establish an optimization method suitable for evaluating the service functions of rubber agroforestry ecosystem. By comprehensively evaluating its ecological benefits and comprehensively evaluating the ecological service functions under different rubber agroforestry models, scientific and reliable data support can be provided for the development of rubber agroforestry systems, and the exploration and practice of more sustainable rubber forest development models can be promoted. Summary of the invention

[0007] In view of this, the present invention provides a comprehensive evaluation method for the ecological service function of a rubber composite planting system.

[0008] In order to solve the above technical problems, the present invention adopts the following technical solutions:

[0009] A comprehensive evaluation method for the ecological service function of a rubber composite planting system comprises the following steps:

[0010] Step 1: Classify the ecological service functions of the rubber agroforestry system and obtain multiple functional items;

[0011] Step 2: Determine the indicators involved in multiple functional items according to the actual situation;

[0012] Step 3: Measure the indicators of multiple functional items and perform data standardization conversion to obtain the initial scores of multiple functional items and the initial comprehensive score of ecological service functions;

[0013] Step 4: Assign weights to the indicators of the multiple functions, obtain weight scores of the multiple functional items and perform superposition calculations to obtain a comprehensive evaluation result of the ecological service function of the rubber agroforestry system.

[0014] Preferably, in step 1, the service functions of the rubber agroforestry system are classified into a primary level according to whether their economic value can be directly measured, and direct functions and indirect functions are obtained;

[0015] Among them, the functional items representing the direct functions are mainly product supply functions, including agricultural products and agricultural and sideline products; the functional items representing the indirect functions mainly include soil and water conservation functions, gas regulation functions, and biodiversity maintenance functions;

[0016] Specifically, the sub-function items characterizing the soil and water conservation function include soil conservation function and water regulation function; the sub-function items characterizing the gas regulation function include soil greenhouse gas emissions and global warming potential; the sub-function items characterizing the biodiversity maintenance function include plant diversity maintenance function, earthworm diversity maintenance function, weed suppression function and soil microbial diversity maintenance function.

[0017] Preferably, in step 2, the indicators involved in the product supply function include crop yield and biomass, and a system economic benefit analysis is performed.

[0018] Preferably, the soil conservation function characterized by the soil conservation function involves indicators including: soil organic matter, total nitrogen, available phosphorus and potassium, bulk density, and pH; the water regulation function characterized by the soil mass water content and volume water content;

[0019] Soil greenhouse gas emissions include soil CO 2 、N2 O、CH 4 emission fluxes and emission rates;

[0020] Biodiversity maintenance function, among which the plant diversity maintenance function involves indicators including: plant species, biomass and Shannon diversity index; the weed suppression function involves indicators mainly including weed species and biomass; the earthworm diversity maintenance function involves indicators mainly including earthworm biomass; the soil microbial diversity maintenance function involves indicators including: soil enzyme activity, soil microbial biomass carbon, soil microbial biomass nitrogen, and soil bacterial community diversity index.

[0021] Preferably, the economic benefit analysis is performed by analyzing the input-output of production cycles of different production systems to obtain the dynamics of cash inflows and outflows in the production system and record production inputs and outputs; the recorded production inputs include fertilizers, organic fertilizers, pesticides, diesel, irrigation, and manpower, and the production outputs include harvested products, straw, and timber.

[0022] Preferably, the specific method of step 3 is: conducting field test measurements on indicators of multiple functional items, analyzing the impact of the rubber agroforestry system on ecological service functions such as product supply, soil conservation, water regulation, gas regulation and biodiversity maintenance;

[0023] Specifically, the crop biomass involved in the product supply function is mainly the biomass of rubber trees and intercrops. The biomass of rubber trees is estimated by measuring their plant height and stem diameter. The calculation formula is shown in (1):

[0024] B r =W t +W r ……(1)

[0025] In the formula, B r is the tree biomass (kg), W t is the aboveground biomass (kg), W r is the underground biomass (kg); the underground biomass W r , stem biomass W s , branch biomass W b , leaf biomass W i , aboveground biomass W t The calculation formulas are shown in formula (2), formula (3), formula (4), formula (5) and formula (6), where 0.24 is the root-to-crown ratio in tropical areas;

[0026] W r =w t ×0.24……(2)

[0027] Ws =0.0509(DBH 2 ×TH) 0.919 ……(3)

[0028] W b =0.00893(DBH 2 ×TH) 0.977 ……(4)

[0029] W 1 =0.0140(DBH 2 ×TH) 0.669 ……(5)

[0030] W t =W s +W b +W 1 ……(6)

[0031] Where DBH is the diameter at breast height (DBH, 1.3 meters), TH is the total height, W s is stem biomass (kg), W b is the branch biomass (kg), W i is leaf biomass (kg);

[0032] The biomass of intercrops was randomly sampled, and multiple representative crops were selected for repeated sampling. The fresh weight was measured, and then placed in an oven, fixed at 105°C for 15 minutes, and dried at 80°C until the weight no longer changed, and the dry weight was measured.

[0033] The formulas for calculating the cost present value (Cost of cultivation), the benefit present value (Costofreturn), and the net present value (NPV) according to the discounted cash flow technique are shown in formula (8), formula (9), and formula (10) respectively:

[0034]

[0035]

[0036]

[0037] Among them C i is the annual cost, B i is the annual return, n is the number of years, r is the discount rate (expressed as 12%), and i is the time period;

[0038] The calculation formulas for soil organic matter, total nitrogen, available phosphorus and potassium reserves are as follows:

[0039] S i =ρ*C i ……(11)

[0040] S i Refers to the soil storage of the i-th nutrient (g·cm -3 );ρ is the soil bulk density of 0-20cm (g·cm -3 );C i is the content of the i-th nutrient in farmland soil (%);

[0041]

[0042] θ Vi =θ Mi ×ρ bi ×100%……(13)

[0043] Where θ M ,θ V Respectively represent soil mass water content and soil volume water content; W wi , W di Respectively represent the weight of fresh soil and oven-dried soil of each soil layer (g); ρ bi Indicates the soil bulk density of each soil layer (g·cm -3 );D i Indicates the depth of each soil layer (m);

[0044] The gas conditioning function uses a static box to collect CO emitted from farmland soil 2 、N 2 O、CH 4 The soil greenhouse gas emission flux and rate are determined by measuring the gas composition using a gas chromatograph. The emission flux F is calculated as shown in formula (14):

[0045]

[0046] Where M is the molar mass of the greenhouse gas (g mol -1 ), V 0 Refers to the molar volume of greenhouse gases under standard conditions; P and T refer to the actual air pressure (Pa) and temperature (℃) respectively; P 0 , T 0 They refer to the pressure (Pa) and temperature (℃) under the ideal gas standard state, H refers to the box height (m); d c / d t Refers to the slope of the regression curve of the target gas concentration in the box changing with time;

[0047] The plant diversity maintenance function represented by the biodiversity maintenance function is calculated by measuring the plant species and biomass of 50 cm × 50 cm plots to calculate species richness and Shannon index; the calculation formula of Shannon index is shown in formula (15):

[0048]

[0049] Where H is the Shannon index, S is the total number of unique species observed in a plot, and p i is the proportion of S that is composed of the ith species;

[0050] The above indicators are scored in the range of 0.1-1 through a standardized conversion method to obtain the initial scores of different functional indicators; the calculation formula is shown in formula (16):

[0051]

[0052] Among them, T i and P i is the scaled transformation and actual value of parameter i in the system; P min and P max are the maximum and minimum values ​​of the same parameter in the entire production system;

[0053] In the case of greenhouse gas emissions, by subtracting T from 1.1 i After reverse conversion, the calculation formula is shown in formula (17):

[0054]

[0055] The initial comprehensive score T of the ecological service function is obtained by superimposing the initial scores of different functional indicators. The calculation formula is shown in formula (18):

[0056]

[0057] Preferably, in step 4, the specific method is: using SPSS statistical software to perform principal component analysis to obtain the total variance explanation rate and component matrix of the relevant indicators, i.e., the loading coefficient, and weighting the indicators of the multiple functional items; firstly calculating the linear combination coefficient matrix, the comprehensive score coefficients and weights of different indicators, and the calculation formulas are shown in formulas (19), (20) and (21), respectively:

[0058] The formula for calculating the linear combination coefficient matrix is:

[0059]

[0060] Among them, U i is the linear combination coefficient, A i is the factor loading coefficient, λ i is the characteristic value;

[0061] The formula for calculating the comprehensive score coefficients of different indicators is:

[0062]

[0063] Among them, x i The comprehensive score coefficient of the i-th indicator, q i The corresponding variance explained rate, Q cumulative variance explained rate;

[0064] The formula for obtaining the weight value of each indicator by summing and normalizing the comprehensive score coefficients of different indicators is:

[0065]

[0066] Among them, w i is the weight value of the i-th indicator;

[0067] Then, according to the weight value of each indicator, the weight score of different indicators is calculated, and the weight scores of the functional indicators are superimposed to obtain the comprehensive evaluation results of the ecological service function of the rubber agroforestry system to evaluate the comprehensive ecological service function performance of the system. The specific calculation formula is shown in formula (22):

[0068]

[0069] Among them, F is the weighted comprehensive score, T i is the initial score of the ith indicator, w i is the weight value of the ith indicator.

[0070] Compared with the prior art, the present invention has achieved the following technical effects:

[0071] This method first constructs a comprehensive evaluation system for the ecological service functions of the rubber agroforestry system through functional classification, and comprehensively evaluates the ecological service functions of the rubber agroforestry system based on the comprehensive evaluation system for the ecological service functions of the rubber agroforestry system. It can more intuitively reflect the ecological service functions of the rubber agroforestry system, provide reliable data support for its development, and promote the exploration and practice of more sustainable rubber forest development models. BRIEF DESCRIPTION OF THE DRAWINGS

[0072] Figure 1 The present invention is a flow chart of a method for comprehensively evaluating the ecological service function of a rubber composite planting system. DETAILED DESCRIPTION

[0073] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0074] like Figure 1 As shown, the present invention discloses a comprehensive evaluation method for the ecological service function of a rubber composite planting system, comprising the following steps:

[0075] Step 1: Classify the ecological service functions of the rubber agroforestry system and obtain multiple functional items;

[0076] The service functions of rubber agroforestry system were classified into direct function and indirect function according to whether their economic value can be directly measured.

[0077] Among them, the functional items representing the direct functions are mainly product supply functions, including agricultural products and agricultural and sideline products; the functional items representing the indirect functions mainly include soil and water conservation functions, gas regulation functions, and biodiversity maintenance functions;

[0078] Specifically, the sub-function items characterizing the soil and water conservation function include soil conservation function and water regulation function; the sub-function items characterizing the gas regulation function include soil greenhouse gas emissions and global warming potential; the sub-function items characterizing the biodiversity maintenance function include plant diversity maintenance function, earthworm diversity maintenance function, weed suppression function and soil microbial diversity maintenance function;

[0079] The soil and water conservation function includes the following indicators: soil organic matter, total nitrogen, available phosphorus and potassium, bulk density, and pH; the water regulation function includes the following indicators: soil mass water content and volume water content;

[0080] Soil greenhouse gas emissions include soil CO 2 、N 2 O、CH 4 emission fluxes and emission rates;

[0081] Biodiversity maintenance function: the plant diversity maintenance function involves indicators including: plant species, biomass and Shannon diversity index; the weed suppression function involves indicators mainly including weed species and biomass; the earthworm diversity maintenance function involves indicators mainly including earthworm biomass; the soil microbial diversity maintenance function involves indicators including: soil enzyme activity, soil microbial biomass carbon, soil microbial biomass nitrogen, soil bacterial community diversity index;

[0082] Step 2: Determine the indicators involved in multiple functional items according to the actual situation;

[0083] The indicators involved in the product supply function include crop yield and biomass, and the system economic benefit analysis is carried out;

[0084] The economic benefit analysis is to obtain the dynamics of cash inflow and outflow in the production system through input-output analysis of the production cycle of different production systems, and record production input and output; the recorded production input includes fertilizer, organic fertilizer, pesticide, diesel, irrigation, and manpower, and the production output includes harvested products, straw, and wood;

[0085] Step 3: Measure the indicators of multiple functional items and perform data standardization conversion to obtain the initial scores of multiple functional items and the initial comprehensive score of ecological service functions;

[0086] Conduct field tests on indicators of multiple functional items to analyze the impact of rubber agroforestry systems on ecological service functions such as product supply, soil conservation, water regulation, gas regulation, and biodiversity maintenance;

[0087] Specifically, the crop biomass involved in the product supply function is mainly the biomass of rubber trees and intercrops. The biomass of rubber trees is estimated by measuring their plant height and stem diameter. The calculation formula is shown in (1):

[0088] B r =W t +W r ……(1)

[0089] In the formula, B r is the tree biomass (kg), W t is the aboveground biomass (kg), W r is the underground biomass (kg); the underground biomass W r , stem biomass W s , branch biomass W b , leaf biomass W i , aboveground biomass W t The calculation formulas are shown in formula (2), formula (3), formula (4), formula (5) and formula (6), where 0.24 is the root-to-crown ratio in tropical areas;

[0090] W r =w t ×0.24……(2)

[0091] W s =0.0509(DBH 2 ×TH) 0.919 ……(3)

[0092] W b =0.00893(DBH 2 ×TH) 0.977 ……(4)

[0093] W 1 =0.0140(DBH2 ×TH) 0.669 ……(5)

[0094] W t =W s +W b +W 1 ……(6)

[0095] Where DBH is the diameter at breast height (DBH, 1.3 meters), TH is the total height, W s is stem biomass (kg), W b is the branch biomass (kg), W i is leaf biomass (kg);

[0096] The biomass of intercrops was randomly sampled, and multiple representative crops were selected for repeated sampling. The fresh weight was measured, and then placed in an oven, fixed at 105°C for 15 minutes, and dried at 80°C until the weight no longer changed, and the dry weight was measured.

[0097] The formulas for calculating the cost present value (Cost of cultivation), the benefit present value (Costofreturn), and the net present value (NPV) according to the discounted cash flow technique are shown in formula (8), formula (9), and formula (10) respectively:

[0098]

[0099]

[0100]

[0101] Among them C i is the annual cost, B i is the annual return, n is the number of years, r is the discount rate (expressed as 12%), and i is the time period;

[0102] The calculation formulas for soil organic matter, total nitrogen, available phosphorus and potassium reserves are as follows:

[0103] S i =ρ*C i ……(11)

[0104] S i Refers to the soil storage of the i-th nutrient (g·cm -3 );ρ is the soil bulk density of 0-20cm (g·cm -3 );C i is the content of the i-th nutrient in farmland soil (%);

[0105]

[0106] θVi =θ Mi ×ρ bi ×100%……(13)

[0107] Where θ M ,θ V Respectively represent soil mass water content and soil volume water content; W wi , W di Respectively represent the weight of fresh soil and oven-dried soil of each soil layer (g); ρ bi Indicates the soil bulk density of each soil layer (g·cm -3 );D i Indicates the depth of each soil layer (m);

[0108] The gas conditioning function uses a static box to collect CO emitted from farmland soil 2 、N 2 O、CH 4 The soil greenhouse gas emission flux and rate are determined by measuring the gas composition using a gas chromatograph. The emission flux F is calculated as shown in formula (14):

[0109]

[0110] Where M is the molar mass of the greenhouse gas (g mol -1 ), V 0 Refers to the molar volume of greenhouse gases under standard conditions; P and T refer to the actual air pressure (Pa) and temperature (℃) respectively; P 0 , T 0 They refer to the pressure (Pa) and temperature (℃) under the ideal gas standard state, H refers to the box height (m); d c / d t Refers to the slope of the regression curve of the target gas concentration in the box changing with time;

[0111] The plant diversity maintenance function represented by the biodiversity maintenance function is calculated by measuring the plant species and biomass of 50 cm × 50 cm plots to calculate species richness and Shannon index; the calculation formula of Shannon index is shown in formula (15):

[0112]

[0113] Where H is the Shannon index, S is the total number of unique species observed in a plot, and p i is the proportion of S that is composed of the ith species;

[0114] The above indicators are scored in the range of 0.1-1 through a standardized conversion method to obtain the initial scores of different functional indicators; the calculation formula is shown in formula (16):

[0115]

[0116] Among them, T i and P i is the scaled transformation and actual value of parameter i in the system; P min and P max are the maximum and minimum values ​​of the same parameter in the entire production system;

[0117] In the case of greenhouse gas emissions, by subtracting T from 1.1 i After reverse conversion, the calculation formula is shown in formula (17):

[0118]

[0119] The initial comprehensive score T of the ecological service function is obtained by superimposing the initial scores of different functional indicators. The calculation formula is shown in formula (18):

[0120]

[0121] Step 4: weight the indicators of the multiple functions, obtain the weight scores of the multiple function items and perform superposition calculation to obtain the comprehensive evaluation results of the ecological service function of the rubber agroforestry system;

[0122] SPSS statistical software was used to perform principal component analysis to obtain the total variance explanation rate and component matrix of the relevant indicators, i.e., the loading coefficient, and to assign weights to the indicators of the multiple functional items. The linear combination coefficient matrix, the comprehensive score coefficients and weights of different indicators were first calculated. The calculation formulas are shown in formulas (19), (20), and (21), respectively:

[0123] The formula for calculating the linear combination coefficient matrix is:

[0124]

[0125] Among them, U i is the linear combination coefficient, A i is the factor loading coefficient, λ i is the characteristic value;

[0126] The formula for calculating the comprehensive score coefficients of different indicators is:

[0127]

[0128] Among them, x i The comprehensive score coefficient of the i-th indicator, q i The corresponding variance explained rate, Q cumulative variance explained rate;

[0129] The formula for obtaining the weight value of each indicator by summing and normalizing the comprehensive score coefficients of different indicators is:

[0130]

[0131] Among them, w i is the weight value of the i-th indicator;

[0132] Then, according to the weight value of each indicator, the weight score of different indicators is calculated, and the weight scores of the functional indicators are superimposed to obtain the comprehensive evaluation results of the ecological service function of the rubber agroforestry system to evaluate the comprehensive ecological service function performance of the system. The specific calculation formula is shown in formula (22):

[0133]

[0134] Among them, F is the weighted comprehensive score, T i is the initial score of the ith indicator, w i is the weight value of the ith indicator.

[0135] Example 1: “Rubber-Yiyi” agroforestry model

[0136] The case overview of this embodiment is as follows: This case is located in Danzhou City, Hainan Province, and rubber monoculture and "rubber-Yiqi" are used for comparison. The rubber village age is 15 years old and the Yiqi is 4 years old; the rubber tree spacing is 3m, the row spacing is 7m, the Yiqi plant spacing is 1m, the row spacing is 2m, and 3 rows are planted between the rows. The field management of rubber trees and Yiqi is carried out according to local customs.

[0137] The following steps are involved:

[0138] Step 1: Classify the ecological service functions of the rubber agroforestry system and obtain multiple functional items;

[0139] According to whether the economic value can be directly measured, the service functions of the "rubber-yizhi" composite system are classified into direct functions and indirect functions;

[0140] Among them, the functional items representing the direct functions are mainly product supply functions, including agricultural products and agricultural and sideline products; the functional items representing the indirect functions mainly include soil and water conservation functions, gas regulation functions, and biodiversity maintenance functions;

[0141] Step 2: Determine the indicators involved in multiple functional items according to the actual situation;

[0142] This case takes the "rubber-alpinia" composite system as the research object and the pure rubber forest as the control model. Specifically, the indicators involved in the product supply function include the yield and biomass of rubber trees and alpinia, and the system economic benefit analysis is carried out. The above indicators are calculated according to formulas (1)-(6) and (8)-(10);

[0143] Soil and water conservation function The soil conservation function involved indicators include soil organic matter, total nitrogen, available phosphorus and potassium, bulk density, and pH; the water regulation function involved indicators include soil mass water content and volume water content. The above indicators are calculated according to formulas (11)-(13);

[0144] Indicators involved in the gas regulation function include soil CO 2 、N 2 O、CH 4 Emission flux and emission rate and calculation of global warming potential, the above indicators are calculated according to formula (14);

[0145] Biodiversity maintenance function The plant diversity maintenance function involves indicators including: plant species, biomass and Shannon diversity index. The above indicators are calculated according to formula (15);

[0146] The indicators involved in the weed suppression function characterized are mainly the types and biomass of weeds;

[0147] At each point, a 50cm×50cm sample plot was surveyed, and the samples were brought back to the laboratory to measure their fresh weight and identify their species. They were then dried and measured for dry weight, and the diversity and biomass data were summarized.

[0148] The indicators involved in the earthworm diversity maintenance function characterized are mainly the biomass of earthworms. For each point of the earthworm diversity maintenance function, a 25cm×25cm×20cm soil sample was selected to extract earthworms, which were brought back to the laboratory and weighed for fresh weight to estimate earthworm density and biomass;

[0149] The indicators involved in the soil microbial diversity maintenance function characterized include: soil enzyme activity, soil microbial carbon and nitrogen, and soil bacterial community diversity index;

[0150] Soil samples at a depth of 0-20 cm were collected and stored at low temperature. Soil enzyme activity was determined by enzyme-linked immunosorbent assay, soil microbial carbon and nitrogen were calculated by chloroform fumigation method, and soil bacterial community diversity index was calculated according to formula (15);

[0151] Step 3: Measure the indicators of multiple functional items and perform data standardization conversion to obtain the initial scores of multiple functional items and the initial comprehensive score of ecological service functions;

[0152] Conduct field tests on indicators of multiple functional items to analyze the impact of the "rubber-alpinia" composite system on ecological service functions such as product supply, soil conservation, water regulation, gas regulation and biodiversity maintenance. Through correlation analysis between ecological service function indicators, determine the trade-offs and synergies between them;

[0153] The data standardization conversion method was used to obtain the initial scores of different functional indicators of the "rubber-alpinia" composite system, and the initial comprehensive score of the ecological service function of the "rubber-alpinia" composite system was obtained by superimposing the initial scores of different functional indicators. The above indicators were calculated according to formulas (16)-(18);

[0154] Step 4: weight the indicators of the multiple functions, obtain the weight scores of the multiple function items and perform superposition calculation to obtain the comprehensive evaluation results of the ecological service function of the rubber agroforestry system;

[0155] Specifically, SPSS statistical software was used to perform principal component analysis (PCA) to obtain the total variance explanation rate and component matrix of the relevant indicators, i.e., the loading coefficient, and the weights of the indicators of the multiple functional items were assigned through formula calculation;

[0156] According to the weight value of each indicator, the weight score of different indicators is calculated, and the weight scores of the functional item indicators are superimposed to obtain the comprehensive evaluation results of the ecological service function of the "rubber-alpinia" composite system to evaluate the comprehensive ecological service function performance of the system; the above indicators are calculated according to formulas (19)-(22).

[0157] Analysis of measurement results:

[0158] From the perspective of initial scores, the initial score of the comprehensive index of the "rubber-yizhi" composite system is 11.442, and that of the pure rubber forest is 11.040. The comprehensive index score of the composite system is 3.64% higher than that of the pure rubber forest, as shown in Table 1; from the perspective of weight scores, the weight score of the comprehensive index of the composite system is 0.634, and that of the pure rubber forest is 0.331. The comprehensive index score of the composite system is 91.46% higher than that of the pure rubber forest, as shown in Table 2.

[0159] Table 1 Initial scores of ecosystem service function indicators

[0160]

[0161]

[0162] Table 2 Ecosystem service function indicator weight score

[0163]

[0164]

[0165] Therefore, from the perspective of comprehensive evaluation of ecological service functions, the "rubber-alpinia" composite system is more conducive to promotion and planting. This method first constructs a comprehensive evaluation system of the ecological service functions of the rubber agroforestry system through functional classification, and comprehensively evaluates the ecological service functions of the rubber agroforestry system based on the comprehensive evaluation system of the ecological service functions of the rubber agroforestry system. It can more intuitively reflect the ecological service functions of the rubber agroforestry system, provide reliable data support for its development, and promote the exploration and practice of a more sustainable rubber forest development model.

[0166] The above description is only a preferred embodiment of the present invention and does not limit the technical scope of the present invention. Therefore, any slight modifications, equivalent changes and modifications made to the above embodiments based on the technical essence of the present invention are still within the scope of the technical solution of the present invention.

Claims

1. A comprehensive evaluation method for the ecological service function of a rubber composite planting system, characterized in that: The steps include: Step 1: Classify the ecological service functions of the rubber agroforestry system and obtain multiple functional items; Step 2: Determine the indicators involved in multiple functional items according to the actual situation; Step 3: Measure the indicators of multiple functional items and perform data standardization conversion to obtain the initial scores of multiple functional items and the initial comprehensive score of ecological service functions; Step 4: Assign weights to the indicators of the multiple functions, obtain weight scores of the multiple functional items and perform superposition calculations to obtain a comprehensive evaluation result of the ecological service function of the rubber agroforestry system.

2. The method for comprehensively evaluating the ecological service function of a rubber composite planting system according to claim 1, characterized in that: In the step 1, the service functions of the rubber agroforestry system are classified into a primary level according to whether the economic value can be directly measured, and direct functions and indirect functions are obtained; Among them, the functional items representing the direct functions are mainly product supply functions, including agricultural products and agricultural and sideline products; the functional items representing the indirect functions mainly include soil and water conservation functions, gas regulation functions, and biodiversity maintenance functions; Specifically, the sub-function items characterizing the soil and water conservation function include soil conservation function and water regulation function; the sub-function items characterizing the gas regulation function include soil greenhouse gas emissions and global warming potential; the sub-function items characterizing the biodiversity maintenance function include plant diversity maintenance function, earthworm diversity maintenance function, weed suppression function and soil microbial diversity maintenance function.

3. The comprehensive evaluation method for the ecological service function of a rubber composite planting system according to claim 1 is characterized in that: In step 2, the indicators involved in the product supply function include crop yield and biomass, and a system economic benefit analysis is performed.

4. The method for comprehensively evaluating the ecological service function of a rubber composite planting system according to claim 2, characterized in that: The soil and water conservation function includes the following indicators: soil organic matter, total nitrogen, available phosphorus and potassium, bulk density, and pH; the water regulation function includes the following indicators: soil mass water content and volume water content; Soil greenhouse gas emissions include soil CO2, N2O, and CH4 emission fluxes and emission rates; Biodiversity maintenance function, among which the plant diversity maintenance function involves indicators including: plant species, biomass and Shannon diversity index; the weed suppression function involves indicators mainly including weed species and biomass; the earthworm diversity maintenance function involves indicators mainly including earthworm biomass; the soil microbial diversity maintenance function involves indicators including: soil enzyme activity, soil microbial biomass carbon, soil microbial biomass nitrogen, and soil bacterial community diversity index.

5. The comprehensive evaluation method of the ecological service function of a rubber composite planting system according to claim 3 is characterized in that: The economic benefit analysis is to obtain the dynamics of cash inflow and outflow in the production system and record production input and output through input-output analysis of the production cycle of different production systems; the recorded production input includes fertilizer, organic fertilizer, pesticide, diesel, irrigation, and manpower, and the production output includes harvested products, straw, and wood.

6. The comprehensive evaluation method of the ecological service function of the rubber composite planting system according to claim 3 is characterized in that: The specific method of step 3 is: conducting field test measurements on indicators of multiple functional items, analyzing the impact of the rubber agroforestry system on ecological service functions such as product supply, soil conservation, water regulation, gas regulation and biodiversity maintenance; Specifically, the crop biomass involved in the product supply function is mainly the biomass of rubber trees and intercrops. The biomass of rubber trees is estimated by measuring their plant height and stem diameter. The calculation formula is shown in (1): B r =W t +W r ……(1) In the formula, B r is the tree biomass (kg), W t is the aboveground biomass (kg), W r is the underground biomass (kg); the underground biomass W r , stem biomass W s , branch biomass W b , leaf biomass W i , aboveground biomass W t The calculation formulas are shown in formula (2), formula (3), formula (4), formula (5) and formula (6), where 0.24 is the root-to-crown ratio in tropical areas; IN r =in t ×0.24……(2) W s =0.0509(DBH 2 ×TH) 0.919 ……(3) W b =0.00893(DBH 2 ×TH) 0.977 ……(4) W1=0.0140(DBH 2 ×TH) 0.669 ……(5) W t =W s +W b +W1……(6) Where DBH is the diameter at breast height (DBH, 1.3 meters), TH is the total height, W s is stem biomass (kg), W b is the branch biomass (kg), W i is leaf biomass (kg); The biomass of intercrops was randomly sampled, and multiple representative crops were selected for repeated sampling. The fresh weight was measured, and then placed in an oven, fixed at 105°C for 15 minutes, and dried at 80°C until the weight no longer changed, and the dry weight was measured. The formulas for calculating the cost present value (Cost of cultivation), the benefit present value (Costofreturn), and the net present value (NPV) according to the discounted cash flow technique are shown in formula (8), formula (9), and formula (10) respectively: Among them C i is the annual cost, B i is the annual return, n is the number of years, r is the discount rate (expressed as 12%), and i is the time period; The calculation formulas for soil organic matter, total nitrogen, available phosphorus and potassium reserves are as follows: S i =ρ*C i ……(11) S i Refers to the soil storage of the i-th nutrient (g·cm -3 );ρ is the soil bulk density of 0-20cm (g·cm -3 );C i is the content of the i-th nutrient in farmland soil (%); i Vi =θ Mi ×r bi ×100%……(13) Where θ M ,θ V Respectively represent soil mass water content and soil volume water content; W wi , W di Respectively represent the weight of fresh soil and oven-dried soil of each soil layer (g); ρ bi Indicates the soil bulk density of each soil layer (g·cm -3 );D i Indicates the depth of each soil layer (m); The gas regulation function uses a static box to collect CO2, N2O, and CH4 emitted from farmland soil, and uses a gas chromatograph to measure the gas composition to determine the soil greenhouse gas emission flux and rate. The emission flux F calculation formula is shown in formula (14): Where M is the molar mass of the greenhouse gas (g mol -1 ), V0 refers to the molar volume of greenhouse gas under standard conditions; P and T refer to the actual air pressure (Pa) and air temperature (℃) respectively; P0 and T0 refer to the pressure (Pa) and temperature (℃) under ideal gas standard conditions respectively, and H refers to the height of the box (m); d c / d t Refers to the slope of the regression curve of the target gas concentration in the box changing with time; The plant diversity maintenance function represented by the biodiversity maintenance function is calculated by measuring the plant species and biomass of 50 cm × 50 cm plots to calculate species richness and Shannon index; the calculation formula of Shannon index is shown in formula (15): Where H is the Shannon index, S is the total number of unique species observed in a plot, and p i is the proportion of S that is composed of the ith species; The above indicators are scored in the range of 0.1-1 through a standardized conversion method to obtain the initial scores of different functional indicators; the calculation formula is shown in formula (16): Among them, T i and P i is the scaled transformation and actual value of parameter i in the system; P min and P max are the maximum and minimum values ​​of the same parameter in the entire production system; In the case of greenhouse gas emissions, by subtracting T from 1.1 i After reverse conversion, the calculation formula is shown in formula (17): The initial comprehensive score T of the ecological service function is obtained by superimposing the initial scores of different functional indicators. The calculation formula is shown in formula (18):

7. The comprehensive evaluation method of the ecological service function of a rubber composite planting system according to claim 1 is characterized in that: In step 4, the specific method is: using SPSS statistical software to perform principal component analysis to obtain the total variance explanation rate and component matrix of the relevant indicators, i.e., the loading coefficient, and weight allocation for the indicators of the multiple functional items; firstly calculating the linear combination coefficient matrix, the comprehensive score coefficients and weights of different indicators, and the calculation formulas are shown in formulas (19), (20), and (21), respectively: The formula for calculating the linear combination coefficient matrix is: Among them, U i is the linear combination coefficient, A i is the factor loading coefficient, λ i is the characteristic value; The formula for calculating the comprehensive score coefficients of different indicators is: Among them, x i The comprehensive score coefficient of the i-th indicator, q i The corresponding variance explained rate, Q cumulative variance explained rate; The formula for obtaining the weight value of each indicator by summing and normalizing the comprehensive score coefficients of different indicators is: Among them, w i is the weight value of the i-th indicator; Then, according to the weight value of each indicator, the weight score of different indicators is calculated, and the weight scores of the functional indicators are superimposed to obtain the comprehensive evaluation results of the ecological service function of the rubber agroforestry system to evaluate the comprehensive ecological service function performance of the system. The specific calculation formula is shown in formula (22): Among them, F is the weighted comprehensive score, T i is the initial score of the ith indicator, w i is the weight value of the ith indicator.

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