Coastal Areas Research Articles

Response of bottom dissolved oxygen reduction to net ecosystem production observed by a wave-driven profiler in the Changjiang River Plume

Coastal hypoxia, exacerbated by the combined influence of eutrophication and global warming, presents a significant environmental challenge. However, the lag correlation between organic matter (OM) export from the upper layers and bottom dissolved oxygen (DOBOT) reduction still lack clear elucidation. This study investigated the coupling between net ecosystem production (NEP, representing the maximum OM export) and DOBOT in the Changjiang River plume (CRP), using a wave-driven profiler system. The high-resolution profiles revealed rhythmic fluctuations in water column NEP, with sediment-water exchange (−74.6%) and NEP (−4.0%) dominating DOBOT reduction. Notably, surface NEP impacts DOBOT with a lag time of 25.65 h, indicating an OM sinking speed of 1.32 mm s−1. NEP at a depth of 3.4 m exerted the most significant influence on DOBOT, explaining a 12% reduction. These findings elucidate the response mechanism of DOBOT reduction to upper OM export and provide insights for hypoxia prediction in coastal and estuarine areas.

Anthropogenic activities affect the diverse autotrophic communities of coastal sediments

Coastal sediments are a critical domain for carbon sequestration and are profoundly impacted by human activities. Therefore, it is essential to understand the structure and components of benthic autotrophs that play a crucial role in carbon sequestration processes, as well as the influence of anthropogenic activities on their communities. This study utilized an urban estuary, an industrial sea bay, a maricultural sea region, and two mangrove coastlines within the coastal areas of Guangdong Province, China. The micro-benthos in these environments, including prokaryotes and eukaryotes, were identified through high-throughput sequencing of 16S rRNA and 18S rRNA genes. The findings show that the autotrophic composition was altered by the interactions of anthropogenic heavy metals (Cd and Zn) and micro-eukaryotes (protazoa, metazoa, and parasitic organisms). Industrial pollution reduced the abundance of both prokaryotic and eukaryotic autotrophs. Mangroves induced a substantial transformation in the sediment eukaryotic and prokaryotic composition, increasing the proportion of autotrophs, notably sulfur-oxidizing and iron-oxidizing bacteria and microalgae. This alteration suggests an increase in specific sulfur and iron cycling with simultaneous carbon sequestration within mangrove sediments. These results indicate that anthropogenic activities affect sediment carbon sequestration by altering autotrophic assemblages along coastlines, thereby inducing consequential shifts in overall elemental cycling processes.

Using metabolomics to explore the effects of epigenetic-modification strategies on the metabolites of Acanthus ilicifolius L. endophytic fungi against ovarian cancer

Ovarian cancer is a serious threat to women's health and safety. So far, people have discovered more than 130 small molecule compounds of natural origin for anti-tumor, of which approximately 50% are of microbial origin. The Acanthus ilicifolius L. species is primarily distributed in the Guangdong, Hainan, and Guangxi regions of China and grows in tidally accessible coastal areas. Recent studies have revealed that Acanthus ilicifolius L. extracts are endowed with a range of pharmacological properties, including anti-inflammatory, hepatoprotective, antioxidant, and antitumor activities. Endophytic fungi are commonly found in the healthy tissue and organs of medicinal plants. These fungi and the plants they inhabit form mutually beneficial symbiotic relationships. Endophytic fungi produce a series of secondary metabolites, with active substances having shown great economic value and applications prospects in drug research and development as well as for the biological control of plant diseases. Secondary metabolites production by endophytic fungi is regulated by specific gene clusters, and several techniques have been used to stimulate the secondary metabolic processes of fungi, including epigenetic-modification and OSMAC (one strain many compounds) strategies, co-culturing, and gene modification. Among these, epigenetic modification has been shown to be effective; this strategy involves the addition of small-molecule epigenetic modifiers to the culture medium, thereby activating silenced biosynthetic gene clusters without altering the DNA sequences of the fungi. This approach facilitates the expression of silenced genes in endophytic fungi, thereby increasing the number and diversity of secondary metabolites. Furthermore, it assists in overcoming the inhibition of microbial secondary-metabolite synthesis under laboratory conditions, and enhances silenced-gene expressions. The advent of novel analytical techniques and bioinformatics has provided a comprehensive, multifaceted, and holistic understanding of fungal metabolism through the development of metabolomics as a research platform. However, few studies have combined anti-ovarian cancer-activity screening with metabolomic approaches in the search for activity-differentiating metabolites from endophytic fungi under the intervention of epigenetic modifiers. Herein, we investigated the impact of epigenetic modifiers on the secondary metabolites of the endophytic Diaporthe goulteri fungus from Acanthus ilicifolius L. to determine their potential anti-ovarian cancer activities. Crude extracts were obtained by controlling three variables: the number of fermentation days, the type of epigenetic modifier, and its concentration, with activities screened using the CCK-8 (cell counting kit-8) method. Ultra performance liquid chromatography-tandem mass spectrometry (UPLC-MS/MS) was subsequently employed for non-targeted metabolomic analysis. A multivariate statistical analysis model was constructed using principal component analysis and orthogonal partial least squares-discriminant analysis, which combines model and variable importance projection, with qualitative screening performed and significant changes (variable importance in the projection (VIP)≥1; P<0. 05) determined. Fifteen differential metabolites were identified in the fungal and epigenetic modification group, primarily comprising polyketides, amino acids, derivatives, alkaloids, and organic acids, including prenderol, glycine, valine, 2-ethylcaproic acid, rubratoxin B, finasteride, 6-silaspiro[5.5]undecane, 1-(2-nitrophenoxy)octane, heptadecene, 1-pentadecene, 11-ketoetiocholanolone, 3-(1-ethyl-1,3,3-trimethyl-2,3-dihydro-1H-inden-5-yl)butanal, N2-benzoylarginine, tabutrex, (3aR,6S,6aS)-6-(4-hydroxy-2-methoxy-2-butanyl)-4,4-dimethylhexahydro-1(2H)-pentalenone, and 8-aminoquinoline. The expressions of prenderol, 1-(2-nitrophenoxy)octane, 3-(1-ethyl-1,3,3-trimethyl-2,3-dihydro-1H-inden-5-yl)butanal, N2-benzoylarginine, and 8-aminoquinoline were downregulated, whereas the expressions of the remaining 10 substances were upregulated. Polyketides were the main components that exhibited higher expressions. This study showed that latent active differential metabolites can be searched by combining anti-ovarian cancer-activity screening with metabolomics analysis, thereby providing a reference for the further development of Acanthus ilicifolius L. resources and the subsequent targeted isolation of active compounds.

Establishing a plastic waste map using remote sensing data in the coastal area of Thanh Hoa province (Vietnam)

Plastic pollution, particularly in oceans, is a growing environmental threat. Monitoring this pollution is challenging due to the shortage of data and tools. Remote sensing offers a promising solution by using various types of satellite and aerial images to detect and track plastic waste movement. Purpose. The study aims to establish a plastic waste map using remote sensing technology, focusing on the case study of the coastal area of Thanh Hoa province, Vietnam. Methodology. The study involves several steps, including the collection of plastic waste data (samples in the case study and indices from remote sensing images) as well as topographic and base map collection, statistics of plastic samples, grid design, calculation, interpolation, accuracy assessment, and mapping. Field surveys involved taking pictures of plastic debris along designated routes and a grid system was used to classify and calculate waste samples. Satellite images, especially Sentinel-2 MSI optical satellite imagery, are utilized to identify water areas of high plastic concentration. Findings. A map of plastic wastes in coastal areas of Thanh Hoa was created, with indices like NDWI (Normalized Difference Water Index) and FDI (Floating Debris Index) helping identify potential plastic waste signals. The resulting map reveals high concentrations of plastic waste in sea areas near the major river mouths of the Ma River basin and tourist areas, which aligns with areas of high human activity. Originality. This is the first study of plastic waste in the coastal area using remote sensing data in Thanh Hoa province, Vietnam. Practical value. This study can contribute to the effective management of marine plastic waste in Thanh Hoa while opening up opportunities for applying the method to create marine plastic waste maps throughout Vietnam and foster long-term monitoring and management.

Analysis of Groundwater Salinity Distribution Based on Electrical Conductivity (EC) and Hydrochemical Approaches to Deep Wells in Sayung Subdistrict, Demak Central Java

In coastal areas, obtaining groundwater is not easy due to the lack of geological support conditions that cause water in the area to have poor quality such as groundwater that becomes salty. The coastal area of Sayung Subdistrict has geomorphological conditions whose surface tends to be flat with elevations 0-5 m higher than sea level and is dominated by alluvial material so that it can cause seawater infiltration to increase. The purpose of this research was to determine the distribution of salinity of groundwater in the coastal area of Sayung Subdistrict and to determine the cause of groundwater becoming salty. The method used in this research is the electrical conductivity (DHL) approach which is then classified based on the level of saltiness of groundwater. And then, well water from the sample points was tested using a hydrochemical test with the parameters used, namely the content of cations (Na, K, Mg, Ca) and anions (Cl, CO3, HCO3, SO4, NO3). This research was conducted at 33 well points spread across Sayung sub-district. The results of this study show that the electrical conductivity value obtained is between the range of 928-7,199 μS/cm which is divided into 3 classifications namely fresh water, fresh-brackish water, and brackish water. The analysis of the Trilinier Piper diagram shows that the saltiness of the groundwater is due to indications of seawater mixing characterized by a chloride (Cl) content that is increasingly greater towards the sea.

Local Use of Mangroves on the Coast of Southeastern México

Mangroves are essential for the well-being of the inhabitants of coastal areas, who have extensive knowledge about the use and exploitation of this resource. However, this knowledge is decreasing, which could trigger negative repercussions for this ecosystem. Ethnobiological investigations make it possible to gather information on the use, management, and exploitation of this resource. Hence, this paper presents a study that is framed around the coastal area of the state of Tabasco, in southeast México, and consists of 74 semi-structured interviews that were carried out, while the local relevance of each mangrove species was evaluated using ethnobiological indices. Three species of mangrove were identified, Avicennia germinans, Laguncularia racemosa, and Rhizophora mangle, and the latter species had the highest Use-Value (UV) Index value of 6.08. A total of 27 forms of forestry use were found, 11 for non-timber use and 16 for timber use. Firewood stood out as the main use with 12.6%, while the use of needles to make cloth and crafts represented the lowest percentage with 0.3%. The uses given by the coastal population to the mangroves and their respective species were influenced by immediate needs and specific characteristics of each species. To ensure the sustainability of mangroves, it is essential to design environmental strategies that integrate local ethnobiological knowledge and promote the active participation of direct users of this ecosystem. These strategies should be incorporated into public conservation policies, recognizing the cultural and economic value that mangroves hold for local communities. By implementing these actions, the relationship between communities and their environment will be strengthened, laying the groundwork for further exploration of coastal ethnobiology.

PROGRESSO DO BRASIL NA IMPLEMENTAÇÃO DE ÁREAS COSTEIRAS E MARINHAS PROTEGIDAS COM FOCO NA META 11 DE AICHI

he rapid global loss of biodiversity has promoted initiatives to develop a global network of Protected Areas (PAs), with the Aichi targets suggesting that countries protect at least 17% of continental areas and 10% of marine and coastal areas. For Brazil, there is a knowledge gap regarding the evaluation of qualitative and quantitative objectives through practical indicators of goal achievement and effective management. This study holistically addresses the conservation status of Brazil concerning Aichi Target 11 for marine and coastal ecosystems, using systematic literature review and marine spatial coverage analysis. The results show an increase to 26% of marine spatial coverage, with greater coverage by Environmental Protection Areas. There is a predominance of studies on "Management Effectiveness," with less focus on equitable management and integration between terrestrial and marine landscapes. Indicators primarily focus on "Ecological" and "Governance" dimensions, neglecting "Social" and "Economic" dimensions. Key challenges include the need for increased financial investment, connectivity between protected areas with different social and ecological contexts, and local community involvement in equitable management. Additionally, there is a need for increased coverage of integral protection areas and standardization of qualitative assessments. Keywords: Protected areas; Management effectiveness; Aichi Target 11; Conservation policy; Coastal and marine systems.

Wave–Tide–Surge Interaction Modulates Storm Waves in the Bohai Sea

Typhoons, extratropical cyclones, and cold fronts cause strong winds leading to storm surges and waves in the Bohai Sea. A wave–flow coupled numerical model is established for storm events observed in 2022 caused by three weather systems, to investigate how storm waves are modulated by wave–tide–surge interaction (WTSI). Wave response is basically controlled by water level change in coastal areas, where bottom friction or breaking dominates the energy dissipation, and determined by the current field in deep water by altering whitecapping. Wave height increases/decreases are induced by positive/negative water level or obtuse/acute wave–current interaction angle, leading to six types of field patterns for significant wave height (Hs) responses. For the three storm events, Hs basically changed within ±5% in central deep water, while the maximum increase/decrease reached 160%/−60% in the coastal area of Laizhou Bay/Liaodong Bay. Based on maximum Hs and its occurrence time, WTSI modulation is manifested as the superposition effect of wave–tide and wave–surge interactions in both space and time scales, and occurrence time depends more on tide than surge for all three storms. The enhancement/abatement of WTSI modulation happens for consistent/opposite changing trends of wave–tide and wave–surge interaction, with the ultimate result showing the side with a higher effect.

Inequalities in healthy life expectancy and risk factors for poor health in small geographic areas

Abstract Background Reducing inequality in healthy life expectancy (HLE) is a UK government ambition and requires more detailed knowledge of interrelated morbidity and mortality risks at smaller areas than is routinely available. We assessed HLE and risk factors in small areas. Methods We used publicly available data to estimate HLE in 2011 and 2021 at birth and age 65 for males and females for 128 Middle layer Super Output Areas (MSOA) in Norfolk and Waveney, described the distribution using geospatial mapping, and analysed associations with risk factors using linear regression. Results Mean HLE at birth was 66.5 years (standard deviation 4.3; range 52.0 to 73.0) for men and 67.5 (3.9; 56.0 to 74.0) for women, and at age 65 was 10.9 years (1.8; 6.0 to 16.0) and 12.2 (1.9; 5.0 to 15.0) respectively in 2021. The range in HLE increased between 2011 and 2021 by 2.8 years for men and 1.6 years for women. HLE was usually lower and risks higher in urban and coastal areas. Lower HLE at area level was associated with lower weekly income, physical inactivity, air pollution, alcohol admissions, living alone as an older person and diet not meeting ‘5 a Day’. HLE at age 65 in 2021 increased by: 0.2 (95% CI 0.1,0.2) years for men and 0.2 (0.2,0.3) for women for each £10 rise in weekly net income after housing expenditure; 0.1 (0.1,0.2) years for men for each 10 fewer alcohol attributable hospital admissions per 100,000 admissions; 0.66 (0.31,1.00) years for men and 0.53 (0.15,0.91) years for women per 1 μg/m3 less 2.5 mm particulate matter concentration in air pollution; 0.6 (0.2,1.0) years for men and 0.6 (0.1,1.0) years for women for each 10% fewer people being physically inactive (multiple regression). Conclusions This innovative approach can be used to monitor risks and inform targeted public health interventions at a local level more relevant to local policy makers. Stronger public health surveillance systems are needed to accurately monitor a wider variety of local data on risks. Key messages • Healthy life expectancy at age 65 varies by over 10 years for men and women between different small geographic areas in an English county, alongside local variation in risk factors for poor health. • Lower HLE at area level was associated with lower weekly income, physical inactivity, air pollution, alcohol admissions, living alone as an older person and diet not meeting ‘5 a Day’.

Mitigating Effect of the Sea on Temperatures Along Mediterranean Coastal Areas: The Case of the Vine Territory of the Matera DOP in Basilicata (Italy)

This study aims to assess temperature variations caused by ongoing climate change in the Basilicata region, southern Italy—Ionian side of the Gulf of Taranto—on the territory of the Matera DOP vineyard. In particular, it aims to assess the influence of the sea on temperature trends, and particularly to its “mitigating effect” in the context of ongoing climate change. Temperature trends were analyzed using ERA5-Land data from 1981 to 2022 and data from weather stations of the Lucanian Agency for Development and Innovation in Agriculture from 2000 to 2023. Temperature trends were studied considering both the period of the vegetative-productive season of the vineyards and the whole year. The results of this study show that, for the historical period analyzed, the Matera DOP area showed a significant upward trend in temperatures, particularly in the inland areas. This increase, especially for minimum temperatures, is more evident at higher elevations than at lower elevations near the sea. Indeed, coastal areas benefit from the thermoregulatory effect of the Ionian Sea, which moderates temperature increases at lower elevations. It follows that the Matera DOP wine-growing areas, and particularly those furthest from the coastal strip, will have to adapt to harsh climatic conditions that will certainly affect the quality and typicality of the wines.

Assessing the impacts of climate change on the vulnerability of coastal aquifers to the seawater intrusion

In most coastal areas, groundwater is affected by saltwater intrusion. Climate change effects, such as the sea-level rise and rainfall change are the climatic factors affecting the saltwater intrusion into groundwater. This study examines the vulnerability of the Abdan-Lamidan coastal aquifer to the intrusion of Persian Gulf saline waters under different hydrological conditions. First, the SIMCLIM model was used to calculate the regional sea-level rise of the Gulf under 24 future AOGCMs projections. The results showed that the increase in water level under the ensemble of AOGCM models and two RCP2.6 and RCP8.5 scenarios is 6.7 and 7.8 cm in 2050 compared to 2013. Then, the GALDIT vulnerability index was used to assess the vulnerability of the aquifer under the current condition and future scenarios. The results showed that parts of the aquifer that are currently at lower levels would be more vulnerable to sea-level rise in the future periods.

Prediction of the potential Brazilian distribution for invasive mollusc Melanoides tuberculata (Müller, 1774), including a new record from Northern Coastal Region

The freshwater snail Melanoides tuberculata (Müller, 1774) native from Africa and Asia, recently spreads out over the world. Records of invasive species are extremely important, because it helps in future invasions mitigation. Here, we report for the first time the occurrence of M. tuberculata in a protected area of Northern Brazilian Coast and use predictive distribution modeling to know the potential Brazilian distribution for this species. The gastropod M. tuberculata were collected in the municipalities of Tutóia and Santo Amaro - Maranhão State. According to the results of the predictive map distribution for Brazil, the regions with the highest susceptibility are the northeast, southeast and midwest. Preciptation of month and Isothermalithy were de variables that most contribute to the species’ potential distribution. This species presented high to medium suitability of occurrence in 32 national protected areas. Futher studies are recommended to monitor the growth and dispersion, in order to determine its real impact.

The relationship government, community, companions and economic empowerment of coastal women in Sampang Regency – Indonesia

The purpose of the research to study the role of stakeholders in empowerment economy Woman the coast in Sampang Regency Indonesia. Stakeholder involvement in empowerment programs economy Woman Coast is a very important role in the success of the program. This study uses a qualitative method with a descriptive research type. The location used in this study is in the coastal area of Sampang Regency. Data collection techniques are carried out using observation, interviews and documentation. While the data analysis technique uses a model Creswell. The results of the study state from the three stakeholders are government, community and companions Still not optimal. This is seen from the role of government in empowering coastal women's economy, both in organizing and implementing programs, has been quite good, but women's response Coast as program targets are still less. Besides less response is also very lacking in program sustainability so that the program that has been implemented not enough give optimal results. In addition, the activities of the assistants are only limited to the implementation of program activities. The role of assistants in understanding the success of empowerment programs and creating new entrepreneurs is still lacking.

MW‐SAM:Mangrove wetland remote sensing image segmentation network based on segment anything model

AbstractMangrove wetlands are important ecosystems in tropical and subtropical coastal areas, providing wind and wave attenuation and embankment protection functions. However, mangrove wetlands worldwide are facing severe loss and degradation. Accurate identification of mangrove wetland extent is crucial for their protection, but traditional methods struggle to meet the requirements of large‐scale, high‐precision identification. Furthermore, field data collection and annotation in wetlands in complex intertidal zones pose challenges, and the lack of high‐quality training samples limits the application of deep learning methods in this field. This paper proposes a novel semantic segmentation framework for mangrove wetlands called mangrove wetland remote sensing image segmentation network based on segment anything model (MW‐SAM) to address these issues. MW‐SAM is based on the pre‐trained SAM and achieves cross‐domain adaptation through parameter‐efficient fine‐tuning techniques. It introduces wetland‐specific prompts, auxiliary branches, semi‐supervised training, and iterative optimization strategies to improve accuracy and tackle the problem of sample scarcity. Moreover, on the mangrove wetland dataset constructed in this paper, MW‐SAM significantly outperforms SAM and other traditional methods. MW‐SAM provides a new technology for monitoring and protecting mangrove wetlands, and the constructed dataset will be made publicly available, which is expected to promote the development of mangrove wetland conservation efforts.

32 years of changes in river paths and coastal landscape in Bangladesh, Bengal Basin

AbstractThis study examines the geomorphological changes and environmental impacts on the coastline and the evolution of major river systems in Bangladesh over the past 32 years using remote sensing and GIS analyses. The central coastal area, characterized by fine sediments, has experienced significant land erosion due to the dynamics of the Meghna Estuary and its depositional patterns. In contrast, the southwestern Sundarbans Forest coast has remained relatively stable, aided by mangrove root stabilization despite anthropogenic threats. Channel migration analysis revealed the Brahmaputra River’s persistent braided configuration, while its tributaries, Teesta and Dharla, increased meandering nature due to reduced water availability and human interventions. The Ganges-Padma system displayed a shift towards a more sinuous channel pattern driven by reduced water discharge due to the Farakka Barrage construction in the upstream and a minor decrease in precipitation. The Upper Meghna River maintained moderate sinuosity with stable anastomosed patterns, whereas the lower Meghna River’s convergence with the Jamuna and Padma Rivers increased its susceptibility to erosion. These findings highlight the interplay of natural processes and human activities in shaping the coastal and fluvial landscapes of Bangladesh and the Bengal Basin, emphasizing the need for sustainable land-use practices and adaptive management strategies to mitigate future risks associated with sea-level rise and river course changes.

Integrative taxonomy reveals two new species of Maritrema Nicoll, 1907 (Digenea: Microphallidae Ward, 1901), parasitizing birds in the Gulf of Mexico.

Members of the genus Maritrema Nicoll, 1907 include endoparasites of aquatic birds and mammals, distributed worldwide. Adult specimens were collected from the intestines of three bird species (the great black hawks, Buteogallus urubitinga Gmelin; laughing gull, Leucophaeus atricilla Linnaeus; and the willet, Tringa semipalmata Gmelin) in three localities along the Gulf of Mexico. Photogenophores were sequenced for the large subunit (LSU) from nuclear rDNA, and the new sequences were aligned with other microphalloid sequences available in GenBank. The maximum likelihood and Bayesian inference analyses revealed three independent lineages, one corresponding to a previously described species, Maritrema corai Hernández-Orts, Pinacho-Pinacho, García-Varela & Kostadinova, 2016, and two representing two undescribed species. These two new species are described in the current study. Maritrema itzamnai n. sp. can be morphologically differentiated from its four congeneric species occurring in coastal areas of Mexico by having smaller oral (20-29 × 20-38 μm) and ventral (20-39 × 19-33 μm) suckers. In addition, Maritrema itzamnai n. sp. possess annular vitellarium instead of a horseshoe-shaped vitellarium. Maritrema kukulkanni n. sp. can be distinguished from its congeneric species reported from Mexico by possessing a larger oesophagus (44-117μm) and by having a vitellarium distributed in both the hindbody and forebody. Maritrema corai is the third species recorded in this study parasitizing the great black hawk (Buteogallus urubitinga); this represents a new host and locality record, expanding its distribution range from the Mexican Pacific Ocean to the Gulf of Mexico.

Assessing Climate Change Impact on Habitat Suitability and Ecological Connectivity of Wych Elm (Ulmus glabra Huds.) in Türkiye

Understanding how climate change influences the geographical distribution of species within an ecological niche is essential for predicting habitat shifts and informing conservation efforts. This study evaluates the impact of climate change on habitat suitability and ecological connectivity of wych elm (Ulmus glabra Huds.) in Türkiye. The study explores the future distribution of U. glabra and how its connectivity is affected by habitat fragmentation arising from changing climatic conditions. Contextually, this paper aims to achieve two primary objectives: estimating the potential geographical ranges of U. glabra under different climate scenarios and assessing alterations in ecological connections between current and future habitats. The maximum entropy (MaxEnt) model was used along with Morphological Spatial Pattern Analysis (MSPA), and the Probability of Connectivity (PC) index was applied to show possible transformations in distribution patterns of U. glabra over time. The findings suggest that there will be a reduction in the suitability of locations for the species. Moreover, it is expected that under future climate scenarios, ecological connectivity will decline, especially from 2061 to 2100 in the SSP585 scenario. Notably, significant alterations are anticipated during the latter half of the twenty-first century, mainly outside the coastal areas of the Black Sea, where extensive regions would become unsuitable. Additionally, the species is projected to shift its range, decreasing its presence in inland regions while expanding along the coasts. The results show the vulnerability of this species against climate change, thereby demanding adaptive conservation measures to preserve it within the forest ecosystems of Türkiye.

Monitoring and Modelling Fluxes of Water and Nutrients to Surface Drainage Network From Irrigated Agricultural Fields in a Hydraulically Reclaimed Coastal Area

ABSTRACTThis paper describes the application of a physically based agrohydrological model (named FLOWS), coupled with a kinematic wave approach model (named KWV) for water and solute runoff routing, for interpreting the fate of water and nutrients coming from cultivated fields to surface drainage network located in ‘Piana del Sassu’ in the Arborea plain, a hydraulically reclaimed area with shallow groundwater. Modelling was supported by a large complex database on soil, groundwater and surface drainage water, which was used for establishing the boundary conditions for simulations, as well as for calibrating and validating the model. The model FLOWS provided the water and nutrient fluxes to the surface water, which were passed to the KWV model for their routing along the elementary fields in the experimental area and from these to the ditches and finally to the drainage channel. The modelling approach effectively predicted the water and solute distribution along the soil profile, as well as the losses of water and nutrients to the surface water. The results showed a significant amount of water and dissolved nutrients to flow quickly from the soil uppermost layer to the surface drainage network during both the irrigation season and during rainfall events. During irrigation applications, losses were mostly due to rainfall intensity exceeding the maximum infiltration velocity of the shallow soil layer in the case of sprinkler irrigation and to subsurface lateral drainage in the case of exceeding irrigation water provided by drip irrigation. This makes the Sassu plain a significant contributor of nutrients (nitrate and phosphorus) to the surface water. Consequently, even though the agricultural activities might not be an important issue for the groundwater vulnerability, the management of water and nutrients should be significantly improved to avoid ecohydrological threats to the important coastal water bodies present in the area.

Synthesizing Landsat images using time series model-fitting methods for China’s coastal areas against sparse and irregular observations

ABSTRACT Long historical records and free accessibility have made Landsat data valuable for time-series analysis. However, Landsat time-series analysis is restricted for coastal areas due to the lack of sufficient numbers of clear images. The generation of synthetic Landsat images using model-fitting methods is accepted as an effective means of overcoming this problem. But for coastal areas, available observations are typically sparse and irregular, leading to ill-fitted models that distort synthetic Landsat images. In this study, we propose a linear harmonic model with different orders and implement it on an annual basis to generate synthetic Landsat images based on the Google Earth Engine (GEE) platform. First, we incorporated the available observations from adjacent years and filtered them by season to address the problems of data sparsity and irregularity. Then, we combined the threshold segmentation and ridge regression approaches to address the fake cloud problem, which sometimes contaminates synthetic Landsat images in summer. All cloud-free real Landsat images from five typical sites along China’s coasts during 1986–2020 were used to evaluate the accuracy and robustness of the synthetic Landsat images generated using our proposed methods. The principal results are as follows: (1) the R2 value of the linear harmonic model averaged across different Landsat bands and land cover types was 0.640, and the model was especially successful in simulating the surface reflectance in near NIR bands in forest and grassland areas; (2) 81.1% of the synthetic Landsat images covered by fake clouds were effectively restored, and there was the particular need to remove fake clouds for the synthetic Landsat images at low latitudes; (3) The mean absolute error for our synthetic Landsat images was 0.015, with the rate of 0.124; this was achieved under the clear-sky probability of only 36% and the average number of annual observations below 9, indicating a good performance. Compared with the continuous change detection and classification (CCDC) and seasonal median composite (SMC) methods, our proposed method offers advantages in both the accuracy and integrity of synthetic Landsat images. Our proposed method for synthesizing images also has potential for application to global coastal areas and other satellite datasets.

Identifying key monitoring areas for tree insect pest risks in China under climate change.

Climate change can exacerbate pest population growth, posing significant threats to ecosystem functions and services, social development, and food security. Risk assessment is a valuable tool for effective pest management that identifies potential pest expansion and ecosystem dispersal patterns. We applied a habitat suitability model coupled with priority protection planning software to determine key monitoring areas (KMA) for tree insect pest risks under climate change and used forest ecoregions and nature reserves to assess the ecological risk of insect pest invasion. Finally, we collated the prevention and control measures for reducing future pest invasions. The KMA for tree insect pests in our current and future climate is mainly concentrated in eastern and southern China. However, with climate change, the KMA gradually expands from southeastern to northeastern China. In the current and future climate scenarios, ecoregions requiring high monitoring levels were restricted to the eastern and southern coastal areas of China, and nature reserves requiring the highest monitoring levels were mainly distributed in southeastern China. Tree insect pest invasion assessment using ecoregions and nature reserves identified that future climates increase the risk of pest invasions in forest ecoregions and nature reserves, especially in northeastern China. The increased risk and severity of tree insect pest invasions require implementing monitoring and preventative measures in these areas. We effectively assessed the pest invasion risks using forest ecoregions and nature reserves under climate change. Our assessments suggest that monitoring and early prevention should focus on southeastern and northeastern China.