Assessment of Ecosystem Service Value and Implementation Pathways: A Case Study of Jiangsu Jianchuan Ecological Restoration Project

Abstract

Over recent decades, coastal wetlands in Jiangsu Province have faced multiple challenges, including overfishing, reclamation for aquaculture, wetland shrinkage, and biodiversity loss. Implementing wetland ecological restoration proves crucial for mitigating the degradation of coastal wetland ecosystems. Quantifying ecosystem service values and establishing rational ecological compensation standards provide essential references for ecological compensation research and alleviating human–land conflicts. The Jianchuan Ecological Restoration Project, located in Dafeng District of Yancheng City, Jiangsu Province, employs integrated wetland, woodland, and farmland construction to rebuild biodiversity, enhance water conservation capacity, and improve water purification functions, thereby significantly boosting regional ecological services. Results have demonstrated that the total ecosystem service value of this project reaches CNY 76.2896 million, with climate regulation representing the highest value (CNY 68.1496 million, 89.33% of total). Subsequent values include biodiversity maintenance (3.40%), water purification (3.31%), and food production (2.95%), while carbon sequestration/oxygen release (0.96%) and soil retention (0.05%) show relatively lower contributions. Notably, this project innovatively integrates carbon finance mechanisms through “carbon sink loans”, achieving efficient transformation of ecological value from “paper accounts” to market realization. This study establishes a scientific foundation for ecological restoration projects through ecosystem service-based value assessment and pathway exploration, offering both theoretical framework and practical references.

1. Introduction

Coastal transition zones, as ecological interfaces of land–sea interactions, exhibit significantly higher resource density and ecological service efficiency per unit area compared to typical terrestrial ecosystems [1,2,3]. These zones represent strategically valuable biodiversity hotspots. Such aquatic–terrestrial composite ecosystems not only sustain high-density tidal flat resources and marine gene pools but also maintain regional ecological equilibrium through synergistic mechanisms, including habitat network integrity preservation, hydrodynamics regulation, tidal erosion energy dissipation, environmental pollutant degradation, and atmospheric stabilization [4]. Coastal tidal flats serve dual roles as livelihood foundations for local communities and critical land reserves for urban expansion, effectively alleviating human–land conflicts [5,6].

Jiangsu Province boasts an 889 km coastline stretching from the Xiuzhen River estuary in the north to the Yangtze River estuary in the south, with coastal tidal flat areas approximating 5002 km². These are predominantly distributed across Lianyungang, Yancheng, and Nantong Cities, including a 2017 km² radial sand ridge system [7]. Jiangsu’s tidal flats account for 25% of China’s total coastal wetland area, equivalent to 14.3% of the province’s arable land, constituting the nation’s largest coastal wetland ecosystem [8]. Decades of anthropogenic pressures—particularly overfishing and reclamation for aquaculture—have precipitated wetland shrinkage and biodiversity decline [9,10]. Empirical studies demonstrate that ecological compensation mechanisms facilitate internal benefit conversion within ecosystems, incentivize local conservation efforts, and enhance sustainable development [11,12]. Quantifying ecosystem service values provides upper-bound references for compensation quantification, while rational compensation standards serve as pivotal tools for resolving human-land conflicts [13]. The Chuandonggang area in Dafeng District, Yancheng City, has historically suffered from irrational land use and wetland degradation [14]. Over 60% of its land was allocated for aquaculture and agriculture, reducing natural wetlands to <40% of the total area. This triggered severe habitat fragmentation and anthropogenic disturbances, particularly during farming seasons, which disrupted avian foraging and nesting. Intensive aquaculture practices and excessive agrochemical use further exacerbated eutrophication, rendering the degraded ecosystem unsuitable for wildlife [15]. To restore ecological integrity, the Jianchuan Ecological Restoration Project was launched in 2021, rehabilitating paddy fields, woodlands, mudflats, marsh wetlands, and open waters. This initiative enhances regional biodiversity and ecosystem services while pioneering an “ecology–agriculture” synergy model for coastal wetlands.

Carbon sink loans, a green financial instrument, utilize carbon sequestration rights from forestry, agriculture, or wetlands as collateral [16]. For instance, a Weihai nursery secured loans using future forestry carbon sink revenues, with preferential rates contingent on successful CCER project development [17]. The Dongtai Branch of China Postal Savings Bank issued a loan of CNY 20 million to Tiaozini Wetland Management Company for benthic organism procurement and biodiversity conservation, using annual carbon sink valuation (CNY ≈ 1.25 million) as supplementary collateral [18]. Such mechanisms transform carbon assets into bankable resources, addressing ecological financing bottlenecks [19]. This study innovatively develops a full-process carbon sink financing model that demonstrates the operational mechanism of pledging coastal wetland carbon sink revenue rights as a novel financing instrument. By transforming the assessed carbon sequestration services of wetlands into pledgeable financial assets, it thereby establishes market-based financing channels for ecological restoration projects. Assessing ecosystem service values and implementation pathways in Chuandonggang holds scientific significance for resource conservation and eco-economic coordination. This study evaluates ecological services of the Dafeng Jianchuan restoration project through field investigations and data analysis, proposing actionable pathways to inform regional ecological governance and sustainable development.

2. Materials and Methods

2.1. Study Area and Project Overview

The Jianchuan Ecological Restoration Project of Chuandong Port in Dafeng is located between Yancheng National Rare Bird Nature Reserve and Jiangsu Dafeng Milu National Nature Reserve (119°51′25″ E–121°5′47″ E, 32°36′51″ N–34°28′32″ N), with a total area of 108 ha (Figure 1). This area belongs to the transitional zone between warm temperate and subtropical zones, exhibiting typical coastal wetland ecological characteristics. The tidal flat area in the project site serves as an important habitat for various rare birds, including Grus japonensis and Ciconia boyciana [5]. Through implementing ecological restoration projects in the project area, including the construction of paddy fields, shallow beaches, marsh wetlands, open water surfaces, and woodland along with supporting management road engineering, vegetation restoration engineering, and fish/benthic organism restoration engineering, a healthy and complete ecosystem is established to create a naturally beautiful ecological environment, transforming original fishponds into ecological wetlands suitable for rare animal habitats. During the ecological restoration process, guided by upper-level planning and oriented by the functional positioning of the project area, the focus is on constructing ecological wetlands suitable for bird habitats in the nature reserve. Through targeted terrain shaping, plant selection, and creation of wetland microhabitats suitable for bird inhabitation, it provides habitats for breeding and overwintering birds.

2.2. Ecological Value Assessment Methods

The study area was originally a reclaimed area, later converted into fishponds and agricultural planting areas. Before project implementation, the ecological types were relatively singular, mainly consisting of pond wetlands and farmland ecosystems, with relatively few river-lake wetlands and marsh wetland ecosystems. Referring to the “Technical Regulation for Wetland Ecosystem Service Assessment” (Forestry Industry Standard of the People’s Republic of China. Technical Regulation for Wetland Ecosystem Service Assessment: LY/T 2899-2023) [20], we initially established three first-level indicators (supporting services, regulating services, and provisioning services) and six second-level indicators (biodiversity conservation, soil conservation, water quality purification, carbon sequestration and oxygen release, climate regulation, and food production) to study the ecosystem service value of the project area after engineering implementation.

2.2.1. Supporting Services

The outcome reference method was used to evaluate the biodiversity conservation value in the project area. Considering that the project area does not contain endemic species or ancient/famous trees, targeted adjustments were made to the original assessment model [20].

$$V_1=\left(1+{\sum }_{i=1}^n{Q}_n\times 0.1\right)\times S\times P$$

(1)

In the formula, V₁ represents the value of wetland biodiversity conservation (CNY); Q_n denotes the endangered species index score for species n; n indicates the number of species for which the endangered species index is calculated; S stands for the wetland area (ha); and P represents the unit area value of biodiversity conservation in wetlands (CNY/ha). The weighting method for different threat categories are shown in Tables S1–S3. The per unit area biodiversity conservation value (P) of wetlands is determined by the biodiversity index (BI). According to avian survey data from the Evaluation Report on the Ecological Restoration Project of Chuandonggang Nanjianchuan in the Decommissioned Aquaculture Area of Dafeng Coastal Group, the Shannon–Wiener index for birds in the project area was calculated as 2.98, corresponding to a p-value of CNY 15,000/(ha·yr).

The Shannon–Wiener index quantifies the information entropy of species diversity within a sampled ecosystem, calculated as

$$H^{’}=-\sum _{i=1}^S{\displaystyle \frac{n_i}{N}}\ln {\displaystyle \frac{n_i}{N}}$$

(2)

In the formula, H′ represents the Shannon–Weiner index of the community; n_i denotes the total number of individuals for the i-th species; N indicates the total number of all organisms; S refers to the species richness. The study area harbors one vulnerable (VU) species listed in The IUCN Red List of Threatened Species, namely Anser cygnoides, along with four near-threatened (NT) species: Vanellus vanellus, Calamornis heudei, Limosa limosa, and Mareca falcata.

$${\sum }_{i=1}^n{Q}_n=1\times 2+4\times 1=6$$

(3)

2.2.2. Regulating Service Value

The service value of soil conservation in the project area was assessed through the shadow engineering approach. This methodology quantifies the economic equivalence of ecosystem-mediated soil retention by estimating the hypothetical costs required to reconstruct equivalent artificial water and soil conservation systems [20].

$$V_2=S\times \left(X_2-X_1\right)\times {\displaystyle \frac{P_{soil}}{\rho }}$$

(4)

where V₂ represents the soil conservation value of wetlands (CNY); S is the total area of wetlands minus the water area at the lowest water level (ha); X₁ is the soil erosion modulus with wetland vegetation (t/ha); X₂ is the soil erosion modulus without wetland vegetation (t/ha); ρ is the soil bulk density (t/m³); P_soil is the local unit area earthwork price for the current year (CNY/m³). The revised universal soil loss equation was used to determine the soil erosion modulus [21].

$$A=R\times K\times LS\times C\times P$$

(5)

In the equation, A represents the soil erosion modulus [t/(ha·yr)], R denotes the rainfall erosivity factor [MJ·mm/(ha·h·yr)], and K is the soil erodibility factor [t·h/(MJ·mm)]. The dimensionless factors LS, C, and P correspond to the topographic factor, vegetation cover and management factor, and soil conservation practice factor, respectively. The mean annual rainfall erosivity was determined as 5944.03 MJ·mm/(ha·h·yr). Based on the Pan-Third Pole regional soil erodibility dataset encompassing the study area and adjacent regions [22], the soil erodibility factor was assigned a mean value of 0.35 t·h/(MJ·mm).

The slope length and steepness factor (LS) accounts for the slope length and steepness of the area, calculated as follows [23]:

$$L={\left({\displaystyle \frac{\gamma }{22.3}}\right)}^{\alpha }$$

(6)

$$\alpha ={\displaystyle \frac{\beta }{1+\beta }}$$

(7)

$$\beta ={\displaystyle \frac{\left(\frac{\sin \theta }{0.0896}\right)}{\left(3\times {\sin \theta }^{0.8}+0.56\right)}}$$

(8)

$$S=\left\{\begin{array}{c}10.8\sin \theta +0.03 0°\le \theta <9°\\ 16.8\sin \theta -0.5 9°\le \theta 159°\\ 21.91\sin \theta -0.96 \theta \ge 14°\end{array}\right.$$

(9)

where, L is the slope length factor; S is the slope steepness factor; $\gamma$ is the slope length; $\theta$ is the slope angle.

The vegetation cover factor (C) represents the ratio of soil loss from vegetated land to that from bare land under identical topographic conditions. Due to data accessibility and refinements in parameter calculation methodologies, this study adopts the vegetation cover factor dataset computed by Li et al. [24], approximating values for target years using data from adjacent years. Considering the regional characteristics, for wetland vegetation areas, soil erosion modulus was calculated under 80% vegetation coverage (X₁=0 t/ha), and non-wetland vegetation areas were computed with 50% vegetation coverage (X₂= 46.8 t/ha). The soil bulk density was set as 1.4 g/cm³ according to previous studies in surrounding project areas [25].

The conservation practice factor (P) is defined as the ratio of soil loss with specific conservation practices to soil loss without such practices. Its value ranges from 0 to 1, where 0 indicates complete prevention of soil erosion through conservation measures, and 1 indicates no conservation practices. Since all slopes in the study area are less than 5°, the conservation practice factor (P) was assigned a value of 0.11 [26].

2.2.3. Water Purification Service Valuation

Following technical specifications, the pollution control cost method was employed to estimate the regulatory service value of water quality purification in the study area. The calculation formula is as follows [27]:

$${\mathrm{V}}_3={\sum }_{i=1}^n{Q}_i\times P_i\times R$$

(10)

where V₃ is value of pollutant degradation by wetlands (CNY); Q_i is annual influx of the i-th pollutant into wetlands (t); P_i is treatment cost for the i-th pollutant (CNY/t); R is the average pollutant removal rate of wetlands (%); i is the pollutant category. According to seminal studies on reed wetlands in the northern Jiangsu coastal zone [28,29,30], these ecosystems demonstrate an annual purification capacity of 0.095 t/ha for total nitrogen (TN) and 0.026 t/ha for total phosphorus (TP). The treatment costs were standardized at CNY 36,400/t for TN and CNY 765,700/t for TP, based on regional environmental management practices. With a total wetland area of 108 ha, the valuation framework incorporates these spatial and operational parameters.

2.2.4. Carbon Sequestration and Oxygen Release Service Value

The regulatory service values of carbon sequestration and oxygen release in the study area were estimated using the carbon tax method and shadow engineering method, respectively [31]. The calculation formula is

$$V_4=\left(24.5\times M_{{CH}_4}+M_{{CO}_2}\right)\times S\times P$$

(11)

where V₄ represents the carbon sequestration value of wetland (CNY); $M_{{CH}_4}$ represents the net CH₄ exchange flux in wetland (t/ha); $M_{{CO}_2}$ represents the net CO₂ exchange flux in wetland (t/ha); S represents the wetland area (ha); P represents the carbon trading price in domestic carbon market (CNY/t). The calculation employs the global warming potential (GWP) conversion factor, where 1 kg of CH₄ is equivalent to 24.5 kg of CO₂ in terms of greenhouse effect. Based on wetland greenhouse gas exchange patterns and emission studies [32], the annual average CH₄ flux in the study area was determined as 0.14 t/ha, while the CO₂ flux reached 2.14 t/ha. Considering significant price fluctuations and regional disparities in domestic carbon trading markets, this study adopted the 2023 Swedish carbon tax price (approximately CNY 893/t) for calculation, following established practices in ecosystem service value assessment research.

$$V_5=1.19\times S\times W\times P_{O_2}$$

(12)

V₅ represents the oxygen release value of wetlands (CNY); S denotes wetland area (ha); W stands for vegetation biomass in wetlands (t/ha); $P_{O_2}$ indicates the annual oxygen price (CNY/t); the coefficient 1.19 reflects that 1.19 tons of O₂ are released per ton of dry matter accumulated by plants. The study area comprises 108 ha of wetland. Based on project specifications and the 2022 vegetation survey data from the Ecological Restoration Project Assessment Report for the Chuangang South Construction Area in the Retreating Aquaculture Zone of Dafeng Coastal Group, the wetland vegetation biomass was estimated at 3.16 t/ha. The average liquid oxygen price in 2023 was CNY 489/t.

2.2.5. Climate Regulation Service Value

The replacement cost method was employed to evaluate the climate regulation service value of humidity enhancement in the project area [33]. The calculation formula is

$$V_6=\left(Q_w\times S_1+Q_p\times S_2\right)\times 10\times P_{air}$$

(13)

where V₆ represents the humidity regulation value (CNY); Q_w denotes the annual evaporation from wetland water surfaces (mm); Q_p indicates the evapotranspiration from wetland vegetation (mm); S₁ is the area of wetland water surfaces (ha); S₂ is the area of wetland vegetation (ha); P_air refers to the unit cost of air humidification (CNY/t).

According to the post-construction land use composition data from the Ecological Restoration Evaluation Report of Chuandonggang South Jianchuan Project in Dafeng Coastal Group’s Decommissioned Aquaculture Zone, the water surface area (classified as lake surface) in the project area is 50 ha, while the vegetation area (including cropland, forestland, inland tidal flats, and marsh wetlands) totals 103 ha. Parameter values were determined as follows: the average water surface evaporation in Jiangsu Province is 1425 mm [34], with a natural water evaporation reduction coefficient of 0.8; the average wetland vegetation evapotranspiration is 872 mm [35]; the energy consumption for converting 1 ton of water into vapor is approximately 125 kWh [36]. Based on the electricity pricing standard (State Grid Jiangsu Electric Power Company, 2023), the residential electricity price in Jiangsu Province is CNY 0.5283/kWh.

2.2.6. Provisioning Service Value

The paddy field restoration project was implemented in the study area, where rice (Oryza sativa L.) served as the dominant aquatic vegetation in the wetland ecosystem. The market value approach was employed to estimate the food production value of the wetland ecosystem using the following expression [37]:

$$V_7=Q_{rice}\times P_{rice}$$

(14)

where V₇ represents the annual economic value of plant products from the wetland (CNY), Q_rice denotes the annual rice yield (t), and P_rice indicates the local market price of rice (CNY/t). The restored farmland covered a total area of 42 ha. In accordance with engineering specifications, a portion of rice production was reserved annually for avian supplementary feeding at a yield rate of 3750 kg/ha [38]. The study area generated 112.5 t of green organic rice annually. Based on regional product pricing strategies, the branded rice was valued at CNY 20/kg. Consequently, the annual economic output from rice production was calculated as 157.5 × 1000 × 20 = CNY 2,250,000.

3. Results and Analysis

3.1. Ecosystem Service Value in the Project Area

Through methodological calculations, the total ecosystem service value of Jianchuan Ecological Restoration Project implemented by Jiangsu Dafeng Coastal Group reached CNY 76.2896 million (

Table 1. Ecosystem service value accounting results for the Jianchuan Ecological Restoration Project.

Primary Indicators	Secondary Indicators	Ecosystem Service Value (Million CNY)	Proportion (%)
Supporting services	Biodiversity	2.592	3.40
Regulating services	Soil retention	0.0388	0.05
	Water quality purification	2.5235	3.31
	Carbon sequestration and oxygen release	0.7357	0.96
	Climate regulation	68.1496	89.33
Provisioning services	Food production	2.25	2.95
Total		76.2896	100.00

). Among the six assessed indicators, climate regulation service showed the highest value at CNY 68.1496 million, accounting for 89.33% of the total. This was followed by biodiversity conservation (CNY 2.592 million, 3.40%), water purification (CNY 2.5235 million, 3.31%), and food production (CNY 2.25 million, 2.95%), while carbon sequestration and soil conservation services contributed 0.96% and 0.05%, respectively. The accounting results demonstrate that the ecological restoration project has significantly enhanced regional ecosystem service values, with wetland-mediated climate regulation services making the most substantial contribution. By improving microclimatic conditions, promoting vegetation growth, and optimizing avian habitats, the restored wetlands provide critical climate regulation services. The predominant share of climate regulation services (89.33%) reflects wetlands’ multifunctional ecological roles during restoration, including humidity enhancement, microclimate improvement, and biodiversity habitat enrichment, highlighting their significance in climate modulation.

Within supporting services, biodiversity conservation contributed CNY 2.5920 million. Although proportionally modest, its strategic importance in ecological restoration remains paramount. Wetland recovery provides essential habitats for avian roosting, breeding, and overwintering, particularly for rare species, thereby reinforcing biodiversity conservation. The restored biodiversity not only enhances ecosystem stability but also establishes foundations for long-term protected area sustainability. Water purification services amounted to CNY 2.5235 million, constituting 3.31% of the total value. Wetland ecosystems play vital roles in water quality enhancement, particularly through improved self-purification capacities via rhizofiltration and sedimentation processes that effectively remove aquatic pollutants. This restoration project proves crucial for water quality improvement and ecological environment recovery. Comparatively lower contributions from carbon sequestration and soil conservation likely relate to the project’s priority areas, spatial scale, and restoration objectives. While essential for ecosystem health, these services demonstrate less pronounced economic values than climate regulation and biodiversity conservation. Regarding provisioning services, food production contributed CNY 2.25 million (2.95%), primarily calculated from rice production economic values, reflecting the post-restoration agricultural potential. Per project specifications, cultivated rice provides dual functions: supplying avian food resources and generating economic returns. This balance between agricultural production and ecological restoration supports both environmental goals and regional sustainable development.

The value of water quality purification services is CNY 2.5235 million, accounting for 3.31% of the total service value. The wetland ecosystem plays a significant role in water quality purification, particularly in enhancing the self-purification capacity of water bodies. Wetlands effectively remove pollutants from water through the filtering and sedimentation functions of plant root systems. The wetland restoration project in the study area is crucial for improving water quality and restoring the ecological environment. Additionally, the contribution of services such as carbon sequestration and oxygen release as well as soil retention is relatively low, which may be related to the focus areas of the wetland ecological restoration project, the project area, and the project objectives. Although these services are important for ecosystem health, their economic value is less prominent compared to climate regulation and biodiversity conservation. In terms of provisioning services, the value of food production is CNY 2.25 million, accounting for 2.95% of the total service value. This service primarily calculates the economic value of rice production, reflecting the potential for agricultural production, especially rice cultivation, after wetland restoration. According to project requirements, the rice planted in the project area can provide a certain food source for birds while also generating economic benefits for the landowners. Balancing agricultural production with ecological restoration not only meets the goals of ecological restoration but also supports the long-term sustainable development of the local ecosystem.

3.2. Implementation Pathways

3.2.1. Realization of Ecological Product Value

With the advancement of ecological civilization construction and the proposal of dual carbon goals, the value realization mechanism of ecological products has become a focal issue in recent eco-economic research and practice [39]. Ecological products have evolved beyond mere ecosystem service functions to become green assets convertible into economic benefits [40,41]. The Jiangsu Jianchuan Wetland Restoration Project, as a representative aquaculture-to-wetland conversion initiative, has established a relatively comprehensive ecological product system based on effective restoration of wetland ecosystem structure and functions, including climate regulation, water purification, and biodiversity conservation. Ecosystem service valuation results reveal significant potential for monetary conversion of ecological value in this region. However, ecological products do not inherently possess market attributes, requiring institutional design, market mechanisms, and technological support for value realization. During the initial phase of China’s ecological product value realization, constraints persist, including unclear ecological asset property rights, imperfect market transaction mechanisms, and limited financial instruments [42]. Therefore, clarifying ecological product realization mechanisms and innovating asset conversion pathways are crucial for actualizing the ecological value of the Jianchuan Project.

3.2.2. Carbon Sink Loans

As a vital form of ecosystem service, carbon sink refers to the capacity of wetlands, forests, grasslands, and other ecosystems to absorb and sequester CO₂ through plant photosynthesis, representing a quintessential ecological product that is measurable, quantifiable, and tradable [43,44]. The Jianchuan Ecological Restoration Project has restored approximately 103 ha of wetland area through the initiative of “converting aquaculture areas back into wetlands”, resulting in significant carbon sequestration capabilities. According to evaluation results, the project area is projected to achieve CO₂ emission reductions totaling 64,381.64 tons over a 20-year accounting period, providing substantial support for carbon neutrality goals. In August 2022, Industrial Bank’s Nanjing Branch issued Jiangsu Province’s first wetland carbon sink pledge loan of CNY 10 million to Yancheng Dafeng Huafeng Agricultural Development Co., Ltd., based on this foundation. This milestone marked a concrete step forward in realizing ecological product value through carbon finance [45]. The model utilizes future carbon sink as loan collateral, relying on professional evaluation agencies to verify and certify the project’s carbon sequestration potential, thereby bridging ecological value with financial capital. This innovative approach not only overcomes financing barriers caused by the “asset-light and long-cycle” nature of ecological restoration projects but also revitalizes previously non-quantifiable and non-tradable ecological resources, establishing an exemplary precedent. During the loan approval process, Industrial Bank established a green channel, prioritized credit quotas, and enhanced approval efficiency, providing timely financial support to ensure sustainable project maintenance and subsequent operations. From a social benefit perspective, this model strengthens the synergy between ecological restoration and financial mechanisms. It not only incentivizes corporate participation in ecological conservation but also elevates societal awareness of ecological asset value. This mechanism serves as an effective approach for realizing ecological product value under the “Dual Carbon” goals [46].

Relevant studies indicate that the carbon sink loan model demonstrates both innovation and substantial practical effectiveness. Operational data from the Yancheng Coastal Wetlands in Jiangsu, China, the Zhanjiang Mangrove Reserve in Guangdong and the Poyang Lake International Wetlands comprehensively corroborate this observation. First, regarding financing scale and costs. The Yancheng project has cumulatively disbursed loans totaling CNY 420 million (representing 38% of China’s total wetland carbon sink loan volume), with an average interest rate 1.2 percentage points lower than that of agricultural loans during the corresponding period, according to official banking data [47]. The Zhanjiang mangrove project achieved a single-loan ceiling of CNY 8 million, with a pledge rate reaching 65% of the carbon sink appraisal value (compared to 40% under traditional models) [48]. Second, in terms of carbon sink monitoring efficiency, following the adoption of InSAR remote sensing technology, the carbon sink accounting error margin in the Poyang Lake Wetlands decreased from ±15% to ±6.7% [49]. Concurrently, the actual carbon sequestration rate in Yancheng Reed Wetlands measured 3.8 ± 0.3 t CO₂/ha, showing 91.4% alignment with pledged valuations [50]. Third, examining risk control performance, the dynamic interest rate adjustment mechanism effectively mitigated impacts from the 2024 Yangtze River flood season. When water levels exceeded warning thresholds, automatic rate hikes of 25 basis points were triggered, reducing default risk to zero [51]. The pledged carbon sink value volatility was contained at 7.2% (versus 8.9% in the national carbon market during the same period) [52]. Finally, assessing policy integration outcomes, the research has been incorporated into the Ministry of Natural Resources’ Guidelines for Realizing the Value of Wetland Ecological Products (Trial) [53]. It additionally spurred a nationwide increase of CNY 2.37 billion in wetland carbon sink pledged loans [54].

3.2.3. Synergistic Multi-Pathway Value Conversion

Beyond carbon sink loans, Jiangsu Jianchuan Ecological Restoration Project demonstrates potential for realizing ecological product value through multiple pathways, forming an integrated system comprising three components: “monetization of ecological services + market mechanism guidance + policy support guarantees” (Figure 2). Regarding government ecological compensation, as part of the national rare bird reserve, the project area undertakes public ecological service responsibilities including wetland restoration and biodiversity conservation, qualifying for provincial/national ecological compensation funds [55]. Following Jiangsu’s ecological compensation regulations, local governments may provide annual compensation based on wetland area, service functions, and conservation costs to support ongoing maintenance and monitoring. In ecological agriculture, the project has restored 42 ha of paddy fields, yielding 157.5 tons of green organic rice annually, with partial harvests allocated for bird feeding in protected areas, establishing a “production–conservation” virtuous cycle. Through branded agricultural systems incorporating green food certification and ecological traceability labeling, market premium capacity of rice products has been enhanced, effectively transferring ecological added value to products and strengthening industrial development. Xing’an League’s green rice brand achieved a CNY 18.026 billion valuation through organic certification (143 km²) and integrated rice-fish farming and quality control systems [56]. Meanwhile, Haimen’s ecological service procurement model elevated manure recycling to 92% via “rice–livestock–mushroom” circular chains, while “GI+Green Certification” strategies increased premium product ratios to 88.74% through agritourism innovations [57]. Both cases demonstrate how ecological farming and institutional mechanisms synergistically enhance brand premiums and regional green transitions. The ecological service procurement mechanism offers additional value realization. Governments, enterprises, or social organizations may establish long-term contracts with project operators to purchase wetland-mediated water purification, climate regulation, and biodiversity maintenance services. This creates stable “ecological supplier–demander” relationships, transforming ecological services from implicit to explicit values. Future development could expand social participation through public welfare platforms and green bonds, attracting more social capital to support ecological construction and achieve full-cycle value circulation. In summary, Jianchuan Project’s ecological value realization should persist in multi-path, multi-stakeholder, and multi-instrument synergies. By establishing replicable models, it will effectively operationalize the transformation pathway from “green mountains and clear waters” to “economic prosperity”.

4. Discussion

4.1. Challenges in Ecosystem Valuation

Ecological product value realization requires integrated institutional design and multi-pathway coordination. Experiences from Liannan Terraces, Taihu Wetland Park, and Yongding River Basin reveal that ecological value monetization depends not only on ecosystem service provision capacity but also on regional governance competence, institutional arrangements, and industrial integration levels. For instance, Taihu National Wetland Park generated approximately CNY 650 million in value spillover by enhancing educational and recreational functions [58], while Zhangjiakou Bashang Plateau achieved ecological–economic synergies through reforestation and grassland restoration policies that boosted ecosystem service values while promoting eco-tourism and forestry employment [59]. Nevertheless, current ecological product value realization faces common challenges. First, ambiguous ecological asset property rights hinder product trading and circulation. As Zhangye City’s case illustrates, imperfect property rights systems and trading platforms often trap ecological products in “valuable but unpriced, functional but untradable” dilemmas [60,61]. Second, market mechanisms remain underdeveloped. The Liannan case reveals that compensation standards based on farmer acceptance rather than actual ecosystem service values often lead to inadequate compensation levels [62]. Third, heavy reliance on fiscal transfers creates unsustainable incentives, exemplified by Huanghai Coastal Wetlands where funding gaps and slow industrial transformation persist despite establishing preliminary ecological product branding systems [63].

In summary, the three case studies demonstrate distinct approaches to ecological governance (

Table 2. Comparative analysis of key factors among the Yongding River, Liannan, and Taihu Projects.

Dimension	Yongding River Basin	Liannan Yaopai Terraces	Taihu Wetland Park
Project Type	Cross-provincial watershed ecological restoration	Terrace wetland conservation and agro-ecosystem	Urban wetland ecotourism and environmental education
Core Mechanisms	Horizontal eco-compensation, market-oriented operation, and regional governance	Farmer compensation system, government leasing model, and ecological farming rules	Self-financing model, ecotourism revenue reinvestment, and scientific research
Benefit Models	Carbon trading (e.g., Zhangjiakou) and eco-industry chains	Direct farmer payments (CNY 5173–CNY 6478/ha), terrace leasing (CNY 7416–CNY 8916/ha)	Ticket/rental income and property value appreciation (9–12% within 1.5 km)
Value Pathways	GEP accounting (51.8% regulatory services) and water rights trading	Quantified ESV (CNY 38,042/ha), water-saving subsidies	Research value (CNY 3039/ha), tourism revenue (94.5% of total)
Key Differences	High cross-regional governance complexity	High farmer participation but abandonment risks	Urban location advantage with high management costs (56.09%)
Data Highlights	2020 GEP: CNY 93.8 B (hydrological regulation 51.8%)	2019-unit value: CNY 38,042/ha (hydrological regulation 42.9%)	2018 value spillover: CNY 645.57 million

). Yongding River Basin represents a cross-provincial watershed restoration project employing horizontal eco-compensation and market mechanisms like carbon trading (e.g., Zhangjiakou case), with significant GEP valuation (CNY 93.8B in 2020) emphasizing hydrological regulation (51.8%). In contrast, Liannan Yaopai Terraces focuses on agro-ecosystem conservation through direct farmer compensation (CNY 5173–CNY 6478/ha) and quantified ESV (CNY 38,042/ha), though facing terrace abandonment risks. Taihu Wetland Park adopts an urban ecotourism model, generating 94.5% revenue from tourism while maintaining high management costs (56.09%), with notable property value appreciation (9–12% within 1.5 km). While Yongding emphasizes regional governance complexity, Liannan prioritizes farmer participation, and Taihu leverages urban advantages, all three showcase innovative value pathways—from water rights trading to research valuation (CNY 3039/ha)—reflecting China’s diversified ecosystem service monetization strategies.

The Jianchuan experience suggests three priority areas for future ecological value realization: (1) strengthening ecological asset property rights registration to facilitate wetland carbon sink “accounting and marketization”; (2) accelerating gross ecosystem product (GEP)-centric ecological performance accounting systems to provide quantitative baselines for financial institutions and market entities; and (3) promoting multi-stakeholder co-governance frameworks under government guidance and establishing diversified value realization mechanisms combining government procurement, social subscription, market trading, and philanthropic support. The Yongding River Basin’s “regional complementarity + industrial synergy + multi-party participation” model exemplifies this approach [64,65]. In conclusion, ecological product value realization serves not only as the cornerstone for sustainable operation of restoration projects but also as the key driver for implementing the “Two Mountains” concept and achieving high-quality development. As Jiangsu’s first coastal wetland carbon sink pledge loan case, Jianchuan’s “ecological restoration–carbon sink assessment–asset financing” pathway demonstrates exemplary significance. Future efforts should focus on systematic integration of policy frameworks, valuation methodologies, and trading mechanisms to enable efficient transformation from ecological assets to economic capital.

4.2. Policy–Market Synergy Model

The synergistic framework for eco-value realization pathways is designed based on a closed-loop logic of “policy-driven incentives, market leverage, and industrial feedback”, wherein the Jianchuan Project establishes a tri-dimensional synergy system. First, through policy–market dual drivers, government eco-compensation funds are prioritized for foundational capacity building such as wetland carbon sink monitoring to provide data support for subsequent carbon trading and ecosystem service procurement. Second, via industry–ecoservice reciprocity, 10% of the green premium revenue from branded rice sales is allocated to ecological monitoring systems, forming a virtuous cycle of premium agricultural products, ecological certification, market premiums, and conservation investment. Finally, public–private capital complementarity is achieved as philanthropic platforms focus investments on carbon-sequestering restoration areas, spatially complementing government compensation funds. Regarding policy–market linkage, 30% of provincial eco-compensation funds are designated for developing wetland carbon sink methodologies during funding applications to comply with Jiangsu Province’s Implementation Plan for Consolidating and Enhancing Ecosystem Carbon Sink Capacity [66]. Leveraging Yancheng’s pioneering wetland blue carbon loan experience [67], compensation funds are transformed into tradable carbon assets, achieving functional evolution from compensation transfusion to market hematopoiesis. In eco-agricultural value chain integration, the bird-friendly rice certification standard [68] mandates purchasers to pay biodiversity conservation fees equivalent to 5% of the transaction value. These fees are incorporated into corporate ESG reporting while serving as contractual performance verification for ecosystem service procurement, enabling dual value capture through product premiums and service payments. This approach translates wetland ecosystem service value into geographical indication premiums, aligning with Xing’an League’s rice branding model. For multi-stakeholder benefit distribution, a tripartite conservator–producer–purchaser agreement is designed: Protected area administrations provide ecological monitoring data, farmers implement organic cultivation protocols, and buyers commit to premium procurement. Carbon revenue is shared at 40%:30%:30%, with allocation ratios optimized using Nantong Haimen’s ecological livestock zone governance model [69]. Empirical synergy validation indicates Changzhou Tianning’s procuratorial carbon synergy mechanism [70] increases per-unit-area value by 217% through integrated eco-compensation and carbon trading, while Yancheng forest farm trials demonstrate that every CNY 10,000 increase in branded agro-product revenue drives CNY 3400 growth in conservation investment [71]. The Jianchuan Project can utilize these quantitative relationships to forecast synergistic benefit multiplication effects under multi-path coordination.

4.3. Carbon Finance Case Study

This study evaluates the pathways for realizing ecological product values based on ecosystem service assessments of Jiangsu Province’s Jianchuan Ecological Restoration Project, demonstrating the market transformation of ecological assets through the innovative “carbon sink loan” case. Results indicate that the annual average total ecosystem service value in the project area exceeds CNY 70 million, demonstrating significant carbon sequestration potential, agricultural–ecological symbiosis capacity, and wetland restoration value. These findings align with ecosystem valuation results from the Bosten Lake, Zhangjiakou Bashang, and Liannan Yaopai Regions [62,72,73], further confirming the critical role of wetland ecosystems in maintaining regional ecological security and providing ecosystem services. Compared with traditional ecological compensation and fiscal transfer approaches, this research highlights the catalytic role of green financial instruments like “carbon sink loans” in ecological value realization. Recent studies have drawn increasing attention to blue carbon systems, particularly coastal wetlands, due to their robust carbon sequestration capacity and sink stability [59,74,75]. Mid-latitude coastal wetlands (e.g., Yancheng and Jiangsu) demonstrate particularly high soil organic carbon density and sediment sequestration potential, positioning them as crucial ecological resources for achieving carbon neutrality in China. Industrial Bank’s innovative “forward carbon sink income right pledge loan” model developed for the Jianchuan Project successfully addresses structural challenges in wetland projects—“light assets, slow returns, and financing difficulties”—providing a replicable paradigm for financial transformation of similar projects nationwide. Compared to government subsidy-dependent models, this market-oriented mechanism enhances the sustainability of ecological conservation initiatives.

The U.S. Wetland Banking System achieves wetland mitigation through a “credit accumulation–market trading” mechanism, requiring developers to purchase wetland credits to offset development impacts, with nationwide transaction volume reaching USD 1.2 billion in 2024 [76]. Compared to the Jianchuan Project, this mechanism emphasizes market-driven approaches under legal mandates but lacks derivative value development such as carbon sequestration. Australia’s Biodiversity Offset Program adopts the “like-for-like ecosystem replacement” principle, mandating developers to establish alternative habitats 2–3 times the size of damaged areas nearby [77]. Its spatial proximity principle holds reference value for agricultural ecosystems like Liannan Terraces. Fujian Sanming’s Forest Carbon Sink Trading, China’s first regional carbon sink trading system, recorded cumulative transactions of 2.87 million tons in 2024 yet faces pricing imbalances with carbon prices (CNY 42/ton) at only 23% of EU ETS levels [78]. European and American systems enforce legal mandates (e.g., Section 404 of the U.S. Clean Water Act) [79], while China primarily relies on policy pilots, with Jianchuan’s “carbon sink loan” remaining a spontaneous innovation by financial institutions. EU corporate participation rates reach 89%, whereas China’s efforts are still government-dominated (76% of funding supply). The Jianchuan Project breaks this limitation through a tripartite “bank–government–farmers” agreement.

Empirical studies confirm that Industrial Bank’s innovative “forward carbon sink pledge loan” product enhanced credit risk coverage to 85% [80]. This was achieved through a 50–70% pledge ratio against certified carbon sink revenues with an initial financing scale of CNY 28 million and a novel dual risk mitigation system combining carbon sink insurance and government risk compensation funds. Comparative analysis demonstrates this model’s superiority over traditional fiscal transfers. In capital efficiency, it achieved a 1:5.3 financial leverage effect and 3.2× annual fund turnover rate [81], significantly outperforming fiscal subsidies’ 1:1 direct allocation. Regarding incentives, its floating interest rate mechanism (−0.5% to −1.2%) tied to carbon sink increments improved ecological management efficiency by 47%, while fiscal subsidy programs showed 23%/year declining conservation investment [82]. Cost–benefit calculations reveal a CNY 22.8 million net present value (5% discount rate) for thousand-hectare wetland restoration over eight years [83]. The market-driven return mechanism effectively resolves fiscal subsidies’ soft budget constraints. We propose a tripartite institutional framework based on empirical findings. The first is fiscal participation as subordinated LPs demonstrated by the Jiangsu pilot to balance risk–return at 20% allocation. The second is introducing carbon sink derivatives to hedge price volatility. The third is establishing an ecological bank evaluation system to holistically address ecological asset valuation maturity mismatches and risk premiums [82].

4.4. Extreme Scenario Testing, Innovations, and Limitations

Under scenarios of ±50% fluctuation in carbon price, the carbon sink loan mechanism of the Jianchuan Wetland Restoration Project will face significant economic challenges. According to the research data, the project area has a 20-year carbon sink potential of 64,381.64 tons of CO₂. Should the carbon price drop by 50% from the baseline of CNY 893/t to CNY 446.5/t, carbon sink revenue would decrease to CNY 28.74 million, potentially weakening financial institutions’ willingness to provide credit based on carbon asset collateral. Conversely, if the carbon price rises by 50% to CNY 1339.5/t, revenue could reach CNY 86.22 million, yet vigilance against market bubble risks is warranted. This volatility underscores the imperfections in the current domestic carbon market pricing mechanism. The introduction of price hedging instruments (e.g., carbon futures) or government guarantee mechanisms is necessary to stabilize expected returns [16]. Furthermore, carbon price fluctuations impact the scientific basis of ecological compensation standards. The study reveals that the project’s climate regulation service value constitutes 89.33% of its total value, the realization of which is highly dependent on the carbon market. Should carbon prices decline, this could lead to a devaluation of the “ ecological account”. Compensatory pathways must be activated to fill this gap, such as government procurement of ecosystem services and eco-product premiums. During periods of rising carbon prices, exploring the development of carbon sink derivatives (e.g., carbon insurance) could lock in gains [18]. It is recommended to establish a dynamic gross ecosystem product (GEP) accounting system, incorporating carbon price sensitivity analysis into the design of ecosystem product trading mechanisms to enhance risk resilience [41].

This study demonstrates innovations in three primary aspects. The first is a breakthrough in carbon finance mechanisms through creating Jiangsu’s pioneering “carbon sink pledge loans” for coastal wetlands (CNY 1 billion credit line), which transform future carbon sink revenue rights into pledgeable assets. This achieves the transition of ecological value from theoretical accounting (total service value: CNY 76.2896 million) to market realization. The second is a multi-path value transformation system establishes a trinity model integrating “ecological service monetization + market guidance + policy safeguards”. This includes applying for provincial/national ecological compensation funds, developing premium green organic rice brands (42-hectare rice fields, CNY 20/kg price premium), and securing long-term service agreements for water purification and climate regulation. The third is a methodological integration combining the LY/T 2899-2023 wetland assessment standard with carbon trading parameters (Sweden’s carbon tax: CNY 893/ton). This innovatively applies GWP conversion (24.5:1 ratio) to CH₄-CO₂ equivalent accounting. Limitations encompass three key areas. Data spatiotemporal constraints restrict coverage to the 2021–2023 restoration phase without full wetland succession cycles (20-year monitoring recommended). CH₄ flux parameters (0.14 tons/hectare) may underestimate intertidal greenhouse gas dynamics. Market mechanisms require refinement, as carbon sink loans rely on policy bank special channels without standardized trading markets. Missing ecological product certification systems (e.g., carbon labeling) impair premium pricing capabilities. Scaling challenges exist, with the current model based on a 108-hectare demonstration site requiring validation for Jiangsu’s 502 km² intertidal zones. Significant cross-regional compensation differentials (e.g., Zhejiang’s Xiangshan: 38% disparity) further complicate scaling. Future recommendations prioritize establishing long-term monitoring networks, exploring carbon sink derivatives (e.g., futures), and advancing local implementation rules for the Wetland Conservation Law to optimize policy coherence.

5. Conclusions

This study adopts the Jianchuan Ecological Restoration Project in Dafeng District, Yancheng City, Jiangsu Province, as a case study, conducting quantitative accounting of ecosystem service functions in the project area and assessing its ecological values in carbon sequestration and oxygen release, water purification, and biodiversity conservation while systematically investigating pathways for ecological product value realization. The project demonstrates an annual gross ecosystem service value exceeding 70 million yuan, with prominent performance in regulatory, supportive, and provisioning services, particularly showing substantial marketization potential in carbon sink (carbon credit generation). The Jianchuan Project exhibits unique advantages in China’s ecological product value realization landscape by innovatively synthesizing ecological rehabilitation with carbon financing mechanisms. This integration enables a quantifiable transition from ecological accounting metrics to market-validated economic values, addressing the critical gap between ecological asset recognition and capitalization. Our findings establish a transdisciplinary framework supporting regional implementation models for ecological product value realization while providing operational pathways to materialize the national strategy of converting “lucid waters and lush mountains” into “golden and silver mountains”.