The assessment of disturbance in moss-lichen layer of cryolitezone fens depending on anthropogenic stress

The results of an expert study of the present status in the moss- lichen cover of the northern tai-ga and forest-tundra fens in the zone of anthropo-genic emissions from factories of Norilsk industrial region (NIR) are given in this paper. Species com-position, projective cover degree and the height of the moss-lichen layer in fens of the background, weak- and heavily polluted areas are presented for the first time. It was found that on the fens, greatly remote from NIR, ecological state of the layer cor-responds to the zonal one. Rich species composi-tion and total projective covering of the ridges and pools by mosses, also a plenty of fruticose and foli-ose lichens show it. Digression of mosses and li-chens is clearly observed on fens in the zone of emission plumes. Their complete extinction took place on positive micro- relief forms, i.e. on the ridges and frozen mounds. The decrease of spe-cies diversity and of total projective moss cover degree, also their height lessening was observed in dry and moderately wet pools. The total copper, nickel, cobalt, lead, sulphur in mosses and lichens of fens in the region of the study was thoroughly analyzed. It was established that as the key plots were located nearer to the emission source, heavy metal concentration increased in mosses and li-chens tens and hundreds times as compared to the background. It was revealed that morphological destructions of the moss and lichen layer on fens in the emission epicenter coincide well with the data on pollutant amount in mosses and lichens. And the total sulphur amount in mosses and lichens in studied fens greatly varies and does not depend on their distance from NIR.