Piotr Migoń
Articles
Controlling factors limiting timberline position and shifts in the Sudetes: A review
Geographia Polonica (2015) vol. 88, iss. 2, pp. 55-70 | 
Full text
doi: https://doi.org/GPol.0015
Abstract
Three isolated massifs in the Sudetes, Central Europe, are elevated sufficiently high to allow for the development of the treeline ecotone. These are the Karkonosze/Krkonoše in the West Sudetes and Hruby Jeseník and Masyw Śnieżnika/Králický Sněžnik in the East Sudetes. The upper limit of closed tree stands (i.e. timberline) is locatedat c. 1250 m a.s.l. on average in the Krkonoše, but with significant variability spanning more than 500 m. In the East Sudetes the respective elevation is higher, above 1300 m a.s.l., and the variability is smaller. While temperature is the primary factor governing the uppermost tree stands, second-order climatic factors play an important role in shaping treeline ecotone position, particularly wind and snow accumulation patterns. Active surface processes such as debris flows and snow avalanches force the timberline to descend and account for its locally very irregular course. There is a history of long-term human impact on the position of the timberline, with its peak in the 17-19th centuries when high-mountain meadows were extensively used for grazing and haymaking. In the last century the overall trend of timberline ascent associated with abandonment of agricultural land and temperature rise has been interrupted by the episode of catastrophic forest decline due to air pollution.
Keywords: treeline ecotone, Karkonosze, Hrubý Jeseník, Masyw Śnieżnika, mountain ecology
, Department of Physical Geography and Geoecology Charles University in Prague Albertov 6, CZ-128 43 Prague: Czech Republic
[piotr.migon@uwr.edu.pl], Institute of Geography and Regional Development University of Wrocław pl. Uniwersytecki 1, 50-137 Wrocław: Poland
Geomorphic diversity of the Sudetes - effects of structure and global change superimposed
Geographia Polonica (2011) vol. 84, Special Issue Part 2, pp. 93-105 | Full text
doi: https://doi.org/GPol.2011.S2.7
Abstract
The Sudetes are mountains of outstanding geomorphic diversity. Reasons reside inlithological and structural variability of bedrock and protracted history of landscape evolutionspanning at least the entire Cenozoic. Over this time span, global changes have exerted a keycontrol on the geomorphic evolution of the Sudetes. Late Cenozoic mountain building in theAlpine-Carpathian region induced differential uplift of the Sudetes and radically changed itsgeomorphic environment, from one typified by a landscape of low relief to one of increasingrelief energy and accelerated erosion. Environmental changes were equally profound but theirgeomorphic effect is less obvious, except for the widespread presence of periglacial landformsof Pleistocene age and localized occurrence of glacial cirques and moraines in the KarkonoszeMts. At the same time, rock control on the location and shape of individual landforms is evidentand large tracts of the Sudetes may be described as having structural morphology. Therefore,unequivocal recognition of relief generations in the Sudetes is problematic.
Keywords: geomorphology, geodiversity, global change, rock control, the Sudetes
[piotr.migon@uwr.edu.pl], Institute of Geography and Regional Development University of Wrocław pl. Uniwersytecki 1, 50-137 Wrocław: Poland
Geographia Polonica (2008) vol. 81, iss. 1, pp. 101-116 | Full text
Abstract
The forested mountains ranges of the Bohemian Massif, including the Sudetes, typifymoderately high mountain geomorphology (Mittelgebirge). However, the most elevated partsof the Sudetes also have landscape elements more readily associated with high-mountain relief.These include sub-alpine meadows and bare regolith-covered slopes, a multitude of relict periglaciallandforms, as well as inherited Pleistocene glacial landforms. The present-day geomorphologicalactivity in the terrain located at and above the timberline is much more evident thanthat recorded in the lower forested belt. Debris flows triggered by occasional downpours arethe most potent geomorphic agents, also influencing hydrological conditions and vegetation patterns.Avalanches play a further role in determining the position of the timberline, but rockfallsare very rare. The contemporary development of certain small-scale periglacial landforms hasbeen recognized, and close correspondence is found to exist between the tiered structure of morphogeneticdomains recognized in the Carpathians and the highest massifs in the Sudetes.
Keywords: high mountains, geomorphology, glaciation, debris flows, Sudetes, Bohemian Massif
[piotr.migon@uwr.edu.pl], Institute of Geography and Regional Development University of Wrocław pl. Uniwersytecki 1, 50-137 Wrocław: Poland
Review
Environmental Change in Mountains and Uplands by M. Beniston, 172 pp., Arnold, London, 2000
Geographia Polonica (2001) vol. 74, iss. 2, pp. 91-94 | Full text
[piotr.migon@uwr.edu.pl], Institute of Geography and Regional Development University of Wrocław pl. Uniwersytecki 1, 50-137 Wrocław: Poland
Articles
Geographia Polonica (1992) vol. 60, pp. 123-136 | Full text
Abstract
Inselbergs are the most striking feature of the granite scenery of the Jelenia Góra Basin. They are either lithologically or fracture controlled. The former are built up of more resistant types of the granite (aplogranite, equigranular granite), while the latter reflect mostly the occurrence of domical structures. Therefore they could be considered as bornhardts. The properties of granite, which forms bornhardts indicate, that the selective deep weathering of Tertiary age following or accompanying by stripping was the most important morphogenetic process leading to the origin and exposure of the residual hills. After the exposure bornhardts were developed in changing morphoclimatic conditions. The formerly steep-sided, bare slopes were remodelled to the form of the boulder-controlled slopes due to strong physical disintegration of domes in the dry environments. The age of this process is probably Late Miocene. Both Pliocene and Pleistocene morphogenesis, which took place respectively in temperate and cold conditions, did not change the inselberg landscape considerably.
[piotr.migon@uwr.edu.pl], Institute of Geography and Regional Development University of Wrocław pl. Uniwersytecki 1, 50-137 Wrocław: Poland