2001 Volume 90 Pages 293-305
The effect of habitat conditions on the size and number of phycobiont cells, on the content of chlorophylls and carotenoids in the thalli of Cetraria islandiea, Cladina arbuscula, Hypogymnia physodes, Parmelia sulcata and Peltigera rufescens were investigated. Seasonal differences were found in the size of phycobiont cells. The mean size of algal cells increases from February to October, the smallest were observed in the winter. Lichen species collected from the sites distant from town were characterised by the largest number of phycobiont cells and the highest percentage of live cells, hence the high content of photosynthetic pigments. Seasonal differences were observed in chlorophyll content in lichen thalli. The highest pigment concentration was found in thalli collected in the winter and spring, the lowest were noted in the summer.