Epiphytic lichen vegetation in an old oak wood, Kaas Skov [Quercus robur, forest, Denmark, Evernia prunastri, Hypogymnia physodes, Lecanactis abietina, Lecanora chlarotera, Lepraria incana, Parmelia sulcata, Pertusaria amara, Pertusaria pertusa, Phylctis argena, Protoblastenia quernea, Lecanora expallens]
1980
Pedersen, I. (Copenhagen Univ. (Denmark). Inst. of Thallophytes)
The lichen vegetation on oak trunks was studied in relation to exposure and trunk diameter/tree age. The quantitative composition of the lichen vegetation was analyzed at 1.3 m above ground on 50 randomly selected trees. Gridded quadrats of 10 x 40 cm were placed on the N-, E-, S-, and W-sides of the trunks and percentage cover of the lichen species was found according to the pin-point method. Eight selected lichen species were studied in regard to occurrence on the trees. The vegetation centering around these species was analyzed. The diameters of all trees were measured. For each tree the bark relief was recorded. pH of bark samples from 29 trees was measured. The age of 20 trees was determined by ring counts on tree cores. The lichen species exhibit differences in frequency and cover values between two categories of trees, namely those more than 30 cm in diameter/100 years old and those less this size/age. The distribution of species on the trunks can be related to bark relief and microclimate. The lichen vegetation is uniform on all exposures of young trees. On several old trees, distinction can be made between a western, a northeastern, and a southern sector, each supporting particular communities. Lichen vegetation and lichen communities are described for the two categories of trees.
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