Effects of deforestation and afforestation on climate

Forests cover 29% of the continents. Their importance for mankind is not only due to wood production but also by their manyfold influences on the biosphere. The properties of forest stands influence climate, water balance, air constituents and the dynamic of atmosphere. The welfare functions of forests can be observed in the global as well as in the local or microscale. Anthropogenic measures, as deforestation and air pollution, endanger the forests and by that one of the main pillars of nature on earth.     

Recent trends of urban development and town planning in Spain

With the socio-economic change from rural to industrial, Spain has experienced an enormous urbanisation boom during the last 20 years. This has produced a concentration of high-rise apartment blocks not only in the big cities but also in medium-sized towns and even within the medieval town centres. More astonishing, compared with Central Europe, seems however, the spatial distribution of the social classes which, with a centre-periphery gradient, still corresponds to the model of the pre-industrial town. The paper investigates the impact of town planning, house building policy, and behavioural aspects on these structural patterns.     

The Danube-Black Sea Canal and its impact on Southern Romania

The Romanian Danube-Black Sea Canal, opened in 1984, is the latest development in the European network of Class 6 waterways. Construction began in 1978 and involved the mobilisation of labour and equipment on an unprecedented scale to expedite work in four construction zones between the Danube at Cernavoda and the Black Sea at South Constanta-Agigea. The paper outlines the construction work and also discusses three other themes. First the history of abortive canal projects which extends back for more than a century, including the notorious scheme of 1949–1953 in the Stalin era, which has to be seen in the context of available waterways through the Danube delta and a complex of economic, political and technical issues. Second the interest of the present Romanian government in pressing ahead with the project at a time of severe economic difficulty: the changing economic geography of the country is thoroughly examined. And third the likely impact of the canal which is very difficult to assess in an international context in view of the alternative route through the Danube delta at Sulina. However the hinterland of Constanta has been greatly improved and further canal schemes in Romania will generate more traffic for water transport in the years ahead.     

The effect of climate on the growth of early maize at Kabba,Nigeria

This study attempts regression/correlation analysis between maize yield and weather variables based on data analysed for the entire growing season and the different physiological stages of the crop's growth for Kabba in the wet sub-humid climate of Nigeria. The implications of the relationships obtained are examined for maize growth at the station.     

Land use history of Jebel Marra,Sudan, as related to the present distribution of woody vegetation

This study attempts to relate vegetation distribution to land use history in Jebel Marra, the Democratic Republic of the Sudan. There are evidences that most,if not all, of the woody vegetation communities in Jebel Marra have been derived from some more complex types by continuous disturbance ssince antiquity. Here past and contemporary land use types are described and associated to woody plants distribution. Empirical stratified sampling methods of plant geographers and ecologists are applied to both natural and artificial systems. Frequencies, densities and diversities for all woody plant communities are estimated by standard ecological indices. It was found that throughout known history woody plant communities were subjected to different degrees of suppression. Thus, the present distribution of the woody plant communities reflects the different stages as well as modes of suppression. Drastic population movements and the resulting changes in land use types since antiquity, seem to be the chief explanation behind the variations in modes of suppression.     

Problems of the „Pannonian Median Massif“ and the plate tectonic concept. Contributions based on the distribution of Late Paleozoic — Early Mesozoic isopic zones

After a short historical review of conceptions about the Pannonian Median Massif or Tisia, the distribution of Middle-Upper Carboniferous and Lower Triassic-Liassic facies is briefly examined on the two sides of the Zagreb-Zemplin line dividing into two main segments the basement of the Carpathian basin. It shows on the one hand, that the Igal-Bükk zone (Igal-Bükk eugeosyncline ofWein, 1969), thought to establish a connection between the NW-Dinarides and the Dinaric-type Bükkium, is only a tectonic zone and could never have been a paleogeographical unit. On the other hand, the northern, marginal part of Tisia (Mecsek-Bihor crystalline belt and its sedimentary cover;Dank &Bodzay, 1971) exhibits a development and facies characteristic of the northern (northeastern) marginal complex of the Tethys. Also, facies-transitions from the foreland toward the open sea are always of N S direction. All autochthonous explanations must face the striking differences along the Zagreb-Zemplin line, which seem to exclude the possibility that the northern part of Tisia was a central, partly emerged crystalline ridge (no facies-transitions toward N!); it was rather part of the northern (northeastern) marginal complex of Tethys. Therefore allochthonous models suggesting largerscale horizontal movements give a much more plausible explanation. The style of Late Hercynian development and the distribution of Lower Triassic-Liassic facies zones suggest, that Tisia was part of the northern (northeastern) shelf of the Tethys until the end of the Liassic (in accordance with the opinion ofBleahu), then split off and was wedged in by horizontal movements between the NW-Dinarides and the Dinaric-type Bükkium by the end of the Jurassic — beginning of the Cretaceous.

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Zusammenfassung Nach einem kurzgefaßten historischen Überblick zur Deutung des Pannonischen Massivs oder Tisia wird die Verteilung der Fazies von Mittel- und Oberkarbon sowie Untertrias bis Lias auf den beiden Seiten der Zagreb-Zemplin-Linie — welche den Untergrund des Karpatenbeckens in zwei Abschnitte zerteilt — kurz untersucht. Sie zeigt einerseits, daß die Igal-Bükk-Zone (die Igal-Bükk Eugeosynklinal vonWein, 1969)-welche eine Verbindung zwischen den NW Dinariden und dem dinarisch-typischen Bükkium darstellen soll — nur eine tektonische Zone ist, hingegen nie eine paleogeographische Einheit gewesen sein kann.Der nördliche, äußerste Teil des Tisia (Mecsek-Bihor kristalliner Gürtel und seine sedimentäre Decke;Dank u.Bodzay, 1971) weist eine Ausbildung und Fazies auf, welche für den nördlichen (nordöstlichen) marginalen Komplex der Tethys typisch ist. Auch Faziesübergänge vom Vorland in der Richtung der offenen See sind immer N S gerichtet. Alle Erklärungen, die eine autochthone Lage der Zonen entlang der Zagreb-Zemplin-Linie mit einbeziehen, müssen mit der Tatsache fertig werden, daß der nördliche Teil der Tisia einen zentralen Teil eines teilweise emporgehobenen Kristallinrückens darstellt (kein Faziesübergang nach Norden). Sie war eher Teil der nördlichen (nordöstlichen) marginalen Serie der Tethys. Daher erscheinen allochthone Modelle, welche horizontale Bewegungen in größerem Maßstabe andeuten, eher glaubwürdig zu sein. Der Stil der spätherzynischen Entwicklung und die Verteilung der Fazieszonen von Untertrias bis Lias deuten an, daß der Tisia Teil der nördlichen (nordöstliche) Shelf der Tethys bis Ende Lias war (übereinstimmend mit der Meinung vonBleahu 1976); dann spaltete er sich ab und keilte sich mit horizontalen Bewegungen zwischen den NW Dinariden und dem Bükkium dinarischen Types ein; dies könnte Ende Jura-Anfang Kreide stattgefunden haben.

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Résumé Après une brève revue historique des conceptions sur la »Masse médiane pannonienne« ou la »Tisia«, on examine brièvement la distribution des facies du Carbonifère moyen-supérieur et du Trias-Lias aux deux cotés de la ligne de Zagreb-Zemplin divisant le soubassement du Bassin Carpathique en deux ségments principaux.Ce qui est démontré, c'est d'une part que la zone Igal-Bükk (le »géosynclinal Igal-Bükk«, Wein, 1969), considérée comme l'établissement d'une communication entre les Dinarides du NW et le Bükkium de type dinarique, ne représente qu'une zone tectonique, mais qu'elle ne peut jamais être une unité paléogéographique. D'autre part la partie septentrionale, marginale de la »Tisia« (la ceinture crystalline de» Mecsek-Bihor« et sa couverture sédimentaire; Dank-Bodzay, 1971) présente un développement et un faciès caractéristique du complexe marginal septentrional (nordoriental) de la Téthys. Les transitions de faciès de l'avant-pays vers la mer ouverte sont également de direction N-S. Toutes les explications autochtonistes doivent faire face aux différences accentuées le long de la ligne Zagreb-Zemplin, ce qui semble exclure la possibilité que le Nord de la »Tisia« ait été une dorsale cristalline centrale, émergée (aucune transition de faciès vers le N!); elle a fait plutôt partie du complexe marginal du N (NE) de la Téthys. C'est pourquoi les modèles allochtonistes suggérant des mouvements horizontaux plus vastes donnent une explication plus plausible. Le style du développement éohercynien et la distribution des zones faciales du Trias inférieur-Lias suggèrent que la »Tisia« a fait partie du shelf septentrional (nordoriental) de la Téthys jusqu'à la fin du Lias (en accord complet avec l'opinion de Bleahu, 1976) et qu'ensuite elle s'était décollée et coinné par des mouvements horizontaux entre les Dinarides du NW et le Bükkium de type dinarique vers la fin du Jurassique et le début du Crétacé.

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Because of shortage of place, only some of the most important non-Hungarian literature and the latest Hungarian works concerned with this region are listed up here: for a more detailed list of reference the reader is referred to the papers ofBalogh (1972) andKovács (1980).