Remotely sensed data fusion for spatiotemporal geostatistical analysis of forest fire hazard

Sakellariou, S., Cabral, P., Caetano, M., Pla, F., Painho, M., Christopoulou, O., ... Vasilakos, C. (2020). Remotely sensed data fusion for spatiotemporal geostatistical analysis of forest fire hazard. Sensors (Switzerland), 20(17), 1-20. [5014]. https://doi.org/10.3390/s20175014Forest fires are a natural phenomenon which might have severe implications on natural and anthropogenic ecosystems. Future projections predict that, under a climate change environment, the fire season would be lengthier with higher levels of droughts, leading to higher fire severity. The main aim of this paper is to perform a spatiotemporal analysis and explore the variability of fire hazard in a small Greek island, Skiathos (a prototype case of fragile environment) where the land uses mixture is very high. First, a comparative assessment of two robust modeling techniques was examined, namely, the Analytical Hierarchy Process (AHP) knowledge-based and the fuzzy logic AHP to estimate the fire hazard in a timeframe of 20 years (1996–2016). The former technique was proven more representative after the comparative assessment with the real fire perimeters recorded on the island (1984–2016). Next, we explored the spatiotemporal dynamics of fire hazard, highlighting the risk changes in space and time through the individual and collective contribution of the most significant factors (topography, vegetation features, anthropogenic influence). The fire hazard changes were not dramatic, however, some changes have been observed in the southwestern and northern part of the island. The geostatistical analysis revealed a significant clustering process of high-risk values in the southwestern and northern part of the study area, whereas some clusters of low-risk values have been located in the northern territory. The degree of spatial autocorrelation tends to be greater for 1996 rather than for 2016, indicating the potential higher transmission of fires at the most susceptible regions in the past. The knowledge of long-term fire hazard dynamics, based on multiple types of remotely sensed data, may provide the fire and land managers with valuable fire prevention and land use planning tools.publishersversionpublishe

Contribution of Agro-Environmental Factors to Yield and Plant Diversity of Olive Grove Ecosystems (Olea europaea L.) in the Mediterranean Landscape

Olive cultivation (Olea europaea L.) is one of the most significant sources of income for agricultural areas in the Mediterranean basin, and the olive oil industry as well as the environmental protection are an important part of the Greek agricultural sector. Generalized Linear Models were applied in order to investigate the predictive strength of several biodiversity components and agro-environmental factors for yield and herbaceous plant diversity (species richness) in organic and conventional olive groves of Greece. Our study highlights an increase in yields of organic olive groves by increasing manure application and the earthworms’ density. In the conventional olive groves, yields increase by increasing soil organic matter and the application of inorganic fertilizer N. Also, the herbaceous plant species richness increases with increasing the Shannon diversity index of herbaceous plants, the field area, the application of organic fertilizer K and the manure in organic olive groves. As for the conventional ones, herbaceous plant species richness increases with the increase of the application of inorganic fertilizer N. Moreover, some plant species could be regarded as indicators of the differently managed olive groves. Conclusively, this study contributes to the integration of biodiversity conservation with ecologically sustainable agriculture and conservation of agroecosystem. Finally, it could be utilized as a decision and management tool to the scientific and agricultural community reinforcing the knowledge about the agro-environmental impact in olive grove management systems

Contribution of Agro-Environmental Factors to Yield and Plant Diversity of Olive Grove Ecosystems (<i>Olea europaea</i> L.) in the Mediterranean Landscape

Olive cultivation (Olea europaea L.) is one of the most significant sources of income for agricultural areas in the Mediterranean basin, and the olive oil industry as well as the environmental protection are an important part of the Greek agricultural sector. Generalized Linear Models were applied in order to investigate the predictive strength of several biodiversity components and agro-environmental factors for yield and herbaceous plant diversity (species richness) in organic and conventional olive groves of Greece. Our study highlights an increase in yields of organic olive groves by increasing manure application and the earthworms’ density. In the conventional olive groves, yields increase by increasing soil organic matter and the application of inorganic fertilizer N. Also, the herbaceous plant species richness increases with increasing the Shannon diversity index of herbaceous plants, the field area, the application of organic fertilizer K and the manure in organic olive groves. As for the conventional ones, herbaceous plant species richness increases with the increase of the application of inorganic fertilizer N. Moreover, some plant species could be regarded as indicators of the differently managed olive groves. Conclusively, this study contributes to the integration of biodiversity conservation with ecologically sustainable agriculture and conservation of agroecosystem. Finally, it could be utilized as a decision and management tool to the scientific and agricultural community reinforcing the knowledge about the agro-environmental impact in olive grove management systems

Topsoil Seed Bank as Feeding Ground for Farmland Birds: A Comparative Assessment in Agricultural Habitats

The topsoil seed bank was studied in four types of agricultural bird habitats: fields with cereals, maize, clover and tilled fields of a Mediterranean plain to determine the potentially richest habitat based on food supply for the wintering farmland birds. The diversity and abundance of topsoil seeds differed between seasons but did not differ significantly between habitats. The cereal habitat was the richest in food supply for the overwintering of farmland birds. The topsoil seed bank was dominated by Chenopodium album, Polygonum aviculare and Amaranthus retroflexus. The findings of this study provide insight for low-intensity management of higher-elevation mount agricultural areas of southern Mediterranean by preserving seed-rich habitats for farmland avifauna

Enhancing Antioxidant Properties of <i>Prunus spinosa</i> Fruit Extracts via Extraction Optimization

Prunus spinosa fruit, commonly known as blackthorn or sloe, possesses a wide range of health-promoting properties, including antioxidant and antibacterial activities. In this study, we investigated the effects of various extraction parameters, such as temperature, time, and solvent composition, on the extraction of bioactive compounds from P. spinosa fruit. Response surface methodology was employed to optimize these parameters and evaluate their impact on the antioxidant properties of the extracts. Furthermore, techniques such as ultrasound (US) and pulsed electric field (PEF) were applied, both individually and in combination, to explore their potential effects on the extraction process. The optimal extraction technique proved to be the combination of PEF and US, followed by stirring. The most suitable solvent was 75% ethanol, whereas the optimum extraction time and temperature were 30 min and 80 °C, respectively. Our findings revealed that under the optimum extraction parameters, a significant improvement in the extraction efficiency of bioactive compounds from P. spinosa fruit was achieved. More specifically, the optimal conditions, according to partial least squares (PLS) analysis, were a combination of all three extraction modes (PEF-US-ST), the shorter extraction time of the present study (30 min), and the corresponding higher temperature (80 °C). As expected, the presence of ethanol was considered necessary, even in an amount of 25%. The total polyphenol content was found to be 30.74 mg gallic acid equivalent (GAE)/g, the total flavonoids content 3.23 mg rutin equivalents (RtE)/g and the total anthocyanins 125.2 μg cyanidin-3-O-glucoside equivalents (CyE)/g. HPLC-DAD analysis showed that neochlorogenic acid was the polyphenol with the highest concentration (4.13 mg GAE/g) in P. spinosa fruit. The antioxidant activity of the optimized, according to PLS analysis, extract was evaluated and found to be 146.09 μmol ascorbic acid equivalent (AAE)/g determined by ferric reducing antioxidant power (FRAP) assay, and by the radical scavenging activity (DPPH) assay was 18.56 μmol AAE/g. Additionally, the ascorbic acid was determined to be 119.4 mg/100 g. Overall, this study contributes valuable insights into the extraction optimization process and the potential applications of P. spinosa fruit in the development of functional foods and pharmaceutical products

Enhancing the Nutritional Profile of <em>Crataegus monogyna</em> Fruits by Optimizing the Extraction Conditions

Crataegus monogyna (CM) fruits are highly regarded for their rich nutritional content, boasting elevated levels of various beneficial secondary metabolites like total polyphenols, including anthocyanins, and ample amounts of ascorbic acid and antioxidant activity. Despite the acknowledged benefits of CM fruits, researchers have directed more attention toward its leaves and flowers. Consequently, the current research attempts to optimize extraction techniques for CM fruit using a multifaceted approach involving varied durations, temperatures, and concentrations of ethanol solvent to isolate the diverse range of bioactive components present effectively. High-performance liquid chromatography coupled with a diode array detector (HPLC-DAD) is employed for the identification and quantification of polyphenolic compounds. According to the results, by following the optimum extraction parameters (50% ethanolic solvent, 50 °C extraction temperature, and 60 min extraction time), the total polyphenol content can be increased up to 410%, reaching 55.59 mg gallic acid equivalents/g. Using 50% ethanolic solvent, 80 °C extraction temperature, and extraction time of 90 min, the total anthocyanin content can be enhanced by more than 560%, reaching a quantity of 51.83 μg cyanidin equivalents/g. Moreover, the antioxidant activity of CM fruit extracts can reach 415.95 μmol ascorbic acid equivalents (AAE)/g dw (by FRAP method), using 50% ethanolic solvent, 50 °C extraction temperature, and 60 min extraction time, and 270.26 μmol AAE/g dw (by DPPH method) and 1053.28 mg/100 g dw ascorbic acid content, using 50% ethanolic solvent, 80 °C extraction temperature, and 90 min extraction time. This comprehensive study seeks to augment the already substantial content of bioactive compounds found in CM, resulting in an extract with promising applications across the pharmaceutical, food, and cosmetics industries

Broad‐front migration leads to strong migratory connectivity in the lesser kestrel (Falco naumanni)

Aim: Migratory animals regularly move between often distant breeding and non‐breeding ranges. Knowledge about how these ranges are linked by movements of individuals from different populations is crucial for unravelling temporal variability in population spatial structuring and for identifying environmental drivers of population dynamics acting at different spatio‐temporal scales. We performed a large‐scale individual‐based migration tracking study of an Afro‐Palaearctic migratory raptor, to determine the patterns of migratory connectivity of European breeding populations. Location: Europe, Africa. Methods: Migration data were recorded using different devices (geolocators, satellite transmitters, Global Positioning System dataloggers) from 87 individuals breeding in the three core European populations, located in the Iberian, Italian and Balkan peninsulas. We estimated connectivity by the Mantel correlation coefficient (rM), and computed both the degree of separation between the non‐breeding areas of individuals from the same population (i.e. the population spread) and the relative size of the non‐breeding range (i.e. the non‐breeding range spread). Results: European lesser kestrels migrated on a broad front across the Mediterranean Sea and Sahara Desert, with different populations using different routes. Iberian birds migrated to western Sahel (Senegal, Mauritania, western Mali), Balkan birds migrated chiefly to central‐eastern Sahel (Niger, Nigeria, Chad), whereas Italian ones spread from eastern Mali to Nigeria. Spatial differentiation of non‐breeding areas led to a strong migratory connectivity (rM = .58), associated with a relatively high population (637 km) and non‐breeding range (1,149 km) spread. Main conclusions: Our comprehensive analysis of the non‐breeding distribution of European lesser kestrel populations revealed a strong migratory connectivity, a rare occurrence in long‐distance avian migrants. The geographical conformation of the species’ breeding and non‐breeding ranges, together with broad‐front migration across ecological barriers, promoted the differentiation of migratory routes and non‐breeding areas. Strong connectivity could then arise because of both high population spread and broad non‐breeding range.CLH; FCC Energía/Enerstar Villena S.A.; Alcalá de Henares Municipality; EDF Énergies Nouvelles S.A.; EuroNatur; Fundación Iberdrola España, Grant/Award Number: Project Migra; MAVA Foundation; French Ministry of Ecology, Grant/Award Number: Lesser Kestrel National Action Plan; Greek Green Fund; European Commission, Grant/Award Number: LIFE11 NAT/IT/000068, LIFE11 NAT/BG/000360 and NAT/GR/001011; Córdoba Zoo; Seiit‐R‐4; Consejería de Agricultura, Medio Ambiente y Desarrollo Rural de Castilla‐La Mancha; MIUR, Grant/Award Number: PRIN 2010‐2011/20180‐TZKHC