A method for evaluating the growth performance of mangrove seedlings in a high salinity environment of an estuary

Abstract

The application discloses a method for evaluating the growth performance of mangrove seedlings in a high-salinity environment of an estuary, constructs an analysis framework of a dynamic salinity stress system coupled with multidimensional monitoring technology, and realizes accurate evaluation of the environmental adaptability of the mangrove seedlings. First, aseptic germination and substrate domestication are carried out on a target estuary seed source, then a three-dimensional stress model including basic salinity maintenance, sudden salinity impact and tidal cycle fluctuation is established, the amplitude of the sudden salinity impact is strictly controlled within 20% of the historical extreme value of the estuary, three-dimensional laser scanning technology is used to synchronously obtain the crown volume and root configuration parameters of the seedlings, and a morphological database is constructed in combination with leaf apparent characteristic records; through transmission electron microscope observation, subcellular structure indexes such as cell wall thickening, chloroplast membrane integrity and mitochondrial ridge density are analyzed, the molecular mechanism of osmotic regulation and energy metabolism is revealed, and the water body suspended matter concentration, sediment oxidation-reduction potential and microbial functional diversity are synchronously monitored.

Description

TECHNICAL FIELD

[0001] The present application relates to the field of ecology and environmental science, and in particular to a method for evaluating the growth performance of mangrove seedlings in a high-salinity environment in an estuary. BACKGROUND

[0002] Mangrove seedlings are an important life stage in mangrove ecosystems. Estuarine mangrove ecosystems, as an important transitional zone connecting land and sea, play an irreplaceable role in coastal protection, biodiversity protection, and carbon sink function. However, high-salinity environments pose significant challenges to the growth of mangrove seedlings. Accurate evaluation of their growth performance is of great significance for understanding the ecological adaptation mechanisms of mangroves and developing scientific protection strategies.

[0003] Static salinity culture mode under traditional laboratory conditions cannot truly reflect the comprehensive environmental stress faced by seedlings, resulting in significant limitations in analyzing growth response mechanisms. The existing evaluation technology system mainly has four defects: first, salinity stress simulation mostly uses linear gradient increase or fixed high-salinity treatment, which cannot reproduce the sudden changes in natural salinity and is prone to cause non-physiological death due to extreme parameter settings; second, morphological monitoring relies on manual sampling and measurement, which is limited by plant damage caused by contact sampling and two-dimensional observation dimension limitations, making it difficult to simultaneously obtain crown volume dynamics and root architecture parameters; third, physiological response analysis is limited to macroscopic indicators such as chlorophyll content and proline accumulation, lacking analysis of microscopic mechanisms such as cell wall structure remodeling and chloroplast membrane system stability; fourth, environmental factor research mainly focuses on a single salinity variable, ignoring the interaction of ecological elements such as water suspended sedimentation, sediment anaerobic state, and microbial community function, resulting in significant deviations between evaluation results and actual field performance. Therefore, a method for evaluating the growth performance of mangrove seedlings in a high-salinity environment in an estuary is proposed. SUMMARY

[0004] The present application provides the following technical solution: a method for evaluating the growth performance of mangrove seedlings in a high-salinity environment in an estuary, comprising the following steps:

[0005] S1, species adaptability pretreatment step:

[0006] Mature mangrove seeds are collected from the target estuarine ecological zone, germinated on sterile medium, and seedlings with equal height and intact roots are selected as experimental materials before transplantation for substrate adaptability acclimation;

[0007] S2, salinity gradient dynamic simulation step:

[0008] Based on the seasonal variation of the target estuary salinity, a three-dimensional stress system including a basic salinity maintenance group, a sudden salinity shock group, and a tidal cycle fluctuation group is constructed, wherein the instantaneous salinity increase of the sudden salinity shock group does not exceed 20% of the historical extreme value of the estuary;

[0009] S3. Multi-dimensional morphological monitoring step:

[0010] The three-dimensional laser scanning technology is used to regularly obtain the crown volume of the aboveground part and the root architecture parameters of the seedlings, and the apparent characteristic parameters of the leaves are recorded synchronously.

[0011] S4. Physiological response analysis step:

[0012] Transmission electron microscopy is used to observe the leaf and root tissues collected during the experiment period, and the changes in cell wall thickening degree, chloroplast membrane integrity, and mitochondrial cristae density are analyzed.

[0013] S5. Ecological factor coupling analysis step:

[0014] The concentration of suspended solids in the water body, the sediment oxidation-reduction potential gradient, and the functional diversity index of microbial communities in the experimental container are monitored synchronously, and an ecological factor-growth index correlation network is constructed.

[0015] S6. Comprehensive evaluation system construction step:

[0016] The morphological monitoring data, physiological response indicators, and ecological factor parameters are integrated to establish an intelligent analysis platform containing growth resilience index, physiological limit threshold, and ecological service efficiency evaluation module.

[0017] S7. Resilience tracking evaluation step:

[0018] During the experimental period, a phased salinity stress relief stage is set, and the dynamic recovery trajectory of the seedling growth parameters is continuously monitored to quantify the physiological compensation ability after the salinity stress is relieved.

[0019] S8. Engineering repair scheme output step:

[0020] Based on the comprehensive evaluation results, an ecological restoration engineering design scheme containing species configuration density gradient, salinity buffer zone spatial layout, and microtopography reconstruction parameters is automatically generated.

[0021] Species adaptability pretreatment step:

[0022] Mature mangrove seeds are collected from the target estuary ecological area, germinated on sterile medium, and seedlings with a height difference of no more than 5% and intact roots are selected as experimental materials. Before transplantation, the substrate formula is gradually changed (containing a mixture of target estuary sediments and artificial mixed substrates) for a period of not more than 14 days of adaptive acclimation. The survival rate of seedlings and the number of new root germination are monitored daily during the acclimation period.

[0023] Salt gradient dynamic simulation step:

[0024] Based on the seasonal variation of the target estuary salinity, a three-dimensional stress system is constructed:

[0025] Basic salinity maintenance group: The salinity value is set to be within ±2‰ of the historical monthly average salinity data of the estuary;

[0026] Sudden salinity shock group: The instantaneous salinity increase is not more than 20% of the historical extreme value of the estuary, and the shock duration is not more than 48 hours;

[0027] Tidal cycle fluctuation group: Simulate daily salinity fluctuations, with a fluctuation amplitude within ±15% of the measured tidal range data of the target estuary;

[0028] Multi-dimensional morphological monitoring step:

[0029] Using three-dimensional laser scanning technology, the aboveground canopy volume and underground root configuration parameters of the seedlings are obtained every 72 hours, including main root length, lateral root number, root surface area, and fractal dimension. The leaf apparent characteristic parameters are recorded simultaneously, including leaf angle coefficient of variation, leaf area index, and petiole bending degree;

[0030] Physiological response analysis step:

[0031] Transmission electron microscopy is used to observe the leaf and root tissues collected during the experiment period, focusing on the analysis of:

[0032] Cell wall thickening degree: Measure the ratio of primary cell wall thickness to secondary cell wall thickness;

[0033] Chloroplast envelope integrity: Calculate the order degree of grana lamella arrangement;

[0034] Mitochondrial cristae density change: Calculate the number of cristae structures per unit area;

[0035] Ecological factor coupling analysis step:

[0036] Simultaneously monitor the water suspended matter concentration in the experimental container (detected by laser particle size analyzer), sediment oxidation-reduction potential gradient (microelectrode array with a spacing of ≤2 cm), and microbial community functional diversity index (based on Biolog ECO plate carbon source utilization spectrum), to construct an ecological factor-growth index correlation network. The network nodes include 12 environmental parameters and 18 morphological and physiological indicators;

[0037] Comprehensive evaluation system construction step:

[0038] Integrate morphological monitoring data, physiological response indicators, and ecological factor parameters to establish an intelligent analysis platform, including:

[0039] Growth resilience index: calculated based on canopy volume recovery rate and root architecture stability;

[0040] Physiological limit threshold: determined by chloroplast envelope breakage rate mutation point;

[0041] Ecological service performance evaluation module: quantifying carbon sink capacity and bank protection function maintenance degree;

[0042] Resilience tracking evaluation step

[0043] During the experimental period, set up a staged salinity stress relief stage, monitor the dynamic recovery trajectory of seedling growth parameters for 72 hours, quantify the recovery rate of leaf apparent characteristic parameters and the compensation rate of root architecture parameters after salinity stress relief;

[0044] Engineering repair scheme output step:

[0045] Based on the comprehensive evaluation results, automatically generate an ecological restoration engineering design scheme, including:

[0046] Species configuration density gradient: according to the growth resilience index, divide the density interval of 0-100 plants / m²;

[0047] Salt buffer zone spatial layout: optimize the buffer zone width according to the tidal cycle fluctuation group data;

[0048] Microtopography modification parameters: combine root architecture parameters to design sediment accumulation slope.

[0049] Preferably, in the species adaptability pretreatment step, the substrate adaptability domestication adopts a stepwise salinity increase method, with a weekly salinity increase of no more than 2‰, until the average salinity of the target estuary is consistent. During the substrate adaptability domestication stage, the stepwise salinity increase method is implemented, with the initial salinity as the benchmark, the salinity is gradually increased by no more than 2‰ per week, until the salinity value is consistent with the measured average salinity of the target estuary. During the process, an automatic control system is used to monitor the salinity changes in real time, and a gradual adjustment is used to ensure the stability of the domestication environment.

[0050] Preferably, in the salinity gradient dynamic simulation step, the salinity change frequency of the tidal cycle fluctuation group is synchronized with the measured tidal cycle of the target estuary, and the daily salinity fluctuation amplitude is not more than 5‰. In the salinity gradient dynamic simulation link, set up a tidal cycle fluctuation group, whose salinity change frequency is completely synchronized with the measured tidal cycle of the target estuary, and through a precise control device, ensure that the daily salinity fluctuation amplitude is not more than 5‰, use a multi-parameter sensor to collect salinity data in real time, and dynamically compare and calibrate with the preset tidal model.

[0051] Preferably, in the multi-dimensional morphological monitoring step, the underground root system architecture parameter analysis includes the quantitative indicators of taproot bending degree, lateral root branch angle and root hair density. In the underground root system architecture parameter analysis, the three-dimensional root system scanning system is combined with image analysis software to quantitatively determine the taproot bending degree, lateral root branch angle and root hair density, and through the setting of a standard sampling frame and an automatic counting algorithm, the standardized collection and statistical analysis of the root system morphological parameters are realized.

[0052] Preferably, in the physiological response analysis step, the cell wall thickening degree is represented by the cellulose crystallinity index, and the chloroplast envelope integrity is observed by fluorescence staining. In the physiological response analysis stage, the X-ray diffraction method is used to determine the cellulose crystallinity index to represent the cell wall thickening degree, and the fluorescence staining method (such as neutral red staining) is simultaneously applied to observe the chloroplast envelope integrity. The stained tissue section images are obtained by a microscopic imaging system, and quantitative evaluation is performed by combining image analysis software.

[0053] Preferably, in the ecological factor coupling analysis step, the microbial community functional diversity index is determined by the Biolog EcoPlate™ method, and the difference in carbon source utilization mode is focused on. In the determination of microbial community functional diversity, the Biolog EcoPlate™ method is used for carbon source metabolic fingerprint analysis. The utilization of 31 kinds of carbon sources by microorganisms is monitored through 96-hour continuous culture, and the difference characteristics of carbon source utilization mode between different salinity treatment groups are analyzed by principal component analysis (PCA).

[0054] Preferably, in the recovery force tracking evaluation step, the period of relieving the stage salinity stress is set to be no more than 72 hours, and the monitoring frequency during the recovery period is set to be no less than once every 6 hours to record the key morphological indicators. In the recovery force tracking evaluation, the period of relieving the stage salinity stress is set to be no more than 72 hours, and the automatic monitoring system is used to record the key morphological indicators such as plant height and leaf number at intervals of every 6 hours. The recovery rate is quantified by time series analysis.

[0055] Preferably, in the recovery force tracking evaluation step, the physiological compensation capacity is quantitatively represented by the recovery rate of chlorophyll content in new leaves and the proportion of root regeneration length. The chlorophyll content in new leaves is detected regularly by a portable chlorophyll meter, and the root regeneration length per unit time is determined by a root scanning system. The recovery rate of chlorophyll content and the proportion of root regeneration length are calculated to establish a quantitative model of physiological compensation capacity.

[0056] Preferably, in the comprehensive evaluation system construction step, the growth resilience index calculation weight is set as: morphological index accounts for 55%, physiological index accounts for 30%, and ecological factor accounts for 15%. In the growth resilience index calculation, the analytic hierarchy process (AHP) is used to set the weight: morphological index (55%), physiological index (30%), and ecological factor (15%), a comprehensive evaluation model is constructed through expert scoring matrix and consistency check, and multi-dimensional data is standardized and integrated.

[0057] Preferably, in the engineering repair scheme output step, the salinity buffer zone spatial layout adopts a gradual salinity gradient design, and the microtopography reconstruction parameters include optimized values of tidal ditch density and beach elevation. In the salinity buffer zone spatial layout design, the gradual salinity gradient design principle is adopted, the beach elevation and tidal ditch density parameters are optimized in combination with a hydrodynamic model, spatial interpolation analysis is performed through a geographic information system (GIS), and a microtopography reconstruction parameter atlas is generated.

[0058] In summary, compared with the prior art, the present application provides a method for evaluating the growth performance of mangrove seedlings in a high-salinity environment in an estuary, which has the following beneficial effects:

[0059] The present application creatively constructs a three-dimensional stress model through a salinity gradient dynamic simulation system, wherein the instantaneous increase amplitude control strategy of the sudden salinity impact group not only truly restores the natural scene of the sudden change of salinity in an estuary, but also avoids the unnatural death phenomenon caused by extreme parameters, and the introduction of the tidal cycle fluctuation group forms a space-time coupling of hydrodynamic conditions and salinity changes, which can more accurately analyze the response mechanism of mangrove seedlings to dynamic environment compared with the static salinity culture mode;

[0060] The application of three-dimensional laser scanning technology in morphological monitoring realizes non-contact and full-dimensional data acquisition, and its centimeter-level spatial resolution can synchronously obtain the dynamic volume of the aboveground canopy and the configuration parameters of the underground root system, thereby breaking through the subjectivity and destructiveness limitations of traditional manual measurement methods, and the real-time recording of leaf apparent characteristic parameters further enriches the morphological evaluation dimension, and provides a data basis for establishing the quantitative relationship between growth phenotype and environmental factors.

[0061] The physiological response analysis link extends the evaluation scale to the subcellular structure level for the first time through transmission electron microscope observation technology, the cell wall thickening degree analysis reveals the microscopic mechanism of osmotic regulation, the chloroplast envelope integrity evaluation is related to the damage threshold of photosynthetic mechanism, and the change of mitochondrial ridge density reflects the reconstruction process of energy metabolism, and the quantitative analysis of these indexes provides a molecular cytological evidence chain for understanding the salt stress tolerance mechanism.

[0062] The ecological factor coupling analysis method breaks through the limitation of single environmental factor research, reveals the comprehensive regulation path of multi-factor interaction on seedling growth by constructing the correlation network of water body suspended matter concentration, sediment oxidation-reduction potential gradient and microbial functional diversity, and the evaluation framework of the system biology perspective more truly reflects the synergistic mechanism of the complex ecological system of the estuary. BRIEF DESCRIPTION OF DRAWINGS

[0063] Figure 1 is the schematic diagram of the evaluation method of the present application. DETAILED DESCRIPTION

[0064] The technical solutions in the embodiments of the present application will be clearly and completely described below with reference to the drawings in the embodiments of the present application. Obviously, the described embodiments are only a part of the embodiments of the present application, rather than all the embodiments. Based on the embodiments in the present application, all other embodiments obtained by those skilled in the art without creative labor fall within the scope of protection of the present application.

[0065] Please refer to Figure 1 The present application provides a technical solution, a method for evaluating the growth performance of mangrove seedlings in a high-salinity environment of an estuary, comprising the following steps:

[0066] S1, species adaptability pretreatment step:

[0067] Mature mangrove seeds are collected from the target estuary ecological area, germinated after sterile medium, and seedlings with equal height and complete root system are selected as experimental materials before transplantation for substrate adaptability domestication;

[0068] S2, salt gradient dynamic simulation step:

[0069] Based on the seasonal variation law of the salinity of the target estuary, a three-dimensional stress system including a basic salinity maintenance group, a sudden salinity shock group and a tidal cycle fluctuation group is constructed, wherein the salinity of the sudden salinity shock group is instantaneously increased by no more than 20% of the historical extreme value of the estuary;

[0070] S3, multi-dimensional morphological monitoring step:

[0071] The three-dimensional laser scanning technology is used to regularly obtain the crown volume of the aboveground part of the seedlings and the root configuration parameters of the underground part, and the apparent characteristic parameters of the leaves are recorded synchronously;

[0072] S4, physiological response analysis step:

[0073] The leaf and root tissues collected during the experimental period are observed by transmission electron microscope, and the changes of cell wall thickening degree, chloroplast membrane integrity and mitochondrial ridge density are analyzed;

[0074] S5, ecological factor coupling analysis step:

[0075] Synchronization monitoring of water body suspended substance concentration, sediment oxidation-reduction potential gradient and microbial community functional diversity index in the experimental container, and construction of ecological factor-growth index correlation network;

[0076] S6, comprehensive evaluation system construction step:

[0077] Integrating morphological monitoring data, physiological response indicators and ecological factor parameters, an intelligent analysis platform is established, which includes growth resilience index, physiological limit threshold and ecological service efficiency evaluation module;

[0078] S7, resilience tracking evaluation step:

[0079] During the experimental period, a stage salt stress relief stage is set, and the dynamic recovery trajectory of the growth parameters of the seedlings is continuously monitored to quantify the physiological compensation capacity after salt stress relief;

[0080] S8, engineering repair scheme output step:

[0081] Based on the comprehensive evaluation results, an ecological restoration engineering design scheme is automatically generated, which includes species configuration density gradient, salt buffer zone spatial layout and micro-topography reconstruction parameters.

[0082] Species adaptability pretreatment step:

[0083] Mature mangrove seeds are collected from the target estuary ecological area, germinated on sterile medium, and seedlings with a height difference of not more than 5% and intact root systems are selected as experimental materials. Before transplantation, gradual replacement of the substrate formula (containing a mixture of target estuary sediments and artificial proportioning substrate) is carried out for not more than 14 days of adaptive acclimation. The survival rate of seedlings and the number of new root germination are monitored daily during the acclimation period;

[0084] Salt gradient dynamic simulation step:

[0085] Based on the seasonal variation law of the target estuary salinity, a three-dimensional stress system is constructed:

[0086] Basic salinity maintenance group: the salinity value is set to be within ±2‰ of the historical monthly average salinity data of the estuary;

[0087] Sudden salt shock group: the instantaneous salinity increase amplitude is not more than 20% of the historical extreme value of the estuary, and the impact duration is not more than 48 hours;

[0088] Tidal cycle fluctuation group: simulate daily salinity fluctuation, and the fluctuation amplitude is within ±15% of the measured tidal range data of the target estuary;

[0089] Multi-dimensional morphological monitoring step:

[0090] The three-dimensional laser scanning technology was used to obtain the crown volume of the aboveground part and the root architecture parameters of the underground part of the seedlings every 72 hours, including the main root length, the number of lateral roots, the root surface area, and the fractal dimension. The apparent characteristic parameters of the leaves were also recorded simultaneously, including the leaf angle coefficient of variation, the leaf area index, and the petiole bending degree.

[0091] Physiological response analysis steps:

[0092] Transmission electron microscopy was used to observe the leaf and root tissues collected during the experiment period, focusing on the analysis of:

[0093] Cell wall thickening degree: measure the ratio of primary cell wall thickness to secondary cell wall thickness;

[0094] Chloroplast envelope integrity: count the degree of order of grana lamella arrangement;

[0095] Mitochondrial cristae density change: calculate the number of cristae structures per unit area;

[0096] Ecological factor coupling analysis steps:

[0097] The concentration of suspended solids in the water body in the experimental container was monitored simultaneously (detected by a laser particle size analyzer), the sediment oxidation-reduction potential gradient was measured (a microelectrode array was arranged with a spacing of ≤2 cm), and the microbial community functional diversity index was calculated based on the Biolog ECO plate carbon source utilization spectrum. The correlation network between ecological factors and growth indicators was constructed, and the network nodes included 12 environmental parameters and 18 morphological and physiological indicators.

[0098] Comprehensive evaluation system construction steps:

[0099] Integrate morphological monitoring data, physiological response indicators, and ecological factor parameters to establish an intelligent analysis platform, including:

[0100] Growth resilience index: calculated based on the recovery rate of crown volume and the stability of root architecture;

[0101] Physiological limit threshold: determined by the sudden change point of chloroplast envelope damage rate;

[0102] Ecological service efficiency evaluation module: quantifies carbon sink capacity and bank protection function maintenance degree;

[0103] Resilience tracking evaluation steps

[0104] During the experimental period, a staged salinity stress relief stage was set up, and the dynamic recovery trajectory of the seedling growth parameters was monitored continuously for 72 hours to quantify the recovery rate of the leaf apparent characteristic parameters and the compensation rate of the root architecture parameters after the salinity stress was relieved.

[0105] Engineering repair scheme output steps:

[0106] Based on the comprehensive evaluation results, an ecological restoration engineering design scheme is automatically generated, including:

[0107] Species configuration density gradient: According to the growth resilience index, divide the 0-100 plant / m² density interval;

[0108] Salinity buffer zone spatial layout: According to the tidal cycle fluctuation group data, optimize the buffer zone width;

[0109] Microtopography reconstruction parameters: Combined with root architecture parameters, design sediment accumulation slope;

[0110] Through the species adaptability preprocessing step, ensure that the genetic background of the experimental material is highly consistent with the target estuary ecological area, eliminate the influence of seed source difference on the evaluation results, and improve the experimental repeatability;

[0111] The salinity gradient dynamic simulation system truly reflects the spatial and temporal heterogeneity of estuary salinity. The sudden salinity impact group design takes into account the ecological safety threshold and extreme event simulation needs, avoiding excessive stress leading to unnatural death;

[0112] Multi-dimensional morphological monitoring technology realizes the synchronous acquisition of aboveground and underground parameters, and three-dimensional laser scanning precision can capture early warning signals of root architecture;

[0113] Physiological response analysis focuses on subcellular structure changes, transmission electron microscopy reveals cell wall thickening and energy metabolism regulation mechanism, providing microscopic evidence chain for salt tolerance mechanism research;

[0114] Ecological factor coupling analysis establishes a multi-parameter correlation network, breaking through the limitations of traditional single-factor experiments, and clarifying the influence weight of water-sediment-microorganism interface interaction on seedling growth;

[0115] The comprehensive evaluation system integrates multi-source heterogeneous data, quantifies species resistance potential through growth resilience indicators, defines safe cultivation boundaries through physiological limit thresholds, and directly connects engineering application needs through ecological service efficiency evaluation;

[0116] Resilience tracking evaluation breaks through the traditional survival rate evaluation mode, quantifies physiological compensation capacity through dynamic recovery trajectory, and provides resilience evaluation index for saline-alkali land vegetation reconstruction;

[0117] The output module of the engineering restoration scheme realizes the closed loop of evaluation-design, and the density gradient configuration and microtopography parameter optimization improve the survival rate of the restoration project, and the salinity buffer zone design prolongs the maintenance period of ecological service function.

[0118] In the species adaptation pretreatment step, the substrate adaptation acclimation adopts a stepwise salinity increase method, with a weekly salinity increase of no more than 2‰, until the average salinity of the target estuary is consistent. In the substrate adaptation acclimation stage, the stepwise salinity increase method is adopted, and the salinity is gradually increased by no more than 2‰ per week based on the initial salinity, until the salinity value is consistent with the measured average salinity of the target estuary. During the process, an automatic control system is used to monitor the salinity change in real time, and a gradual adjustment is used to ensure the stability of the acclimation environment. Slow salinity increase can effectively induce plants to produce osmotic regulation adaptation mechanism, avoid physiological damage caused by sudden change of salinity, and significantly improve the survival rate and adaptability of target species in the salinity environment of the target estuary.

[0119] In the salinity gradient dynamic simulation step, the salinity change frequency of the tidal cycle fluctuation group is synchronized with the measured tidal cycle of the target estuary, and the daily salinity fluctuation amplitude is not more than 5‰. In the salinity gradient dynamic simulation link, the tidal cycle fluctuation group is set, and the salinity change frequency is completely synchronized with the measured tidal cycle of the target estuary. Through precise control device, the daily salinity fluctuation amplitude is not more than 5‰, and the multi-parameter sensor is used to collect salinity data in real time. The data is dynamically compared and calibrated with the preset tidal model, and the synchronous tidal cycle and salinity fluctuation can accurately reproduce the natural hydrological conditions, providing an experimental environment with high ecological correlation for studying the salt response mechanism of plants, and significantly improving the field applicability of the simulation experiment results.

[0120] In the multi-dimensional morphological monitoring step, the underground root system configuration parameter analysis includes the quantitative indicators of main root bending degree, lateral root branch angle and root hair density. In the underground root system configuration parameter analysis, the three-dimensional root system scanning system is combined with image analysis software to quantitatively determine the main root bending degree, lateral root branch angle and root hair density. Through setting standard sampling frame and automatic counting algorithm, the standardization collection and statistical analysis of root system morphological parameters are realized. Quantitative root system configuration parameters can reveal the influence mechanism of salinity stress on underground resource acquisition capacity, and provide scientific basis for main root growth direction optimization and lateral root development regulation, and help to build an efficient root system improvement scheme.

[0121] In the physiological response analysis step, the cell wall thickening degree is represented by the cellulose crystallinity index, and the chloroplast envelope integrity is observed by fluorescence staining method. In the physiological response analysis stage, the cellulose crystallinity index is determined by X-ray diffraction method to represent the cell wall thickening degree, and the fluorescence staining method (such as neutral red staining) is used to observe the chloroplast envelope integrity. The stained tissue section images are obtained by a microscopic imaging system, and quantitative evaluation is carried out by image analysis software. Multi-index physiological detection can systematically analyze the dynamic changes of cell structure and function under salinity stress, and provide data support for screening of stress-resistant physiological markers and development of physiological enhancement technology.

[0122] In the ecological factor coupling analysis step, the microbial community functional diversity index is determined by the Biolog EcoPlate™ method, and the difference in carbon source utilization mode is focused on. In the microbial community functional diversity determination, the Biolog EcoPlate™ method is used for carbon source metabolic fingerprint analysis, the utilization of 31 kinds of carbon sources by microorganisms is monitored through 96-hour continuous culture, the difference characteristics of carbon source utilization mode between different salinity treatment groups are analyzed by principal component analysis (PCA), and the functional diversity index analysis can reveal the functional response law of microbial community to salinity gradient, providing ecological basis for constructing plant-microorganism collaborative remediation system.

[0123] In the resilience tracking evaluation step, the period of phased salinity stress relief is set to be no more than 72 hours, and the monitoring frequency during the recovery period is set to be no less than once every 6 hours to record key morphological indicators. In the resilience tracking evaluation, the period of phased salinity stress relief is set to be no more than 72 hours, and an automatic monitoring system is used to record key morphological indicators such as plant height and leaf number at intervals of every 6 hours. Through time series analysis, the recovery rate is quantified, and high-frequency monitoring can accurately capture the rapid recovery stage after stress relief, providing time threshold reference for determining the optimal salinity pulse management strategy and optimizing the dynamic regulation scheme of ecological remediation engineering.

[0124] In the resilience tracking evaluation step, the physiological compensation capacity is quantitatively characterized by the recovery rate of chlorophyll content in new leaves and the proportion of root regeneration length. The chlorophyll content of new leaves is detected regularly by a portable chlorophyll meter, and the root regeneration length per unit time is measured by a root scanning system. The recovery rate of chlorophyll content and the proportion of root regeneration length are calculated to establish a quantitative model of physiological compensation capacity. The quantification of physiological indicators can directly reflect the resource reallocation ability of plants in a salt fluctuating environment, and provide comparable biological parameters for evaluating the resilience potential of different species.

[0125] In the comprehensive evaluation system construction step, the weight setting of growth resilience index calculation is: morphological indicators account for 55%, physiological indicators account for 30%, and ecological factors account for 15%. In the growth resilience index calculation, the weights are set by the analytic hierarchy process (AHP): morphological indicators (55%), physiological indicators (30%), and ecological factors (15%). A comprehensive evaluation model is constructed through expert scoring matrix and consistency check to realize the standardized integration of multi-dimensional data. The weight distribution system can balance the contribution of different evaluation dimensions, avoid single index evaluation bias, and significantly improve the accuracy of ecological remediation effect prediction.

[0126] In the output step of the engineering repair scheme, the spatial layout of the salinity buffer zone adopts a gradual salinity gradient design, and the micro-topographic reconstruction parameters include the optimal values of tidal ditch density and beach elevation. In the spatial layout design of the salinity buffer zone, the gradual salinity gradient design principle is adopted, the beach elevation and tidal ditch density parameters are optimized in combination with the hydrodynamic model, the micro-topographic reconstruction parameter map is generated through spatial interpolation analysis by a geographic information system (GIS), and the gradual design can simulate the ecological function of the natural salinity transition zone. The micro-topographic optimization can significantly improve the hydrological connectivity and species diversity of the buffer zone, and provide a practical spatial solution for estuary ecological restoration engineering.

[0127] The scheme: Collect mature mangrove seeds from the target estuary ecological zone, and screen seedlings with a height difference of no more than 5% and intact root systems as experimental materials after germination on sterile culture medium; Before transplantation, adaptive acclimatization is carried out for no more than 14 days by gradually changing the substrate formula, the substrate formula is mixed with the target estuary sediment and the artificial ratio substrate at a volume ratio of 3:7 to 7:3, and the survival rate of seedlings and the number of new root germination are monitored daily during the acclimatization period; During the substrate adaptive acclimatization stage, the stepwise salinity increase method is implemented, the initial salinity is taken as the benchmark, the salinity is gradually increased by no more than 2‰ per week, until the salinity value is consistent with the average salinity measured in the target estuary, and during the process, an automatic control system is used to monitor the salinity change in real time and ensure the stability of the acclimatization environment through gradual adjustment;

[0128] A three-dimensional stress system is constructed according to the seasonal variation law of the salinity of the target estuary, including a basic salinity maintenance group, a sudden salinity shock group, and a tidal cycle fluctuation group; The salinity value of the basic salinity maintenance group is set to be within ±2‰ of the historical monthly average salinity data of the estuary; The salinity of the sudden salinity shock group is instantaneously increased by no more than 20% of the historical extreme value of the estuary and the shock duration is no more than 48 hours; The tidal cycle fluctuation group simulates daily cycle salinity fluctuation, the fluctuation amplitude is within ±15% of the measured tidal range data of the target estuary, the salinity change frequency is completely synchronized with the measured tidal cycle of the target estuary, and the daily salinity fluctuation amplitude is no more than 5‰ through precise control device;

[0129] The three-dimensional laser scanning technology is used to obtain the aboveground canopy volume and underground root configuration parameters of the seedlings with a cycle of 72 hours, the aboveground parameters include canopy volume, leaf inclination coefficient of variation, leaf area index and petiole bending degree, and the underground parameters include main root length, lateral root number, root surface area, fractal dimension, main root bending degree, lateral root branching angle and root hair density; The leaf apparent characteristic parameters are recorded synchronously, the standard sampling frame and automatic counting algorithm are used to realize the standardized collection and statistical analysis of the root morphological parameters,

[0130] S4, physiological response analysis step: Transmission electron microscopy is used to observe the leaf and root system tissues collected during the experimental period, focusing on analyzing the thickness of the cell wall, the integrity of the chloroplast envelope, and the changes in the density of mitochondrial cristae; the thickness of the cell wall is represented by the crystallinity index of cellulose determined by X-ray diffraction, the integrity of the chloroplast envelope is observed by neutral red fluorescence staining to measure the order of grana lamella arrangement, and the density of mitochondrial cristae is calculated by counting the number of cristae structures per unit area;

[0131] The concentration of suspended solids in the water body, the redox potential gradient of the sediment, and the functional diversity index of the microbial community in the experimental container are monitored simultaneously. The concentration of suspended solids in the water body is detected by a laser particle size analyzer, the redox potential of the sediment is obtained by a microelectrode array with a spacing of ≤2 cm, and the functional diversity of the microbial community is determined by the Biolog EcoPlate™ method to focus on the differences in carbon source utilization patterns. An ecological factor-growth index correlation network is constructed, including 12 environmental parameters and 18 morphological and physiological indicators.

[0132] Integrating morphological monitoring data, physiological response indicators, and ecological factor parameters, an intelligent analysis platform is established, including a growth resilience index, a physiological limit threshold, and an ecological service efficiency evaluation module. The growth resilience index calculation weight is set as 55% for morphological indicators, 30% for physiological indicators, and 15% for ecological factors. The weight is set by the analytic hierarchy process, and the comprehensive evaluation model is constructed through expert scoring matrix and consistency check. The physiological limit threshold is determined by the breakage rate mutation point of the chloroplast envelope, and the ecological service efficiency evaluation module quantifies the carbon sink capacity and the maintenance degree of the bank protection function.

[0133] During the experimental period, a stage salt stress relief stage is set, the stress relief period does not exceed 72 hours, and the recovery period monitoring frequency is set to record key morphological indicators no less than every 6 hours. By monitoring the dynamic recovery trajectory of seedling growth parameters for 72 consecutive hours, the recovery rate of leaf apparent characteristic parameters and the compensation rate of root architecture parameters after salt stress relief are quantified, and the physiological compensation capacity is quantified and characterized by the recovery rate of chlorophyll content in new leaves and the proportion of root regeneration length.

[0134] Based on the comprehensive evaluation results, an ecological restoration engineering design scheme is automatically generated, including species configuration density gradient, salt buffer zone spatial layout, and micro-topography reconstruction parameters. The species configuration density gradient is divided into 0-100 plant / m² density intervals according to the growth resilience index quantification results, the salt buffer zone spatial layout is designed with a gradual salt gradient and optimized buffer zone width based on tidal cycle fluctuation group data, and the micro-topography reconstruction parameters include sediment accumulation slope, tidal ditch density, and beach elevation optimization values.

[0135] It is to be understood that the terminology used herein is for the purpose of describing particular embodiments only and is not intended to be limiting; it is not intended to exclude myriad other embodiments of the present application that other inventors can develop based on the same general inventive concepts embodied by the described embodiments. That is, although the present application is described in terms of particular embodiments and illustrative figures, it should be apparent that the scope of the present application is not limited to these specific embodiments.

[0136] While the embodiments of the application have been shown and described herein, it will be understood by those of ordinary skill in the art that various changes, modifications, alternatives, and variations can be made to the embodiments without departing from the spirit and scope of the application, which is defined by the appended claims and their equivalents.

Claims

1. A method for evaluating the growth performance of mangrove seedlings in a high-salinity estuarine environment, characterized in that, The experiment includes the following steps: S1. Species Adaptation Pretreatment: Mature mangrove embryos are collected from the target estuarine ecosystem. After germination in a sterile culture medium, seedlings with uniform height and intact root systems are selected as experimental materials. Substrate adaptation is performed before transplanting. S2. Salinity Gradient Dynamic Simulation: Based on the seasonal variation of salinity in the target estuary, a three-dimensional stress system is constructed, including a baseline salinity maintenance group, a sudden salinity shock group, and a tidal cycle fluctuation group. The instantaneous increase in salinity in the sudden salinity shock group does not exceed 20% of the historical extreme value of the estuary. S3. Multi-dimensional Morphological Monitoring: Three-dimensional laser scanning technology is used to periodically obtain the aboveground canopy volume and underground root system configuration parameters of seedlings, and leaf phenotypic parameters are recorded simultaneously. S4. Physiological Response Analysis: Transmission electron microscopy is used to observe the leaf and root tissues collected during the experimental period, focusing on the analysis of cell wall thickening, chloroplast membrane integrity, and mitochondrial cristae density changes. S5. Ecological Factor Coupling Analysis: The concentration of suspended solids in the water, the redox potential gradient of sediments, and the functional diversity index of microbial communities are monitored simultaneously in the experimental container. S6. Comprehensive Assessment System Construction Steps: Integrate morphological monitoring data, physiological response indicators, and ecological factor parameters to establish an intelligent analysis platform that includes growth resilience index, physiological limit threshold, and ecosystem service efficiency assessment modules; S7. Resilience Tracking Assessment Steps: Set up phased salinity stress relief stages within the experimental period, and quantify the physiological compensation capacity after salinity stress relief by continuously monitoring the dynamic recovery trajectory of seedling growth parameters; S8. Engineering Restoration Scheme Output Steps: Based on the comprehensive assessment results, automatically generate an ecological restoration engineering design scheme that includes species configuration density gradient, salinity buffer zone spatial layout, and micro-topography modification parameters.

2. The method for evaluating the growth performance of mangrove seedlings in a high-salinity environment in an estuary, as described in claim 1, is characterized in that: In the species adaptation pretreatment step, the substrate adaptation acclimatization adopts a step-by-step salinity increase method, with the salinity increase not exceeding 2‰ per week, until it is consistent with the average salinity of the target estuary.

3. The method for evaluating the growth performance of mangrove seedlings in a high-salinity environment in an estuary, as described in claim 1, is characterized in that: In the dynamic simulation step of salinity gradient, the salinity change frequency of the tidal cycle fluctuation group is synchronized with the measured tidal cycle of the target estuary, and the daily salinity fluctuation amplitude does not exceed 5‰.

4. The method for evaluating the growth performance of mangrove seedlings in a high-salinity environment in an estuary, as described in claim 1, is characterized in that: In the multi-dimensional morphological monitoring step, the analysis of underground root system configuration parameters includes quantitative indicators such as taproot curvature, lateral root branching angle, and root hair density.

5. The method for evaluating the growth performance of mangrove seedlings in a high-salinity environment in an estuary, as described in claim 1, is characterized in that: In the physiological response analysis step, the degree of cell wall thickening is characterized by the cellulose crystallinity index, and the integrity of the chloroplast membrane is observed by fluorescence staining.

6. The method for evaluating the growth performance of mangrove seedlings in a high-salinity environment in an estuary, as described in claim 1, is characterized in that: In the ecological factor coupling analysis step, the biologEcoPlate™ method was used to determine the functional diversity index of the microbial community, with a focus on differences in carbon source utilization patterns.

7. The method for evaluating the growth performance of mangrove seedlings in a high-salinity environment in an estuary, as described in claim 1, is characterized in that: In the recovery tracking and assessment step, the period for relieving phased salinity stress is set to no more than 72 hours, and the monitoring frequency during the recovery period is set to record key morphological indicators no less than once every 6 hours.

8. The method for evaluating the growth performance of mangrove seedlings in a high-salinity environment in an estuary, as described in claim 1, is characterized in that: In the resilience tracking and evaluation step, physiological compensation capacity is quantitatively characterized by the recovery rate of chlorophyll content in new leaves and the proportion of root regeneration length.

9. The method for evaluating the growth performance of mangrove seedlings in a high-salinity environment in an estuary, as described in claim 1, is characterized in that: In the construction steps of the comprehensive evaluation system, the weights for calculating the growth resilience index are set as follows: morphological indicators account for 55%, physiological indicators account for 30%, and ecological factors account for 15%.

10. The method for evaluating the growth performance of mangrove seedlings in a high-salinity environment in an estuary, as described in claim 1, is characterized in that: In the output steps of the engineering restoration scheme, the spatial layout of the salinity buffer zone adopts a gradual salinity gradient design, and the micro-topography modification parameters include the optimized values ​​of tidal channel density and beach elevation.

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