Ecosystem Service Value Evaluation and Spatial Function Change under Town and Village Layout Planning: A Case of Jintan District

: This study proposes a systematic classiﬁcation of production–living–ecological function indicators based on ecosystem services, thereby clarifying the spatial functions of villages. Based on the land use change survey data of the Jintan District in 2012 and 2018, the ecological impact of town and village layout planning in Jintan District was analysed by using a quantitative measurement model of ecosystem services. The ﬁndings revealed that the ecosystem service value (ESV) decreased by 792 million CNY in the Jintan District, with the largest decrease in water ecosystem services valued at 700 million CNY and in hydrological regulation valued at 576 million CNY. A clear regional difference in ESV was observed, with villages on the east and west coasts of Changdang Lake being higher-value areas and most villages or communities in urban areas being lower-value areas. The areas of cultivated land, construction land, and unused land have increased, while land types with higher ecosystem service value coefﬁcients, such as wetland, water area, and grassland, have declined. The spatial pattern of production and living functions was quite similar, while there was a signiﬁcant spatial aggregation characteristic of ecological functions.


Introduction
Villages and towns are multiscale settlements within rural regional systems and serve as the nuclei of rural communities [1,2].In the face of China's ongoing industrialisation and urbanisation, there has been a substantial shift in the role and form of rural settlements [3].Over the past two decades, the Chinese government has introduced a range of initiatives to promote the development of new rural areas, foster coordinated urban-rural development, and encourage integrated urban-rural growth [4].Within this context, territorial spatial planning has become a key strategy in shaping the relationship between urban and rural spaces and influencing the distribution of development opportunities [5][6][7].As a critical component of territorial spatial planning, town and village layout planning plays a pivotal role in enhancing the efficient and sustainable use of rural land, improving the ecological environment and optimising the interplay of production, living, and ecological spaces [8].
The reform of spatial planning systems is a crucial strategy for advancing the construction of ecosystem civilisation in China.It refers to coordinating the protection and utilisation of natural resources by constructing a territorial spatial planning system.However, the practice of ecological civilisation is still not realistic in territorial spatial planning systems [9].Ecosystem services are central to the functioning of ecosystems and human Land 2023, 12, 1832 2 of 16 well-being [10], and can serve as a means of promoting resource allocation and stakeholder coordination in support of ecological civilisation [11].The benefits derived from ecosystem functions are rooted in the ecological systems that sustain them [12,13].With the gradual improvement in territorial spatial planning systems, some researchers have sought to incorporate ecosystem services into territorial spatial planning and investigated topics such as ecological compensation [14,15], the impacts of territorial planning on the environment [16], and the ecological prospects of highly urbanised areas [17,18].The interplay between ecosystem services and human well-being plays a pivotal role in enhancing the optimisation of territorial spaces and promoting planning decisions that better align with the principles of ecological civilisation [9].Given the growing importance of ecosystem services in territorial spatial planning, there is a pressing need for research that integrates these two domains.
This study established a functional classification system for villages and towns that considered ecosystem services.Our analysis focused on the relationship between town and village layout planning and ecosystem services, and drew on the concept of ecosystem service value to provide a basis for our research.By evaluating the ecological impacts of land use changes that have arisen from town and village layout planning in Jintan District, Jiangsu Province, we provided insights into the effectiveness of territorial planning and its role in realising the goals of ecological protection.Jintan District is located in southern Jiangsu Province and is characterised by diverse topography, including low mountains, hills, plains, and combinations of mountains, water bodies, forests, and trees.In recent years, Jintan District has undergone significant transformations following efforts to improve rural environments and enhance the beauty of rural settlements.Our study provided a qualitative and quantitative examination of the structure and function of ecosystem services in Jintan District after town and village layout planning and offered insights that can inform efforts to achieve ecological protection goals in the district.

Theoretical Framework 2.1. Support of Ecosystem Services to Town and Village Layout Planning
Town and village layout planning is crucial for optimising village development.It seeks to address issues related to population, industry, construction, and facilities by analysing their characteristics, determining the best course of action for the village's overall layout, integrating urban and rural areas, and reducing construction land use.The planning process involves a reasonable classification of village types, functional zoning of the village, protection of historical and cultural values, and provision of equalised basic public services.Furthermore, the plan aims to determine the boundaries of the village and regulate its construction by considering land utilisation and development.The impact of human activity on ecosystems is a critical issue that can be addressed in the context of town and village layout planning.The village and town ecosystem is a complex natural-artificial system that entails interactions between people and the environment [19,20].Human activities, including the implementation of town and village layout planning, can have a direct or indirect impact on regional ecosystem services by changing their structure, processes, and functions [21].This process can affect the regional economy, natural environment, culture, and overall human welfare (Figure 1).
It is imperative to consider the relationship between town and village layout planning and the provision of ecosystem services.Ecosystem services are the foundation of human survival and development, and any changes to them will have far-reaching consequences for human well-being [13].Town and village layout planning must, therefore, be implemented in a way that considers the impact on ecosystem services and incorporates measures to mitigate adverse effects.In conclusion, town and village layout planning is a crucial aspect of rural development that must consider the interplay between human activity and the provision of ecosystem services.To ensure sustainable rural development, the planning process must balance economic development, environmental protection, and cultural preservation.

Classification of Village and Town Spatial Functions Based on Ecosystem Services
Villages and towns host agglomerations for various production, living, and ecological elements within the rural regional system [22].They represent different forms of spatial organisation shaped by the arrangement of these elements in the region.The primary spatial functions of villages and towns are production, living, and ecological functions [23].The relative strengths of these functions are dependent on the composition and structure of the aforementioned elements, which dictate the trajectory of their functional evolution [12,24].The functional evolution of villages and towns changes in response to the integration and optimisation of spatial elements, shifts in external environments, and evolving societal needs [25].
The market demand for villages and towns was limited in the early stages of industrialisation and urbanisation.Agriculture dominated the national economy and accounted for a substantial share of it.To accommodate the needs of urban development, most regions chose rural support for cities and agricultural support for industry, which led to the outflow of various resource elements from rural to urban areas.Hence, the predominant spatial functions of villages and towns were centred on living and agricultural production.As industrialisation and urbanisation progress, the heterogeneity of urban-rural spaces begins to facilitate the convection of factors and industrial integration.Villages can undertake the industrial transfer of cities while providing labour, resources, and other production factors for cities.The relationship between urban and rural areas evolves from simple mutual interaction to symbiotic integration, thereby broadening the connotation of production functions and elevating the significance of industrial production functions.However, industrialisation and urbanisation have also resulted in environmental degradation and pollution, thereby leading to a growing recognition of the importance of ecological conservation.Consequently, ecological functions have become increasingly important in

Classification of Village and Town Spatial Functions Based on Ecosystem Services
Villages and towns host agglomerations for various production, living, and ecological elements within the rural regional system [22].They represent different forms of spatial organisation shaped by the arrangement of these elements in the region.The primary spatial functions of villages and towns are production, living, and ecological functions [23].The relative strengths of these functions are dependent on the composition and structure of the aforementioned elements, which dictate the trajectory of their functional evolution [12,24].The functional evolution of villages and towns changes in response to the integration and optimisation of spatial elements, shifts in external environments, and evolving societal needs [25].
The market demand for villages and towns was limited in the early stages of industrialisation and urbanisation.Agriculture dominated the national economy and accounted for a substantial share of it.To accommodate the needs of urban development, most regions chose rural support for cities and agricultural support for industry, which led to the outflow of various resource elements from rural to urban areas.Hence, the predominant spatial functions of villages and towns were centred on living and agricultural production.As industrialisation and urbanisation progress, the heterogeneity of urban-rural spaces begins to facilitate the convection of factors and industrial integration.Villages can undertake the industrial transfer of cities while providing labour, resources, and other production factors for cities.The relationship between urban and rural areas evolves from simple mutual interaction to symbiotic integration, thereby broadening the connotation of production functions and elevating the significance of industrial production functions.However, industrialisation and urbanisation have also resulted in environmental degradation and pollution, thereby leading to a growing recognition of the importance of ecological conservation.Consequently, ecological functions have become increasingly important in the later stages of urbanisation and industrialisation, which causes a transformation of spatial functions into an organic integration of production, living, and ecological functions (Figure 2). the later stages of urbanisation and industrialisation, which causes a transformation of spatial functions into an organic integration of production, living, and ecological functions (Figure 2).Ecosystem services are products and services that support human life and are directly or indirectly obtained from ecosystem [26].Since Costanza first proposed the assessment method and value coefficients for ecosystem service values in 1997 [27], the value of ecosystem services has been studied extensively [28][29][30].In China, Xie Gaodi reviewed the results of Costanza and developed the Chinese Land Ecosystem Services Value Equivalent Factor Table [31][32][33].In the theory of territorial spatial planning, the functional space of a region comprises ecological, production, and living spaces, which correspond to the ecological, production, and living functions of ecosystems, respectively [34].Based on the classification of Xie Gaodi and the connotation of rural spatial functions, this study constructed a classification system of rural spatial functions based on ecosystem services.Generally speaking, the territorial space has the leading function of production function, living function, and ecological function.In order to give full play to the overall function of the territorial space system, it is necessary to distinguish the leading function of the territorial space.Ecological functions are regulation and partial support services.Hydrology, soil, climate, biology, and vegetation are the basic elements that constitute ecological functions in the biosphere.A random combination of these elements forms specific function types, including gas regulation, climate regulation, waste disposal, hydrological regulation, soil conservation, and nutrient cycling.Production functions correspond to supply and support services, including food production, raw material production, water supply, and biodiversity protection.Food production and water supply are the most important functions of the ecosystem and are essential for human survival.Raw material production serves human development and provides the basic raw materials for production.Biodiversity protection maintains the gene pool of species, which is the premise of human food and raw material production.Living function is mainly used for cultural services, including aesthetic landscapes.Natural and human landscapes are fundamental to the pursuit of spirituality in ecosystems (Figure 3).
Therefore, this study established an evaluation index system for the spatial functions of villages and towns based on ecosystem services and clarified the multiple value attributes of spatial resources.It can be used to scientifically and effectively identify the types and connotations of spatial production, living, and ecological functions in the study area.Ecosystem services are products and services that support human life and are directly or indirectly obtained from ecosystem [26].Since Costanza first proposed the assessment method and value coefficients for ecosystem service values in 1997 [27], the value of ecosystem services has been studied extensively [28][29][30].In China, Xie Gaodi reviewed the results of Costanza and developed the Chinese Land Ecosystem Services Value Equivalent Factor Table [31][32][33].In the theory of territorial spatial planning, the functional space of a region comprises ecological, production, and living spaces, which correspond to the ecological, production, and living functions of ecosystems, respectively [34].Based on the classification of Xie Gaodi and the connotation of rural spatial functions, this study constructed a classification system of rural spatial functions based on ecosystem services.Generally speaking, the territorial space has the leading function of production function, living function, and ecological function.In order to give full play to the overall function of the territorial space system, it is necessary to distinguish the leading function of the territorial space.Ecological functions are regulation and partial support services.Hydrology, soil, climate, biology, and vegetation are the basic elements that constitute ecological functions in the biosphere.A random combination of these elements forms specific function types, including gas regulation, climate regulation, waste disposal, hydrological regulation, soil conservation, and nutrient cycling.Production functions correspond to supply and support services, including food production, raw material production, water supply, and biodiversity protection.Food production and water supply are the most important functions of the ecosystem and are essential for human survival.Raw material production serves human development and provides the basic raw materials for production.Biodiversity protection maintains the gene pool of species, which is the premise of human food and raw material production.Living function is mainly used for cultural services, including aesthetic landscapes.Natural and human landscapes are fundamental to the pursuit of spirituality in ecosystems (Figure 3).Therefore, this study established an evaluation index system for the spatial functions of villages and towns based on ecosystem services and clarified the multiple value attributes of spatial resources.It can be used to scientifically and effectively identify the types and connotations of spatial production, living, and ecological functions in the study area.4).The terrain gradually becomes gentle from west to east, with hills and mountains in the west and low-lying plains in the east.Jintan District is rich in natural landscape resources and has important ecological service functions.Jintan District comprises 97 administrative villages, 8 communities, a street office, a forest farm, 2 tea farms, 2 fisheries, a livestock farm, and a comprehensive agricultural service station, with a total area of approximately 894.87 km 2 .In 2018, the permanent population was 562,000, and the population density was 628 people per square kilometre.In recent years, the rapid development of industry and service industry has also had a certain degree of impact on the ecological system of Jintan District.Therefore, it is urgent to evaluate its ecosystem services and clarify the dominant functions of villages and towns.

Study Area
Jintan District is situated at the confluence of Jiangsu, Zhejiang, and Anhui provinces within the Ningzhen-Maoshan Mountain and Taihu Plain regions.It lies in the middle and lower reaches of the Yangtze River and is characterised by its geographic coordinates ranging from 119°17′45″ E to 119°44′59″ E and from 31°33′42″ N to 31°53′22″ N (Figure 4).The terrain gradually becomes gentle from west to east, with hills and mountains in the west and low-lying plains in the east.Jintan District is rich in natural landscape resources and has important ecological service functions.Jintan District comprises 97 administrative villages, 8 communities, a street office, a forest farm, 2 tea farms, 2 fisheries, a livestock farm, and a comprehensive agricultural service station, with a total area of approximately 894.87 km 2 .In 2018, the permanent population was 562,000, and the population density was 628 people per square kilometre.In recent years, the rapid development of industry and service industry has also had a certain degree of impact on the ecological system of Jintan District.Therefore, it is urgent to evaluate its ecosystem services and clarify the dominant functions of villages and towns.

Model of Ecosystem Services Value Calculation
This paper is based on the 'Chinese Land Ecosystem Services Value Equivalent Factor Table ' established by Xie Gaodi [33], which serves as the foundation for this study's ESV calculation.The standard equivalent is to define the economic value of the natural food produced by 1 hm 2 of cultivated land in a year at the national average yield as 1, and its economic value is equal to 1/7 of the annual market value of grain produced per hectare of cultivated land.Other ecosystem service value equivalence factors refer to the contribution of a certain kind of service value of a certain type of ecosystem to the food production service of cultivated land [31].Considering the ecosystem services provided by different land use types, garden land was found to possess homogeneous functions distinct from those of forest land and cultivated land; thus, the average value of forest land and dry land was used as the equivalent coefficient.Meanwhile, most construction land in the study area was found to consist of impervious surfaces, which have a negative impact on various ecosystem functions such as water supply, gas regulation, and waste disposal.The values assigned to these ecosystem functions were based on previous studies [35] and desert values [36] (Table 1).
where E the value of food production service function per unit area of farmland ecosystem, CNY/hm 2 ; m i is the sown area of i food crops, hm 2 ; p i is the average price of i food crops, CNY/kg; q i is the yield of i food crops, kg/hm 2 ; M is the total sown area of major food crops, hm 2 .
where ESV is the ecosystem service value, A i is the area of land use type i, VC i is the value coefficient of the ecosystem service of land use type i, ESV f represents the value of the f-th service function of the ecosystem, and VC f i is the value coefficient of the f-th service function of land use type i.In accordance with Xie Gaodi's proposals, the 'Chinese Land Ecosystem Services Value Equivalent Factor Table' was used to estimate the food production value of cultivated land.However, the research scale of Xie Gaodi is at the national level and, therefore, may need to be adjusted based on the local conditions of the study area.To account for it, a correction coefficient was calculated as the ratio of grain production per unit area between Jintan District and China [37].The formulae are as follows: where λ is the correction factor of the study area; Q and Q 0 are the grain production per unit area in Jintan District and China, respectively; E i is the equivalent factor of the i type of land use after revision; and E io is the equivalent factor of the i type of land use.
Based on data from the Changzhou Statistical Yearbook 2019, the predominant grain crops in the Jintan District were rice and wheat.These crops were used to estimate the grain yield per unit area.However, data were not available; therefore, the average net profit per unit area of rice and wheat in Jiangsu Province was used, obtained from the Compilation of National Agricultural Product Cost-Benefit Data 2019.To mitigate the impact of factors such as food price fluctuations and currency inflation, the average net profit of rice and wheat in 2018 was selected as the base price.Using data obtained from the Changzhou Statistical Yearbook 2019, Compilation of National Agricultural Product Cost-Benefit Data 2019, and the National Bureau of Statistics, the correction coefficient for the equivalent factor in the Jintan District was calculated to be 1.227.The resulting ecosystem service value per unit of the standard equivalent factor was determined to be 2660.34CNY/hm 2 .This information was used to determine the per unit area's ESV of Jintan District, which is presented in Table 2.The dynamic degree of ecosystem service value (EV) was utilised in this study as a means to represent the alteration of ecosystem service value for a specific land use type within the study area.The calculation of this dynamic degree was based on the following formula [38]: where EV is the dynamic degree of ecosystem service value; ESV a and ESV b represent the ecosystem service value of a certain type of land use at the beginning and end of the study, respectively; T is the research period of 6 years.

Results
This study used the natural breaks (Jenks) method to categorise the ecosystem service value and spatial functions of towns and villages into five groups: lower-value areas, low-value areas, medium-value areas, high-value areas, and higher-value areas.To further examine the spatial heterogeneity of villages, the Getis-Ord Gi* index was used for hotspot analysis, and the results were divided into five groups: colder, cold, medium, hot, and hotter spot areas.

Temporal Variation Characteristics of Ecosystem Service Value
An analysis of the land use changes revealed important insights into the distribution and dynamics of different land use types in the Jintan District.In 2012, the district covered an area of 894.87 km 2 , with cultivated land accounting for 39.10% (349.91 km 2 ), water area accounting for 26.45% (236.68 km 2 ), construction land accounting for 20.56% (183.95km 2 ), and garden land accounting for 8.25% (73.85 km 2 ).By 2018, the cultivated land area had increased slightly to 39.46% (353.08 km 2 ), whereas grassland, wetland, and unused land had slightly decreased.Construction land had increased to 22.63% (202.47 km 2 ), while the area of forest land and garden land had decreased to 4.36% (39.04 km 2 ) and 7.81% (69.92 km 2 ), respectively.This shift in land use patterns highlights the potential implications of ecosystem services provision in the district (Table 3).During the study period from 2012 to 2018, the ecosystem service value exhibited a downward trend, with a reduction of 792 million CYN or 7.83% in Jintan District.Among the different land types, the water area, which constituted 24.45-26.54% of the total area, made the largest contribution to the ecosystem service value and accounted for 96.04-96.69% of it.Conversely, despite accounting for a substantial proportion of the total area of the district (39.1-39.46%), the ecosystem service value of cultivated land only accounted for 4.42-4.84% of the ecosystem service value.Forestland accounted for approximately half of the garden land area, but its contribution to the value of ecosystem services was equivalent to that of garden land.Meanwhile, construction land, which accounted for 20.56-22.63% of the total area, had a negative impact on ecosystem service value, and contributed 6.97-8.32%.This decline in ecosystem service value was largely due to the rapid expansion of construction land, which reduced the areas of garden land, forestland, grassland, and water, except for cultivated and unused land (Table 3).
In a study of the composition of ecosystem service value in Jintan District, the value of hydrological regulation service had the highest value and accounted for a significant proportion (83.02-83.21%) of the total ecosystem service value.By contrast, the value of the water supply service was the smallest.This disparity might be due to the fact that construction land and cultivated land (paddy field) hinder water supply and negatively impacts its service value.Table 4 also indicates that, during the study period, the values of each ecosystem service function decreased to varying degrees.The hydrological regulation service experienced the largest decrease (6.93%), with a reduction of 5.76 million CNY.Conversely, the least decrease was observed in raw material production and nutrient cycling, thus exhibiting relatively stable changes compared with other ecosystem services (Table 4).The present study provides an in-depth investigation into the spatial distribution of ecosystem service values at village scale in the Jintan District.The results indicate that the distribution of ecosystem service value in Jintan District is heterogeneous, with the presence of high-value and low-value areas.In 2012, villages with higher ecosystem service values were primarily situated in the vicinity of Changdang Lake, the Maoshan Mountains in the west, and the northern aquaculture area, with a total of 14 villages.This distribution is concentrated in the vicinity of Changdang Lake.Meanwhile, 23 villages were found to have high ecosystem service values, mostly located in Zhiqian, Xicheng Street, Zhulin, and Zhixi.However, 28 villages had low ecosystem service value, with about half of them located in the foothills of Maoshan Mountain in Xuebu Town and along the Yangli Expressway line.Villages with lower ecosystem service values were mainly situated at the junction of Dongcheng Street and Xicheng Street, with a total of 12 villages.The degree of spatial agglomeration of ecosystem service value in the Jintan District in 2012 was high, and the distribution was relatively concentrated.The hotspot areas and hotter spot areas were mainly located in the Changdang Lake area in the south, referring to villages under the jurisdiction of Zhiqian Town and Rulin Town.The colder spot areas were distributed west of Dongcheng Street and north of Xicheng Street, and the cold spot areas were located in Jincheng Town, Dongcheng Street, and Xicheng Street, surrounding the colder spot areas.In 2018, the villages with higher and high ecosystem service values remained largely unchanged, with 13 and 25 villages, respectively.However, the number of villages with low ecosystem service value in Xuebu Town in the west decreased, whereas the number of villages with lower ecosystem service value in the northeast of Jintan District increased.Furthermore, the degree of spatial agglomeration of ecosystem service value in the Jintan District was further strengthened in 2018.The colder and cold spot areas expanded gradually to the east, while the hotter spot areas and hot spot areas were slightly reduced and further concentrated in the southern parts of Rulin Town and Zhiqian Town.The observed changes in the distribution of ecosystem service value in Jintan District may be related to the development and construction of the Jintan Economic Development Zone during the research period.The decline in the value of urban ecosystem services may have caused an eastward shift in the colder spot areas (Figure 5).

Dynamic Degree of Ecosystem Service Value
The dynamic degree of ecosystem service value reflects land use change to a certain extent.We assessed the temporal changes in the ecosystem service value of 113 administrative villages in the Jintan District at the village scale.Figure 6 presents the dynamic degree of ecosystem service value for each administrative village, in which the horizontal axis indicates the administrative villages and the vertical axis shows the corresponding dynamic degree of ecosystem service value.
service value in the Jintan District was further strengthened in 2018.The colder and cold spot areas expanded gradually to the east, while the hotter spot areas and hot spot areas were slightly reduced and further concentrated in the southern parts of Rulin Town and Zhiqian Town.The observed changes in the distribution of ecosystem service value in Jintan District may be related to the development and construction of the Jintan Economic Development Zone during the research period.The decline in the value of urban ecosystem services may have caused an eastward shift in the colder spot areas (Figure 5).

Dynamic Degree of Ecosystem Service Value
The dynamic degree of ecosystem service value reflects land use change to a certain extent.We assessed the temporal changes in the ecosystem service value of 113 administrative villages in the Jintan District at the village scale.Figure 6 presents the dynamic degree of ecosystem service value for each administrative village, in which the horizontal axis indicates the administrative villages and the vertical axis shows the corresponding dynamic degree of ecosystem service value.The results showed that the dynamic degree of ecosystem service value of culti land, construction land, and unused land in most administrative villages exhibited tive changes, thereby indicating that the area increased during the research period.ever, the dynamic degree of ecosystem service value of garden land, forestland, grass wetland, and water area revealed negative changes, thus indicating that the are creased to varying degrees during the research period.Further analysis revealed th ministrative villages that experienced a significant increase in cultivated land area mostly located in Xuebu Town.Meanwhile, villages with a large decrease in culti land area were situated primarily on Dongcheng Street.During the study period, ad istrative villages with a slight decrease in construction land area were predominant uated in Xuebu Town, whereas those with a substantial increase in construction land were mostly located in Dongcheng Street, Yaotang Street, Xicheng Street, and Jinc  The results showed that the dynamic degree of ecosystem service value of cultivated land, construction land, and unused land in most administrative villages exhibited positive changes, thereby indicating that the area increased during the research period.However, the dynamic degree of ecosystem service value of garden land, forestland, grassland, wetland, and water area revealed negative changes, thus indicating that the area decreased to varying degrees during the research period.Further analysis revealed that administrative villages that experienced a significant increase in cultivated land area were mostly located in Xuebu Town.Meanwhile, villages with a large decrease in cultivated land area were situated primarily on Dongcheng Street.During the study period, administrative villages with a slight decrease in construction land area were predominantly situated in Xuebu Town, whereas those with a substantial increase in construction land area were mostly located in Dongcheng Street, Yaotang Street, Xicheng Street, and Jincheng Town (Figure 6).

Change in Village and Town Spatial Functions
According to Figure 7, the results demonstrated the spatial distribution of villages with varying levels of production, living, and ecological functions in the Jintan District in 2012 and 2018.In 2012, villages with higher production functions were primarily situated in Rulin Town, southern Zhiqian Town, and western Xuebu Town.Furthermore, the villages with high production function were primarily concentrated in the north-central part of Zhiqian Town, the south of Zhulin Town, the central part of Xuebu Town, and the central part of Jincheng Town.In contrast, villages with lower production functions were mainly located on Dongcheng Street and north of Xicheng Street, with some additional distribution observed in the central and southern parts of Xuebu Town.Villages with low production function were mostly concentrated in the south of Jincheng Town and the intersection of Xuebu Town and Zhulin Town.Regarding living function, only a few villages exhibited higher living functions and were mainly situated in the central and northern parts of Rulin Town and the western and southern parts of Xuebu Town.In contrast, many villages with high living functions were located in Zhulin, Jincheng, and Zhiqian.Villages with lower living functions were widely distributed in the study area, with no obvious spatial agglomeration, and were observed on Dongcheng Street, Xicheng Street, Zhixi Town, Xuebu Town, and YaoTang Street.Villages with higher ecological function were found to be more dispersed in Jintan District, with concentrations observed in southern Rulin Town and Zhiqian Town.Some scattered higher-value villages are also located in northern Jincheng Town and western Xuebu Town.Compared with the production and living functions, there were fewer villages with lower ecological functions, mostly situated on Dongcheng Street and Xicheng Street.In 2018, the spatial distribution of villages in higher-value and highvalue areas of production, living, and ecological functions remained relatively unchanged.However, the number of villages with lower-value production functions expanded towards the north, and the distribution of villages with lower living functions became more discrete.Conversely, the number of villages with lower-value and low-value ecological functions decreased, while the number of villages with medium-value ecological functions increased significantly (Figure 7).
Through hotspot analysis, we found that the south of Rulin Town and Zhiqian Town had common hotter and hotspot areas for the three functions.However, hotspot areas and hotspot areas of production and living functions were found to have a broader spatial distribution than that of the ecological function.The production function had two hot spot areas in the central part of Xuebu Town and southeast of Zhixi Town, while the living function had a north-south hotter spot area in the northwest of Xuebu Town.In the two time periods under examination, the colder spot areas were located in Dongcheng Street, Xicheng Street, and villages in the southeast of Zhixi Town in the urban area.Compared with 2012, the colder and cold spot areas of the production function expanded to encompass Dongcheng Street in 2018, with a tendency to extend to Yaotang Street.Meanwhile, the colder spot areas and cold spot areas of the living function remained unchanged, whereas the colder spot areas and cold spot areas of the ecological function increased slightly.Moreover, villages located on both sides of the western hills and around Changdang Lake showed high ecological system service values, manifesting as higher-value or high-value agglomeration areas.Conversely, in the administrative centres, towns, and economic development zones represented by Dongcheng Street, Xicheng Street, and Yaotang Street, the value of ecosystem services has declined, forming low-value agglomeration areas spatially (Figure 8).
on Dongcheng Street and Xicheng Street.In 2018, the spatial distribution of villages in higher-value and high-value areas of production, living, and ecological functions remained relatively unchanged.However, the number of villages with lower-value production functions expanded towards the north, and the distribution of villages with lower living functions became more discrete.Conversely, the number of villages with lowervalue and low-value ecological functions decreased, while the number of villages with medium-value ecological functions increased significantly (Figure 7).Through hotspot analysis, we found that the south of Rulin Town and Zhiqian Town had common hotter and hotspot areas for the three functions.However, hotspot areas and hotspot areas of production and living functions were found to have a broader spatial distribution than that of the ecological function.The production function had two hot spot areas in the central part of Xuebu Town and southeast of Zhixi Town, while the living function had a north-south hotter spot area in the northwest of Xuebu Town.In the two time periods under examination, the colder spot areas were located in Dongcheng Street, Xicheng Street, and villages in the southeast of Zhixi Town in the urban area.Compared with 2012, the colder and cold spot areas of the production function expanded to encompass Dongcheng Street in 2018, with a tendency to extend to Yaotang Street.Meanwhile, the colder spot areas and cold spot areas of the living function remained unchanged, whereas the colder spot areas and cold spot areas of the ecological function increased slightly.Moreover, villages located on both sides of the western hills and around Changdang Lake showed high ecological system service values, manifesting as higher-value or high-value agglomeration areas.Conversely, in the administrative centres, towns, and economic development zones represented by Dongcheng Street, Xicheng Street, and Yaotang Street, the value of ecosystem services has declined, forming low-value agglomeration areas spatially (Figure 8).

Discussion
The planning of town and village layouts is crucial for the allocation of public resources and the advancement of rural development.In the face of rapid urbanisation, traditional rural development has often resulted in the loss of arable land and environmental degradation and led to rural depopulation, industrial decline, and environmental pollution [39].At present, the intensification of land use, equal distribution of public services, and construction of rural communities are central elements of rural development [8].Currently, the spatial planning system in the present era has imposed strict requirements for bottom-line control [40], particularly the 'three zones and three lines', which are set in terms of scale and line type and cannot be altered after being established [41].Under the influence of bottom-line control, the main objective of town and village layout planning should be to clarify the relationship between villages and the 'three zones and three lines' concept.Typically, town and village layout planning aims to avoid constructive expansion-prohibited zones and constructive expansion-restricted zones in higher-level plans,

Discussion
The planning of town and village layouts is crucial for the allocation of public resources and the advancement of rural development.In the face of rapid urbanisation, traditional rural development has often resulted in the loss of arable land and environmental degradation and led to rural depopulation, industrial decline, and environmental pollution [39].At present, the intensification of land use, equal distribution of public services, and construction of rural communities are central elements of rural development [8].Currently, the spatial planning system in the present era has imposed strict requirements for bottom-line control [40], particularly the 'three zones and three lines', which are set in terms of scale and line type and cannot be altered after being established [41].Under the influence of bottom-line control, the main objective of town and village layout planning should be to clarify the relationship between villages and the 'three zones and three lines' concept.Typically, town and village layout planning aims to avoid constructive expansion-prohibited zones and constructive expansion-restricted zones in higher-level plans, such as the permanent basic farmland protection red line and ecological protection red line.Among them, the permanent basic farmland protection red lines protect high-quality farmland in the region.The ecological protection red line is to protect the natural ecosystem and key environmental resources in the area [42].During the process of demarcating the 'three zones and three lines', most villages will fall within the agricultural space [43], including permanent basic farmland, general farmland, and villages.However, the dominant functions of the 'three zones' do not necessarily indicate that these villages have an agricultural function [44].
To enhance the production, living, and ecological functions of villages, it is necessary to consider their overall patterns in the region [45].Production functions such as food and raw material production can provide guidelines for the designation of permanent basic farmland reserve zones, zoning grain production, and major agro-product conservation, thus ensuring the prioritisation of food production using limited arable land resources [46].Therefore, when adjusting the layout of agricultural production in the future, Jintan District should give priority to towns with higher production functions, such as Rulin Town, Zhiqian Town, and Zhulin Town, and give full play to their leading functions in grain production.The ecological protection red line in Jintan District encompasses the Maoshan Mountain area in the west, Tianhuang Lake wetland in the north, and Qianzi Lake and Changdang Lake [47].This result is consistent with the findings of this study that the ecosystem service value is highest in the Changdang Lake area, the Maoshan Mountain range to the west, and the aquaculture area to the north.Thus, Jintan District can utilise the permanent basic farmland protection red line and the ecological protection red line as a foundation, in conjunction with the spatial functions identified in this study, to coordinate the management of mountains-rivers-forests-farmlands-lakes-grassland systems in the region [48].This process includes the following measures: (1) Linking ecological patches with high ecological value, such as water, woodlands, and wetlands.(2) Promoting ecological restoration of mountains in Xuebu Town.(3) Enhancing important ecological services such as water retention and soil conservation in the Maoshan Mountain area.(4) Strengthening shoreline control and wetland protection of Qianzi Lake and Changdang Lake.(5) Improving the water environment through ecological dredging and the return of fishing to lakes.
This study focuses on the district of Jintan in southern Jiangsu, and examines the relationship between town and village layout planning and ecosystem services by analysing ecosystem service values.Despite the value of this study, some limitations also need to be acknowledged.First, the current evaluation index system utilised in the study is not comprehensive because it only evaluates the welfare of humans from an ecological perspective and does not fully reflect the land output in a given region over a certain period of time.However, further improvements are required in this regard.Second, the study recognises the disparity in the intensity, functional orientation, and development direction of different national spaces, which could lead to imbalances between socioeconomic development and ecological protection in these spaces.It highlights the need for a more nuanced and context-specific approach to consider the intersection between town and village layout planning and ecosystem services.

Conclusions
Based on Xie Gaodi's ecosystem service theory, this paper constructed a classification of village and town spatial functions for ecosystem services and analysed the impact of town and village layout planning on the value of ecosystem services and the changes in village and town spatial functions in Jintan District.The following conclusions were drawn from this paper: (1) From 2012 to 2018, the dominant land use types in Jintan District were cultivated land, water bodies, and construction land.The Jintan District experienced economic rapid growth, leading to an increased demand for construction land and, subsequently, expanding the area designated for construction purposes.The rapid growth in construction land resulted in the occupation of other land types, such as waters, gardens, woodlands, and grasslands, which, in turn, caused a decline in the value of ecosystem services in Jintan District, estimated at 792 million CNY. (2) This transformation also had adverse effects on the water bodies and their hydrological regulation capacity, further contributing to a decrease in the value of hydrological regulation services.Construction land was more allocated to urban and town areas, which led to the decline in ecosystem service value in the region, while rural areas near Changdang Lake and western Maoshan Mountain, which have large forest land and water areas and a relatively stable land use structure, maintained high values of ecosystem services.(3) The study findings revealed a spatial differentiation in the functions of production and living, consistent with the spatial distribution of ecosystem service value.However, it is important to note that the spatial pattern of ecological functions differed significantly from that of production and livelihood functions.Hence, it is imperative to implement a range of ecological restoration measures to achieve harmony and coordination among production, livelihood, and ecological functions.

Figure 1 .
Figure 1.Cognitive framework of town and village layout planning and ecosystem services.

Figure 1 .
Figure 1.Cognitive framework of town and village layout planning and ecosystem services.

Figure 2 .
Figure 2. Spatial function evolution of villages and towns.

Figure 2 .
Figure 2. Spatial function evolution of villages and towns.

Figure 3 .Figure 3 .
Figure 3. Classification of spatial functions of villages and towns based on ecosystem services.3.Materials and Methods 3.1.Study Area and Data Sources 3.1.1.Study Area

3 . 1 .
Study Area and Data Sources 3.1.1.Study Area Jintan District is situated at the confluence of Jiangsu, Zhejiang, and Anhui provinces within the Ningzhen-Maoshan Mountain and Taihu Plain regions.It lies in the middle and lower reaches of the Yangtze River and is characterised by its geographic coordinates ranging from 119 • 17 45 E to 119 • 44 59 E and from 31 • 33 42 N to 31 • 53 22 N (Figure

Figure 3 .
Figure 3. Classification of spatial functions of villages and towns based on ecosystem services.

Figure 4 .
Figure 4. Location of the study area.Figure 4. Location of the study area.

Figure 4 .
Figure 4. Location of the study area.Figure 4. Location of the study area.
3.1.2.Data SourcesThe land use data utilised in this study were obtained from the land use change survey data of the Jintan District in 2012 and 2018.In accordance with the land classification system of China and previous studies[32,35], the land use types in the research area were divided into eight first-level types: cultivated land, garden land, forestland, grassland, wetland, unused land, water area, and construction land, among which cultivated land includes two second-level types, namely, dry land and paddy fields.In addition, the data for crop planting area and average net profit utilised in this study were obtained from publicly available sources, including the Changzhou Statistical Yearbook 2019, Compilation of National Agricultural Product Cost-Benefit Data 2019, and the National Bureau of Statistics.Land 2023, 12, 1832 6 of 16

Figure 5 .
Figure 5. Ecosystem service value and its spatial distribution from 2012 to 2018.

Figure 5 . 11 Figure 6 .
Figure 5. Ecosystem service value and its spatial distribution from 2012 to 2018.Land 2023, 12, x FOR PEER REVIEW 11 the figure represent the administrative villages of Jintan District.

Figure 6 .
Figure 6.The dynamic degree of ecosystem service value of the different land use types.

Figure 7 .
Figure 7. Changes in spatial function of villages and towns in Jintan District.

Figure 7 . 16 Figure 8 .
Figure 7. Changes in spatial function of villages and towns in Jintan District.Land 2023, 12, x FOR PEER REVIEW 13 of 16

Figure 8 .
Figure 8. Distribution pattern of spatial function of villages and towns in Jintan District.
aspect of rural development that must consider the interplay between human activity and the provision of ecosystem services.To ensure sustainable rural development, the planning process must balance economic development, environmental protection, and cultural preservation. crucial

Table 1 .
Chinese Land Ecosystem Services Value Equivalent Factor Table.

Table 3 .
Area and ecosystem service value of different land use types in Jintan District.

Table 4 .
The composition of and change in ecosystem service value in Jintan District/CNY.