Agnieszka Błońska

Excavations of the Twardowice Plateau (Silesian Upland) as refuges for xerothermic plant species

Abstract Paper concerns the flora of excavations from the area of the Twardowice Plateau, one of the regions of the Silesian Upland. These are rather shallow and small pits, which are remnants of exploitation of Triassic limestone and, rarely, iron ore. The studies showed that these excavations are the places where many species of vascular plants occurred. Xerothermic plants, which penetrated from adjacent grasslands, form the largest group (33%) among the 212 noted species. Some of them occurred much more frequently in the excavations than in the grasslands and some were found only in the excavations. It should be emphasized that 8 protected species were present in the investigated objects. Results from the Twardowice Plateau proved that many xerothermic plants could find suitable conditions for growth and survival in limestone excavations.

New localities of Orobanche bartlingii Griseb. in the Silesian-Cracow Upland as a result of the spread of Libanotis pyrenaica (L.) Bourg. due to the changes in land use

Abstract Human activity is a factor strongly influencing the current state of vegetation. The abandonment of traditional land use enables uncontrolled secondary succession. Libanotis pyrenaica, a host plant for Orobanche bartlingii, is a great example of species that spread as a result of this process, especially in the area of the Silesian-Cracow Upland. The aim of this study is to show that the expansion of L. pyrenaica caused by changes in land use promotes spreading of O. bartlingii - a species rare in Poland and Europe. During the field research conducted in the last decade, further localities of O. bartlingii were found. The gathered data were summarized to supplement the known distribution of the species and to present floristic and ecological characteristics of the phytocenoses with the participation of L. pyrenaica and O. bartlingii.

Xerothermic grasslands of Pilica surroundings - diversity, threats and directions of changes

Xerothermic grasslands of Pilica surroundings - diversity, threats and directions of changes Xerothermic grasslands from three stands in the surroundings of the town of Pilica in the Kraków-Częstochowa Upland were investigated. It was ascertained that they represent two phytosociological units: Adonido-Brachypodietum (with two variants) and Silene otites-Thymus austriacus community. Moreover, phytocoenoses with a high contribution of xerothermic plants (Thymus-Anthyllis vulneraria community) were found in some places on the abandoned fields. On the basis of the comparison of new data and old phytosociological relevés, only slight changes over 30 years were observed. The differences concerned mostly the coverage of particular species. However, some plants disappeared and other were new (e.g. seedlings of trees and shrubs). Generally, these species were not too frequent and had inconsiderable cover. The changes which occurred manifested themselves also in the differences of mean values of some ecological indicators and in the increase of competitors, as well as clonal species.

Population structure of Liparis loeselii (L.) Rich. in relation to habitat conditions in the Warta River valley (Poland)

Abstract The paper presents results of a study on the population structure of the orchid Liparis loeselii growing in the Warta River valley peat bog in Myszków (Woźnicko-Wieluńska Upland, S. Poland). Individuals of L. loeselii occurred in patches of Menyantho trifoliatae-Sphagnetum teretis and Eleocharitetum pauciflorae – associations. The demographic structure of L. loeselii populations was described by variations in plant height, the length and width of leaves and the number of flowers of the constituting individuals. It was observed that habitat conditions such as conductivity, pH and the percentage cover of tall perennials had the strongest effect on the structure of L. loeselii populations.