The recapitulation of the investigations on oribatid mite fauna carried out at various kinds of abandoned galena-calamine wastelands in the south of Poland is presented. Soil samples were collected at nine sites in three regions of zinc-lead mining. In total, 24267 oribatid individuals belonging to 160 species were analyzed. The sites differing in the period of ceasing exploitation, species composition of plants and their stage of succession were chosen. The abundance and species richness of oribatid mites were generally higher on afforested sites and sites of older origin. The abundance of oribatids noted on wastelands was generally lower than in most natural or semi-natural biotopes. Surprisingly, the species richness on afforested wastelands was higher than in many natural forest biotopes. With regard to species similarity, the oribatid communities have been grouped due to localities instead of been organized due to the type of wastelands or vegetation. Correspondence analysis (CA) indicated that certain species of Oribatida preferentially occurred in a certain type of wastelands. Species characteristic of afforested new and old or unforested wastelands were distinguished. The biodiversity of oribatid fauna on galena-calamine wastelands was high with many new species for the Polish fauna ( 15). Some of them were recorded only from a few localities in the world.

In polar regions, apart from tundra and glaciers, geothermally active areas

with elevated temperatures are important elements of ecosystems. One such geothermally

active region characterized by mosaic ecosystems and vast areas covered by recent lava

fields is Iceland. The aim of our study was to explore the diversity of invertebrates

inhabiting geothermally active lava fields in the Krafla area (Iceland). Eight bryophyte

samples were collected from a warm surface, mainly from the steaming areas. We have

found Nematoda, Rotifera, Tardigrada and Oribatida in the samples. Habitat analysis

demonstrated there to be 12 bryophyte species (five liverworts and seven mosses).

The diversity of bryophytes in a single sample ranged from one to six species. The

most common bryophyte was Racomitrium lanuginosum (Hedw.) Brid. Four species

of tardigrades were found, including one that was new. Pilatobius islandicus sp. nov.

is described herein by morphological, morphometric and molecular approaches (COI,

28S rRNA, 18S rRNA). Oribatida mites were identified as two species (Malaconothrus

monodactylus (Michael, 1888) and Camisia foveolata Hammer, 1955). The average density

of invertebrates was 13.1 ind./g with a maximum of 40.8 ind./g calculated per dry

material. The tardigrades found in our study belonged to herbivores, microbivores and

omnivores, whereas the mites belonged to saprophages, which indicates complex trophic

networks in geothermally active lava fields.

In the present paper several species of moss-mites (Acari, Oribatida), including a species new for science (Halozetes impeditus sp. nov.) caught in the vicinity of the Polish "H. Arctowski" Station on King George Island (South Shetlands) are discussed.