Stanisław Kędzia

Abstract

The paper presents problems faced when using a new method for defining the growth curves of the thalli of the rockylichen Rhizocarpon spp in the Polish section of the Tatra and Karkonosze Mountains. Lichenometric curves based onpre‑existing data were defined for two climatic‑vegetation zones in the Tatra Mountains. These were mainly representativeof substrates located in the central parts of these zones. In the new lichenometric curve which was constructed forthe Tatra and Karkonosze Mts., the thallus growth curve for the first 100 years was defined in a linear manner in relationto altitude. Therefore the curve can be easily used for dating items located in any part of the altitude zone for which thecurve was defined. The paper also tackles the problem regarding the number of thalli that should be assessed when dating. An approach which assesses a certain number of the largest thalli of a similar diameter seems to be the most suitable for small‑scale landforms (with small numbers of thalli) which were formed during one event. The shape of the thallus growth curve is strongly influenced by the landforms (either convex or concave) and the vertical extent of the zone in which the measurement is performed. The presence of multiannual snow patches in close proximity and air pollution also influence thallus growth onthe mountains investigated. The geomorphic processes taking place turned out to be a significant problem for proper dating of the items – depending on their interpretation they can either help dating or obscure the reconstruction of the event.

Keywords: Rhizocarpon, lichenometry, Tatra Mts., Karkonosze Mts.

Stanisław Kędzia [kedzia@zg.pan.krakow.pl], Institute of Geography and Spatial Organization Polish Academy of Sciences, Św. Jana 22, 31-018 Kraków, Poland

Abstract

In the hitherto works concerning the course of the upper tree-limit or mountain pine-limit and their relation with mean annual temperature, the limits of vegetation horizons were determined much more precisely than the location of isotherms - the latter were determined bas-ing on interpolation and extrapolation of data from meteorological stations. Thanks to the applica-tion of Onset HOBO data loggers, the measurements of air temperature were carried out in select-ed sites at the upper tree-limit in Sucha Woda Valley in the Tatra Mountains. The measurements were conducted every hour during 4 months in warm period in 2007. The measurement sites were located in different land reliefs of different exposition. The lowest temperature was recorded in the depression of a channel shape located about 100 m below the other sites. Also in the next site located in a concave land form - the bottom of the Czarny Potok valley, the recorded temperature was lower than in the sites located in non-dismembered area. Despite the fact that the investiga-tions had only a preliminary character, they showed that the upper tree-limit and probably also the mountain pine-limit should not be compared with the course of mean annual temperatures deter-mined basing on interpolation and extrapolation. Only direct measurements of temperature in the field give a true picture of relation between the relief and microclimate and the upper tree-limit.

Keywords: relief, climate, tree-limit, the Tatra Mts.

Stanisław Kędzia [kedzia@zg.pan.krakow.pl], Institute of Geography and Spatial Organization Polish Academy of Sciences, Św. Jana 22, 31-018 Kraków, Poland

Abstract

The age of recent glacial, glacifluvial/fluvial forms is determined using lichenometric dating in two Alpine valleys of the Massif des Ecrins in France. A lichen growth-curve is based on data from natural sites, such as boulder-fields, moraine ridges etc. of known age on recently deglaciated terrain. The maximum extent of the glacial system of the Veneon and Etangons valleys during the Little Ice Age was 15 km in length. The maximum lichen diameter of 90-95 mm characterizes the stage of recession correlated with AD. 1650-1660. Analysis of the systems of terraces and paleochannels of the progla-cial rivers supported by lichenometric dating allows three periods of intensified fluvial activity to be distinguished for the Little Ice Age.

Keywords: deglaciation landforms, lichenometry, Little Ice Age, Massif des Ecrins, France

Maria Baumgart-Kotarba, Institute of Geography and Spatial Organization Polish Academy of Sciences, Św. Jana 22, 31-018 Kraków, Poland
Jean-Paul Bravard, Université de Lyon 2, Faculté GHHAT, 5, av. Pierre Mendes, 69676 Bron, France
Michel Chardon, Institut de Géographie Alpine, 14 bis av. Marie-Reynoard, 38100 Grenoble, France
Vincent Jomelli, Institut de Géographie, Université Paris I-Sorbonne, 191, rue Saint-Jacques, 75005 Paris, CNRS Laboratoire de Géographie Physique 1, pl. A.Briand 92195, Meudon Cedex, France
Stanisław Kędzia [kedzia@zg.pan.krakow.pl], Institute of Geography and Spatial Organization Polish Academy of Sciences, Św. Jana 22, 31-018 Kraków, Poland
Adam Kotarba [kotarba@zg.pan.krakow.pl], Institute of Geography and Spatial Organization Polish Academy of Sciences, Św. Jana 22, 31-018 Kraków, Poland
Pierre Pech [pierre.pech@univ-paris1.f], Institut de Géographie, Université Paris I-Sorbonne, 191, rue Saint-Jacques, 75005 Paris, CNRS Laboratoire de Géographie Physique 1, pl. A.Briand 92195, Meudon Cedex, France
Zofia Rączkowska [raczk@zg.pan.krakow.pl], Institute of Geography and Spatial Organization Polish Academy of Sciences, Św. Jana 22, 31-018 Kraków, Poland