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The geographic distribution and occurrence conditions of Juniperus thurifera subsp. africana in Morocco were studied. The literature and herbaria data, together with field observations formed the basis of detailed maps of distribution of the species in the Middle and High Atlas and allow us to analyze its vertical distribution. The taxon occurs in the sub-arid and arid zones of the Middle and High Atlas with a separate population in the Anti-Atlas, mostly between altitudes 2000 and 2700 m, with an altitudinal maximum at 3400 m and a minimum at 1700 m. It forms forests in the area of about 30 000 ha. In many places of the High Atlas it is the only wood source for local populations. It is strongly endangered because of over exploitation of the wood, over pasturing and lack of seedlings and young specimens.
Spatial distribution of heathlands in Pomerania (the north-western part of Poland) was described based on the results of questionnaires sent out to the registered offices of all forest divisions (96), national (4) and landscape (15) parks of this area. According to the inventory, heathlands occur in 28 forest divisions and 3 national and landscape parks. The frequency of occurrence and the area covered by heathlands were determined. All the data were compiled in the form of a spatial database with the use of Geographic Information Systems. The paper also contains the geographical distribution of heath habitats in the area of Pomerania according to particular syntaxa. Additionally, the content of the database CORINE Land Cover was analysed at the third level for the area of Pomerania, completed for the years of 2000 and 2006. The area and the number of patches were described according to three land cover categories: heaths (code 322), conflagration sites (code 334) and peat bogs (code 412).
This paper discusses the status of Lecanora semipallida H. Magn. in Poland, with special emphasis to its known distribution. The species was fi rst reported from the area of Poland in the 19th century under the name ‘L. flotoviana Spr.’ and was neglected for over a century. Based on current study it is found to be a common, widespread species occurring on calcareous rocks and concrete in all kinds of environment; L. flotoviana Spreng. was not confi rmed as occurring in Poland.
Spatial statistics allows to assess geographic distribution of phenomena – its concentration, magnitude and orientation of dispersion as well regularity or trends in occurrence within a space. The paper presents adaptation of point-based methods to measure spatial distribution of areal phenomena that concern agriculture: area of agricultural land, area of fertile agricultural land and soil pH. The source data in a form of chorochromatic maps (e.g. a vector soil map) are processed to 1 x 1 km grid data with use of the algorithm created in Model Builder. The research area – Lower Silesia – characterizes various environmental conditions that results in changeability of agricultural land productivity. Spatial statistics performed for a whole region would bring only global information on spatial distribution. Hence the Authors propose to conduct analysis within subareas that depict local changeability of studied phenomena. As the research is conducted in agricultural context, the subareas of similar agricultural land areas are created regarding the administrative units. Spatial distribution is described by: mean centre, standard distance and standard deviational ellipse. All three measures are weighted by a variable (i.e. the intensity of the phenomenon) as spatial distribution is not only about location, but the value of the phenomenon in particular location is important. Measures of spatial distribution drawn on a map yields clear and usually easy to interpret information on spatial character of a phenomenon. In some cases it may be useful to present these qualitative characteristics complemented with another type of cartographic visualization (e.g. a choropleth map. This paper presents maps about the application of spatial distribution measures into assessment of agricultural land productivity in the research.
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Geographic distribution of Turkish oaks

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Distribution of Turkish Quercus L. has a crucial value since Turkey is a transition place between Europe and Asia and located at the meeting point of three phytogeographical regions. To compare the diversity of species and to find the distribution patterns of oaks, species richness of the most current distributions were studied. Relationships of phytogeographical regions and presence of the Anatolian Diagonal relevant to oak distributions were also investigated. Analyses were performed on Davis'grid square system. The highest richness of Quercus species were found at north-western Turkey which were located in the meeting place of Asia and Europe. The lowest richness scores were found at eastern and south-eastern Anatolia. Moreover, latitude, longitude and altitude histograms showed a correlation with species richness. However, the presence of Anatolian Diagonal is partially supported.
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