Pingtan Island Research Articles

Microbial Response to Coastal-Offshore Gradients in Taiwan Straits: Community Metabolism and Total Prokaryotic Abundance as Potential Proxies

Located between the South and the East China Sea, the Taiwan Straits (TWS) are a marine shelf-channel area, with unique hydrological and geomorphological features affected by rivers inflow and with recent algal blooms with red tide events. This study aimed at assessing microbial distribution and function and their modulation in response to environmental gradients. Surface (0.5 m) water samples from 16 stations along five north to south transects were collected; total prokaryotic abundance by epifluorescence microscope and carbon substrate utilization patterns by Biolog Ecoplates were estimated. Spatially, a patchy microbial distribution was found, with the highest microbial metabolic levels and prokaryotic abundance in the TWS area between Minjiang River estuary and Pingtan Island, and progressive decreases towards offshore stations. Complex carbon sources and carbohydrates were preferentially metabolized. This study provides a snapshot of the microbial abundance and activity in TWS as a model site of aquatic ecosystems impacted from land inputs; obtained data highlights that microbial metabolism is more sensitive than abundance to environmental changes.

Invasive Alien Plants and Invasion Risk Assessment on Pingtan Island

Pingtan Island is the largest island in Fujian Province and the fifth largest island in China. The invasion of a large number of alien plants has had a profound impact on the local ecological environment. Because the harm caused by alien invasive plants varies greatly between different ecosystems and even in different habitats, the risk assessment index system suitable for one region may not be suitable for other regions. Therefore, it is necessary to establish a risk assessment index system for invasive alien plants on Pingtan Island. Alien plant communities in different habitats were studied by means of quadrat investigation and professional literature review. Some invasive alien species were selected and compiled into a list of invasive alien plants on Pingtan Island, and their species composition, origin, flora, life forms, and habitats were statistically grouped. There were 104 species in 80 genera and 37 families of alien invasive plants. Asteraceae, Fabaceae, Amaranthaceae, and Poaceae were the main families, accounting for 26.7%, 6.7%, 6.7% and 5.8% of the total species, respectively. The geographical components of families and genera have obvious tropical properties, accounting for 51.3% and 66.6% of the total species, respectively. These originated mainly from South America and North America, accounting for 45.5% and 30.1% of the total frequency, respectively. Annual herbs, biennial herbs, and perennial herbs accounted for 84.6% of the total species. Based on a DPSIR conceptual model and an AHP method, an invasion risk assessment of 104 invasive alien plants was conducted. The ecological adaptability, habitat distribution and landscape impact of species were considered in the selection of indicators and the formulation of standards. A total of 23 high-risk invasive species were identified at level I, 37 medium-risk invasive species at level II, and 44 low-risk invasive species at level III. Lantana camara L. had the highest risk score (49), followed by Cenchrus echinatus L. (45), Spartina alterniflora Loisel. (45), and Panicum repens L. (43.5). Suggestions are put forward to prevent the invasion of alien plants on Pingtan Island and to provide a theoretical basis for promoting the healthy and stable development of the ecological environment on the island.

Remotely Sensed Ecological Protection Redline and Security Pattern Construction: A Comparative Analysis of Pingtan (China) and Durban (South Africa)

The unprecedented regional urbanization has brought great pressure on the ecological environment. Building an ecological security pattern and guide regional land and space development is an important technique to ensure regional ecological security and stability to achieve sustainable development. In this study, the Pingtan Island of China and the Durban city of South Africa were chosen as case study area for a comparative study of different scales. The importance of ecosystem services and ecological sensitivity were evaluated, respectively. The core area of landscape which is vital for ecological function maintenance was extracted by morphological spatial pattern analysis (MSPA) and landscape connectivity analysis. Furthermore, the ecological sources were determined by combining the results of ecological protection redline delimitation and core area landscape extraction. The potential ecological corridors were identified based on the minimum cumulative resistance model, and the ecological security pattern of study areas was constructed. The results showed that the ecological protection redline areas of Pingtan and Durban were 42.78 km2 and 389.07 km2, respectively, which were mainly distributed in mountainous areas with good habitat quality. Pingtan ecological security pattern is composed of 15 ecological sources, 16 ecological corridors, 10 stepping stone patches and 15 ecological obstacle points. The total length of corridors is 112.23 km, which is radially distributed in the form of “one ring, three belts”. The ecological security pattern of Durban is composed of 15 ecological sources, 17 ecological corridors, 11 stepping stone patches and 18 ecological obstacle points. The total length of corridors is 274.25 km, which is radially distributed in the form of “two rings and three belts”. The research results can provide an important reference for the land space construction planning and ecological restoration projects in Pingtan and Durban.

Application of a Zoning Methodology for Groundwater Suitability on Islands, a Case Study of Pingtan Island, China

A groundwater function evaluation systems and associated model was applied to Pingtan Island in China, to support future development, use and protection of groundwater. Groundwater function was assigned to resource, ecology and geological environmental functions, and then further sub-divided, based on hydrogeological conditions, development status, planning and Chine policy requirements. At the same time, it is the first time to try to apply the technical requirements for the division of groundwater resources in island areas. According to the planning and utilization of groundwater resources in Pingtan Island, established a second-level system of shallow groundwater function zoning. Then, by comparing the strong and weak relationships among the groundwater resource function, ecology function, and geological environment function, developed a scoring system of the shallow groundwater function zoning. The division of shallow groundwater function zones in Pingtan Island was finally carried out. The zoning result will play an essential role in the future development, utilization, and protection of groundwater in Pingtan Island. At the same time, it provides the first example for the application of groundwater function zoning in island areas and improves the theoretical results of groundwater function zoning.

A multi-dimensional vulnerability assessment of Pingtan Island (China) and Nile Delta (Egypt) using ecological Sensitivity-Resilience-Pressure (SRP) model

Despite the recent progress on Ecological Vulnerability studies by developing index models, similar studies on the coastal areas are still rare. Pingtan’s main island of Fujian Province in China and the coastal area of Nile Delta in Egypt, have witnessed unprecedented development associated with fragile coastal areas. SRP model is a comprehensive model, utilized to evaluate the ecological vulnerability to provide a solid reference for the development of SRP model development. Research results indicated that the ecological vulnerability of the coastal areas of Nile Delta was slightly better than that of Pingtan’s main island in 2018, the former was almost at a micro level, while the latter was almost at a mild level (micro and mild vulnerable area accounted for 65.99%). Pingtan’s main island, showed a slight deterioration trend from west to east, and the characteristics of massive regional distribution, with a slight deterioration of the overall ecological environment of the planning area from 2013 to 2018. For the coastal area of Nile Delta, the ecological vulnerability was gradually increasing from the middle of the basin to the periphery, and the extremely vulnerable area was mainly distributed in the northern coastal area and the arid desert areas from 2018 to 2019. Moreover, according to the statistics results about the maximum weight of ecological pressure was 0.4989 on Pingtan’s main island and 0.4960 in the coastal area of Nile Delta, ecological sensitivity and pressure played a vital role in ecological vulnerability and spatial pattern of two study areas, which contain climate (mainly involving temperature, precipitation), vegetation, and human activities (mainly involving land-use, economy, and population). The current study not only confirmed the close relationship between ecological vulnerability, natural attributes, and human activities, also showed the strong applicability of SRP model in the coastal ecological fragile area.

The responses of Spinifex littoreus to sand burial on the coastal area of Pingtan Island, Fujian Province, South China

ABSTRACT The adaptive capacity of psammophytes to sand burial is crucial for the ecological restoration of coastal dune systems. The responses of Spinifex littoreus to different sand burial depths and levels were examined on the coast of Pingtan Island, Fujian Province, South China. The results indicated that, compared with the control group (CG), sand burial on the S. littoreus stolons had no significant impact on the vertical growth of its conjoint ramets. However, the horizontal growth of S. littoreus stolons was stimulated and significantly increased in half-intense (HI) and complete-intense (CI) sand burial treatments by 24.56% and 40.79%, respectively. Throughout the experiment, about 96% of adventitious roots were observed on the base section of stolons, while no roots in the control group (CG). After 20-day artificial sand burial treatments, the dry weight ratio between stem and leaf of S. littoreus was decreased in all three sections of stolons, especially for the top sections. Overall, S. littoreus can adapt to the complete and intense sand burial in growing season by rapid growth of stolons, abundant production of adventitious roots on the stolon base, and more germination of leaves on the stolon top.

Identification of 'Blue tears' and its relationship with water quality of coastal waters in Pingtan Island

Identification of 'Blue tears' and its relationship with water quality of coastal waters in Pingtan Island

Identification of 'Blue tears' and its relationship with water quality of coastal waters in Pingtan Island

Identification of 'Blue tears' and its relationship with water quality of coastal waters in Pingtan Island

Species diversity and geographical distribution of marine, benthic, shell-bearing mollusks on the coast and adjacent area of Pingtan Island, Fujian Province

Species diversity and geographical distribution of marine, benthic, shell-bearing mollusks on the coast and adjacent area of Pingtan Island, Fujian Province

Groundwater Vulnerability Assessment of Pingtan Island in Fuzhou City, China, Based on DRASLI-QUE

AbstractBased on the DRASTIC model [A model for groundwater vulnerability assessment including seven indexes: depth to groundwater (D), net recharge (R), aquifer medium (A), soil type (S), topograp...

3-D isotropic and anisotropic shallow crustal structure on Pingtan Island, Fujian, southeastern coast of China

Pingtan Island is located on the southeastern coast of China between the Changle-Zhao'an and Binhai fault zones. We use P- and S-wave traveltime data from marine large-volume airgun sources for 3-D velocity structure inversion, and the spatial resolution is high at depths of 1–3 km. The isotropic inversion results show that the velocity in the island is higher in the midwestern area, which consists of sedimentary plains. The velocity is lower in the southern and eastern areas, which consist of eroded hills. Then we perform azimuthally anisotropic inversion using the obtained isotropic model as the initial model. The fast directions in the island are predominantly NE-SW and NNE-SSW, consistent with the main fault structures along the southeastern coast of China. The magnitude of anisotropy gradually decreases from south to north, consistent with the decreasing intensity of fault activity from south to north. On the southeastern coast of China, the fast direction in the upper crust is nearly orthogonal to that in the upper mantle from previous studies, which is nearly parallel to the absolute plate motion in the lower crust and upper mantle. The faults along the Fujian coastal area and Taiwan formed at different time period. But the fast directions in these two areas are similar. Therefore, the fast direction is mainly dominated by the trends of faults and fractures in the upper crust. And it is dominated by aligned olivine crystals induced by plate motion in the lower crust and upper mantle.

Paleoproterozoic basement beneath the Eastern Cathaysia Block revealed by zircon xenocrysts from late Mesozoic volcanics

The Eastern Cathaysia Block located to the western side of the Pacific Plate was mainly covered by late Mesozoic intrusive and volcanic rocks, and the age and composition of its basement remain enigmatic. Here we firstly report U–Pb and Hf isotopes in zircon xenocrysts from late Mesozoic mafic sub-volcanic rocks in Pingtan Island, the east coastal area of the Eastern Cathaysia Block, with surprising Paleoproterozoic to Archean U–Pb isotopic ages. Neither ca. 1.8 Ga nor 1.0–0.7 Ga age peaks that are very typical in the outcropping rocks (including the Neoproterozoic sedimentary rocks in Pingtan Island) in the South China Block is identified. The two main Precambrian age peaks of 3.4–3.0 Ga and 2.6–2.2 Ga of these zircon xenocrysts are explained by contamination from the sediments in the unexposed basement. The youngest two Paleoproterozoic zircon xenocrysts may indicate the deposition of the basement close to ca. 1.8 Ga. The identification provides clues to the existence of the Paleoproterozoic basement in the Eastern Cathaysia Block. It may further suggest that the late Mesozoic (continental arc?) magmatism in the Eastern Cathaysia Block was most likely developed on and contaminated by the Paleoproterozoic basement.

Post-orogenic thermal reset of the Pingtan-Dongshan metamorphic belt (SE China): Insights from zircon fission track and U-Pb double dating

Abstract Zircon double dating technique for U-Pb and fission track (FT) ages is used to reassess the cooling conditions for the Pingtan-Dongshan Metamorphic Belt (PDMB). Three Cretaceous gneissic bodies from the Chinmen area and two dioritic plutons from the Zhangzhou Igneous Complex (ZIC) in two sides of the Changle-Nanao fault are studied. U-Pb dating results define the magma emplacement of gneisses at 144–134 Ma and dioritic rocks at 102–99 Ma, and FT dating results give ages of 96–86 Ma and ~87 Ma for corresponding samples. Combining 40Ar/39Ar mineral ages reported previously, the fast cooling curve (86 °C/Myr; 100–96 Ma) of ZIC plutons matches near-surface intrusives. However, those for deep-seated Chinmen gneisses are problematic as their resultant conditions are similar to ZIC samples. A recent concept favors the Early to Late Cretaceous tecto-magmatic evolution in the coastal SE China involving episodes of orogenic magmatism (147–130 Ma) and shallow magmatism under post-orogenic extension (110–85 Ma). As the Pingtan island in northern PDMB is considered as a remnant piece of colliding fragment, the cooling rate known for gneissic bodies in this island (35 °C/Myr; 130–120 Ma) can better represent the record of this collision. On the basis of these features, we advocate a magmatic quiescence at 130–120 Ma representing collision between PDMB and a concealed microcontinent which resulted in rapid uplift of this metamorphic belt. Cooling curves obtained for Chinmen gneisses are suggested to have further subjected to thermal reset by high temperature magmatism taking place during the post-orogenic stage.

Exotic origin of Pingtan Island in the Pingtan-Dongshan Metamorphic Belt (SE China): Zircon U-Pb age and Hf isotope evidences

Cathaysia Block in South China had accreted tremendous amounts of Mesozoic magmatic rocks. Recent zircon UPb age results revealed existence of some Early Jurassic gneissic granites (200–190 Ma) in the Pingtan-Dongshan Metamorphic Belt (PDMB), coastal SE China which corresponds one stage of magmatic quiescence in the rest part of East Cathaysia. To better understand Mesozoic thermal evolution of the PDMB, UPb geochronology and Hf isotope composition of zircon separates (LA-ICPMS) and inclusions (NanoSIMS, age only) are examined for two granitic rocks and one meta-sandstone in Pingtan area (northern PDMB) and three granites in Matsu Islands further north. For Pingtan rocks, ages of discrete zircons give two Early Jurassic ages (196 Ma and 173 Ma) and prossess in dominance positive ɛHf(t) values (−0.2 to 7.5). On the other hand, zircon inclusions within rock-forming minerals yield a wide age span from Permo-Triassic to Early Cretaceous in six clusters, namely 270–206 Ma, 191–170 Ma, 168–151 Ma, 146–132 Ma, 126–119 Ma and 109–100 Ma that basically coincide the major Mesozoic thermal episodes in Cathaysia except the second cluster. For Matsu granites, discrete zircons exhibit Late Jurassic (162–158 Ma) and Early Cretaceous (137 Ma) ages with ɛHf(t) values of −9.1 to −1.6 and −4.9 to −0.8, respectively. Nevertheless, zircon inclusions show ages corresponding to Pingtan samples in the last four clusters. With reference to Mesozoic magmatic rock units in the neighboring Southeast China Magmatic Belt (SCMB), our data suggest irrelevance of Pingtan samples to the Cathaysia and linkage of off-shore Matsu granites to the PDMB. Noting that there are similarities of zircon ages and ɛHf(t) values between the granite-schist associations in Tananao Metamorphic Belt (TMB) of eastern Taiwan and Pingtan island of northern PDMB, these Early Jurassic granites were probably originated from a same source. Three consistent Early Cretaceous age clusters of zircon inclusions over the studied samples match two well-known magma prevailing episodes in the coastal SE China, with one tectonic episode (128–119 Ma) in the PDMB that is often invisible from the zircon separates remains unexplainable. In response to a plausible tectonic evolution, we support the earlier proposition for a now-concealed microcontinent that had impinged on Cathaysia around 125 Ma, but further suggest that it left Pingtan Island behind as a remnant fragment when drifted away at later time.

Ecological Suitability of Island Development Based on Ecosystem Services Value, Biocapacity and Ecological Footprint: A Case Study of Pingtan Island, Fujian, China

The ecological environment and resource endowment of an island are more vulnerable compared to the mainland, and special assessment and measurement of the ecological suitability for development are significant. Pingtan Island (Fujian, China) was taken as a case study. Changes in ecosystem services value and the profit-and-loss balance between ecological footprint and biocapacity were assessed using land use/cover changes based on remote-sensing images taken in 2009, 2014 and 2017, and the ecological suitability of development was measured. Results show that island development led to a decrease in the ecosystem services value and an increase in ecological footprint and biocapacity. The key ecological factors restricting the scale of island development are topography, vegetation with special functions and freshwater. Biocapacity of islands can increase not only by changing from lower-yield land types to higher-yield construction land types but also by external investment. A new measurement framework was proposed that simply and clearly reveals the ecological suitability of island development and the underlying key constraints.

DYNAMIC STATE OF ECOSYSTEM CARRYING CAPACITY UNDER ISLAND URBANIZATION: A CASE STUDY OF PINGTAN ISLAND IN THE SOUTHEASTERN COAST OF CHINA

The assessment of ecological environment during the large-scale development of islands is a major topic in the study of current coastal islands. Choosing the appropriate assessment method to evaluate the suitability of carrying capacity of islands and making relevant suggestions are significant to the sustainable development of islands. Ecological footprint method is used to analyze the ecological carrying capacity of Pingtan Island (PI) from 2005 to 2016 for promoting the coordinated rational development and construction and ecological environment of the island. Although PI is in rapid urban development and construction, the island maintains secure and stable ecological conditions. PI is used as a research case to analyze the sustainable development of the ecological environment through the carrying capacity of the island ecosystem.

A Preliminary Study on The Prevention and Control of Seawater Intrusion in Northern Pingtan Island with Freshwater Recharge Curtain

Seawater intrusion caused by groundwater over-exploitation is a kind of geological disaster caused by human economic activities and natural environment changes. Using freshwater recharge curtain technology is an effective means to prevent seawater intrusion. Based on the analysis of the characteristics of seawater intrusion in Pingtan island, Fujian Province, and in view of the possible seawater intrusion problems in the construction of Luyangpu underground reservoir in Pingtan Island, this paper expounds the basic principle of seawater intrusion prevention with freshwater recharge curtain , the technical measures of installing a row of recharge wells in the northern coastal zone of Luyangpu plain in Pingtan Island and using freshwater recharge curtain are put forward to prevent seawater intrusion. Through groundwater numerical simulation, the dynamic distribution of groundwater level in the north of Pingtan Island in the next 20 years is analyzed and predicted. The results show that the seawater intrusion can be effectively prevented by installing freshwater curtain recharge wells in the northern coast of Luyangpu.

Petrogenesis of granitic rocks in the Pingtan Island, Fujian Province: Constraints from zircon U-Pb dating, O-Hf isotopes and biotite mineral chemistry

Petrogenesis of granitic rocks in the Pingtan Island, Fujian Province: Constraints from zircon U-Pb dating, O-Hf isotopes and biotite mineral chemistry

Petrogenesis of granitic rocks in the Pingtan Island, Fujian Province: Constraints from zircon U-Pb dating, O-Hf isotopes and biotite mineral chemistry

东南沿海地区发育具有'等同位素组成'特征的晚中生代双峰式火成岩，其成因备受争论。本文选择了福建省平潭岛双峰式杂岩体中的花岗闪长岩、英云闪长岩与花岗岩开展了高精度锆石U-Pb定年、原位O-Hf同位素和黑云母矿物化学方面的研究，以探讨这些花岗质岩石的成因。分析结果显示，花岗闪长岩、英云闪长岩与花岗岩的锆石U-Pb年龄分别为116.8±1.0Ma、116.3±1.0Ma与117.4±1.0Ma，表明它们均侵位于早白垩世。这三类岩石也有较为相似的锆石O-Hf同位素组成。其中，锆石的δ18O分别变化为4.6%~5.3‰、4.8%~5.3‰及5.0%~5.6‰，与地幔的O同位素值基本一致。锆石的eHf（t）变化范围分别为+2.0~+7.1、+2.8~+6.5及+1.8~+5.6，相应的两阶段模式年龄tDM2分别为741~1046Ma、754~995Ma及815~1058Ma。锆石O-Hf同位素数据反映其熔融源区主要为相对较年轻的地壳物质，来自华夏地块古老基底的贡献较少。另外，黑云母矿物化学暗示这三类岩石具有Ⅰ型花岗岩的特征。但是，黑云母种属在不同岩性间存在差异，其中花岗闪长岩与英云闪长岩中的黑云母为镁质类型，花岗岩中的黑云母为铁质类型。从花岗闪长岩、英云闪长岩到花岗岩，黑云母的结晶温度和岩浆体系的氧逸度均逐渐降低，这与钙碱性岩浆分异演化的趋势基本一致。结合前人研究资料及区域地质演化历程，我们认为平潭岛杂岩体中的花岗质岩石形成于古太平洋俯冲背景，其熔融源区主要为新增生地壳物质。花岗质岩石内部岩性的差别主要是母岩浆经历不同程度分异演化的结果。我们的研究结果暗示壳幔岩浆混合在东南沿海早白垩世长英质岩石形成过程中所具有的作用可能较为有限。

The construction of virtual simulation platform for pingtan experimental area based on HTML5 and WebGL

ABSTRACT Field geological practice is not only an important part of teaching. However, how to vividly explain the geological practice in the field and intuitively show the geographical environment and its evolution is a difficult problem for geological educators. In this study, we use Pingtan Island as a research case. Based on HTML 5 and open-source framework Three.js of network graphics library WebGL, 3D interactions were embedded in the website. Besides, POI was built through Java, and annotation and image information were marked so as to realise data uploading, navigation, and 3D simulation platform functions. The research is to form a theoretical and practical teaching system.