A comprehensive evaluation method for ecological service functions of a rubber complex plantation system

Abstract

The application discloses a kind of rubber composite planting system ecological service function comprehensive evaluation method, comprising the following steps: step one, the ecological service function classification of rubber agroforestry system is carried out, obtains multiple function items;Step two, according to actual situation, determine the index involved in multiple function items;Step three, the index of multiple function items is determined and data standardization conversion, obtains the initial score of multiple function items and the initial comprehensive score of ecological service function;Step four, the index of multiple function is allocated weight, obtains the weight score of multiple function items and is superimposed calculation, obtains the comprehensive evaluation result of rubber agroforestry system ecological service function.The application can more directly reflect the ecological service function of rubber agroforestry system, provide reliable data support for its development, promote the exploration and practice of more sustainable rubber forest development mode.

Description

TECHNICAL FIELD

[0001] The present application relates to the field of ecological evaluation of agricultural systems, and particularly relates to a comprehensive evaluation method for ecological service functions of rubber complex planting systems. BACKGROUND

[0002] With the rapid expansion of the area of rubber tree monoculture, the impact of rubber planting on the ecological environment has increasingly attracted attention. Some studies have compared it with primary natural forests and pointed out that it may bring about negative effects such as biodiversity decline and soil erosion. To address these problems, many studies have proposed that rubber agroforestry models can improve ecological diversity, increase resource utilization efficiency and comprehensive output, and become an important direction for optimizing rubber planting systems.

[0003] Rubber agroforestry technology is widely recognized as an effective way to improve rubber monoculture. However, the comprehensive evaluation of its ecological benefits still needs further in-depth study. In fact, the ecological benefits of agricultural and forestry planting systems involve multiple dimensions, and a single or small number of indicators often cannot fully reflect the overall advantages and disadvantages. Therefore, it is particularly important to use a comprehensive evaluation method with multiple dimensions. Among them, the evaluation of ecosystem services as a comprehensive evaluation method has been widely used in agriculture and forestry fields to scientifically measure the ecological benefits and sustainability of these planting systems.

[0004] Ecosystem services refer to the natural environmental conditions and benefits that humans rely on for survival provided by ecosystems and their processes. For many years, the evaluation method of ecosystem services has been widely used in many research fields at home and abroad. According to the classification framework of ecosystem services proposed by the Millennium Assessment Working Group (MA), current ecosystem services can be mainly divided into four categories: product supply, regulation function, support function and cultural function.

[0005] However, agricultural and forestry ecosystems are extremely diverse in type, and the application scenarios of ecosystem services also have certain limitations. For example, rubber forest-based ecosystems, although they can be effectively evaluated in terms of product supply, regulation function and support function (except for coastal wind and sand fixation function), there are certain difficulties in evaluating cultural service function. Obviously, the applicability of the existing evaluation method of ecosystem services in rubber forest ecosystems still has deficiencies.

[0006] Therefore, it is necessary to establish an optimized method suitable for evaluating the ecosystem service functions of rubber agroforestry systems. By comprehensively evaluating their ecological benefits, the ecological service functions of different rubber agroforestry models can be fully evaluated, and 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

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

[0008] To solve the above technical problems, the present application adopts the following technical solutions:

[0009] A comprehensive evaluation method for ecological service function of rubber complex planting system, comprising the following steps:

[0010] Step 1: classifying the ecological service function of rubber agroforestry system to obtain a plurality of function items;

[0011] Step 2: determining the indexes involved in the plurality of function items according to the actual situation;

[0012] Step 3: measuring and data standardization converting the indexes of the plurality of function items to obtain the initial scores of the plurality of function items and the initial comprehensive score of the ecological service function;

[0013] Step 4: weight distribution of the indexes of the plurality of functions, obtaining the weight score of the plurality of function items and superimposing calculation to obtain the comprehensive evaluation result of the ecological service function of rubber agroforestry system.

[0014] Preferably, in step 1, the service function of rubber agroforestry system is classified according to whether it can directly measure economic value to obtain direct function and indirect function;

[0015] Among them, the function item representing the direct function is mainly product supply function, including agricultural products and sideline products; the function item representing the indirect function mainly includes soil and water conservation function, gas regulation function and biodiversity maintenance function;

[0016] Specifically, the sub-function items representing the soil and water conservation function include soil conservation function and water regulation function; the sub-function items representing the gas regulation function include soil greenhouse gas emission and global warming potential; the sub-function items representing 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 indexes involved in the product supply function include the yield and biomass of crops, and the system economic benefit analysis is carried out.

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

[0019] The soil greenhouse gas emission includes soil CO2, N2O and CH4 emission flux and emission rate;

[0020] The plant diversity maintenance function characterized by the index includes plant species, biomass and shannon diversity index; the weed suppression function characterized by the index mainly includes weed species and biomass; the earthworm diversity maintenance function characterized by the index mainly includes earthworm biomass; the soil microbial diversity maintenance function characterized by the index includes soil enzyme activity, soil microbial carbon, soil microbial nitrogen and soil bacterial community diversity index.

[0021] Preferably, the economic benefit analysis is obtained by input-output analysis of different production systems in a production cycle, the dynamic of cash inflow and outflow in the production system is obtained, and the production input and output are recorded; the recorded production input includes chemical fertilizer, organic fertilizer, pesticide, diesel, irrigation and manpower, and the production output includes harvested products, straw and wood.

[0022] Preferably, the specific method of step 3 is to conduct field test determination on the index of multiple function items, and analyze the influence of the rubber agroforestry system on product supply, soil conservation, water regulation, gas regulation and biodiversity maintenance and other ecological service functions;

[0023] Specifically, the crop biomass involved in the product supply function mainly includes the biomass of rubber trees and intercropped crops, wherein the biomass of rubber trees is estimated by measuring the tree height and stem diameter, and the calculation formula is shown as formula (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), and W r is the underground biomass (kg); the calculation formulas of the underground biomass W r , stem biomass W s , branch biomass W b , leaf biomass W i and aboveground biomass W t are respectively shown as formula (2), formula (3), formula (4), formula (5) and formula (6), wherein 0.24 is the root-shoot ratio in tropical regions;

[0026] W r = w t ×0.24……(2)

[0027] W s= 0.0509(DBH 2 x TH) 0.919 …(3)

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

[0029] W1= 0.0140(DBH 2 x TH) 0.669 …(5)

[0030] W t = W s + W b + W1…(6)

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

[0032] The biomass of the intercropped crops was repeatedly sampled by randomly selecting multiple representative crops, weighing the fresh weight, then placing them in an oven, killing green at 105°C for 15 min, and drying at 80°C until the weight no longer changed, and weighing the dry weight;

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

[0034]

[0035]

[0036]

[0037] where C i is the annual cost, B i is the annual income, n is the number of years, r is the discount rate (12% represents), and i is the time period;

[0038] The formula for calculating the soil organic matter, total nitrogen, available phosphorus, and potassium reserves is as follows:

[0039] S i = p * C i …(11)

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

[0041]

[0042] θ Vi = θ Mi × ρ bi × 100% ……(13)

[0043] In the formula, θ M and θ V represent the soil mass moisture content and the soil volume moisture content, respectively; W wi and W di represent the fresh soil weight and the oven-dried soil weight (g) in each soil layer, respectively; ρ bi represents the soil bulk density (g·cm -3 ) in each soil layer; D i represents the depth (m) of each soil layer.

[0044] The gas regulation function collects the CO2, N2O and CH4 emitted by the farmland soil by using a static box, measures the gas composition by using a gas chromatograph to determine the soil greenhouse gas emission flux and rate, and the emission flux F is calculated according to the formula (14):

[0045]

[0046] In the formula, M represents the molar mass (g mol -1 ) of the greenhouse gas, V0 represents the molar volume of the greenhouse gas under the standard state; P and T represent the actual air pressure (Pa) and the air temperature (℃), respectively; P0 and T0 represent the pressure (Pa) and the temperature (℃) under the standard state of the ideal gas, respectively; H represents the height (m) of the box; d c / d t represents the regression curve slope of the target gas concentration in the box with respect to time;

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

[0048]

[0049] In the formula, 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 composed of the i-th species.

[0050] The above indicators are converted by a standardization conversion method, scored in the range of 0.1-1, and the initial scores of different functional indicators are obtained; the calculation formula is shown in formula (16):

[0051]

[0052] Wherein, T i and P i are the scaling 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, the reverse conversion is performed by subtracting T i from 1.1, and the calculation formula is shown in formula (17):

[0054]

[0055] And the initial comprehensive score T of ecological service function is obtained by superimposing the initial scores of different functional indicators, and 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 (i.e. loading coefficient) of the relevant indicators, and to perform weight distribution on the indicators of multiple functional items; first, calculate the linear combination coefficient matrix, the comprehensive score coefficient and weight of different indicators, and the calculation formulas are shown in formula (19), formula (20) and formula (21) respectively:

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

[0059]

[0060] Wherein, U i is the linear combination coefficient, A i is the factor loading coefficient, and λ i is the eigenvalue;

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

[0062]

[0063] Wherein, x i is the comprehensive score coefficient of the i-th indicator, q i is the corresponding variance explanation rate, and Q is the cumulative variance explanation rate;

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

[0065]

[0066] Wherein, w i is the weight value of the i th index;

[0067] Then, according to the weight value of each index, the weight score of different indexes is calculated, the weight score of the function item index is superimposed and calculated, and the comprehensive evaluation result of the ecological service function of the rubber agroforestry system is obtained, so as to evaluate the comprehensive ecological service function performance of the system. The specific calculation formula is shown in formula (22):

[0068]

[0069] Wherein, F is the weight comprehensive score, T i is the initial score of the i th index, w i is the weight value of the i th index.

[0070] The present application has the following technical effects compared with the prior art:

[0071] The method first constructs a comprehensive evaluation system of ecological service function of rubber agroforestry system through function classification, and comprehensively evaluates the ecological service function of rubber agroforestry system based on the comprehensive evaluation system of ecological service function of rubber agroforestry system, so as to more directly reflect the ecological service function of rubber agroforestry system, provide reliable data support for its development, and promote the exploration and practice of more sustainable rubber forest development mode. BRIEF DESCRIPTION OF DRAWINGS

[0072] Figure 1 The flowchart of the comprehensive evaluation method of ecological service function of the rubber composite planting system. DETAILED DESCRIPTION

[0073] The technical solutions in the embodiments of the present application will be described clearly and completely below with reference to the drawings in the embodiments of the present application. Obviously, the described embodiments are only part of the embodiments of the present application, not all. Based on the embodiments in the present application, all other embodiments obtained by those skilled in the art without creative labor are within the scope of protection of the present application.

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

[0075] Step one, classifying the ecological service function of rubber agroforestry system to obtain a plurality of function items;

[0076] According to whether the economic value can be directly measured, the service functions of the rubber agroforestry system are classified into direct functions and indirect functions;

[0077] Among them, the function item representing the direct function is mainly the product supply function, including agricultural products and sideline products; the function item representing the indirect function mainly includes water and soil conservation function, gas regulation function, biodiversity maintenance function;

[0078] Specifically, the sub-function item representing the water and soil conservation function includes soil conservation function and water regulation function; the sub-function item representing the gas regulation function includes soil greenhouse gas emission and global warming potential; the sub-function item representing the biodiversity maintenance function includes plant diversity maintenance function, earthworm diversity maintenance function, weed suppression function and soil microbial diversity maintenance function;

[0079] The soil conservation function represented by the soil conservation function involves indexes including soil organic matter, total nitrogen, available phosphorus and potassium, bulk density, pH; the water regulation function involves indexes including soil moisture content and volume moisture content;

[0080] The soil greenhouse gas emission includes soil CO2, N2O and CH4 emission flux and emission rate;

[0081] The biodiversity maintenance function represented by the plant diversity maintenance function involves indexes including plant species, biomass and shannon diversity index; the weed suppression function involves indexes mainly including weed species and biomass; the earthworm diversity maintenance function involves indexes mainly including earthworm biomass; the soil microbial diversity maintenance function involves indexes including soil enzyme activity, soil microbial biomass carbon, soil microbial biomass nitrogen and soil bacterial community diversity index;

[0082] Step two, according to the actual situation, determine the indexes involved in multiple function items;

[0083] The product supply function involves indexes including crop yield and biomass, and the system economic benefit analysis is carried out;

[0084] The economic benefit analysis is obtained by input-output analysis of different production systems in production cycle, to obtain the dynamic of cash inflow and outflow in production system, to record production input and output; the recording production input includes chemical fertilizer, organic fertilizer, pesticide, diesel, irrigation, manpower, and the production output includes harvested products, straw and timber;

[0085] Step three, measure the indexes of multiple function items and carry out data standardization conversion, to obtain the initial scores of multiple function items and the initial comprehensive score of ecological service function;

[0086] The indicators of the plurality of function items are determined by field test, and the influence of the rubber agroforestry system on the ecological service functions such as product supply, soil conservation, water regulation, gas regulation and biodiversity maintenance is analyzed;

[0087] Specifically, the crop biomass involved in the product supply function mainly includes the biomass of rubber trees and the biomass of intercropped crops, wherein the biomass of rubber trees is estimated by measuring the tree height and the stem diameter, and the calculation formula is shown as formula (1):

[0088] B r = W t +W r ……(1)

[0089] In the formula, B r is the biomass of trees (kg), W t is the aboveground biomass (kg), and W r is the underground biomass (kg); the calculation formulas of the underground biomass W r , the stem biomass W s , the branch biomass W b , the leaf biomass W i and the aboveground biomass W t are respectively shown as formula (2), formula (3), formula (4), formula (5) and formula (6), wherein 0.24 is the root-shoot ratio in tropical regions;

[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] W1= 0.0140(DBH 2 ×TH) 0.669 ……(5)

[0094] W t = W s +W b +W1……(6)

[0095] In the formula, DBH is the diameter at breast height (DBH, 1.3 meters), TH is the total height, W s is the stem biomass (kg), W b is the branch biomass (kg), and Wi Leaf biomass (kg) ;

[0096] The biomass of interplanting crops was repeatedly sampled by randomly selecting multiple representative crops, weighing their fresh weight, then placing them in an oven, killing green at 105°C for 15 min, and drying at 80°C until the weight no longer changed, and weighing the dry weight;

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

[0098]

[0099]

[0100]

[0101] where C i is the annual cost, B i is the annual benefit, n is the number of years, r is the discount rate (12% indicates), and i is the time period;

[0102] The formula for calculating the soil organic matter, total nitrogen, available phosphorus, and potassium reserves is as follows:

[0103] S i = p * C i ……(11)

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

[0105]

[0106] θ Vi = θ Mi * p bi * 100% ……(13)

[0107] In the formula, θ M , θ V represent the soil mass moisture content and the soil volume moisture content, respectively; W wi , W di represent the fresh soil and dried soil weight of each soil layer (g); p bi represents the soil bulk density of each soil layer (g·cm -3 ); D iindicates the depth of each soil layer (m);

[0108] The gas regulation function collects CO2, N2O and CH4 emitted by farmland soil using a static box, and determines the soil greenhouse gas emission flux and rate by measuring the gas composition using a gas chromatograph. The emission flux F is calculated according to formula (14):

[0109]

[0110] In the formula, M refers to the molar mass (g mol -1 ) of the greenhouse gas; V0 refers to the molar volume of the 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 the standard conditions of an ideal gas, respectively; H refers to the height of the box (m); d c / d t is the regression curve slope of the concentration of the target gas in the box over time;

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

[0112]

[0113] In the formula, 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 composed of the i-th species.

[0114] The above indicators are converted by a standardization conversion method to score in the range of 0.1-1 to obtain the initial scores of different function indicators. The calculation formula is shown in formula (16):

[0115]

[0116] In the formula, T i and P i are the scaling 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, the reverse conversion is performed by subtracting T i from 1.1, and the calculation formula is shown in formula (17):

[0118]

[0119] And through the different functional indicators initial score superposition calculation, get the initial comprehensive score T of ecological service function, the formula is shown as formula (18):

[0120]

[0121] Step four, a plurality of said function index weight distribution, get a plurality of function item weight score and superposition calculation, get the rubber agroforestry system ecological service function comprehensive evaluation results;

[0122] Using SPSS statistical software for principal component analysis, get the total variance of the relevant indicators explained rate and component matrix, namely the load coefficient, the weight distribution of a plurality of said function item index;First calculate the linear combination coefficient matrix, different index comprehensive score coefficient and weight, the formula is shown as formula (19), formula (20) and formula (21):

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

[0124]

[0125] Wherein, U i is the linear combination coefficient, A i is the factor loading coefficient, λ i is the eigenvalue;

[0126] The formula for calculating the comprehensive score coefficient of different indexes is:

[0127]

[0128] Wherein, x i The comprehensive score coefficient of the ith index, q i The corresponding variance explained rate, Q cumulative variance explained rate;

[0129] The formula for summing and normalizing the comprehensive score coefficient of different indexes to obtain the weight value of each index is:

[0130]

[0131] Wherein, w i is the weight value of the ith index;

[0132] Then according to the weight value of each index, calculate the weight score of different indexes, superimpose the weight score of said function item index, get the rubber agroforestry system ecological service function comprehensive evaluation results, to evaluate the comprehensive ecological service function performance of the system. The specific calculation formula is shown as formula (22):

[0133]

[0134] wherein F is the weighted comprehensive score, T i is the initial score of the i-th indicator, w i is the weight value of the i-th indicator.

[0135] Example 1: Rubber-Canarium lucidum Agroforestry Model

[0136] The case profile of this example is as follows: the case is located in Danzhou City, Hainan Province, and compares rubber monoculture and "rubber-Canarium lucidum" as the object, the rubber village age is 15 years old, and Canarium lucidum is 4 years old; the distance between rubber trees is 3m, the row spacing is 7m, the distance between Canarium lucidum trees is 1m, the row spacing is 2m, and 3 rows are planted between the rows, and the interplant management of rubber trees and Canarium lucidum is operated according to local customs.

[0137] comprising the following steps:

[0138] Step one, classifying the ecological service functions of the rubber agroforestry system to obtain multiple function items;

[0139] According to whether it can directly measure economic value, the service functions of the "rubber-Canarium lucidum" complex system are classified into direct functions and indirect functions;

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

[0141] Step two, according to the actual situation, determine the indicators involved in multiple function items;

[0142] This case takes the "rubber-Canarium lucidum" complex system as the research object, and takes 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 Canarium lucidum, and the system economic benefit analysis is carried out. The above indicators are calculated according to formulas (1)-(6) and (8)-(10);

[0143] The soil conservation function represented 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 involves indicators including soil moisture content and volume water content. The above indicators are calculated according to formulas (11)-(13);

[0144] The indicators involved in the gas regulation function include soil CO2, N2O, CH4 emission flux and emission rate, and calculation of global warming potential. The above indicators are calculated according to formula (14);

[0145] The plant diversity maintenance function characterized by the indicators including: plant species, biomass and shannon diversity index, which are calculated according to formula (15);

[0146] The weed suppression function characterized by the indicators mainly including the species and biomass of weeds;

[0147] Each point surveys a 50cm*50cm quadrat, and the sample is taken back to the laboratory to measure the fresh weight and identify the species, and then the dry weight is measured after drying, and the diversity and biomass data are obtained by summarizing;

[0148] The earthworm diversity maintenance function characterized by the indicators mainly including the biomass of earthworms. The earthworm diversity maintenance function selects a 25cm*25cm*20cm soil quadrat to extract earthworms at each point, which are taken back to the laboratory to weigh the fresh weight to estimate the earthworm density and biomass;

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

[0150] Soil samples are taken from the depth of 0-20cm, and are stored at low temperature. The soil enzyme activity is measured by enzyme-linked immunoassay, the soil microbial carbon and nitrogen are calculated by chloroform fumigation method, and the soil bacterial community diversity index is calculated according to formula (15);

[0151] Step three, the indicators of multiple function items are measured and data standardized, to obtain the initial scores of multiple function items and the initial comprehensive scores of ecological service functions;

[0152] The indicators of multiple function items are measured in field tests, and the influence of the "rubber-yizhi" complex system on the ecological service functions such as product supply, soil conservation, water regulation, gas regulation and biodiversity maintenance is analyzed. The trade-off and synergistic effect between them are determined by correlation analysis of the ecological service function indicators;

[0153] The initial scores of different function indicators of the "rubber-yizhi" complex system are obtained by using data standardization conversion method, and the initial comprehensive scores of the ecological service functions of the "rubber-yizhi" complex system are obtained by superposition calculation of different function indicator initial scores. The above indicators are calculated according to formula (16)-(18);

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

[0155] Specifically, the SPSS statistical software is used for principal component analysis (PCA) to obtain total variance explanation rate of the related indexes and component matrix, i.e., loading coefficient, and the weight distribution of the indexes of multiple function items is calculated through a formula.

[0156] According to the weight values of the indexes, the weight scores of different indexes are calculated, the weight scores of the indexes of the function items are superimposed, and the comprehensive evaluation result of the ecological service function of the "rubber- intelligence" compound system is obtained to evaluate the comprehensive ecological service function performance of the system.

[0157] Analysis of the determination results:

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

[0159] Table 1: Initial score of the ecological system service function index

[0160]

[0161]

[0162] Table 2: Weight score of the ecological system service function index

[0163]

[0164]

[0165] Therefore, from the perspective of comprehensive evaluation of ecological service function, the "rubber-intelligence" compound system is more conducive to promotion and planting. The method first constructs a comprehensive evaluation system of ecological service function of rubber agroforestry compound system through function classification, and comprehensively evaluates the ecological service function of rubber agroforestry compound system based on the comprehensive evaluation system of ecological service function of rubber agroforestry compound system, which can more directly reflect the ecological service function of rubber agroforestry compound system, provide reliable data support for its development, and promote the exploration and practice of more sustainable rubber forest development mode.

[0166] The above is only a preferred embodiment of the present application, and does not limit the technical scope of the present application in any way. Any slight modification, equivalent change and modification made according to the technical essence of the present application to the above embodiment are still within the scope of the technical solution of the present application.

Claims

1. A comprehensive evaluation method of ecological service functions of a rubber complex plantation system, characterized by, The method comprises the following steps: Step 1, classifying the ecological service functions of the rubber agroforestry system to obtain a plurality of function items; Step 2, determining the indexes involved in the plurality of function items according to the actual situation; Step 3, measuring and standardizing 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 functions; Step 4, distributing the weights of the indexes of the plurality of function items, obtaining the weighted scores of the plurality of function items, and performing superposition calculation to obtain the comprehensive evaluation result of the ecological service functions of the rubber agroforestry system; In step 1, the service functions of the rubber agroforestry system are classified into direct functions and indirect functions according to whether the economic value can be directly measured. The function items representing the direct functions include product supply functions, including agricultural products and sideline products; the function items representing the indirect functions include water and soil conservation functions, gas regulation functions, and biodiversity maintenance functions. Specifically, the sub-function items representing the water and soil conservation functions include soil conservation functions and water regulation functions; the sub-function items representing the gas regulation functions include soil greenhouse gas emissions and global warming potential; and the sub-function items representing the biodiversity maintenance functions include plant diversity maintenance functions, earthworm diversity maintenance functions, weed suppression functions, and soil microbial diversity maintenance functions. The specific method of step 3 is to perform field test measurement on the indexes of the plurality of function items to analyze the influence of the rubber agroforestry system on the ecological service functions of product supply, soil conservation, water regulation, gas regulation, and biodiversity maintenance. The above indexes are scored in the range of 0.1-1 through standardization conversion method to obtain initial scores of different function indexes; the calculation formula is shown as formula (16): ……（16） where T i and P i are the scaled and actual values 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 The reverse conversion is performed, and the calculation formula is shown in equation (17): ……（17） And the initial comprehensive score T of the ecological service functions is obtained by superposition calculation of the initial scores of different function indexes; the calculation formula is shown as formula (18): ……（18）； In step 4, the specific method is to use SPSS statistical software to perform principal component analysis to obtain the total variance explanation rate and component matrix (i.e. loading coefficient) of the related indexes, and distribute the weights of the indexes of the plurality of function items; first, calculate the linear combination coefficient matrix, the comprehensive score coefficient of different indexes, and the comprehensive score weight of different indexes; the calculation formulas are shown as formula (19), formula (20), and formula (21) respectively: The formula of the linear combination coefficient matrix is: ……（19） wherein, is a linear combination coefficient, is a factor loading coefficient, is an eigenvalue; The formula of the comprehensive score coefficient of different indexes is: ……（20） wherein, a coefficient of the composite score of the i-th indicator, a corresponding variance explained, Q cumulative variance explained; The formula of the comprehensive score weight of different indexes is: ……（21） wherein, is the weight value for the i-th indicator; Then, according to the weight values, the weighted scores of different indexes are calculated, the weighted scores of the indexes of the function items are superposed and calculated to obtain the comprehensive evaluation result of the ecological service functions of the rubber agroforestry system, so as to evaluate the comprehensive ecological service function performance of the system; the specific calculation formula is shown as formula (22): ……（22） wherein F is the comprehensive evaluation result, is the initial score of the i-th index, is the weight value of the i-th index.

2. The method according to claim 1, wherein, In step 2, the indexes involved in the product supply function include the yield and biomass of crops, and the system economic benefit analysis is performed.

3. The method according to claim 1, wherein, The soil conservation function characterized by the water and soil conservation function involves indexes including soil organic matter, total nitrogen, available phosphorus and potassium, bulk density, and pH; the water regulation function characterized by the water regulation function involves indexes including soil mass moisture content and volume moisture content; The soil greenhouse gas emission includes soil CO2, N2O, CH4 emission flux and emission rate; The biodiversity maintenance function, wherein the indexes of the plant diversity maintenance function characterized by the biodiversity maintenance function include plant species, biomass, and shannon diversity index; the indexes of the weed suppression function characterized by the biodiversity maintenance function include weed species and biomass; the index of the earthworm diversity maintenance function characterized by the biodiversity maintenance function is earthworm biomass; and the indexes of the soil microorganism diversity maintenance function characterized by the biodiversity maintenance function include soil enzyme activity, soil microbial biomass carbon, soil microbial biomass nitrogen, and soil bacterial community diversity index.

4. The method according to claim 2, wherein, The economic benefit analysis is obtained by input-output analysis of different production systems in a production cycle, and the dynamic of cash inflow and outflow in the production system is recorded, and the production input and output are recorded; the recorded production input includes chemical fertilizer, organic fertilizer, pesticide, diesel, irrigation, and manpower, and the production output includes harvested products, straw, and wood.

5. The method according to claim 3, wherein, Specifically, the crop biomass involved in the product supply function is the biomass of rubber trees and the biomass of intercropped crops, wherein the biomass of rubber trees is estimated by measuring the plant height and stem diameter, and the calculation formula is shown as formula (1): ……（1） wherein B r is the tree biomass in kg, W t is the aboveground biomass in kg, W r is the underground biomass in kg; the underground biomass W r , stem biomass W s , branch biomass W b , leaf biomass W i , aboveground biomass W t is calculated according to formula (2), formula (3), formula (4), formula (5) and formula (6), respectively, wherein 0.24 is the root-shoot ratio in tropical regions; ……（2） ……（3） ……（4） ……（5） ……（6） where DBH is diameter at breast height, TH is total height, W s is stem biomass in kg, b is branch biomass in kg, i is leaf biomass in kg; The biomass of intercropped crops is repeatedly sampled by randomly selecting multiple representative crops, weighing the fresh weight, then placing them in an oven, killing green at 105℃ for 15min, and drying at 80℃ until the weight no longer changes, and weighing the dry weight; The formulas for calculating the cost present value, income present value, and net present value NPV according to the discounted cash flow technique are shown as formula (8), formula (9), and formula (10) respectively: ……（8） ……（9） ……（10） wherein Cp is the cost per year, Rp is the revenue per year, n is the number of years, r is the discount rate, and i is the time period; The calculation formulas of the soil organic matter, total nitrogen, available phosphorus, and potassium reserves are as follows: ……（11） Ri is the soil reserve of the ith nutrient; p is the soil bulk density at 0-20 cm; is the content of the ith nutrient in the farmland soil; ……（12） ……（13） In the formula, θ Mi , θ Vi respectively represent the soil mass water content and the soil volume water content; W wi , W di respectively represent the fresh soil and the oven-dried soil weight of each soil layer, in g; ρ bi represents the soil bulk density of each soil layer, in g·cm -3 ; D i D represents the depth of each soil layer, in meters; The gas regulation function uses a static box to collect CO2, N2O, CH4 emitted from farmland soil, and determines the soil greenhouse gas emission flux and rate by measuring the gas composition with a gas chromatograph, and the calculation formula of the emission flux F is shown as formula (14): ……（14） wherein M represents the molar mass of the greenhouse gas in g.mol -1 -1, V0 represents the molar volume of the greenhouse gas in the standard state; P, T represent the actual pressure and temperature, respectively; P0, T0 represent the pressure and temperature, respectively, in the standard state of an ideal gas; H represents the height of the tank; d c / d t represents the slope of the regression curve of the concentration of the target gas in the tank over time. The plant diversity maintenance function characterized by the biodiversity maintenance function is calculated by measuring the plant species and biomass in a 50cm×50cm quadrat to calculate the species richness and Shannon index; wherein, the calculation formula of the shannon index is shown as formula (15): ……（15） where H is the Shannon index, S is the total number of unique species observed within a plot, p i is the proportion of S that is made up of the ith species.

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