Search Results (26)

Accounting for Gross Ecosystem Product (GEP) is a crucial approach for quantifying ecological value, assessing the contributions of ecosystems to human well-being, and supporting sustainable development decision-making. For the Pingtan Comprehensive Experimental Zone, an island-centered administrative region, we developed a GEP indicator system and accounting framework tailored to islands for integrated accounting of terrestrial and marine ecosystems. We used a functional value approach that combines biophysical models with statistical data and conducts physical and monetary accounting in two steps. The accounting methods and procedures were refined to exclude resource and labor inputs from production processes and eliminate external contributions. From 2015 to 2023, the GEP increased by 9.118 billion CNY, representing an increase of 133.03%. The total GEP exhibited a phased rapid–slow–rapid fluctuation pattern over time. The value structure shifted from being dominated by material supply services to being dominated by cultural services. The high-value areas of flood regulation exhibited a clear expansion trend, whereas water conservation and climate regulation showed a fragmented decline. Carbon sequestration, oxygen release, and soil retention remained relatively stable. The findings support evaluating the effectiveness of ecological conservation, implementing ecological compensation, and formulating sustainable development policies in the Pingtan Comprehensive Experimental Zone. Full article

Aim: This study explored the differences in functional traits and soil physical and chemical properties of coastal plant communities under different disturbance intensities. It investigated the correlations between them to gain a deeper understanding of how plant communities adjust their functional traits in response to habitat changes. However, the mechanisms by which human disturbance influences plant functional traits remain unclear. This research endeavors to reveal the adaptive mechanisms and ecological strategies employed by coastal plant communities under different levels of anthropogenic disturbance. Methods: The study examined plant communities in three levels of disturbance (severe, moderate, and mild) in the coastal areas of Pingtan Island. Nine soil physicochemical property indicators and 16 plant functional trait indicators were collected to analyze the correlation between coastal green space plant functional traits and soil physicochemical properties. Results: Soil physicochemical properties (ST, SS, pH) of coastal plants varied under different disturbance intensities. Concurrently, plant functional traits (SLA, LDMC, LTD, LNC, LCC, LPC, LSC, RTD, RPC) also exhibited significant differences. Notably, the interactions among plant functional traits also varied under different disturbance intensities. Furthermore, plant functional traits exhibited distinct response mechanisms to changes in soil physicochemical properties. The plant community adjusts its resource allocation strategy to adapt to environmental changes, which is specifically manifested in the coordination of SRL, SRA, SLA, RPC, RNC, RCC, RSC, LPC, LNC, LT, LTD, and LDMC. Conclusions: Under severe disturbance, plant communities tend to adopt short-term rapid investment-return strategies to cope with harsh environmental conditions; moderate disturbance prompts slow investment-return strategies for long-term stable growth; mild disturbance triggers rapid investment-return strategies to enhance environmental adaptability. The research results indicate that by selecting appropriate plant resources based on different habitat characteristics, it is beneficial for the survival and reproduction of the plant community. Full article

As unique geographical entities, island cities boast abundant ecological resources and profound cultural values, serving as critical hubs for maintaining ecosystem services in coastal transition zones. Ensuring the stability of ecosystem services is strategically significant for sustainable urban development, while the construction of Ecosystem Service Networks (ESNs) has emerged as a core strategy to enhance ecological functionality and mitigate systemic risks. Based on current research gaps, this study focuses on three key questions: (1) How to construct a Composite Ecosystem Service Index (CESI) for island cities? (2) How to identify the Ecosystem Service Networks (ESNs) of island-type cities? (3) How to optimize the ecosystem service networks of island cities? This study selects Pingtan Island as a representative case, innovatively integrating the InVEST and MaxEnt models to conduct a comprehensive assessment of ecological and cultural services. By employing Principal Component Analysis (PCA), a Composite Ecosystem Service Index (CESI) was established. The research follows a systematic technical approach to construct and optimize the ESN: landscape connectivity indices were applied to identify ecological source areas based on CESI outcomes; multidimensional resistance factors were integrated into the Minimum Cumulative Resistance (MCR) model to develop the foundational ecological network; gradient buffer zone analysis and circuit theory were sequentially employed to refine the network structure and evaluate ecological efficacy. Key findings reveal: (1) Landscape connectivity analysis scientifically delineated 20 ecologically valuable source areas; (2) The coupled MCR model and circuit theory established a hierarchical ESN comprising 45 corridors (12 Level-1, 14 Level-2, and 19 Level-3), identifying 5.75 km² of ecological pinch points, 7.17 km² of ecological barriers, and 84 critical nodes—primarily concentrated in cultivated areas; (3) Buffer zone gradient analysis confirmed 30 m as the optimal corridor width for multi-scale planning; (4) Circuit theory optimization significantly enhanced network current density (1.653→8.224), demonstrating a leapfrog improvement in ecological service efficiency. The proposed “assessment–construction–optimization” integrated methodology establishes an innovative paradigm for deep integration of ecosystem services with urban spatial planning. These findings provide practical spatial guidance for island city planning, supporting corridor design, conservation prioritization, and targeted restoration, thereby enhancing ecosystem service efficiency, biodiversity protection, and resilience against coastal ecosystem fragmentation. Full article

Coastal foredune blowout is a significant indicator of shoreline retreat, activation of backshore dune fields, and land desertification. Among current research on the terminal phase of coastal foredune blowouts, few studies explain blowouts’ morphological and airflow interaction mechanisms in the late stage through comprehensive field surveys and observations. In this study, the coastal blowout on the foredune at Tannanwan Beach, Pingtan Island, China, is investigated to explore the morphodynamics and evolutionary characteristics of blowout morphology. High-resolution RTK GPS technology and two-dimensional ultrasonic anemometers are utilized to repeatedly measure and observe the morphology of late-stage bowl blowouts. The results revealed that the following: (1) During the entire survey period, the bowl blowout is characterized by deepening erosion of the lateral walls and accretion in the deflation basin, with the maximum erosion depth on the east lateral wall reaching up to 3.99 m and the maximum accumulation height occurring in the front half of the deflation basin. (2) The wind direction and the morphology of the bowl blowout significantly impact the airflow characteristics within the blowout, and the airflow distribution within the blowout further affects the development of the blowout morphology. (3) The bowl blowout is in the late stage of its life cycle. Full article

Noctiluca scintillans, known as a global red tide species, is a common red tide species found in Pingtan Island. To examine the bacterial community structure in different environments during the red tide period of N. scintillans on Pingtan Island, samples were collected from the Algal Bloom Area (ABA), Transition Area (TA), and Non-Algal Bloom Area (NBA) on 6 April 2022, and the environmental physicochemical factors and bacterial community were determined. The outbreak of N. scintillans red tide significantly impacted the water quality and bacterial community structure in the affected sea area. The water quality in the ABA has deteriorated markedly, with the contents of COD, NH₄⁺-N, and PO₄³⁻ in the ABA being significantly higher than those in the TA and NBA, while the pH is significantly lower than that in the TA and NBA. The richness, diversity, and evenness of the bacterial community in the ABA are all lower than those of the TA and NBA. For instance, the Shannon index values of the three sampling points are 4.41, 5.41, and 6.37, respectively. At the phylum level, the dominant bacterial phyla in the ABA are Proteobacteria, Firmicutes, and Cyanobacteria; in the TA, they are Proteobacteria, Bacteroidetes, and Firmicutes; and in the NBA, they are Proteobacteria, Bacteroidetes, and Cyanobacteria. At the genus level, the dominant bacterial genera in the ABA are Vibrio, Carnobacterium, Candidatus_Megaira, Planktomarina, and Pseudoalteromonas; in the TA, they are Vibrio, Planktomarina, Lentibacter, Glaciecola, and Jannaschia; and in the NBA, they are Planktomarina, Amylibacter, NS5_marine_group, Aurantivirga, and marine_metagenome. In the ABA, the combined proportion of Vibrio and Carnobacterium exceeds 50%, with Vibrio_splendidus accounting for 93% of the total Vibrio population. These research results can provide a scientific basis for clarifying the environmental characteristics and bacterial composition during the large-scale N. scintillans red tide in Pingtan Island. Full article

Wind plays a crucial role in the formation of coastal dunes, and in China, these dunes are shaped by the combined effects of typhoons and winter monsoons. However, the unique characteristics of Chinese coastal dunes impacted by these forces remain poorly understood, as prior research has predominantly focused on their separate impacts. This study employed RTK-GPS technology to conduct 14 high-precision morphological assessments of coastal dunes in Tannan Bay, Pingtan Island, Fujian, China, between 2014 and 2017, aiming to investigate the response patterns of coastal dunes to typhoons and winter monsoons. Our findings indicate that coastal dunes respond variably to typhoons of differing intensities, with considerable height changes across different sections; however, winter monsoons contribute to an overall increase in dune height. Both dune volume and height increased due to continuous sediment accumulation at the base of the windward slopes. Additionally, the average high-water level advanced seaward by 3.0–4.0 m. We concluded that in Tannan Bay, typhoons exert only a temporary “braking” effect on dune morphology, whereas the winter monsoon is the primary driver of its long-term evolution. These findings contribute to a comprehensive understanding of coastal dune dynamics and provide insights for effective coastal sand management and disaster prevention strategies. Full article

As an indispensable part of the marine ecosystem, the health status of the sea affects the stability and enhancement of the overall ecological function of the ocean. Clarifying the future land and sea utilization pattern and the impacts on the carbon stocks of island ecosystems is of great scientific value for maintaining marine ecological balance and promoting the sustainable development of the island ecosystem. Using Pingtan Island as an example, we simulate and predict changes in island utilization and carbon stocks for historical periods and multiple scenarios in 2030 via the PLUS-InVEST model and the marine biological carbon sink accounting method. The results show that (1) from 2006 to 2022, the carbon stock of Pingtan Island decreased by 7.218 × 10⁴ t, resulting in a cumulative economic loss of approximately USD 13.35 million; furthermore, from 2014 to 2018, the implementation of many reclamation and land reclamation projects led to a severe carbon stock loss of 6.634 × 10⁴ t. (2) By 2030, the projected carbon stock under the three different policy scenarios will be greater than that in 2022. The highest carbon stock of 595.373 × 10⁴ t will be found in the ecological protection scenario (EPS), which will be 4.270 × 10⁴ t more than that in 2022. With the strong carbon sequestration effect of the ocean, the total social carbon cost due to changes in island utilization is projected to decrease in 2030. (3) The factors driving changes in island utilization will vary in the design of different future scenarios. The results of this study not only provide a solid scientific basis for the sustainable development of island areas, but they also highlight the unique contribution of islands in the field of marine ecological conservation and carbon management, contributing to the realization of the dual-carbon goal. Full article

Dalian Island, located in the northwest of Pingtan County, Fujian Province, China, has been an important junction on the Maritime Silk Road since the Tang dynasty. This study focuses on sauce-glazed ceramic ware from the Song dynasty salvaged from the waters near Dalian Island Wharf. The composition, phase attributes, and microstructures of the marine organism remains attached to the ceramic ware were analyzed using an optical microscope, scanning electron microscope, and micro-Raman spectrometer to investigate the influence of marine organisms on the degradation of the ceramic ware. Long-term abrasion by sea wave-borne debris led to the increased surface roughness and wettability of the ceramic ware, facilitating the attachment of marine organisms. Differences in surface roughness between the inner and outer walls led to varying levels of biomass. Coralline algae secreted inducers to attract the larvae of macrofoulers. The attachment of different types of marine organisms had varying effects on the degradation of the ceramic ware. Firmly attached unitary organisms could alleviate the scouring of sea wave-borne debris and hinder the intrusion of foreign pollutants, thereby playing a ‘bio-protective’ role. In contrast, the group skeletons of modular organisms could reinforce the mechanically damaged surface but failed to block the intrusion of iron rust and other pollutants, resulting in chemical alterations of the glaze. Therefore, the specific species of the attached marine organisms should be considered in subsequent conservation efforts. Full article

In this paper, the landscape of typical roadway trees and their planting parameters on Pingtan Island are investigated and analyzed in the field. A three-dimensional model of street trees was created using AutoCAD 2020, and Ansys Fluent 2022 was used to simulate the wind condition of trees with various planting parameters under high wind circumstances. The study explores the stress and adaptability of roadway trees in the wind environment under different planting parameters, such as different heights, plant spacing, lower shrub heights, and two-row and three-row planting with different row spacings. The results show that the wind resistance of street trees is connected to the planting parameters and that modifying the appropriate planting parameters can improve the wind stability of road green space. The height of street trees is more suitable between 6.0~9.0 m. The planting spacing should be not less than 1.0 times the crown and not more than 1.75 times the crown. The form of planting has an important effect on wind resistance. Two rows of planting of street trees have a better utility and wind resistance, and a row spacing of 2.0~6.0 m is more appropriate. The height of the lower shrubs should be lower than the height of the first branch, with 0.5~1.0 m being more suitable. Based on the results of the data simulation and analysis, this paper proposes corresponding tree species selections and planting strategies for road green belts on Pingtan Island from the perspective of street tree species, planting parameters, and planting forms to provide references for the upgrading and planning of roadway tree landscapes on Pingtan Island as well as in similar climatic regions. Full article

The investigation of taxonomic diversity within island plant communities stands as a central focus in the field of island biogeography. Phylogenetic diversity is crucial for unraveling the evolutionary history, ecological functions, and species combinations within island plant communities. Island effects (area and isolation effect) may shape species distribution patterns, habitat heterogeneity affects habitat diversity, and anthropogenic disturbances can lead to species extinction and habitat destruction, thus impacting both species diversity and phylogenetic diversity. To investigate how taxonomic and phylogenetic diversity in island natural plant communities respond to island effects, habitat heterogeneity, and anthropogenic disturbances, we took the main island of Haitan (a land-bridge island) and nine surrounding islands (oceanic islands) of varying sizes as the subjects of our study on the Pingtan islands. We aim to elucidate the influence of island effects, habitat heterogeneity, and anthropogenic disturbances on taxonomic and phylogenetic diversity. The results showed that, (1) Both the taxonomic and phylogenetic diversity of plants on the Pingtan islands followed the island area effect, indicating that as the island area increases, both taxonomic and phylogenetic diversity also increase. (2) Island effects and habitat heterogeneity were found to enhance taxonomic and phylogenetic diversity, whereas anthropogenic disturbances were associated with a decrease in both taxonomic and phylogenetic diversity. Furthermore, the synergistic influence of island effects, habitat heterogeneity, and anthropogenic disturbances collectively exerted a negative impact on both taxonomic and phylogenetic diversity. (3) The contribution of explanatory variables of anthropogenic disturbances for taxonomic and phylogenetic diversity was higher than that of island effects and habitat heterogeneity. Additionally, the contribution of the explanatory variables under the combined influence of island effects, habitat heterogeneity, and anthropogenic disturbances is higher than that of the individual variables for island effects and habitat heterogeneity. These findings suggest that anthropogenic disturbances emerged as the dominant factors influencing both taxonomic and phylogenetic diversity. These findings demonstrate the intricate interplay between island effects, habitat heterogeneity, and anthropogenic disturbances, highlighting their combined influence on both taxonomic and phylogenetic diversity on island. Full article

Island plants form the foundation for maintaining the ecology of an island. With the development of the island’s infrastructure, its ecosystems become damaged to a certain extent. A comprehensive understanding of island habitats and plant community characteristics is crucial for the development of island plant communities. This paper focuses on Pingtan Island in Fujian Province, China, as the research subject. Firstly, considering the significance of the wind environment on the island, this study constructed a wind environment model for the entire island of Pingtan to evaluate the ecological sensitivity from a macro perspective. Subsequently, 33 typical sample plots were selected based on different ecologically sensitive areas to conduct a micro-survey and the characterization of the montane plant communities on Pingtan Island. The findings reveal that (1) Pingtan Island’s ecological sensitivity is dominated by areas with ecological insensitivity (35.72%), moderate ecological sensitivity (33.99%), and high ecological sensitivity (18.02%). The soil texture, wind environment, and land use type are the primary influencing factors in the ecological sensitivity of Pingtan Island. (2) A total of 47 families, 82 genera, and 93 species of plants were investigated in a typical sample site in the mountainous area of Pingtan Island. The plant community structure was dominated by the successional stage of shrubs and herbs. There is some similarity in the plant composition of different ecologically sensitive areas. High ecologically sensitive areas have more species. As sensitivity increases, the dominant species in the three ecologically sensitive areas continue to undergo plant succession from Acacia confusa to Pinus thunbergii to Eurya emarginata. (3) Both community characteristics and species diversity vary between sensitive areas. The canopy density (CD) and the mean height of tree layer (MHTL) are higher in moderate ecologically sensitive areas. The mean tree diameter at breast height (MDBH) and the mean height of shrub layer (MHSL) are higher in high ecologically sensitive areas, while the mean height of herb layer (MHHL) is higher in extreme ecologically sensitive areas. Four diversity indicators increase with increasing sensitivity. In the moderate and high ecologically sensitive areas, Casuarina equisetifolia and A. confusa thrive, with Pinus thunbergii showing the opposite trend. However, species diversity is better characterized by A. confusa and P. thunbergii, with C. equisetifolia being the least diverse. Both the community characteristics and species diversity of P. thunbergii are optimal in extreme ecologically sensitive areas. In this study, the ecological sensitivity of Pingtan Island and the characteristics of montane plant communities were systematically analyzed to explore more stable montane plant communities on the island, aiming to provide a scientific basis and model reference for the ecological restoration and sustainable development of Pingtan Island and other islands. Full article

The optimal selection of characteristic bands and retrieval models for the hyperspectral retrieval of soil heavy metal concentrations poses a significant challenge. Additionally, satellite-based hyperspectral retrieval encounters several issues, including atmospheric effects, limitations in temporal and radiometric resolution, and data acquisition, among others. Given this, the retrieval performance of the soil arsenic (As) concentration in Pingtan Island, the largest island in Fujian Province and the fifth largest in China, is currently unclear. This study aimed to elucidate this issue by identifying optimal characteristic bands from the full spectrum from both statistical and physical perspectives. We tested three linear models, namely Multiple Linear Regression (MLR), Partial Least Squares Regression (PLSR) and Geographically Weighted Regression (GWR), as well as three nonlinear machine learning models, including Back Propagation Neural Network (BP), Support Vector Machine Regression (SVR) and Random Forest Regression (RFR). We then retrieved soil arsenic content using ground-based soil full spectrum data on Pingtan Island. Our results indicate that the RFR model consistently outperformed all others when using both original and optimal characteristic bands. This superior performance suggests a complex, nonlinear relationship between soil arsenic concentration and spectral variables, influenced by diverse landscape factors. The GWR model, which considers spatial non-stationarity and heterogeneity, outperformed traditional models such as BP and SVR. This finding underscores the potential of incorporating spatial characteristics to enhance traditional machine learning models in geospatial studies. When evaluating retrieval model accuracy based on optimal characteristic bands, the RFR model maintained its top performance, and linear models (MLR, PLSR and GWR) showed notable improvement. Specifically, the GWR model achieved the highest r value for the validation data, indicating that selecting optimal characteristic bands based on high Pearson’s correlation coefficients (e.g., abs(Pearson’s correlation coefficient) ≥0.45) and high sensitivity to soil active materials successfully mitigates uncertainties linked to characteristic band selection solely based on Pearson’s correlation coefficients. Consequently, two effective retrieval models were generated: the best-performing RFR model and the improved GWR model. Our study on Pingtan Island provides theoretical and technical support for monitoring and evaluating soil arsenic concentrations using satellite-based spectroscopy in densely populated, relatively independent island towns in China and worldwide. Full article

Due to the special geographical location and unique ecosystem of islands, appropriate development and protection of islands is important for promoting the sustainable development of islands. By using the Pingtan Islands as an example, this study constructed a system of suitability evaluation indexes for marine ecological space, marine agricultural production space and marine construction space under the principle of land–sea coordination. To evaluate the spatial suitability of the sea area around islands, a GIS spatial analysis method and a hierarchical analysis method (AHP) were used, which provided useful references for the integration of land and sea and for developing islands sustainably. The research results showed that the suitability area of ecological space in the Pingtan Islands accounted for around 64.3%, the construction space accounted for around 2.1% and the agricultural production space accounted for 33.5%. Full article

Understanding the spatial distribution of soil organic matter (SOM) is important for land use management, but conventional sampling methods require significant human and financial resources. How to map SOM and monitor its changes using a limited number of sample points combined with remote sensing techniques that provide long-time series data is crucial. This study aimed to generate a regional-scale near-surface SOM map using 70 soil samples and covariate environmental factors extracted mainly from Landsat 8 OLI. Firstly, the sensitivity of each environmental factor to SOM was tested using a geographic detector model (GDM). Secondly, the tested factors were selected for modeling and mapping by ordinary least squares (OLS) and geographically weighted regression kriging (GWRK). The performance of these two models was compared. Finally, the mapping results of the better model (GWRK) were compared and analyzed with the traditional interpolation results based solely on sampling points to verify the rationality of the proposed method. The results show that three environmental factors, ratio vegetation index (RVI), differential vegetation index (DVI), and terrain roughness (TR), have a strong influence on the spatial variability of SOM. Using these three factors in combination with the GWRK method, a more accurate and refined spatial distribution map of SOM can be obtained. Comparing the SOM maps of GWRK and the traditional interpolation method, the results show that the accuracy of GWRK (R² = 0.405; mean absolute error = 0.637, and root mean square error = 0.813) is higher than that of traditional interpolation methods (R² = 0.291, MAE = 0.609, and RMSE = 0.863). The spatial recognition rate (fineness) of SOM patches at all levels using the GWRK method increased by more than 73 times compared to the traditional kriging. We conclude that the combination of limited SOM samples, environmental variables, GDM, and GWRK is a pragmatic approach for estimating regional-scale SOM. Full article

With the acceleration of urbanization, problems such as urban ecological environment quality have become increasingly prominent. How to scientifically analyze and evaluate the spatial pattern of urban ecological environment changes and influential variables is a prerequisite for achieving green development and ecological priority new in urban planning. Our study was conducted on Pingtan Island, located in Fujian Province, China. First, we selected Landsat 8 OLI images in 2013, 2017, and 2021. Second, we extracted the remote sensing ecological index (RSEI) from these images and created RSEI maps to assess the spatial-temporal variations and spatial autocorrelation of the ecological environment condition in Pingtan Island. Third, the proportion of land-use types, road, and population density were selected as independent variable factors, RSEI as the dependent variable, least squares regression (OLS), geographically weighted regression (GWR), and multi-scale geographically weighted regression (MGWR) were used to establish global and local regression models. According to the regression coefficients of the model and its spatial distribution, the spatial heterogeneity between the ecological environment and the influencing factors was assessed. The results indicated that: (1) the mean value of the RSEI increased from 0.422 to 0.504 during 2013–2021, indicating that the overall ecological environment improved. (2) Based on the global Moran’s I value, the distribution of ecological environment quality was positively correlated. The local Moran’s I cluster map showed that the high-high cluster gradually extended to the northwest high-altitude region. Low-low clustering gradually extended to the more populous areas in the southeast. (3) The $R_{adj}^2$ of the MGWR model was 0.866, which was better than the results of the OLS model and GWR model, indicating that MGWR had obvious advantages in revealing the spatial heterogeneity between the ecological environment and the influencing factors. Importantly, the results indicate that population density, road density, and the proportion of cropland land and impervious surface in land-use types have varying degrees of negative effects on the urban ecological environment, with the impervious surface being more severe, followed by population density, while forest land in land-use types shows significant positive effects. Full article