The Influence of Position and Site on the Height Growth of Young Populus tremula L. Ramets in Low Elevation Formations in Northeastern Greece

This study was carried out in the central part of Nestos Valley in northeastern Greece. The main objective was to examine the effect of different position (dominant, suppressed, side-shaded) and site productivities on the height growth of young Populus tremula L. clonal ramets in low elevation formations of the species. Fifty-four ramets growing in different positions and sites were cut and studied. Stem analysis was conducted and the height of each ramet at the age of 10 years was calculated. The main results of this research indicate that the dominant ramets on good productivity sites have greater height at the age of 10 years, when compared with the corresponding ramets on medium productivity sites. On the contrary, in suppressed and side-shaded ramets, there is no statistically significant difference in height at the age of 10 years between the two site types. This pattern indicates that competition is the procedure that characterizes the relationships between ramets in the investigated formations. The heights of dominant P. tremula ramets presented in this study are very satisfactory for the species, compared with the height of P. tremula trees from other regions of the species expansion reported in other studies

Regeneration Αnalysis of the Juniperus excelsa Mixed Stands in Prespa National Park of Greece as a Base for the Assessment of the Appropriate Silvicultural Treatment for the Conservation of the Species

Analysis of the regeneration of mixed stands of Juniperus excelsa (Greek juniper) in Prespa National Park revealed two distinct structural types: a) stands with small gaps, and b) stands without gaps. Fifteen 500-square-meter sample plots were established in each structural type. All plant species were counted in each plot, and Greek juniper plants were classified into two groups based on their regeneration status. Plants that have been established and grow under the facilitation of other plants fall into the first group, while those that have been established and grow in light, in canopy gaps, belong to the second. Regarding the regeneration of Greek juniper in the Greek juniper mixed stands with small gaps, facilitation is not the primary mechanism at work. There are less Greek juniper regeneration plants in the gap-free structural type, compared with the small-gap type. Greek juniper regeneration plant density will decrease if gaps close. Finally, in both structural types, the other species\u27 regeneration plants exhibit higher density than those of Greek juniper. Creating gaps around Greek juniper trees by extensive intervention is one of the most successful ways for the forest practice to protect the Greek juniper mixed stands

Assessment of How Natural Stand Structure for Narrow Endemic Cedrus brevifolia Henry Supports Silvicultural Treatments for Its Sustainable Management

Cedrus brevifolia Henry is a narrow endemic tree species of Cyprus flora. The objectives of this study are to develop silvicultural treatments for the conservation of the species formations based on the stand structure analysis of C. brevifolia natural forest and to present the characteristics of the first application of the treatments through silvicultural interventions. Six structural types were distinguished in C. brevifolia formations in the study area located in the state forest of Paphos. For each structural type, six circular plots of approximately 500 m2 were established. In each plot, various measurements and estimations were recorded. Then, silvicultural interventions were applied in the plots of the mixed C. brevifolia formations. In the formations of C. brevifolia a great number of trees grow in the understory. In the very productive and in the poorly productive sites C. brevifolia occurs only in pure formations. The basal area of C. brevifolia in pure formations ranges from 19.04 m2·ha-1 in poorly productive sites to 38.49 m2·ha-1 in fairly productive sites. Cedrus brevifolia is the most competitive species of the study area as a result of both shade tolerance and the wide range of its site sensitivity behavior. The climax of the study area are the pure stands of C. brevifolia having an understory of Quercus alnifolia Poech and a sparse occurrence of Pinus brutia Ten., mainly in moderately productive sites. Forest practice has to, as much as possible, unite species formations in order to create extensive areas of C. brevifolia formations

Electrical Characterization of Circulation Weather Types in Northern Spain Based on Atmospheric Nanoparticles Measurements: A Pilot Study

The electrical component of the atmosphere is a key element to understand bio-effects of atmospheric processes. In this paper an attempt was made to find possible interactions between air masses arriving in Santander, Northern Spain, and electrical properties of nanoparticles measured in this zone. A methodological approach is proposed to characterize electrically the predominant weather types in the study area. An electrical low pressure impactor device (ELPI +) was used to measure atmospheric particles net charge and particle net charge distribution in real time in July 2018, among other parameters. Data from two specific channels [0.054?0.071 lm] and [2.5?3.0 lm] has been initially used. Atmospheric circulation was defined attending to two, subjective and objective, weather type classifications. Back trajectories of nanoparticles were also computed by the Hybrid Single-Particle Lagrangian Integrated Trajectory model. Results confirm that atmospheric nanoparticles charge varies according to their size. The highest mean absolute charge is associated with local circulation in Santander for both channels. The studied nanoparticles show a quicker reaction to weather conditions than microparticles. They also have a significant correlation with meteorological variables for 18 synoptic groups found, but humidity. Microparticles [2.5?3.0 lm] are negatively related with air humidity, mainly with S-SE circulation pattern.Authors would like to thank Dekati Ltd. for providing the instrument used in this study through the company SOLMA Environmental Solutions SLU. Authors would like to thank NOAA Air researches Laboratory (ARL) for the provision of FNL-HYSPLIT data, the Hysplit transport and dispersion Model, and, the READY web site used in this publication. Also authors acknowledge Cost Action 15211, Atmospheric Electricity Network: coupling with the Earth System, climate and biological systems, for funding a STSM of Prof. P. Kassomenos at the Geobiomet research group at the University of Cantabria, Santander. Authors would like to thank to support from the Spanish National Research Agency – Project CSO2016-75154-R and the European Funds for Regional Development (FEDER)

Higher education in Constantinople in the 15th c.

This PhD thesis aims to examine and present the education system in Constantinople in the 15th c. The Byzantine Empire was dying while the Ottoman danger was already ante portas. However education and the study of the classical works was thriving and flourishing. What were the reasons for this phenomenon? The thesis is separated in two parts: the first part is consisted by four chapters and the second part by two, while three Appendices have been added at the end. The first part examines the Byzantine education in Constantinople from the ascension of Manuel II Paleologos to the byzantine imperial throne (1391) until the first decades under the Ottoman rule after the fall of 1453. The various schools around the capital are being identified along with the scholars and teachers who worked there. In addition, the first part examines the phenomenon of the arrival of the Italian humanists to Byzantium in order to learn the Greek language and Paideia, a phenomenon which caused the transportation of the ancient Greek knowledge to the West, along with the existence of the Patriarchical school, the continuation of the previous Byzantine schools, in Constantinople after 1453. The second part focuses on the more practical subjects of the Byzantine education such as the various school textbooks/manuscripts, which were used during the 15th c. It examines the teaching of each scientific subject of the Trivium and Quadrivium separately along with the reconstruction of the various libraries, which were established in the byzantine capital (Imperial and Patriarchical libraries, monastic libraries, private libraries). The completions of the PhD thesis was based on the examination of the various manuscripts, in the most of the cases in situ, which were connected with the byzantine education curriculum according to their content, their scholia and their interlinear glossae. At the same time, the correspondences of the various scholars of the period were considered along with the other contemporary works. In addition, the rich secondary bibliography helped for a more complete overview of the period. In conclusion, the well-educated Emperor Manuel II Paleologos and his scholar circle gave a new thrust to the education system at the capital after the first years of the 15th c. In addition, the defeat of the Ottomans at the battle of Ankara (1402), which gave a short relief to the byzantine capital, and the close connections of with the West (council of Ferrara-Florence - 1438-39) which caused the arrival of new wealthy Italian students to Constantinople, strengthened even more this last Palaeologan «Renaissance». The Greek Paideia gained the opportunity not only to spread to the West but also to survive at the new Ottoman capital.Η παρούσα διδακτορική διατριβή έχει ως στόχο εξέταση και παρουσίαση του συστήματος της Παιδείας στην Κωνσταντινούπολη τον 15ο αι. Πρόκειται για ένα desideratum της έρευνας έως τώρα κυρίως λόγω της παραδοξότητας της περιόδου που εξετάζει. Συγκεκριμένα, αν και κατά τον 15ο αι. η Βυζαντινή Αυτοκρατορία πνέει τα λοίσθια και ο Οθωμανικός κίνδυνος είναι ήδη προ των πυλών, η εκπαίδευση και η παιδεία ανθούν εντός της πρωτεύουσας. Ποιοί λόγοι συνέτειναν σε αυτό και πως επιτελείται αυτή η ύστατη πνευματική αναγέννηση; Η εργασία χωρίζεται σε δύο μέρη όπου το πρώτο κεφάλαιο αποτελείται από τέσσερα κεφάλαια και το δεύτερο από δύο, ενώ συμπληρώνεται με τρία παραρτήματα στο τέλος. Στο πρώτο μέρος εξετάζεται η πνευματική ζωή και η παιδεία στην Κωνσταντινούπολη από την άνοδο του Μανουήλ Β' στον αυτοκρατορικό θρόνο (1391) μέχρι και τις πρώτες δεκαετίες μετά την άλωση του 1453. Εντοπίζονται τα διάφορα σχολεία εντός της Πόλεως όπως επίσης οι λόγιοι και οι διδάσκαλοι που έδρασαν σε αυτά. Εξετάζεται το φαινόμενο της αφίξεως των Ιταλών Ουμανιστών στην Κωνσταντινούπολη με σκοπό να γίνουν μέτοχοι της ελληνικής παιδείας, γεγονός το οποίο θα ανοίξει τις πόρτες για τη μεταφορά της κλασσικής γραμματείας και παιδείας στη Δύση, όπως επίσης και τη συνέχεια της διδασκαλίας του βυζαντινού εκπαιδευτικού curriculum μέσω της Πατριαρχικής Σχολής μετά την άλωση. Το δεύτερο μέρος ασχολείται με πιο πρακτικά θέματα του αντικειμένου της παιδείας και εστιάζει στον εντοπισμό των διαφόρων διδακτικών εγχειριδίων-χειρογράφων μέσα από διάφορες συλλογές και βιβλιοθήκες, τα οποία χρησιμοποιήθηκαν κατά την εκπαιδευτική διαδικασία της περιόδου που εξετάζουμε.Εξετάζεται η διδασκαλία κάθε επιστημονικού αντικειμένου του Trivium όσο και του Quadrivium ξεχωριστά ενώ παράλληλα γίνεται μια προσπάθεια ανασύστασης των διαφόρων βιβλιοθηκών που υπήρχαν στην πρωτεύουσα τον 15ο αι. (Αυτοκρατορική, Πατριαρχική, Μοναστηριακές, Ιδιωτικές). Η σύνθεση της διατριβής στηρίχθηκε κυρίως στην εξέταση των διαφόρων χειρογράφων που παρουσιάζουν σχέσεις με την βυζαντινή εκπαιδευτική διαδικασία σύμφωνα με το περιεχόμενο τους, τα παρασελίδια σχόλια τους και τις διάστιχες γλώσσες τους. Παράλληλα μελετήθηκαν οι αλληλογραφίες των λογίων της περιόδου όπως και τα λοιπά σύγχρονα τους έργα. Τέλος η πλούσια δευτερεύουσα βιβλιογραφία βοήθησε ως προς την ολοκληρωμένη εξέταση της περιόδου. Συμπερασματικά, η λόγια προσωπικότητα του Αυτοκράτορα Μανουήλ Β' μαζί με τον πνευματικό αυτοκρατορικό κύκλο λογίων που το περιστοίχιζε έδωσαν μια νέα ώθηση στον τομέα της παιδείας στην πρωτεύουσα, ιδιαίτερα από τις αρχές του 15ου αι. Παράλληλα, η ήττα των Οθωμανών στην μάχη της Άγκυρας το 1402 που είχε ως αποτέλεσμα την προσωρινή ανακούφιση της Κωνσταντινούπολης όπως επίσης και οι στενές επαφές με τη Δύση (βλ. σύνοδος Φεράρας-Φλωρεντίας στα 1438-1439) που είχαν ως αποτέλεσμα την άφιξη νέων ξενόγλωσσων πλουσίων μαθητών από τη Δύση στην πρωτεύουσα, ενίσχυσαν ακόμη περισσότερο αυτή την ύστατη πνευματική Παλαιολόγεια Αναγέννηση. Όλα τα προαναφερθέντα υπήρξαν αρκετά για τη συνέχεια της ελληνικής παιδείας τόσο στην Ιταλική Δύση όσο και στην Οθωμανοκρατούμενη πλέον Κωνσταντινούπολη

Analysis of the Environments Where Natural Regeneration Is Established in the Absence of a Wildfire in the Open <i>Pinus brutia</i> Forests in the Middle Elevations of the Central Part of Cyprus

The objective of this research was to analyze the P. brutia natural regeneration and the environments where it was established in the absence of a wildfire in the open formations of the species in the middle elevations of the central part of Cyprus. Forty-eight rectangular plots of 0.1 ha were established in three site productivity types. Individuals of the species with a height from 0.1 m to 1.5 m were considered regeneration plants. Within each plot, various measurements and estimations were made. Moreover, 480 hemispherical photographs were taken. Additionally, hemispherical photographs were taken above each of the recorded naturally regenerated P. brutia plants. In all the site productivity types, the most regeneration plants were established and grew under the process of facilitation. In each of the site productivity types, there were no differences in the light condition diversity between the environments where the regeneration plants grew and the existing light conditions. Regeneration exhibited a small number of plants and constituted only a very small proportion of all trees in the three site productivity types. To achieve sustainability in P. brutia forests, forest practices must develop strategies for the enhancement of P. brutia regeneration in the studied area and in analogous environments

Comparison of the Stand Structure Diversity of Open <i>Pinus brutia</i> Ten. Forests in Areas of Different Productivity in Central Cyprus

The goal of this study is to compare the diversity of the stand structure of open P. brutia forests in areas of different productivity at middle elevations in central Cyprus. This will help us figure out how much biodiversity they can hold. Two plots of 4 ha were randomly established. One 200 m × 200 m square-shaped plot was established in a P. brutia formation in a medium productivity site, and one in a P. brutia formation in a bad productivity site. In each plot, dendrometrical data were recorded. In total, 160 hemispherical photographs were taken on both plots. The stand structure is more heterogeneous and complex at medium productivity sites compared to bad productivity sites. P. brutia formations in medium productivity sites can support greater biodiversity than the corresponding formations in bad productivity sites. In the open P. brutia formations of central Cyprus, forest practice must aim to increase the density of P. brutia trees in some tree groups to reduce light intensity under the group canopy. Moreover, trees with large diameters and/or heights must be protected from disturbances. This approach will increase the ability of formations to support biodiversity

Strategic decision-making processes, international environmental munificence and the accelerated internationalization of SMEs

Motivated by the paucity of studies examining the effects of strategic decision-making processes on accelerated internationalization, this study draws on the organizational information processing theory and the resource-based view of the firm to argue that procedural rationality and politicization have a negative effect on accelerated internationalization of SMEs. Using a sample of 176 internationalized Greek SMEs, the study finds that the procedural rationality and politicization of SMEs reduce the probability of accelerated internationalization. These relationships are more pronounced in munificent international environments, indicating that when accelerated internationalization is constrained by strategic decision-making processes, SMEs may miss opportunities in attractive international markets. The study contributes to the organizational information processing theory, to the literature on the speed of decisionmaking in SMEs, and to the literature on accelerated SME internationalization

Economic Consequences of Coronavirus Disease (COVID-19) on Fisheries in the Eastern Mediterranean (Cyprus)

Fisheries are among the sectors hardest-hit by the coronavirus pandemic (COVID-19) crisis due to the sudden decrease in the demand for seafood. This study employs demand-driven and supply-driven input-output models to conduct an economy-wide assessment of the contraction of the fisheries activities in Cyprus, as well as a questionnaire survey to reveal fishermen&rsquo;s perceptions of COVID-19 crisis impacts. The results at the macroeconomic level reveal that the contraction in the economic output of the fisheries sector does not have any significant impact on the wider economy due to the small size of the sector. However, the COVID-19 crisis has major negative effects on fishermen&rsquo;s income and the livelihoods of fishers&rsquo; households. The average gross margin of the interviewed fishermen for March 2020, i.e., the month where a national quarantine and lockdown was imposed, was four times less the average monthly gross margin for the winter period (December 2019&ndash;February 2020) and 2.5 times less compared to the average monthly gross margin of 2019. The recessionary impacts of the COVID-19 crisis in conjunction with the chronic challenges that fisheries are currently facing in Cyprus, negatively affect the viability of the sector