Southern Coastal Zone Research Articles

Bayesian spatial-temporal analysis and determinants of cardiovascular diseases in Tanzania mainland

BackgroundCardiovascular Diseases (CVDs) are health-threatening conditions that account for high mortality in the world. Approximately 23.6 million deaths due to CVD is expected in the year 2030 worldwide. The CVD burden is more severe in developing countries, including Tanzania.ObjectivesThis study analyzed the spatial-temporal trends and determinants of cardiovascular diseases in Tanzania from 2010 to 2019.MethodsIndividual data were extracted from Jakaya Kikwete Cardiac Institute (JKCI), Mbeya Zonal Referral Hospital (MZRH), Kilimanjaro Christian Medical Centre (KCMC) and Bugando hospitals and the geographical data from TMA. The model containing spatial and temporal components was analyzed using the Bayesian hierarchical method implemented using Integrated Nested Laplace Approximation (INLA).ResultsThe results found that the incidence of CVD increased from 2010 to 2014 and decreased from 2015 to 2019. The southern highlands, lake, central and coastal zones were more likely to have CVD problems than others. It was also revealed that people aged 60–64 years OR = 1.49, females OR = 1.51, smokers OR = 1.76, alcohol drinkers OR = 1.48, and overweight OR = 1.89 were more likely to have CVD problems. Additionally, a 1oC increase in the average annual air maximum temperature was related to a 14% risk of developing CVD problems. The study revealed that the model, which included spatial and temporal random effects, was the best-predicting model.ConclusionThe study shows a decreased CVD incidence rate from 2015 to 2019. The CVD incidences occurred more in Tanzania’s coastal and lake areas between 2010 and 2019. The demographic, lifestyle and geographical risk factors were significantly associated with the CVD.

Two new Bulbine species (Asphodelaceae) from the southern coastal zone of the Western Cape, South Africa

Two new Bulbine species (Asphodelaceae) from the southern coastal zone of the Western Cape, South Africa

Preliminary Study on the Relationship between Location, Infrastructure, and Transportation of Productive Malaysia Cocoa Farmers (PMCF) towards Work Performances in Sarawak, Malaysia

Malaysian cocoa production relied on cocoa farmers since 2006 because they were the major holder (81.4%) of the cocoa cultivation area. As for Sarawak, 100% of cocoa production was from cocoa farmers. Sarawak used to produce 21,200 metric tons of dried cocoa beans in 1990. The government also has spent more on training and fertilizer for cocoa farmers to increase PMCF productivity. However, the production keeps gradually decreasing yearly. In 2021, Sarawak only produced 59 metric tons of dried cocoa beans and the productivity decreased by 10% to 0.19 metric/ton/ha/year compared to 2019 productivity (MCB, 2022). In order to strategies the long-term improvement of cocoa production, this study aims to define the relationship between location, infrastructure, and transportation toward the work performance of Sarawak PMCF. Driven by Iceberg Model, the objectives of this preliminary study are to determine i) the location, infrastructure, and transportation towards work performance levels ii) the relationship between location, infrastructure, and transportation with work performance iii) the most factors (IVs) that contribute more toward work performances. A total number of 35 respondents were involved in this purposive data collection which is only 30% of the sample population of the preliminary study which was 105 PMCF. The sample procedure used the approach of random sampling technique. These 35 respondents were selected involving 3.6% of respondents for each zone population of Sarawak rural areas namely the Northern, Middle, and Southern Coastal Zone. The data was r by IBM SPSS version 25.0. The data were tested by using Exploratory Factor Analysis (EFA) and then analyzed by descriptive, correlation, and regression analysis to answer all objectives. The study found all the variables showed moderate-level indicators. The variables that showed moderate and positive correlation were location and infrastructure. In contrast, location is the most contributing factor to the work performance of PMCF in Sarawak.

The spatial effect of integrated economy on carbon emissions in the era of big data: a case study of China

The digital economy has the characteristics of resource conservation, which can solve China’s high carbon emissions problems. The digital economy can quickly integrate with the real economy, forming an integrated economy. However, it is still unclear whether an integrated economy can effectively reduce carbon emissions and achieve China’s ‘dual carbon goals’. Therefore, this study takes 30 provinces in China as the research object, constructs the integration economy index system through the statistical data from 2011-2021, and explores the spatial effect of the impact of the integration economy on carbon emissions by using principal component analysis, coupled coordination model and spatial econometric model. The research results are as follows. (1) From 2011 to 2021, the comprehensive economy showed a trend of increasing yearly (from 0.667 to 0.828), and carbon emissions showed a slow decrease (from 0.026 to 0.017). (2) Due to the infiltration of China’s economic development from the eastern to the western, the spatial distribution of the integrated economy shows a decreasing trend from east to west. The spatial distribution of carbon emissions may be related to China’s industrial layout of heavy industry in the northern, and light industry in the southern, showing a trend of low in the south and high in the north. (3) The integrated economy can significantly reduce carbon emissions (the coefficients of influence, -0.146), and the reduction effect will be more obvious if spatial spillover effects are taken into account (-0.305). (4) The eastern coast, the middle reaches of the Yangtze River, and the middle reaches of the Yellow River economic zones all increase carbon emissions at a certain level of significance (0.065, 0.148, and 3.890). The Northeast, South Coastal and Southwest economic zones significantly reduce carbon emissions (-0.220, -0.092, and -0.308). The results of the Northern Coast and Northwest are not significant (-0.022 and 0.095). (5) China should tailor regional economic development policies, such as strengthening investment in digital infrastructure in the Northwest Economic Zone and fully leveraging the spatial spillover effects of integrated economy in the Northeast, Southern Coastal, and Southwest Economic Zones to reduce carbon emissions.

Vertical distribution of annual water temperature maxima in the southern coastal zone of Lake Baikal

It is frequently observed that an extreme event, such as a temperature maximum, has a greater impact on a lake ecosystem than changes in average conditions. For the first time, we examine the vertical variability of annual water temperature maxima (AWTM) and dates of their occurrence based on in-situ measurements of water temperature with discreteness of 15 minutes for a stable stratification period over eleven years (since 2005 to 2016 except 2009) in the southern coastal zone of Lake Baikal with a bottom depth of 545 m. The estimated statistical characteristics clearly distinguish various features of the vertical distribution of AWTM. There are significant time shifts (about 86 days) between the uppermost horizon (about 15 m) and the lowest 300 m horizon. The average maximum annual temperatures (15 °C) decrease from the upper horizon to a temperature of 4 °C at 300 m depth. To quantify changes in the annual maximum water temperature, the empirical functions were constructed to estimate relationships between AWTM, dates of their occurrence and depth. These dependencies are not linear and verified by independent data. They have fairly high coefficients of determination.

Spatial and temporal changes of land use land cover distribution in selected sites of the southern coastal zone of Sri Lanka

The southern coastal zone of Sri Lanka has been subjected to a variety of natural and anthropogenic influences over the past three decades. Understanding impacts of such influences on Land Use Land Cover (LULC) is vital for proper management of the coastal zone. This study, therefore, focused on mapping the change/s in the distribution of selected LULC in the selected sites, Bundala, Galle, Kalametiya, and Hambantota of the southern coastal zone, over last 24 years using satellite imagery. LULC maps of nine classes (mangrove, inland vegetation, marsh and grass, sand, bare land, built-up, cultivation, water, and unclassified) were created by employing an on-screen digitization technique achieving an accuracy of >70%. Trend analysis and two-sample proportion tests were used for statistical analyses, whereas geometric calculations were used for descriptive analyses. The results showed the highest overall change in LULC in Kalametiya, followed by Hambantota, Galle, and Bundala. The changes in the LULC classes are mainly attributed to the conversion of water to mangroves, marsh and grass areas in Kalametiya, water to built-up areas in Hambantota, cultivations to built-up areas in Galle, and marsh and grass areas to bare lands in Bundala. The causes of LULC changes were site specific. Trend analyses indicate the least LULC changes in Bundala possibly by 2025. The study highlights the significance of taking into account geographical dislocations when considering and anticipating the potential impacts of development projects over broader extents.

Spatiotemporal Evolution of Production–Living–Ecological Land and Its Eco-Environmental Response in China’s Coastal Zone

High-intensity human activities have caused dramatic transformations of land function in China’s coastal zone, putting enormous pressure on the region’s ecological environment. It is urgent to fully understand the spatiotemporal evolution of the land-use function in the coastal zone to promote sustainable development. Therefore, based on CNLUCC data for 2000, 2010, and 2020, this study quantitatively explored the spatiotemporal evolution of production–living–ecological land (PLEL) and its eco-environmental response in China’s coastal zone by using multiple land-use analysis methods, gradient analysis, and the eco-environmental quality index. The results showed that over the past 20 years, the production land (PL) continued to decrease, whereas the living land (LL) and blue ecological land (BEL) increased. In the vertical direction, PL and the ecological land (EL) dominated in the northern and the southern coastal zone, respectively. In the horizontal direction, with increasing distance from the coastline, the green ecological land (GEL) increased, whereas it was the opposite for BEL. The transformations of PLEL were high and low frequency in the north and south, respectively. From 2000 to 2020, the eco-environmental quality of China’s coastal zone slightly degraded, with conditions that were “excellent in the south and poor in the north”. The eco-environmental qualities of each sub-coastal zone gradually improved with increasing distance from the coastline. The main transformation types that led to eco-environmental improvement and degradation were from other production lands (OPL) to blue ecological land (BEL) and BEL to OPL, respectively. The findings will guide PLEL planning, eco-environmental protection, and science-based land usage.

Agrobiological phenological characteristics of native grape varieties in the conditions of the coastal zone of the Republic of Dagestan

Dagestan is considered one of the centers of origin of cultural grapes. This is evidenced by a huge number of indigenous grape varieties of different ripening periods and directions of use. Native varieties have a number of positive features that are widely used in the breeding process. Among them medium ripening period (Ag raisins, Khatmi), late ripening period (Agadai, Goat raisins), etc. The purpose of the research is to study the influence of weather conditions on agrobiological indicators and the onset of phenological phases of the grape plant. The experiment included 14 native grape varieties of different ripening periods and directions of crop use in the conditions of the southern coastal zone of the Republic of Dagestan. The conducted studies have established: one variety of very early ripening period (Ag emchek); 5 varieties of early ripening period (Hotsatsibil, Budai Shuli, Ceaushnovy, Khatmi); 7 early-middle varieties (Ag chakrak, Ag raisin, Gimra, Dagestan, Dzhagar, Dokur, Dubut) and 1 late-ripening variety (Chili Gulabi). And also determined agrobiological indicators and indicators of crop quality. The number of inflorescences per one developed shoot (K1 is the fruiting coefficient) is the lowest in the Budai Shuli variety-0.55, and the highest in the Gimra variety-1.74. The remaining varieties range from 0.61 to 1.56. According to the coefficient of fruitfulness (K2), the varieties Gimra and Hotsacibil are also distinguished (1.90 and 1.71, respectively). For the rest of the varieties, this indicator ranges from 1, 23-1,68. The studied varieties in the conditions of southern coastal zone were divided into four groups: very early, early, early-middle and late. Varieties Ag Emchek, Gimra and Dokur were quite productive (28.1, 23.6 and 21.0 tons, respectively). In spite of the high yields, all the varieties provided quality corresponding to the required conditions (15-20 g/100cm3).is considered one of the centers of origin of cultural grapes. This is evidenced by a huge number of indigenous grape varieties of different ripening periods and directions of use. Native varieties have a number of positive features that are widely used in the breeding process. Among them are varieties of very early ripening period (Yay white raisins and Yay pink raisins), medium ripening period (Ag raisins, Khatmi), late ripening period (Agadai, Goat raisins), etc. The purpose of the research is to study the influence of weather conditions on agrobiological indicators and the onset of phenological phases of the grape plant. The experiment included 14 native grape varieties of different ripening periods and directions of crop use in the conditions of the southern coastal zone of the Republic of Dagestan. The conducted studies have established: one variety of very early ripening period (Ag emchek); 5 varieties of early ripening period (Hotsatsibil, Budai Shuli, Ceaushnovy, Khatmi); 7 early-middle varieties (Ag chakrak, Ag raisin, Gimra, Dagestan, Dzhagar, Dokur, Dubut) and 1 late-ripening variety (Chili Gulabi). And also determined agrobiological indicators and indicators of crop quality. The number of inflorescences per one developed shoot (K1 is the fruiting coefficient) is the lowest in the Budai Shuli variety-0.55, and the highest in the Gimra variety-1.74. The remaining varieties range from 0.61 to 1.56. According to the coefficient of fruitfulness (K2), the varieties Gimra and Hotsacibil are also distinguished (1.90 and 1.71, respectively). For the rest of the varieties, this indicator ranges from 1, 23-1,68. The studied varieties in the conditions of southern coastal zone were divided into four groups: very early, early, early-middle and late. Varieties Ag Emchek, Gimra and Dokur were quite productive (28.1, 23.6 and 21.0 tons, respectively). In spite of the high yields, all the varieties provided quality corresponding to the required conditions (15-20 g/100cm3).

Distribution and accumulation of metals and metalloids in planktonic food webs of the Mediterranean Sea (MERITE-HIPPOCAMPE campaign)

Particle-size classes (7 fractions from 0.8 to 2000 μm) were collected in the deep chlorophyll maximum along a Mediterranean transect including the northern coastal zone (bays of Toulon and Marseilles, France), the offshore zone (near the North Balearic Thermal Front), and the southern coastal zone (Gulf of Gabès, Tunisia). Concentrations of biotic metals and metalloids (As, Cd, Cr, Cu, Fe, Mn, Ni, Sb, V, Zn) bound to living or dead organisms and faecal pellets were assessed by phosphorus normalisation. Biotic metals and metalloids concentrations (except Cr, Mn, and V) were higher in the offshore zone than in the coastal zones. In addition, biotic Sb and V concentrations appeared to be affected by atmospheric deposition, and biotic Cr concentrations appeared to be affected by local anthropogenic inputs. Essential elements (Cd, Cu, Fe, Mn, Ni, V, Zn) were very likely controlled both by the metabolic activity of certain organisms (nanoeukaryotes, copepods) and trophic structure. In the northern coastal zone, biomagnification of essential elements was controlled by copepods activities. In the offshore zone, metals and metalloids were not biomagnified probably due to homeostasis regulatory processes in organisms. In the southern coastal zone, biomagnification of As, Cu, Cr, Sb could probably induce specific effects within the planktonic network.

Isotopic compositions of copper and zinc in plankton from the Mediterranean Sea (MERITE-HIPPOCAMPE campaign): Tracing trophic transfer and geogenic inputs

This study uses Cu and Zn isotopic compositions as proxies of sources and metal transfers in the planktonic food webs from the Mediterranean Sea. Plankton was collected in spring 2019 in the deep chlorophyll maximum (DCM) along a North-South transect including coastal and offshore zones (MERITE-HIPPOCAMPE campaign). δ65Cu and δ66Zn were determined on four planktonic size fractions from 60 to 2000 μm. Combined δ65Cu and δ66Zn with geochemical tracers (Ti, particulate organic phosphorus) showed that geogenic particles were ubiquitous with plankton assemblages. The δ15N ecological tracer showed that planktonic food web was enriched in heavy isotopes of Cu and Zn in the higher trophic levels. δ65Cu were correlated with picoplankton in the offshore zone, and with zooplankton in the southern coastal zone. Firmicutes bacteria were found correlated with δ66Zn in northern and southern coastal zones suggesting decomposition of particulate matter at the DCM. These findings suggest that biogeochemical process may impact Cu and Zn isotopy in the planktonic community.

Hydrochemical Characteristics and Quality Assessment of Groundwater under the Impact of Seawater Intrusion and Anthropogenic Activity in the Coastal Areas of Zhejiang and Fujian Provinces, China

Abstract Coastal groundwater is an important resource in the developed region associated with human health and sustainable economic development. To identify the origins of salinity and evaluate the impact of water-rock interactions, seawater intrusion (SWI), and evaporation on groundwater in the coastal areas of Zhejiang and Fujian provinces, a comprehensive investigation was performed. Meanwhile, nitrate and fluoride indicators resulting from the anthropogenic activity and SWI were also considered. At last, the water quality index (WQI) of coastal groundwater was evaluated with geochemical and multivariate statistical methods. The results indicated that (1) the groundwater in coastal areas of Zhejiang and Fujian provinces has been affected by SWI to varying degrees. The analysis of selected ion ratios (Na+/Cl− and Br−/Cl−) and isotopic compositions showed that SWI is the predominant cause of increasing salinity in the groundwater of Zhejiang Province, while the cause is water-rock interactions (ion exchange and mineral weathering) in Fujian Province. The hydrochemical evolution path of groundwater in Zhejiang Province is Ca/Mg-HCO3 to Na-Cl, while a different pattern of Ca/Mg-HCO3 to Na (Mg/Ca)-Cl occurs in Fujian Province. However, the trend of SWI development in both provinces was freshening. (2) Nitrification, sewage infiltration, and SWI increased the NO3− content in groundwater. Some of the NO3− concentration in Fujian Province exceeds the standard, and the nitrogen pollution was more serious than in Zhejiang Province. The F− content in coastal groundwater was affected by SWI and mineral dissolution; the F− content in Zhejiang Province was higher than in Fujian Province, which was close to the groundwater standard limit. The average WQI value of Zhejiang was 103.61, and the WQI of Fujian was 61.69, indicating that the coastal groundwater quality in Fujian Province was better than in Zhejiang Province. The results of the study revealed the impact of SWI and anthropogenic activity on groundwater in the southern coastal zone of China and will be valuable for sustainable groundwater resource management.

Oceanographic and human impacts on the compositions of sedimentary organic matter along the southern coast of Zhoushan

Three sediment cores were collected from the southern coastal area of Zhoushan Island, and their lignin-derived phenol, bulk elemental composition, stable carbon isotope, particle size and 210 Pb activities were determined. The objective of this study was to determine the compositional changes of the sedimentary organic matter along this coastal area in the past 80 years as a result of anthropogenic and oceanographic-related processes. The results of this study showed that the sources and distribution of sedimentary organic matter along this coastal area were affected by the accelerated development on these islands and mainland China. Moreover, the increased contribution of terrestrial organic matter from the rivers in the mainland from the 1930s to the 1980s was likely the result of human activities. The drastic increase in the vanillic acid to vanillin ratio, (Ad/Al)v, in the 1970s and 1980s coincided with the start of rapid development in Zhoushan, resulting in the increased erosion of more degraded terrestrial organic matter along the coast. Trends of increasing marine organic matter toward the present could be due to a combination of reduced river input and sea level rise. Overall, our results showed that the sedimentary organic matter along the southern coastal zone of Zhoushan main island was affected by riverine input from the mainland, and showed a tendency toward decreasing terrestrial organic matter and particle size. Thus, local input and increased phytoplankton production will play a more important role in the carbon dynamics in this coastal area in the future. (245 words). • Sedimentary organic matter along the southern coast of Zhoushan main island was affected by human activities. • There was increased signal of marine organic matter due to sea level rise. • Decreased terrestrial organic matter and particle size toward the present could be due to river input from the mainland.

Adoption of Sustainable Dairy Management Practices among Peri-urban Dairy Farmers in Odisha

The research was based on a survey done in 2019 across Odisha’s eastern and southern coastal plain zones to assess sustainability among dairy farms based on various scientific management practices adopted by the farmers. The sustainability index was constructed using primary data acquired through a random sampling approach from 120 dairy households. The results reveal that 61 per cent of the farms belonged to the low sustainable category. The study area’s peri-urban dairy farms had inadequate shelter management, feeding, and animal health practices, as seen by their mean sustainable scores. Space constraints, dung disposal, lack of expertise in planned systematic breeding, paucity of green fodder, lack of refrigerated storage, and timely vaccination were all issues that farmers in the study area faced. These problems can be solved by organizing various capacity building training programmes, creating awareness about the benefits of following various scientific management practices, finding alternative supplements of green fodder as well as encouraging farmers to cultivate green fodder at a commercial level.

How does urbanization affect vegetation productivity in the coastal cities of eastern China?

Changes in terrestrial gross primary productivity (GPP) caused by rapid urbanization may result in negative effects on ecosystem services and ecosystem health. These impacts are of great concern in coastal zones where rapid urbanization is predominant. Knowing how urbanization affects vegetation productivity will be helpful for policymakers to make decisions on urban vegetation and ecosystem management. In this study, we chose 48 cities along the coastal zone of eastern China to evaluate the impacts of urbanization on vegetation GPP. The spatiotemporal comparison was used to identify the changes in built-up lands and vegetation GPP for multiple years (2000, 2005, 2010, and 2015). The area percentage of built-up lands was used to define the urbanization density. It was found that: (1) the actual vegetation GPP changed in different patterns with urbanization gradient from low to high intensity, including straight declining, depressed, and reversed S shapes at the city scale. The vegetation GPP change due to urbanization include both direct impact that is resulted directly from the loss of green land, and indirect impact that is induced by the change of macro-environment associated with urbanization. The slope of direct impacts change from low to high urbanization intensity were − 0.917, −0.925, −0.933, −0.938 for 2000, 2005, 2010, and 2015, respectively. The greater value means urban vegetation GPP loss faster as urbanization intensity increase. (2) A turning point on the maximum values for the indirect impacts was observed at approximately 0.8 of urbanization intensities, although it indicates both positive and negative value for the cities. However, no significant differences were observed for indirect impacts among provinces and coastal zones. The indirect impacts of urbanization on vegetation GPP were generally positive in the northern and middle coastal zones, and they were negative in the southern coastal zones. The results indicated that measures can be applied in the coastal cities in order to mitigate the negative impacts of urbanization on GPP. Our findings are helpful for policymakers to make decisions on urban planning and management.

The off-site implications of deforestation on sedimentation rates and pollution in Abkenar open water (Anzali Lagoon, Caspian Sea) using radionuclide techniques and sediment quality indices

Abkenar open water (AOW) has a 35 km2 distribution and is the largest part of the Anzali Lagoon in the southern coastal zone of the Caspian Sea. The effects of deforestation in the upstream basin of the AOW were assessed by measuring the rate of sedimentation, sediment contamination, and ecological risk for aquatic life and end-users using radioisotopes Cesium-137 and Lead-210. The chronology of the AOW sediment column was studied using the Constant Rate of Supply model. Correlations between environmental changes and the sedimentary regime of the study area highlight the contribution of the AOW authorized international and local wood harvesting companies pre-and-post 1950 in the catchment in terms of the rate of sediment supply and the influx of toxic metals. Historical evidence shows that two specific layers formed during World Wars I and II with the mean rates of 0.185 ± 0.04 (±STD) and 0.32 ± 0.02 kg/(m·y), respectively. The highest influx of alkali elements and toxic metals (nickel, cadmium, lead, zinc, and copper) into the basin occurred in 1945. Two layers of gray mud (16–50 cm) and organic-rich dark loss mud (0–16 cm) correlated well with the programmed wood harvesting projects. These layers accumulated from 1953 to 2000 with a mean rate of 0.6 ± 0.2 and 2 ± 0.7 kg/(m2·y). Thus, aquatic life and end-users have been exposed to moderate to extremely high levels of toxic metals and a moderate level of contamination since the 1950s.

Soil fertility status of coconut and arecanut growing soils

The present study was undertaken to assess the soil fertility status of major coconut and arecanut growing soils in different agro-climatic conditions of Karnataka. Based on the agro-climate variability, thirty typical soil pedons representing five different agro-climatic zones (ACZs) of Karnataka, namely, eastern dry zone (EDZ), southern dry zone (SDZ), southern transitional zone (STZ), hilly zone (HZ), and coastal zone (CZ) were studied for their physicochemical properties. The study revealed that soils of semi-arid (EDZ and SDZ) and sub-humid (STZ) zones have near neutral to moderately alkaline reaction and humid region soils (coastal and hilly zones) have high acidity. The soils are non-saline with low cation exchange capacity. Greater soil organic carbon was recorded in arecanut soils than coconut under all ACZs except coastal zone. The major nutrients status of the soil samples indicated that the available nitrogen is low in all the pedons; the pooled data of available nitrogen content was higher in arecanut (166.3 kg ha-1) than coconut (152.6 kg ha-1), and hilly zone soils recorded higher available nitrogen. A wide range of available P2O5 was noticed in coconut and arecanut soils, ranging from 1.0 to 64.2 kg ha-1. The coconut soils (11.5 kg ha-1) recorded higher available P2O5 than arecanut soils (9.62 kg ha-1) when data were pooled. The soils were low to medium in available potassium, and a higher available K2O content was recorded in arecanut soils (151.7 kg ha-1) compared to coconut (110.1 kg ha-1). The available K2O ranged from 66.8 to 511.7 kg ha-1 in the surface and 37.6 to 461.2 kg ha-1 in sub-surface soils.

The phenolic antioxidants of red wines from the southern coastal zone of Crimea: the role of the grape cultivar

The phenolic antioxidants of red wines from the southern coastal zone of Crimea: the role of the grape cultivar

Euphorbia tirucalli stem bark and phylloclades’ oil quality variability and implication for energy use

Liquid biofuels have emerged as a worldwide alternative fuel with potential to replace fossil fuels. Due to their wide availability as derivatives of organic materials from plants, they have attracted much attention and investment in developing countries including Tanzania, as alternative sources of energy. This study examined effects of oil quality from stem barks and phylloclades of Euphorbia tirucalli trees of different girth sizes (viz., 20 cm, 30 cm, 40 cm, 50 cm, 60 cm, 70 cm, and 80 cm) from semi-arid, coastal, and southern highlands in Dodoma, Dar es Salaam, and Mbeya Southern highland, agro-ecological zones in Tanzania. Using Soxhlet extraction method, oils were extracted from E. tirucalli stem barks with different girth sizes while oils from phylloclades were extracted from matured apical phylloclades collected from shoots of E. tirucalli trees from which the stem bark samples had been collected. Oil yields were determined by measuring the weight of oil (g) by the total weight of sample extracts used (20 g), and the average oil yield on each sample was determined. Oil quality was evaluated as oxidative stability index (OSI), acid values (AVs), and percent free fatty acids (%FFAs). Their results were then compared with the European Union (EU) oil quality standard specifications prescribed in EN 14214 of 6 h, 0.5 mg KOH/g, max and 0.020 maximum wt% limits, respectively. Differences in the quality of E. tirucalli (stem bark and phylloclades) oil were analyzed statistically with paired-sample t test (two-tailed) using the SPSS 15.0 software package. Results showed that the difference in OSIs from stem barks were not significantly higher (3–5 h) than phylloclades (3–4 h) at the p > 0.5 level. Also, the difference in AVs and %FFAs from the stem barks (7.6–7.4 mg KOH and 3.8–3.6%) was not significantly lower than those from the phylloclades (8.4–8.1 mg KOH and 4.3–4.0%) respectively. The quality of oil from stem bark and phylloclades samples at different stem girth sizes semi-arid agro-ecological zone was not significantly higher than from southern highland and coastal agro-ecological zones, respectively. Thus, there were no significant differences in the quality of E. tirucalli oil (stem bark and phylloclades) among stem girth sizes in different agro-ecological zones. The AVs and %FFAs of oils from stem bark and phylloclades were higher than the recommended standards, while the OSIs were below the biofuel standard limit. High AVs and %FFAs reduced oil quality by producing considerably low OSIs values than recommended standards. Finally, the study concluded that E. tirucalli oil requires purification to reduce levels of AV and %FFA contents so that the oil becomes suitable for application as liquid biofuel for energy generations.

Development of the sandy coast: Hydrodynamic and morphodynamic conditions (on the example of the Eastern Gulf of Finland)

Forecasting the coastal zone development under possible climatic changes and technogenic impact is an extremely important task. This forecasting is based on our understanding of the mechanism of the hydrodynamic processes impact on the coastal zone. The goal of this work is to describe the hydrodynamic conditions (currents, sea level, surface waves) of coastal waters and to assess the influence of hydrodynamic parameters on the general dynamics of the beach. The object of this study is a part of the southern coastal zone of the Gulf of Finland (Baltic Sea). The method of research is a full-scale experiment and mathematical modeling. The initial data for the analysis are climatic characteristics of the hydrodynamic regime of the sea (velocity and direction of currents, sea level, integral parameters of wind seas and swell), as well as interannual variations in the position of the coastline in the region of the Izhora village in the eastern part of the Gulf of Finland. Interannual variations in hydrodynamic parameters and volumes of bottom material transported under the influence of wind seas and swell were estimated. Main conclusion: swell waves determine the general background in the patterns of the bottom material transport, and the contribution of wind seas is in the formation of beach properties, namely, the accumulation or decrease of beach material.

Surface properties and changes in morphology of microplastics exposed <italic>in-situ</italic> to Chinese coastal wetlands

Coastal wetlands are key areas of accumulation of microplastics. However, until now only a few studies have focused on the surface properties and morphological changes in microplastics in the real coastal wetland environment. Here, two typical biogeographic coastal soils, the Yellow River Estuary salt marsh wetland in the temperate zone and the Beibu Bay mangrove wetland in the subtropical zone, were selected for study. Polystyrene foams and polyethylene films were used and exposed within two coastal wetlands sites through in situ soil burial (underground exposure) and surface placement (above-ground exposure). The samples were sampled after 6, 12, 18 and 24 months of exposure to reveal the characteristics of the surface properties and morphological changes in microplastics in typical wetlands from the southern and northern biogeographic coastal zones. The surface morphology, microstructures and attached materials were observed using scanning electron microscopy using an energy dispersive spectrometer. Surface properties of the microplastics, i.e. the surface roughness, specific surface area, pore size distribution, functional groups and hydrophobicity, were analyzed by using atomic force microscopy, a surface area analyzer, a mercury porosimeter, Fourier transform infrared spectrometry and a contact angle meter. The surface morphology of the polystyrene foams in the Beibu Bay mangrove wetland exhibited more pits and holes than those in the Yellow River Estuary salt marsh wetland. The polystyrene foams exposed above-ground in the Beibu Bay mangrove wetland showed embrittlement and exfoliation after 18 months, while those exposed underground did not show such features. The specific surface areas of the polystyrene foams and the polyethylene films in the Yellow River Estuary salt marsh wetland were higher than those in the Beibu Bay mangrove wetland. The pore distributions on the surfaces of the two microplastic types mainly comprised macropores and mesopores. However, the porosity of the polyethylene film in the Yellow River Estuary salt marsh wetland was slightly higher than in the Beibu Bay mangrove wetland. The porosities in both regions were higher than in the original control samples. In terms of carbonyl index, rates of change in the Yellow River Estuary salt marsh wetland were higher than those in the Beibu Bay mangrove wetland. The surface hydrophobicity of the polyethylene film in the two regions declined with increasing exposure time. The changes in surface morphology of the polystyrene foams were more rapid than those in the polyethylene films, but the degree of change in specific surface area of the polyethylene films was greater than in the case of the polystyrene foams. It can be concluded that the surface properties and changes in morphology of microplastics in the coastal soil environment are related to multiple factors including the types and conditions of the wetlands, types of microplastics, exposure mode and exposure time. However, the specific mechanisms of these surface changes require further study. In summary, this study provides a scientific basis for research on the chemical processes of the micro-interfaces on the microplastic surfaces and environmental behavior and risk assessment of microplastics in the Chinese coastal zone.