Ecological Land Research Articles

A Study on the Spatiotemporal Dynamics of Land Cover Change and Carbon Storage in the Northern Gulf Economic Zone of Guangxi Based on the InVEST Model

In recent years, the international community has increasingly focused on the “dual carbon” issue, as human-induced land use changes significantly impact ecosystem structure and carbon cycling. This study analyzes land use changes in the economic zone of the northern Gulf of Guangxi from 1980 to 2020, utilizing the InVEST model to simulate spatiotemporal changes in carbon storage and conducting zoning studies through spatial analysis. The findings reveal that ① forest land and arable land dominate the northern Gulf of Guangxi’s land use, with notable changes observed in forest land, unused land, and construction land areas. Forest land and construction land have increased by 1761.5 km2 and 1001.19 km2, respectively, while unused land has decreased by 1881.18 km2 from 2000 to 2020. ② The total carbon storage values in the northern Gulf of Guangxi in 1980, 2000, and 2020 were, respectively, 504.91 × 106/t, 487.29 × 106/t, and 500.31 × 106/t, with the expansion of construction land and conversion of forest land being the main reasons for the decrease in carbon storage. ③ In the northern Gulf of Guangxi, there is a slight upward trend in total carbon storage values over time. Spatially, higher carbon storage values are observed in mountainous and hilly areas at high altitudes, while the central and southern coastal areas exhibit lower carbon storage values. ④ The local spatial autocorrelation results reveal that Pu Bei County exhibits high–high clustering of carbon storage, while He Pu County undergoes a transition from high–low to low–low clustering, and several other administrative areas in Beihai demonstrates low–low clustering. Due to the imperative of economic development, the expansion of urban construction land encroaches upon ecological land, resulting in a decline in carbon storage. Therefore, in the Northern Gulf of Guangxi, it is essential to implement measures such as reforestation and establish ecological protection areas such as forests, grasslands, and wetlands to develop effective carbon sequestration methods and compensate for the carbon loss caused by the expansion of construction land.

Simulating the Impact of Urban Expansion on Ecological Security Pattern from a Multi-Scenario Perspective: A Case Changsha–Zhuzhou–Xiangtan Urban Agglomeration, China

Rapid urbanization has further expanded the scale of construction land in urban agglomerations. The encroachment of urban land on ecological land has led to severe ecological problems and threatened the stability of ecological security in urban agglomerations. Analyzing the characteristics of future urban multi-scenario expansion and its impacts on ecological security patterns (ESP) can provide guidance for formulating ecologically sustainable management and control Policies. Our study focuses on Changsha-Zhuzhou-Xiangtan (CZX) urban agglomeration as the study area and establishes an ESP. Additionally, a cellular automata (CA) was used to simulate future urban expansion patterns under three scenarios (i.e., natural development scenario, urban development scenario, and ecological conservation scenario). The subsequent analysis evaluates their impact on the ESP. The simulation results indicate that from 2020 to 2030, the CZX urban agglomeration will undergo rapid urban expansion under the natural development scenario and urban development scenario, characterized by outward growth surrounding the existing construction land. In the natural development scenario, urban expansion is primarily concentrated in the northwest and south directions of construction land, the proportion of construction land increased by 2.78%; in the urban development scenario, it is concentrated in the southeast direction of construction land, the proportion of construction land increased by 3.24%. Ecological conflicts in the aforementioned development scenarios primarily arise in the southwestern region of Changsha County, as well as the southern areas of Kaifu District and Furong District. Conversely, under the ecological conservation scenario, the rate of urban expansion has significantly decreased, environmental preservation is upheld at its highest level, and the proportion of construction land only increased by 0.04%. Based on the simulation results, we present targeted recommendations for urban land planning and growth management, as well as the protection, restoration, monitoring, and development of ecological land. These suggestions provide effective guidance for improving the stability of ESP in urban agglomerations and promoting high-quality development in Chinese urban agglomerations.

Construction and Optimization of Ecological Security Patterns Based on Ecosystem Services in the Wuhan Metropolitan Area

Rapid urbanization has affected ecosystem stability, and the construction of ecological security patterns (ESPs) can rationally allocate resources and achieve ecological protection. Priority evaluation of critical areas can maximize the benefits of ecological protection, which is crucial for sustainable urban development. However, most prior studies have focused on assessing individual elements of the ESP, rarely considering both the protection priority of ecological sources and corridors. We constructed ESPs for the Wuhan Metropolitan Area (WMA) from 2000 to 2020 and evaluated the priority of ecological sources and corridors for protection. The findings indicated that high-level ecological sources exhibited higher overall landscape connectivity and ecosystem service values with lower patch fragmentation. The average area proportions of primary, secondary, and tertiary ecological sources in 2000, 2010, and 2020 were 41.11%, 23.03%, and 29.86%, respectively. High-level ecological corridors had shorter lengths and offered higher comprehensive ecosystem service values. The total length of secondary corridors exceeded that of primary corridors by 1951.19 km, 650.39 km, and 2238.18 km in 2000, 2010, and 2020, respectively. Primary corridors, which connected fragmented and isolated sources, should have their ecological land percentage increased to enhance connectivity. Secondary corridors connected two independent and distant sources, providing the basis for ecological protection in the intervening area, whose surrounding habitats should be protected. This study identifies the ecological protection priority and offers a theoretical basis and practical reference for balancing urban development with ecological protection.

Understanding future water-carbon-land coupled systems in the era of COP 27: The case of the Hanjiang river Basin, China

The 27th Conference of the Parties (COP 27) emphasized addressing this century's interconnected challenges of food, water, and energy. This study proposes a coupled ecosystem service and multi-scenario land-use change simulation model designed to investigate the future dynamics of water-carbon-land coupled systems in the Hanjiang River Basin (HJRB), the primary objective is to provide valuable insights that can inform strategic spatial management decisions, aligning with the ambitious objectives outlined in COP 27. Specifically, this study utilized the PLUS model, InVEST model, and redundancy analysis to comprehensively analyze the interplay between ecosystem services and land-use changes, with a specific focus on water, carbon, and land dynamics. The results showed that regardless of the simulated scenarios, there was a consistent pattern observed in the changes of land use types within the HJRB, with a decrease in farmland and an increase in forest. However, the water area showed an increasing trend in all scenarios, especially in the ecological land protection (ELP) and sustainable development scenarios. Furthermore, the ELP scenario effectively suppressed the expansion of building land and the erosion of ecological land. Ecosystem services under different scenarios showed similar spatial distribution patterns but presented varying degrees of change related to the impact of future land use and urban development on ecosystem services. The water yield (WY), carbon storage, and soil conservation in the upstream areas increased to varying degrees, while those in the downstream areas decreased. In conclusion, precipitation, land use/land cover change, DEM (Digital Elevation Model), and NDVI (Normalized Difference Vegetation Index) were the main driving factors affecting ecosystem services, with precipitation having the most significant and enduring impact on WY. This study supports the adoption of targeted spatial management measures to promote sustainable development and enhance human well-being.

A Simulation-Based Prediction of Land Use Change Impacts on Carbon Storage from a Regional Imbalance Perspective: A Case Study of Hunan Province, China

Land use imbalances are a critical driving factor contributing to regional disparities in carbon storage (CS). As a significant component of China’s Yangtze River Economic Belt, Hunan Province has undergone substantial shifts in land use types, resulting in an uneven distribution of ecosystem CS and sequestration capacity. Therefore, within the framework of the “dual carbon” strategy, examining the effects of land use changes driven by regional resource imbalances on CS holds practical importance for advancing regional sustainable development. This study focuses on Hunan Province, utilizing the PLUS-InVEST model to assess the spatiotemporal evolution of CS under land use changes from 1990 to 2020. Additionally, multiple scenario-based development modes were employed to predict county-level CS. The results indicate the following: (1) From 1990 to 2020, Hunan Province experienced continuous urban expansion, with forest land and cultivated land, which are core ecological land types, being converted into construction land. (2) Over these 30 years, the province’s total CS increased by 2.47 × 108 t, with significant spatial differentiation. High-value zones were concentrated in bands along the province’s borders, while lower values were observed in the central and northern regions. The highest CS values were recorded in forested areas at the province’s periphery, whereas the lowest values were observed in the northern water bodies. (3) The scenario-based predictions revealed notable differences, with the ecological protection scenario demonstrating a substantial carbon sink effect. By prioritizing forest and cultivated land, CS could be maximized. This research provides valuable insights for enhancing CS and optimizing land use structures in regions facing resource imbalances.

Multi-Scenario Simulation of Land Use and Assessment of Carbon Stocks in Terrestrial Ecosystems Based on SD-PLUS-InVEST Coupled Modeling in Nanjing City

In the context of achieving the goal of carbon neutrality, exploring the changes in land demand and ecological carbon stocks under future scenarios at the urban level is important for optimizing regional ecosystem services and developing a land-use structure consistent with sustainable development strategies. We propose a framework of a coupled system dynamics (SD) model, patch generation land-use simulation (PLUS) model, and integrated valuation of ecosystem services and trade-offs (InVEST) model to dynamically simulate the spatial and temporal changes of land use and land-cover change (LUCC) and ecosystem carbon stocks under the NDS (natural development scenario), EPS (ecological protection scenario), RES (rapid expansion scenario), and HDS (high-quality development scenario) in Nanjing from 2020 to 2040. From 2005 to 2020, the expansion rate of construction land in Nanjing reached 50.76%, a large amount of ecological land shifted to construction land, and the ecological carbon stock declined dramatically. Compared with 2020, the ecosystem carbon stocks of the EPS and HDS increased by 2.4 × 106 t and 1.5 × 106 t, respectively, with a sizable ecological effect. It has been calculated that forest and cultivated land are the two largest carbon pools in Nanjing, and the conservation of both is decisive for the future carbon stock. It is necessary to focus on enhancing the carbon stock of forest ecosystems while designating differentiated carbon sink enhancement plans based on the characteristics of other land types. Fully realizing the carbon sink potential of each ecological functional area will help Nanjing achieve its carbon neutrality goal. The results of the study not only reveal the challenges of ecological conservation in Nanjing but also provide useful guidance for enhancing the carbon stock of urban terrestrial ecosystems and formulating land-use planning in line with sustainable development strategies.

Using the National Land Cover Database as an indicator of shrub-steppe habitat: comparing two large United States federal lands with surrounding regions

ABSTRACT There is a need to assess whether ecological resources are being protected on large, federal lands. The aim of this study was to present a methodology which consistently and transparently determines whether two large Department of Energy (U.S. DOE) facilities have protected valuable ecological lands on their sites compared to the surrounding region. The National Land Cover Database (2019) was used to examine the % shrub-scrub (shrub-steppe) and other habitats on the DOE’s Hanford Site (HS, Washington) and on the Idaho National Laboratory (INL), compared to a 10-km and 30-km diameter band of land surrounding each site. On both sites, over 95% is in shrub-scrub or grassland, compared to the surrounding region. Approximately 70% of 10 km and 30-km bands around INL, and less than 50% of land surrounding HS is located in these two habitat types. INL has preserved a significantly higher % shrub/scrub habitat than HS, but INL allows grazing on 60% of its land. HS has preserved a significantly higher % grassland than INL but no grazing on site is present. The methodology presented may be used to compare key ecological habitat types such as grasslands, forest, and desert among sites in different parts of the country. This methodology enables managers, resource trustees, and the public to (1) make remediation decisions that protect resources, (2) assess whether landowners and managers have adequately characterized and protected environmental resources on their sites, and (3) whether landowners and managers have protected the integrity of that land as well as its climax vegetation.

Evaluation of Land Ecological Status and Diagnosis of Obstacle Factors in Jiangsu, China

By constructing a land ecological evaluation index system at the village scale and using models such as spatial correlation analysis, hotspot analysis, and obstacle factor diagnosis, the basic characteristics, spatial differentiation, and obstacle factors of land ecological status in Jiangsu Province were studied. This study sought to clarify the foundation, structure, function, and benefit characteristics of land ecosystems and optimize land management and policy regulation. The results showed that： ① The spatial distribution of land ecological status in Jiangsu Province was high in the north and low in the south, with multiple high-value areas radiating outward and decreasing, with low value centers radiating outward and increasing. The distribution area of the highest and lower values was relatively small, whereas the area of the middle value area was the largest. The higher values were mainly distributed in the suburbs and edge areas of each county. ② The spatial autocorrelation of land ecological status in Jiangsu Province was significant, with hot spots mainly concentrated in northern Jiangsu and cold spots concentrated in southern Jiangsu, as well as some areas of Taizhou and Nantong. The spatial distribution of cold and hot spots showed a complementary pattern with the level of regional development. The comprehensive index value of land ecology in developed areas was lower, whereas the index value in underdeveloped areas was higher. ③ The natural background conditions of Class Ⅰ land ecological zone in Jiangsu Province were superior, with good ecological construction and benefits and a high level of ecological status. The obstacle factors mainly included the proportion of water bodies and the average annual degradation rate of forest land. The Class Ⅱ land ecological zone was mostly located in the Huainan region and mainly composed of plain landforms. The Class Ⅲ land ecological zone had the largest area, located in the riverside areas of southern Jiangsu. The obstacle factors mainly included the average annual degradation rate of arable land and the proportion of soil pollution area. By controlling land ecological risks, the early warning level of ecological crisis could be improved.

Incorporating embodied carbon transfer and sequestration service flows into regional carbon neutrality assessment in China

Reliable and effective carbon neutrality assessments are crucial prerequisites for implementing various low-carbon policies and achieving carbon neutrality goals. Although the impact of embodied carbon transfer and carbon sequestration service flows on regional carbon neutrality is becoming increasingly significant, these factors are not effectively incorporated into current carbon neutrality assessments. Based on a thorough review of the literature and theoretical analysis, this study attempts to construct a regional carbon neutrality assessment framework that incorporates embodied carbon transfer and carbon sequestration service flows. This framework is then applied to assess carbon neutrality and its influencing factors in China's provinces. Our findings reveal that carbon emissions and sequestration capacities have increased across Chinese provinces, with the highest emissions in North and East China, and the highest sequestration in Southwest China. Economically developed provinces like Beijing, Zhejiang, and Jiangsu transfer substantial embodied carbon to provinces such as Inner Mongolia, Shanxi, and Hebei, while Guangxi, Sichuan, Yunnan, and Qinghai are major providers of carbon sequestration services. Carbon neutrality levels in Chinese provinces show a ring-shaped distribution, increasing from the inner to outer rings. Higher levels are found in Southwest and Northwest provinces (e.g., Yunnan, Qinghai, Guangxi), and lower levels in North and East provinces (e.g., Shanxi, Beijing, Zhejiang). Factors like urbanization rate, population density, per capita GDP, and energy consumption structure negatively impact carbon neutrality levels, whereas ecological land area and annual precipitation have positive impacts. In summary, incorporating embodied carbon transfer and carbon sequestration service flows into the regional carbon neutrality assessment framework facilitates a more comprehensive analysis of regional carbon neutrality levels and their influencing factors. This approach broadens the theoretical and methodological scope of regional carbon neutrality assessments and provides scientific references for the implementation of low-carbon policies and the advancement of carbon neutrality goals.

Evaluating the spatiotemporal land ecological changes in the Yangtze-to-Huaihe Water Diversion Project area.

As a fundamental component of human existence, land is inextricably linked to human development, and its ecological functions are closely associated with multiple sustainable development goals. This paper presents a framework for constructing and optimizing ecological function space, with the Yangtze-to-Huaihe Water Diversion Project area serving as a case study. A comprehensive land ecological index system is established, encompassing natural foundation, land degradation, land production, ecological structure, and ecological protection. An identity-discrepancy-contrary connection method is employed to investigate changes in regional land ecological functions before (2013) and during (2017, 2020, and 2022) the project's construction based on remote sensing data. The results indicated that the mean values of the land ecological index for each period were 0.1883, 0.1981, 0.2253, and 0.1370, respectively. The study calculated the connection, differences, and contradictions in the land ecological impacts across the counties, revealing a gradual decrease in differences and a growing prominence of contradictions. The land ecology of the Yangtze-to-Huaihe Water Diversion Project area is affected by the project construction, particularly within the construction area, showing an overall improvement. Most counties exhibited a trend of ecological improvement compared to the land ecology before the project's construction. However, after the project implementation, most districts demonstrated a trend of ecological deterioration. As the distance from the construction canal increases, the characteristics of each section and stage vary, generally exhibiting an exponential decrease in the land ecological index. The study highlighted the significance of enhancing the land ecological pattern, improving water quality, increasing water supply along the project, and alleviating groundwater overexploitation. The study can serve as a reference for land ecological protection and restoration in water transfer areas and river basins worldwide.

Simulation of the future evolution track of “production–living–ecological” space in coastal cities based on multimodel coupling and wetland protection scenarios

Coastal cities hold a special position in the fields of production, living, and ecological research because of their unique wetland resource advantages. However, with global urbanization and rapid economic development, conflicts among production, living and ecological land are prevalent in coastal cities in the process of maintaining sustainable wetland resources and further developing the social economy. By establishing an SD-PLUS-CCD coupling model, this paper analysed the evolution characteristics and driving mechanism of the production–living–ecological space (PLES) and the effects of wetland protection (WLP) on promoting or inhibiting the coordinated development of the PLES in Dongying city during 2005–2060. The results show that (1) from 2005 to 2020, the increase in urban population resulted in a significant transfer of arable land and a reduction of 914 km2 in production space (PS); (2) from 2020 to 2060, under the WLP scenario, the conversion of wetland ecological space will reduce the PS and living space (LS) by 193.92 km2 and 107.14 km2, respectively, and increase the ecological space (ES) by 327.52 km2; and (3) wetland protection has an inhibitory effect on the coordinated development of PLES in the study area, and the total proportion of noncoordinated areas of PE and living–ecological space will continue to increase during the simulation period. This paper provides a solid theoretical support for the sustainable management and protection of wetlands in coastal cities and possible PLES conflict patterns and provides a scientific basis for future territorial spatial planning and policy balance analysis.

Construction of Landscape Ecological Risk Collaborative Management Network in Mountainous Cities—A Case Study of Zhangjiakou

The prevention of ecological risks is a critical determinant influencing sustainable development. Driven by rapid socio-economic development, the ecosystems of mountainous cities within agro-pastoral transition zones are increasingly vulnerable to complex disturbances, constituting a significant threat to sustainable development and human well-being. To help achieve sustainable development, it is essential to conduct research on addressing and mitigating ecological risks from the perspective of collaborative management networks in mountainous cities. Taking Zhangjiakou as the study area, this paper employed the land use transfer matrix and standard deviation ellipse methods to analyze the dynamic land use changes. Additionally, using Fragstats 4,2 to calculate the landscape indices with land use data, this paper evaluated the landscape ecological risk (LER) from 2000 to 2020. Furthermore, the social network analysis (SNA) method was utilized to explore the spatial correlation characteristics of the LER. The findings indicate that: (1) Cultivated land and grassland were the predominant land use types in Zhangjiakou. During 2000–2020, Zhangjiakou experienced significant changes in land use, dominated by the transfer among cultivated land, forestland, and grassland. It indicated that the issue of unstable ecological land use continued to exist. Affected by human activities, construction land showed a consistent upward trend, primarily concentrated in the urban built-up areas and areas along the Jing-Zhang Railway. (2) The LER of Zhangjiakou was predominantly characterized by low risk, medium risk, and high risk levels. In the transitional areas and foothills, the LER was relatively higher. During 2000–2020, Zhangjiakou showed a declining trend of LER. This suggested that the ecological protection policies in Zhangjiakou were effective, leading to an improvement in the local ecological environment. (3) The LER in Zhangjiakou demonstrated a spatial clustering pattern that exhibited an upward trend, which was supported by both spatial autocorrelation and the SNA analysis. In the LER collaborative management network, Xuanhua, Qiaodong, Qiaoxi, Wanquan and Zhangbei consistently upheld pivotal roles. Based on the number of inward and outward connections, 16 counties in Zhangjiakou were classified into four categories and three zones accompanied by corresponding recommendations. The findings of this study can serve as a valuable reference for subsequent landscape pattern optimization and ecological restoration in Zhangjiakou.

Assessing the impact of human activities on ecosystem asset dynamics in the Yellow River Basin from 2001 to 2020.

The intensification of human activities in the Yellow River Basin has significantly altered its ecosystems, challenging the sustainability of the region's ecosystem assets. This study constructs an ecosystem asset index for the period from 2001 to 2020, integrating it with human footprint maps to analyze the temporal and spatial dynamics of ecosystem assets and human activities within the basin, as well as their interrelationships. Our findings reveal significant improvement of ecosystem assets, mainly attributed to the conversion of farmland back into natural habitats, resulting in a 15,994km2 increase in ecological land use. Notably, 45.88% of the basin has experienced concurrent growth in both human activities and ecosystem assets, with ecosystem assets expanding at a faster rate (22.61%) than human activities (17.25%). Areas with high-quality ecosystem assets are expanding, in contrast to areas with intense human activities, which are facing increased fragmentation. Despite a global escalation in threats from human activities to ecosystem assets, the local threat level within the Yellow River Basin has slightly diminished, indicating a trend towards stabilization. Results highlight the critical importance of integrating spatial and quality considerations into restoration efforts to enhance the overall condition of ecosystem assets, especially under increasing human pressures. Our work assesses the impact of human activities on the dynamics of ecosystem assets in the Yellow River Basin from 2001 to 2020, offering valuable insights for quality development in the region, may provide a scientific basis for general watershed ecological protection and sustainable management in a region heavily influenced by human activity but on a path to recovery.

Urban multi-scale ecological network sequence and spatial structure optimization: A case study in Nanjing city, China

Rapid urbanization has had a segmented effect on the ecological land and natural environment in cities. Constructing an ecological network is of vital importance to protect ecological resources and maintain regional ecological security. However, ecological spaces at different administrative scales have their own ecological functions and elemental characteristics. Therefore, we formed the ecological network sequence to present the integrative connection of multi-scale with municipal area (MA), main urban area (MUA) and central urban area (CUA) in Nanjing. Ecological sources were identified through “landscape—function—structure” framework, and ecosystem services value (ESV) was used as an auxiliary method to identify supplementary sources. Ecological corridors and some key points were identified through circuit theory. The results show that the area of ecological sources in MA, MUA and CUA was 427.3 km2, 62.5 km2 and 16.2 km2, respectively. By integrating sources of three scales, we got 14 sources (442.7 km2) in the first sequence and 10 sources (7.7 km2) in the second sequence. Apart from that, we also got 4 new supplementary sources with area of 13.5 km2. The length of ecological corridors in MA, MUA and CUA was 252.5 km, 263.9 km and 22.7 km, respectively. By integrating corridors of three scales, we found that the western corridors between the ecological sources had a higher gravitation. The ecological nodes are generally distributed in the landscape heterogeneity transition zone, ecological resource fringe zone and ecological spatial contiguous zone. The ecological pinch points are generally distributed along the water system. The ecological barrier points are generally distributed in the combination area among the urban block, village and road. In conclusion, this study made up for the research gap of finding the nesting and integration relationship among ecological networks at multi-scale.

Coupling Coordination Degree of Land, Ecology, and Food and Its Influencing Factors in Henan Province

Studying the spatiotemporal evolution characteristics of the coupling coordination of the land–ecology–food system (LEF) aids in promoting green agricultural development and regional resource management. This study enriches food indicators under the dietary structure and uses the coupling coordination degree model to analyze the coupling coordination relationship among the LEF of 18 cities in Henan Province from 2011 to 2020. The gray relational degree model is used to investigate the main influencing factors determining the synergistic development of the system. The results show that the comprehensive development index of the LEF in Henan Province ranges between 0.4 and 0.6. The overall comprehensive evaluation index of various cities is ranked as Southern Henan > Eastern Henan > Central Henan > Northern Henan > Western Henan, with the greatest fluctuation observed in the food subsystem. During the study period, the coupling degree of Henan’s LEF ranged from 0.277 to 0.996, indicating stages from low- to high-level coupling. The coupling coordination degree ranged from 0.338 to 0.775, generally bordering on imbalance and barely coordinated. The impact of each subsystem evaluation index on the system’s coupling coordination degree can be ranked as food subsystem > ecology subsystem > land subsystem, with the correlation degree of internal indicators of the food and ecology subsystems with the system’s coupling coordination degree being over 85%, emphasizing the importance of strict management. In summary, the coupling coordination of the LEF system in Henan Province urgently needs to be improved; especially, the coordination of the agricultural system is particularly important. Clarifying the spatiotemporal pattern of the LEF coupling and its coordination can provide a scientific basis for the coordinated development of land use, agricultural ecology, and grain production in Henan Province.

Analysis of the Land Ecological Security Pattern in the Zhejiang Urban Circle under Small Sample Scenarios

Analysis of the Land Ecological Security Pattern in the Zhejiang Urban Circle under Small Sample Scenarios

Measuring ecological effects and policy mechanisms of urban land use transition – a case study of Xi'an, China

ABSTRACT Measuring ecological effects and policy mechanisms of urban Land Use Transition (LUT) is the key to understanding regional environmental changes and achieving sustainable urban developments. This paper illustrates and demonstrates a formal method for measuring the ecological effect of LUT characterized by Ecological Security Index (ESI) and Ecosystem Value (ESV), and enhanced with a correlational analysis between the ecological effect model and urban policy mechanism. Using Xi'an, a major capital city of western China as a case study, based on multi-temporal Thematic Mapper (TM) remote sensing images, Digital Elevation Model (DEM) and relevant statistical data, the results show that the method using ESI and ESV, together with the Land Use Transition Probability Matrix (LUTPM) can comprehensively measure the ecological effects of LUT process in Xi'an from 2000 to 2020. The results show that due to the impact of urban expansion, regional construction land increased significantly (by 67.07%), while farmland decreased considerably (by 13.12%). The farmland and forestland around the main urban area of Xi'an were centrally converted into construction land, yet the mutual transition of other types of land was relatively scattered. The total amount of ESV has slightly increased from 40.1 billion yuan to 42.8 billion yuan, and the proportion of ecological service function value presents a decreasing trend in regulation function (65%), support function (22%), supply function (9%), and cultural function (4%). The ESI value slightly decreased from 0.517 to 0.512, and overall it is still in a state of ecological security. The trend of ESV and ESI decreasing from mountainous areas to plains indicates that high-intensity human activities in plain areas have had a significant impact on the ecological environment. The correlation analysis between policy mechanisms and ecological effects indicates that ecological protection policies have improved the ecological environment and maintain ecological security (high ESV-high ESI mode), and may also have limited economic activities and been detrimental to the security of urban composite ecosystems (high ESV-low ESI mode). Spatial expansion policies have driven the rapid growth of construction land and threatened ecological security (low ESV-low ESI mode). Zoning adjustment policies have led to the transformation of ecological land to construction land, threatening ecological security and reducing ESV (low ESV-low ESI mode), and may also have promoted industrial upgrading and economic development, providing economic assurance for improving ecological security (low ESV-high ESI mode). These comprehensive findings provide valuable insights for understanding the ecological effects and policy mechanisms of LUT in Xi'an for achieving sustainable urban development, and demonstrate and explore a novel method to more appropriately and effectively measure LUT by combining ESV and ESI.

Patterns of change, driving forces and future simulation of LULC in the Fuxian Lake Basin based on the IM-RF-Markov-PLUS framework

Studying land use and land cover (LULC) patterns, identifying driving forces, and simulating future scenarios are vital for grasping the complex connection between human actions and the environment. This helps in shaping sustainable land management strategies and preparing for the impacts of climate change. However, there is a necessity for a comprehensive system modeling framework that can accurately capture spatial and temporal changes in LULC, analyze driving mechanisms, and provide an integrated analysis of future simulations. In this paper, a comprehensive IM-RF-Markov-PLUS analysis framework is developed, focusing on the Fuxian Lake Basin (FLB) as a study area. The study aims to achieve accurate prediction of LULC by combining the microscopic LULC change trend and the contribution of macroscopic driving forces. The results show that: (1) The IM-RF-Markov-PLUS framework can explore the change patterns and driving mechanisms of LULC in the FLB, and accurately predict the LULC in the FLB. Compared with the PLUS model, its accuracy is improved by 2 %. (2) IM analysis reveals that LULC transformation in the FLB is both general and specific. Although the area of grassland, buildings, roads and structures converted to desert and bare land is minimal, it shows relatively tendentious and specific change characteristics. (3) Different land types are significantly affected by driving factors, with the expansion of LULCs is constrained by major factors. The distance to the lake has the most significant impact on the distribution of garden land, while the primary road has the greatest impact on the distribution of forestland. (4) Under different scenarios, the spatial heterogeneity of LULC patterns is obvious. In 2035, under baseline and economic development scenarios, cultivated land will decrease, while other LULC types will increase. Under the cultivated land protection scenario, cultivated land is protected, with an increase of 5.85 %. Under the ecological protection scenario, there is an increase in ecological land. The largest increase is in forestland, which increases by a total of 3.46 %. The ecological protection scenario presents a viable approach for ensuring the sustainable development of the FLB. The results of this paper may serve as a reliable foundation for implementing LULC strategies in the FLB and offer guidance for crafting sustainable development regulations at the regional level.

Spatiotemporal characteristics and multi-scenario simulation of land use change and ecological security in the mountainous areas: Implications for supporting sustainable land management and ecological planning

The acceleration of global urbanization has intensified land use activities, which threaten the ecological environment and hinder the achievement of sustainable socioeconomic development goals. With the background of continuous land use expansion, the reasonable management of land use and ecological protection has increasingly become an important issue. This study constructs an ecological security (ES) index to evaluate the ES pattern, and employs the Future Land-Use Simulation (FLUS) model for multi-scenario simulation of land use patterns in mountainous areas. The results showed that from 2000 to 2020, cultivated land and grassland showed a sharp decrease, with areas of −128.64 and −228.18 km² respectively, while forest land, urban land, and other construction land increased, with areas of 116.12, 31.21, and 120.69 km² respectively. Over time, the mountainous areas mainly exhibited low and moderate ES patterns. Furthermore, for 2020–2030, under the natural development scenario, cultivated land, forest land, and grassland will show a decrease, while urban and other construction land will show a sharp increase. In contrast, under the ecological protection scenario, ecological land will show significant increase, and the patch expansion of urban construction land will be smaller. These results confirm the positive contribution of ES protection effects to improving the land use development, and support insightful guidance for formulating policies on ecological management in mountainous areas.

The evolution of habitat quality and its response to land use change in the coastal China, 1985–2020

The coastal region of China is a typical area characterized by a developed economy, yet it faces prominent resource and environmental issues, and it is of great significance to quantitatively assess the ecological effects resulting from rapid urbanization and industrialization. Based on the land use data from 1985 to 2020, and the InVEST modeling and relevant spatial data sources, the paper analyzed the spatial and temporal changes in land use cover and habitat quality in the coastal China over the past 30 years. The results show that: 1) land use cover in the coastal China has changed significantly during the study period, with the area of cultivated land continuing to decrease and construction land expanding; 2) the trend of habitat quality degradation in was obvious, with the area of low-value habitat quality continuing to increase. Spatially, they were mainly located in the three major urban agglomerations undergoing rapid industrialization and urbanization; 3) The average degradation of habitats increased significantly between 1990 and 2000 and 2010–2020. The rate of change in areas with different degradation levels from 1990 to 2000 was higher than in other periods. The low-value areas of habitat degradation are mainly located in hilly and mountainous regions. 4) The transfer of habitat grades was generally characterized by a shift from high grade to low grade. This trend of conversion was due to the large-scale occupation of cultivated land by construction land and the long-term encroachment of ecological land by cultivated land. For future development, it is recommended to improve the land use regulation system based on the principles of sustainable development, with a particular focus on habitat protection. Additionally, efforts should be made to strengthen the development of ecological agriculture, carry out ecological protection and restoration, and improve the mechanisms for coordinating land and sea management.